Quantitative morphometric analysis of the lumbar vertebral facets and evaluation of feasibility of lumbar spinal nerve root and spinal canal decompression using the Goel intraarticular facetal spacer distraction technique: A lumbar/cervical facet comparison

PubMed Central

Satoskar, Savni R.; Goel, Aimee A.; Mehta, Pooja H.; Goel, Atul

2014-01-01

Objective: The authors evaluate the anatomic subtleties of lumbar facets and assess the feasibility and effectiveness of use of ‘Goel facet spacer’ in the treatment of degenerative spinal canal stenosis. Materials and Methods: Twenty-five lumbar vertebral cadaveric dried bones were used for the purpose. A number of morphometric parameters were evaluated both before and after the introduction of Goel facet spacers within the confines of the facet joint. Results: The spacers achieved distraction of facets that was more pronounced in the vertical perspective. Introduction of spacers on both sides resulted in an increase in the intervertebral foraminal height and a circumferential increase in the spinal canal dimensions. Additionally, there was an increase in the disc space or intervertebral body height. The lumbar facets are more vertically and anteroposteriorly oriented when compared to cervical facets that are obliquely and transversely oriented. Conclusions: Understanding the anatomical peculiarities of the lumbar and cervical facets can lead to an optimum utilization of the potential of Goel facet distraction arthrodesis technique in the treatment of spinal degenerative canal stenosis. PMID:25558146

Biomechanics of the L5-S1 motion segment after total disc replacement - Influence of iatrogenic distraction, implant positioning and preoperative disc height on the range of motion and loading of facet joints.

PubMed

Dreischarf, Marcel; Schmidt, Hendrik; Putzier, Michael; Zander, Thomas

2015-09-18

Total disc replacement has been introduced to overcome negative side effects of spinal fusion. The amount of iatrogenic distraction, preoperative disc height and implant positioning have been considered important for surgical success. However, their effect on the postoperative range of motion (RoM) and loading of the facets merits further discussion. A validated osteoligamentous finite element model of the lumbosacral spine was employed and extended with four additional models to account for different disc heights. An artificial disc with a fixed center of rotation (CoR) was implemented in L5-S1. In 4000 simulations, the influence of distraction and the CoR's location on the RoM, facet joint forces (FJFs) and facet capsule ligament forces (FCLFs) was investigated. Distraction substantially altered segmental kinematics in the sagittal plane by decreasing range of flexion (0.5° per 1mm of distraction), increasing range of extension (0.7°/mm) and slightly affecting complete sagittal RoM (0.2°/mm). The distraction already strongly increased the FCLFs during surgery (up to 230N) and in flexion (~12N/mm), with higher values in models with larger preoperative disc heights, and increased FJFs in extension. A more anterior implant location decreased the RoM in all planes. In most loading cases, a more posterior location of the implant's CoR increased the FJFs and FCLFs, whereas a more caudal location increased the FCLFs but decreased the FJFs. The results of this study may explain the worse clinical results in patients with overdistraction after TDR. The complete RoM in the sagittal plane appears to be insensitive to detecting surgery-related biomechanical changes. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Impact of Cage Dimensions, Positioning, and Side of Approach in Extreme Lateral Interbody Fusion.

PubMed

Alimi, Marjan; Lang, Gernot; Navarro-Ramirez, Rodrigo; Perrech, Moritz; Berlin, Connor; Hofstetter, Christoph P; Moriguchi, Yu; Elowitz, Eric; Härtl, Roger

2018-02-01

This is a retrospective single-center study. The aim of the study was to evaluate the impact of cage characteristics and position toward clinical and radiographic outcome measures in patients undergoing extreme lateral interbody fusion (ELIF). ELIF is utilized for indirect decompression and minimally invasive surgical treatment for various degenerative spinal disorders. However, evidence regarding the influence of cage characteristics in patient outcome is minimal. Patients undergoing ELIF between 2007 and 2011 were included in a retrospective study. Demographic and perioperative data, as well as cage characteristics and side of approach were extracted. Radiographic parameters including lumbar lordosis, foraminal height, and disc height as well as clinical outcome parameters (Oswestry Disability Index and Visual Analog Scale) were measured preoperatively, postoperatively, and at the latest follow-up examination. Cage dimensions, in situ position, and type were correlated with radiographic and clinical outcome parameters. In total, 84 patients with a total of 145 functional spinal units were analyzed. At the last follow-up of 17.7 months, radiographic and clinical outcome measures revealed significant improvement compared with before surgery with both, 18 and 22 mm cage anterior-posterior diameter subgroups (P≤0.05). Among cage characteristics, 22 mm cages presented superior restoration of foraminal and disc heights compared with 18 mm cages (P≤0.05). Neither position of the cage (anterior vs. posterior), nor the type (parallel vs. lordotic) had a significant impact on restoration of foraminal height and lumbar lordosis. Moreover, the side of surgical approach did not influence the amount of foraminal height increase. Cage anterior-posterior diameter is the determining factor in restoration of foraminal height in ELIF. Cage height, type, positioning, and side of approach do not have a determining role in radiographic outcome in the present study. Sustainable foraminal height restoration is achieved by implantation of wider cages. Level 3.

Degenerative spinal disease in large felids.

PubMed

Kolmstetter, C; Munson, L; Ramsay, E C

2000-03-01

Degenerative spinal disorders, including intervertebral disc disease and spondylosis, seldom occur in domestic cats. In contrast, a retrospective study of 13 lions (Panthera leo), 16 tigers (Panthera tigris), 4 leopards (Panthera pardis), 1 snow leopard (Panthera uncia), and 3 jaguars (Panthera onca) from the Knoxville Zoo that died or were euthanatized from 1976 to 1996 indicated that degenerative spinal disease is an important problem in large nondomestic felids. The medical record, radiographic data, and the necropsy report of each animal were examined for evidence of intervertebral disc disease or spondylosis. Eight (three lions, four tigers, and one leopard) animals were diagnosed with degenerative spinal disease. Clinical signs included progressively decreased activity, moderate to severe rear limb muscle atrophy, chronic intermittent rear limb paresis, and ataxia. The age at onset of clinical signs was 10-19 yr (median = 18 yr). Radiographic evaluation of the spinal column was useful in assessing the severity of spinal lesions, and results were correlated with necropsy findings. Lesions were frequently multifocal, included intervertebral disc mineralization or herniation with collapsed intervertebral disc spaces, and were most common in the lumbar area but also involved cervical and thoracic vertebrae. Marked spondylosis was present in the cats with intervertebral disc disease, presumably subsequent to vertebral instability. Six of the animals' spinal cords were examined histologically, and five had acute or chronic damage to the spinal cord secondary to disc protrusion. Spinal disease should be suspected in geriatric large felids with decreased appetite or activity. Radiographic evaluation of the spinal column is the most useful method to assess the type and severity of spinal lesions.

Elimination of Subsidence with 26-mm-Wide Cages in Extreme Lateral Interbody Fusion.

PubMed

Lang, Gernot; Navarro-Ramirez, Rodrigo; Gandevia, Lena; Hussain, Ibrahim; Nakhla, Jonathan; Zubkov, Micaella; Härtl, Roger

2017-08-01

Extreme lateral interbody fusion (ELIF) has gained popularity as a minimally invasive technique for indirect decompression. However, graft subsidence potentially threatens long-term success of ELIF. This study evaluated whether 26-mm-wide cages can eliminate subsidence and subsequent loss of decompression in ELIF. Patients undergoing ELIF surgery using a 26-mm-wide cage were analyzed retrospectively. Patient demographics and perioperative data for radiographic and clinical outcomes were recorded. Radiographic parameters included regional sagittal lumbar lordosis and foraminal and disc height. Clinical parameters were evaluated using the Oswestry Disability Index and visual analog scale. Subsidence of 26-mm-wide cages was compared with previous outcomes of patients undergoing ELIF using 18-mm-wide and 22-mm-wide cages. There were 21 patients and 28 spinal segments analyzed. Radiographic outcome measures such as disc and foraminal height revealed significant improvement at follow-up compared with before surgery (P = 0.001). Postoperative to last follow-up cage subsidence translated into 0.34 mm ± 0.26 and -0.55 mm ± 0.64 in disc and foraminal height loss, respectively. Patients with 26-mm-wide cages experienced less subsidence by means of disc (26 mm vs. 18 mm and 22 mm, P ≤ 0.05) and foraminal height (26 mm vs. 18 mm, P = 0.005; 26 mm vs. 22 mm, P = 0.208) loss compared with patients receiving 18-mm-wide and 22-mm-wide cages. The 26-mm-wide cages almost eliminated cage subsidence in ELIF. Compared with 18-mm-wide and 22-mm-wide cages, 26-mm-wide cages significantly reduced cage subsidence in ELIF at midterm follow-up. A 26-mm-wide cage should be used in ELIF to achieve sustained indirect decompression. Copyright © 2017. Published by Elsevier Inc.

Magnetic resonance imaging evaluation after implantation of a titanium cervical disc prosthesis: a comparison of 1.5 and 3 Tesla magnet strength.

PubMed

Sundseth, Jarle; Jacobsen, Eva A; Kolstad, Frode; Nygaard, Oystein P; Zwart, John A; Hol, Per K

2013-10-01

Cervical disc prostheses induce significant amount of artifact in magnetic resonance imaging which may complicate radiologic follow-up after surgery. The purpose of this study was to investigate as to what extent the artifact, induced by the frequently used Discover(®) cervical disc prosthesis, impedes interpretation of the MR images at operated and adjacent levels in 1.5 and 3 Tesla MR. Ten subsequent patients were investigated in both 1.5 and 3 Tesla MR with standard image sequences one year following anterior cervical discectomy with arthroplasty. Two neuroradiologists evaluated the images by consensus. Emphasis was made on signal changes in medulla at all levels and visualization of root canals at operated and adjacent levels. A "blur artifact ratio" was calculated and defined as the height of the artifact on T1 sagittal images related to the operated level. The artifacts induced in 1.5 and 3 Tesla MR were of entirely different character and evaluation of the spinal cord at operated level was impossible in both magnets. Artifacts also made the root canals difficult to assess at operated level and more pronounced in the 3 Tesla MR. At the adjacent levels however, the spinal cord and root canals were completely visualized in all patients. The "blur artifact" induced at operated level was also more pronounced in the 3 Tesla MR. The artifact induced by the Discover(®) titanium disc prosthesis in both 1.5 and 3 Tesla MR, makes interpretation of the spinal cord impossible and visualization of the root canals difficult at operated level. Adjusting the MR sequences to produce the least amount of artifact is important.

Quantitative measurement of intervertebral disc signal using MRI.

PubMed

Niemeläinen, R; Videman, T; Dhillon, S S; Battié, M C

2008-03-01

To investigate the spinal cord as an alternative intra-body reference to cerebrospinal fluid (CSF) in evaluating thoracic disc signal intensity. T2-weighted magnetic resonance imaging (MRI) images of T6-T12 were obtained using 1.5 T machines for a population-based sample of 523 men aged 35-70 years. Quantitative data on the signal intensities were acquired using an image analysis program (SpEx). A random sample of 30 subjects and intraclass correlation coefficients (ICC) were used to examine the repeatability of the spinal cord measurements. The validity of using the spinal cord as a reference was examined by correlating cord and CSF samples. Finally, thoracic disc signal was validated by correlating it with age without adjustment and adjusting for either cord or CSF. Pearson's r was used for correlational analyses. The repeatability of the spinal cord signal measurements was extremely high (>or=0.99). The correlations between the signals of spinal cord and CSF by level were all above 0.9. The spinal cord-adjusted disc signal and age correlated similarly with CSF-adjusted disc signal and age (r=-0.30 to -0.40 versus r=-0.26 to -0.36). Adjacent spinal cord is a good alternative reference to the current reference standard, CSF, for quantitative measurements of disc signal intensity. Clearly fewer levels were excluded when using spinal cord as compared to CSF due to missing reference samples.

Biomechanical implications of lumbar spinal ligament transection.

PubMed

Von Forell, Gregory A; Bowden, Anton E

2014-11-01

Many lumbar spine surgeries either intentionally or inadvertently damage or transect spinal ligaments. The purpose of this work was to quantify the previously unknown biomechanical consequences of isolated spinal ligament transection on the remaining spinal ligaments (stress transfer), vertebrae (bone remodelling stimulus) and intervertebral discs (disc pressure) of the lumbar spine. A finite element model of the full lumbar spine was developed and validated against experimental data and tested in the primary modes of spinal motion in the intact condition. Once a ligament was removed, stress increased in the remaining spinal ligaments and changes occurred in vertebral strain energy, but disc pressure remained similar. All major biomechanical changes occurred at the same spinal level as the transected ligament, with minor changes at adjacent levels. This work demonstrates that iatrogenic damage to spinal ligaments disturbs the load sharing within the spinal ligament network and may induce significant clinically relevant changes in the spinal motion segment.

Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients

PubMed Central

Kruit, Mark C.; Peul, Wilco C.; Vleggeert-Lankamp, Carmen L. A.

2017-01-01

Introduction Correlation between magnetic resonance imaging (MRI) and clinical features in cauda equina syndrome (CES) is unknown; nor is known whether there are differences in MRI spinal canal size between lumbar herniated disc patients with CES versus lumbar herniated discs patients without CES, operated for sciatica. The aims of this study are 1) evaluating the association of MRI features with clinical presentation and outcome of CES and 2) comparing lumbar spinal canal diameters of lumbar herniated disc patients with CES versus lumbar herniated disc patients without CES, operated because of sciatica. Methods MRIs of CES patients were assessed for the following features: level of disc lesion, type (uni- or bilateral) and severity of caudal compression. Pre- and postoperative clinical features (micturition dysfunction, defecation dysfunction, altered sensation of the saddle area) were retrieved from the medical files. In addition, anteroposterior (AP) lumbar spinal canal diameters of CES patients were measured at MRI. AP diameters of lumbar herniated disc patients without CES, operated for sciatica, were measured for comparison. Results 48 CES patients were included. At MRI, bilateral compression was seen in 82%; complete caudal compression in 29%. MRI features were not associated with clinical presentation nor outcome. AP diameter was measured for 26 CES patients and for 31 lumbar herniated disc patients without CES, operated for sciatica. Comparison displayed a significant smaller AP diameter of the lumbar spinal canal in CES patients (largest p = 0.002). Compared to average diameters in literature, diameters of CES patients were significantly more often below average than that of the sciatica patients (largest p = 0.021). Conclusion This is the first study demonstrating differences in lumbar spinal canal size between lumbar herniated disc patients with CES and lumbar herniated disc patients without CES, operated for sciatica. This finding might imply that lumbar herniated disc patients with a relative small lumbar spinal canal might need to be approached differently in managing complaints of herniated disc. Since the number of studied patients is relatively small, further research should be conducted before clinical consequences are considered. PMID:29023556

Lumbar Spine Paraspinal Muscle and Intervertebral Disc Height Changes in Astronauts After Long-Duration Spaceflight on the International Space Station.

PubMed

Chang, Douglas G; Healey, Robert M; Snyder, Alexander J; Sayson, Jojo V; Macias, Brandon R; Coughlin, Dezba G; Bailey, Jeannie F; Parazynski, Scott E; Lotz, Jeffrey C; Hargens, Alan R

2016-12-15

Prospective case series. Evaluate lumbar paraspinal muscle (PSM) cross-sectional area and intervertebral disc (IVD) height changes induced by a 6-month space mission on the International Space Station. The long-term objective of this project is to promote spine health and prevent spinal injury during space missions and here on Earth. National Aeronautics and Space Administration (NASA) crewmembers have a 4.3 times higher risk of herniated IVDs, compared with the general and military aviator populations. The highest risk occurs during the first year after a mission. Microgravity exposure during long-duration spaceflights results in approximately 5 cm lengthening of body height, spinal pain, and skeletal deconditioning. How the PSMs and IVDs respond during spaceflight is not well described. Six NASA crewmembers were imaged supine with a 3 Tesla magnetic resonance imaging. Imaging was conducted preflight, immediately postflight, and then 33 to 67 days after landing. Functional cross-sectional area (FCSA) measurements of the PSMs were performed at the L3-4 level. FCSA was measured by grayscale thresholding within the posterior lumbar extensors to isolate lean muscle on T2-weighted scans. IVD heights were measured at the anterior, middle, and posterior sections of all lumbar levels. Repeated measures analysis of variance was used to determine significance at P < 0.05, followed by post-hoc testing. Paraspinal lean muscle mass, as indicated by the FCSA, decreased from 86% of the total PSM cross-sectional area down to 72%, immediately after the mission. Recovery of 68% of the postflight loss occurred during the next 6 weeks, still leaving a significantly lower lean muscle fractional content compared with preflight values. In contrast, lumbar IVD heights were not appreciably different at any time point. The data reveal lumbar spine PSM atrophy after long-duration spaceflight. Some FCSA recovery was seen with 46 days postflight in a terrestrial environment, but it remained incomplete compared with preflight levels. 4.

Cauda Equina Syndrome Due to Vigorous Back Massage With Spinal Manipulation in a Patient With Pre-Existing Lumbar Disc Herniation: A Case Report and Literature Review.

PubMed

Yang, Si-Dong; Chen, Qian; Ding, Wen-Yuan

2018-04-01

Cauda equina syndrome (CES) resulting from acute lumbar disc herniation due to spinal massage is extremely rare. We present a case of CES caused by the acute worsening of a lumbar disc herniation after a vigorous back massage that included spinal manipulation. After vigorous back massage with spinal manipulation performed by a massage therapist, a 38-yr-old male patient experienced CES with severe numbness in both lower limbs, inability to walk due to weakness of bilateral lower limbs, and incontinence of urine and feces. The magnetic resonance imaging and computer tomography scan results showed that the L4-5 disc herniated down into the spinal canal, extensively compressing the ventral dural sac. The patient was successfully treated with an emergency operation including laminectomy, spinal canal decompression, discectomy, interbody fusion, and pedicle screw fixation. The muscle power in both lower limbs of the patient recovered rapidly to support standing only 1 wk later. Moreover, he regained continence of urine and feces. In conclusion, this case brings us novel knowledge that spinal massage or manipulation may worsen pre-existing disc herniation causing CES, and a timely emergency surgery is necessary and effective for treatment of CES-related symptoms.

Measurement of occlusion of the spinal canal and intervertebral foramen by intervertebral disc bulge

PubMed Central

Cuchanski, Mathieu; Cook, Daniel; Whiting, Donald M.; Cheng, Boyle C.

2011-01-01

Background Disc protrusion has been proposed to be a possible cause of both pain and stenosis in the lower spine. No previous study has described the amount of disc occlusion of the spinal canal and intervertebral foramen that occurs under different loading conditions. The objective of this study was to quantitatively assess the percent occlusion of the spinal canal and intervertebral foramen by disc bulge under different loading conditions. Methods Spinal canal depth and foraminal width were measured on computed tomography–scanned images of 7 human lumbar spine specimens. In vitro disc bulge measurements were completed by use of a previously described method in which single functional spinal units were subjected to 3 separate load protocols in a spine test machine and disc bulge was recorded with an optoelectric motion system that tracked active light-emitting diodes placed on the posterior and posterolateral aspects of the intervertebral disc. Occlusion was defined as percentage of encroachment into area of interest by maximum measured disc bulge at corresponding point of interest (the spinal canal is at the posterior point; the intervertebral foramen is at the posterolateral point). Results The mean spinal canal depth and mean foraminal width were 19 4 ± mm and 5 ± 2 mm, respectively. Mean spinal canal occlusion under a 250-N axial load, ± 2.5 Nm of flexion/extension, and ± 2.5 Nm of lateral bend was 2.5% ± 1.9%, 2.5% ± 1.6%, and 1.5% ± 0.8%, respectively. Mean intervertebral foramen occlusion under a 250-N axial load, ± 2.5 Nm of flexion/extension, and ± 2.5 Nm of lateral bend was 7.8% ± 4.7%, 9.5% ± 5.7%, and 11.3% ± 6.2%, respectively. Conclusion Percent occlusion of the spinal canal and intervertebral foramen is dependent on magnitude and direction of load. Exiting neural elements at the location of the intervertebral foramen are the most vulnerable to impingement and generation of pain. PMID:25802663

Correlation between degenerative spine disease and bone marrow density: a retrospective investigation.

PubMed

Grams, Astrid Ellen; Rehwald, Rafael; Bartsch, Alexander; Honold, Sarah; Freyschlag, Christian Franz; Knoflach, Michael; Gizewski, Elke Ruth; Glodny, Bernhard

2016-02-24

Spondylosis leads to an overestimation of bone mineral density (BMD) with dual-energy x-ray absorptiometry (DXA) but not with quantitative computed tomography (QCT). The correlation between degenerative changes of the spine and QCT-BMD was therefore investigated for the first time. One hundred thirty-four patients (66 female and 68 male) with a mean age of 49.0 ± 14.6 years (range: 19-88 years) who received a CT scan and QCT-BMD measurements of spine and hip were evaluated retrospectively. The occurrence and severity of spondylosis, osteochondrosis, and spondylarthrosis and the height of the vertebral bodies were assessed. A negative correlation was found between spinal BMD and number of spondylophytes (ρ = -0.35; p < 0.01), disc heights (r = -0.33; p < 0.01), number of discal air inclusions (ρ = -0.34; p < 0.01), the number of Schmorl nodules (ρ = -0.25; p < 0.01), the number (ρ = -0.219; p < 0.05) and the degree (ρ = -0.220; p < 0.05) of spondylarthrosis. Spinal and hip BMD correlated moderately, but the latter did not correlate with degenerative changes of the spine. In linear regression models age, osteochondrosis and spondylarthrosis were factors influencing spinal BMD. Degenerative spinal changes may be associated with reduced regional spinal mineralization. This knowledge could lead to a modification of treatment of degenerative spine disease with early treatment of osteopenia to prevent secondary fractures.

Preliminary investigation into a seated unloading movement strategy for the lumbar spine: a pilot study.

PubMed

Fryer, Jerome; Zhang, William

2010-04-01

This study was a preliminary investigation into a seated unloading movement strategy for the lumbar spine using the upper extremities. With the economic burden of LBP estimated in the billions worldwide, and also with a trend towards more jobs related to sitting, a simple distraction exercise coined chair-care is presented. An attempt to objectify using stadiometry was used to measure standing height changes after 15 min of sitting and after the exercise. The results showed significant standing height gains post-exercise when compared to post-sitting and initial standing (2.4 and 2.7 mm, respectively). No significant standing height changes were seen after 15 min of sitting. It is therefore likely that this simple seated exercise creates standing height gains of the spine. Proposed mechanisms are discussed with an emphasis on spinal hydraulics and intervertebral disc nutrition. Reproducible studies are required. Copyright 2008 Elsevier Ltd. All rights reserved.

Biomechanical Characterization of an Annulus Sparing Spinal Disc Prosthesis

PubMed Central

Buttermann, Glenn R.; Beaubien, Brian P.

2009-01-01

Background Context Current spine arthroplasty devices, require disruption of the annulus fibrosus for implantation. Preliminary studies of a unique annulus sparing intervertebral prosthetic disc (IPD), found that preservation of the annulus resulted in load sharing of the annulus with the prosthesis. Purpose Determine flexibility of the IPD versus fusion constructs in normal and degenerated human spines. Study design/Setting Biomechanical comparison of motion segments in the intact, fusion and mechanical nucleus replacement states for normal and degenerated states. Patient setting Thirty lumbar motion segments. Outcomes Measures Intervertebral height; motion segment range-of-motion (ROM), neutral zone (NZ), stiffness. Methods Motion segments had multi-directional flexibility testing to 7.5 Nm for intact discs, discs reconstructed using the IPD (n=12), or after anterior/posterior fusions (n=18). Interbody height and axial compression stiffness changes were determined for the reconstructed discs by applying axial compression to 1500 N. Analysis included stratifying results to normal mobile vs. rigid degenerated intact motion segments. Results The mean interbody height increase was 1.5 mm for IPD reconstructed discs. vs 3.0 mm for fused segments. Axial compression stiffness was 3.0 ± 0.9 kN/mm for intact compared to 1.2 ± 0.4 kN/mm for IPD reconstructed segments. Reconstructed disc ROM was 9.0° ± 3.7° in flexion-extension, 10.6° ± 3.4° in lateral bending and 2.8° ± 1.4° in axial torsion which was similar to intact values and significantly greater than respective fusion values (p<0.001). Mobile intact segments exhibited significantly greater rotation after fusion vs. their more rigid counterparts (p<0.05), however, intact motion was not related to motion after IPD reconstruction. The NZ and rotational stiffness followed similar trends. Differences in NZ between mobile and rigid intact specimens tended to decrease in the IPD reconstructed state. Conclusion The annulus sparing IPD generally reproduced the intact segment biomechanics in terms of ROM, NZ, and stiffness. Furthermore, the IPD reconstructed discs imparted stability by maintaining a small neutral zone. The IPD reconstructed discs were significantly less rigid than the fusion constructs and may be an attractive alternative for the treatment of DDD. PMID:19540816

Lumbar Disc Degenerative Disease: Disc Degeneration Symptoms and Magnetic Resonance Image Findings

PubMed Central

Saleem, Shafaq; Rehmani, Muhammad Asim Khan; Raees, Aisha; Alvi, Arsalan Ahmad; Ashraf, Junaid

2013-01-01

Study Design Cross sectional and observational. Purpose To evaluate the different aspects of lumbar disc degenerative disc disease and relate them with magnetic resonance image (MRI) findings and symptoms. Overview of Literature Lumbar disc degenerative disease has now been proven as the most common cause of low back pain throughout the world. It may present as disc herniation, lumbar spinal stenosis, facet joint arthropathy or any combination. Presenting symptoms of lumbar disc degeneration are lower back pain and sciatica which may be aggravated by standing, walking, bending, straining and coughing. Methods This study was conducted from January 2012 to June 2012. Study was conducted on the diagnosed patients of lumbar disc degeneration. Diagnostic criteria were based upon abnormal findings in MRI. Patients with prior back surgery, spine fractures, sacroiliac arthritis, metabolic bone disease, spinal infection, rheumatoid arthritis, active malignancy, and pregnancy were excluded. Results During the targeted months, 163 patients of lumbar disc degeneration with mean age of 43.92±11.76 years, came into Neurosurgery department. Disc degeneration was most commonly present at the level of L4/L5 105 (64.4%).Commonest types of disc degeneration were disc herniation 109 (66.9%) and lumbar spinal stenosis 37 (22.7%). Spondylolisthesis was commonly present at L5/S1 10 (6.1%) and associated mostly with lumbar spinal stenosis 7 (18.9%). Conclusions Results reported the frequent occurrence of lumbar disc degenerative disease in advance age. Research efforts should endeavor to reduce risk factors and improve the quality of life. PMID:24353850

Human Amniotic Tissue-derived Allograft, NuCel, in Posteriolateral Lumbar Fusions for Degenerative Disc Disease

ClinicalTrials.gov

2017-09-14

Lumbar Degenerative Disc Disease; Spinal Stenosis; Spondylolisthesis; Spondylosis; Intervertebral Disk Displacement; Intervertebral Disk Degeneration; Spinal Diseases; Bone Diseases; Musculoskeletal Diseases; Spondylolysis

Physical examination, magnetic resonance image, and electrodiagnostic study in patients with lumbosacral disc herniation or spinal stenosis.

PubMed

Lee, Jung Hwan; Lee, Sang-Ho

2012-10-01

To compare the clinical implications of electro-diagnostic study with those of magnetic resonance imaging in patients with lumbosacral intervertebral herniated disc or spinal stenosis. Retrospective study of clinical data. Patients with lumbosacral intervertebral herniated disc or spinal stenosis, diagnosed by clinical assessment and magnetic resonance imaging (MRI), were selected. A total of 753 patients (437 with lumbosacral intervertebral herniated disc and 316 with spinal stenosis) were included in the study. Clinical data for electrodiagnostic study (EDX)and MRI were compared and the sensitivity and specificity of these studies were evaluated. Among all subjects, 267 had radiculopathy on EDX (EDX (+)) and 486 no radiculopathy (EDX(-)). Furthermore, 391 had root compression on MRI (MRI (+)) and 362 no root compression on MRI (MRI (-)). Patients with radioculopathy on EDX (+) showed a significantly higher visual analogue scale score for radiating pain and a higher Oswestry Disability Index than those with negative findings by EDX (-) in the total subjects group and the lumbosacral intervertebral herniated disc subgroup, and there was a trend toward higher Oswestry Disability Index in the spinal stenosis subgroup. Although patients with radioculopathy on root compression on MRI (+) also had a higher visual analogue scale for radiating pain than patients with negative findings by MRI (-) in the total subjects group and the lumbosacral intervertebral herniated disc subgroup, no significant difference was seen in the Oswestry Disability Index. EDX revealed a significant correlation with muscle weakness in the total subjects group and the lumbosacral intervertebral herniated disc subgroup, and trends toward muscle weakness in the spinal stenosis subgroup, whereas there was no such significant correlation for MRI findings in any group. Electrodiagnostic study had a higher specificity in terms of physical examination data than MRI, in spite of its lower sensitivity. Electrodiagnostic study was significantly more correlated with clinical data, especially leg muscle weakness and functional status, and showed a higher specificity than MRI in patients with lumbosacral intervertebral herniated disc or spinal stenosis.

Spinal tuberculosis: the association between pedicle involvement and anterior column damage and kyphotic deformity.

PubMed

Yusof, Mohammad Imran; Hassan, Eskandar; Rahmat, Nasazli; Yunus, Rohaizan

2009-04-01

Pedicle involvement in spinal tuberculosis (TB), the prevertebral abscess formation, severity of vertebral body, and disc collapse were evaluated from magnetic resonance imaging (MRI) of the patients. To study the pedicle involvement in spine TB in relation to the degree of vertebral body and disc collapse, prevertebral abscess collection, and degree of kyphosis; and to correlate the occurrence of pedicle involvement and the degree of spinal deformity. There are a few reports describing the posterior element involvement in spinal TB. Typically, the infection resides in the anterior part of the vertebral body endplates and rarely involved the pedicles. There were 31 patients, who had been diagnosed and treated for spinal TB from 2003 to 2007 at our center. Critical evaluation of each patient's MRI was carried out for the pedicle involvement, prevertebral abscess formation, severity of vertebral body, and disc collapse. Spinal TB mostly involved the thoracic level (48.4%). Pedicle involvement was noted in 64.5% of patients, and the highest involvement was at thoracic level. The mean vertebral body, disc collapse, prevertebral abscess, and kyphosis were more severe in pedicle involved group. The posterior spinal element, specifically the pedicle is not uncommonly involved in spinal TB. Pedicle involvement is part of the disease process and usually associated with relatively severe vertebral body and disc destruction, wide prevertebral abscess, and severe kyphosis. Pedicle involvement can be detected early from MRI and need to be documented as it may influence the treatment strategy.

Continuous lumbar hemilaminectomy for intervertebral disc disease in an Amur tiger (Panthera tigris altaica).

PubMed

Flegel, Thomas; Böttcher, Peter; Alef, Michaele; Kiefer, Ingmar; Ludewig, Eberhard; Thielebein, Jens; Grevel, Vera

2008-09-01

A 13-yr-old Amur tiger (Panthera tigris altaica) was presented for an acute onset of paraplegia. Spinal imaging that included plain radiographs, myelography, and computed tomography performed under general anesthesia revealed lateralized spinal cord compression at the intervertebral disc space L4-5 caused by intervertebral disc extrusion. This extrusion was accompanied by an extensive epidural hemorrhage from L3 to L6. Therefore, a continuous hemilaminectomy from L3 to L6 was performed, resulting in complete decompression of the spinal cord. The tiger was ambulatory again 10 days after the surgery. This case suggests that the potential benefit of complete spinal cord decompression may outweigh the risk of causing clinically significant spinal instability after extensive decompression.

Physical inactivity is associated with narrower lumbar intervertebral discs, high fat content of paraspinal muscles and low back pain and disability.

PubMed

Teichtahl, Andrew J; Urquhart, Donna M; Wang, Yuanyuan; Wluka, Anita E; O'Sullivan, Richard; Jones, Graeme; Cicuttini, Flavia M

2015-05-07

Although physical inactivity has been associated with numerous chronic musculoskeletal complaints, few studies have examined its associations with spinal structures. Moreover, previously reported associations between physical activity and low back pain are conflicting. This study examined the associations between physical inactivity and intervertebral disc height, paraspinal fat content and low back pain and disability. Seventy-two community-based volunteers not selected for low back pain underwent magnetic resonance imaging (MRI) of their lumbosacral spine (L1 to S1) between 2011 and 2012. Physical activity was assessed between 2005 and 2008 by questionnaire, while low back pain and disability were assessed by the Chronic Pain Grade Scale at the time of MRI. Intervertebral disc height and cross-sectional area and fat content of multifidus and erector spinae were assessed from MRI. Lower physical activity levels were associated with a more narrow average intervertebral disc height (β -0.63 mm, 95% confidence interval (CI) -1.17 mm to -0.08 mm, P = 0.026) after adjusting for age, gender and body mass index (BMI). There were no significant associations between physical activity levels and the cross-sectional area of multifidus or erector spinae. Lower levels of physical activity were associated with an increased risk of high fat content in multifidus (odds ratio (OR) 2.7, 95% CI 1.1 to 6.7, P = 0.04) and high-intensity pain/disability (OR = 5.0, 95% CI 1.5 to 16.4, P = 0.008) after adjustment for age, gender and BMI. Physical inactivity is associated with narrower intervertebral discs, high fat content of the multifidus and high-intensity low back pain and disability in a dose-dependent manner among community-based adults. Longitudinal studies will help to determine the cause and effect nature of these associations.

The relationship between quantitative measures of disc height and disc signal intensity with Pfirrmann score of disc degeneration.

PubMed

Salamat, Sara; Hutchings, John; Kwong, Clemens; Magnussen, John; Hancock, Mark J

2016-01-01

To assess the relationship between quantitative measures of disc height and signal intensity with the Pfirrmann disc degeneration scoring system and to test the inter-rater reliability of the quantitative measures. Participants were 76 people who had recently recovered from their last episode of acute low back pain and underwent MRI scan on a single 3T machine. At all 380 lumbar discs, quantitative measures of disc height and signal intensity were made by 2 independent raters and compared to Pfirrmann scores from a single radiologist. For quantitative measures of disc height and signal intensity a "raw" score and 2 adjusted ratios were calculated and the relationship with Pfirrmann scores was assessed. The inter-tester reliability of quantitative measures was also investigated. There was a strong linear relationship between quantitative disc signal intensity and Pfirrmann scores for grades 1-4, but not for grades 4 and 5. For disc height only, Pfirrmann grade 5 had significantly reduced disc height compared to all other grades. Results were similar regardless of whether raw or adjusted scores were used. Inter-rater reliability for the quantitative measures was excellent (ICC > 0.97). Quantitative measures of disc signal intensity were strongly related to Pfirrmann scores from grade 1 to 4; however disc height only differentiated between grade 4 and 5 Pfirrmann scores. Using adjusted ratios for quantitative measures of disc height or signal intensity did not significantly alter the relationship with Pfirrmann scores.

Effects of spine loading in a patient with post-decompression lumbar disc herniation: observations using an open weight-bearing MRI.

PubMed

Mahato, Niladri Kumar; Sybert, Daryl; Law, Tim; Clark, Brian

2017-05-01

Our objective was to use an open weight-bearing MRI to identify the effects of different loading conditions on the inter-vertebral anatomy of the lumbar spine in a post-discectomy recurrent lumbar disc herniation patient. A 43-year-old male with a left-sided L5-S1 post-decompression re-herniation underwent MR imaging in three spine-loading conditions: (1) supine, (2) weight-bearing on standing (WB), and (3) WB with 10 % of body mass axial loading (WB + AL) (5 % through each shoulder). A segmentation-based proprietary software was used to calculate and compare linear dimensions, angles and cross sections across the lumbar spine. The L5 vertebrae showed a 4.6 mm posterior shift at L5-S1 in the supine position that changed to an anterior translation >2.0 mm on WB. The spinal canal sagittal thickness at L5-S1 reduced from supine to WB and WB + AL (13.4, 10.6, 9.5 mm) with corresponding increases of 2.4 and 3.5 mm in the L5-S1 disc protrusion with WB and WB + AL, respectively. Change from supine to WB and WB + AL altered the L5-S1 disc heights (10.2, 8.6, 7.0 mm), left L5-S1 foramen heights (12.9, 11.8, 10.9 mm), L5-S1 segmental angles (10.3°, 2.8°, 4.3°), sacral angles (38.5°, 38.3°, 40.3°), L1-L3-L5 angles (161.4°, 157.1°, 155.1°), and the dural sac cross sectional areas (149, 130, 131 mm 2 ). Notably, the adjacent L4-L5 segment demonstrated a retro-listhesis >2.3 mm on WB. We observed that with weight-bearing, measurements indicative of spinal canal narrowing could be detected. These findings suggest that further research is warranted to determine the potential utility of weight-bearing MRI in clinical decision-making.

Moderate-intensity running causes intervertebral disc compression in young adults.

PubMed

Kingsley, Michael Ian; D'Silva, Lindsay Antonio; Jennings, Cameron; Humphries, Brendan; Dalbo, Vincent James; Scanlan, Aaron Terrance

2012-11-01

Decreased intervertebral disc (IVD) volume can result in diminished load-carrying capacity of the spinal region. Although moderate-intensity running is generally advocated for apparently healthy adults, running causes a loss in stature that is thought to reflect IVD compression. The aim of this investigation was to use magnetic resonance imaging (MRI) to quantify the influence of moderate-intensity treadmill running on IVD height and volume in the thoracic and lumbar regions of the vertebral column. A clinic-based repeated-measures design was used in eight healthy young asymptomatic adults. After preliminary measurements and familiarization (day 1), participants reported to the clinic on two further occasions. MRI scans and stature measurements were completed at baseline (day 2), preexercise (day 3), and after 30 min of moderate-intensity treadmill running (postexercise, day 3). Mean height and volume were derived for all thoracic and lumbar IVDs from digitized MRIs, and stature was determined with a stadiometer. Moderate-intensity running resulted in 6.3% ± 0.9% reduction in mean IVD height and 6.9% ± 1.0% reduction in calculated IVD volume. The day-to-day variation in mean IVD height and volume were 0.6% ± 0.6% and 0.4% ± 0.6%, respectively. This is the first study to quantify the influence of moderate-intensity running on IVD height and volume. Changes in IVD height and volume were observed throughout the thoracic and lumbar vertebral regions. These findings suggest that future studies evaluating the influence of various loading activities and recovery techniques on IVD structure should consider thoracic as well as lumbar regions of the spine.

Lumbar spine paraspinal muscle and intervertebral disc height changes in astronauts after long-duration spaceflight on the International Space Station

PubMed Central

Chang, DG; Healey, RM; Snyder, AJ; Sayson, JV; Macias, BR; Coughlin, DG; Bailey, JF; Parazynski, SE; Lotz, JC; Hargens, AR

2017-01-01

Study Design Prospective case series Objective Evaluate lumbar paraspinal muscle (PSM) cross-sectional area and intervertebral disc (IVD) height changes induced by a 6-month space mission on the International Space Station (ISS). The long-term objective of this project is to promote spine health and prevent spinal injury during space missions as well as here on Earth. Summary of Background NASA crewmembers have a 4.3 times higher risk of herniated IVDs, compared to the general and military aviator populations. The highest risk occurs during the first year after a mission. Microgravity exposure during long-duration spaceflights results in ~5cm lengthening of body height, spinal pain, and skeletal deconditioning. How the PSMs and IVDs respond during spaceflight is not well described. Methods Six NASA crewmembers were imaged supine with a 3T MRI. Imaging was conducted pre-flight, immediately post-flight and then 33 to 67 days after landing. Functional cross-sectional area (FCSA) measurements of the PSMs were performed at the L3-4 level. FCSA was measured by grayscale thresholding within the posterior lumbar extensors to isolate lean muscle on T2-weighted scans. IVD heights were measured at the anterior, middle and posterior sections of all lumbar levels. Repeated measures ANOVA was used to determine significance at p<0.05, followed by post-hoc testing. Results Paraspinal lean muscle mass, as indicated by the FCSA, decreased from 86% of the total PSM cross-sectional area down to 72%, immediately after the mission. Recovery of 68% of the post-flight loss occurred over the next 6 weeks, still leaving a significantly lower lean muscle fractional content compared to pre-flight values. In contrast, lumbar IVD heights were not appreciably different at any time point. Conclusions The data reveal lumbar spine PSM atrophy after long-duration spaceflight. Some FCSA recovery was seen with 46 days post-flight in a terrestrial environment, but it remained incomplete compared to pre-flight levels. PMID:27779600

[Enlargement in managment of lumbar spinal stenosis].

PubMed

Steib, J P; Averous, C; Brinckert, D; Lang, G

1996-05-01

Lumbar stenosis has been well discussed recently, especially at the 64th French Orthopaedic Society (SOFCOT: July 1989). The results of different surgical treatments were considered as good, but the indications for surgical treatment were not clear cut. Laminectomy is not the only treatment of spinal stenosis. Laminectomy is an approach with its own rate of complications (dural tear, fibrosis, instability... ).Eight years ago, J. Sénégas described what he called the "recalibrage" (enlargement). His feeling was that, in the spinal canal, we can find two different AP diameters. The first one is a fixed constitutional AP diameter (FCAPD) at the cephalic part of the lamina. The second one is a mobile constitutional AP diameter (MCAPD) marked by the disc and the ligamentum flavum. This diameter is maximal in flexion, minimal in extension. The nerve root proceeds through the lateral part of the canal: first above, between the disc and the superior articular process, then below, in the lateral recess bordered by the pedicle, the vertebral body and the posterior articulation. With the degenerative change the disc space becomes shorter, the superior articular process is worn out with osteophytes. These degenerative events are complicated by inter vertebral instability increasing the stenosis. The idea of the "recalibrage" is to remove only the upper part of the lamina with the ligamentum flavum and to cut the hypertrophied anterior part of the articular process from inside. If needed the disc and other osteophytes are removed. The surgery is finished with a ligamentoplasty reducing the flexion and preventing the extension by a posterior wedge.Our experience in spine surgery especially in scoliosis surgery, showed us that it was possible to cure a radicular compression without opening the canal. The compression is then lifted by the 3D reduction and restoration of an anatomy as normal as possible. Lumbar stenosis is the consequence of a degenerative process. Indeed, hip flexion, obesity or quite simply overuse, involve an increase in the lumbar lordosis. The posterior articulations are worn out and the disc gets damaged by shear forces. The disc space becomes shorter with a bulging disc, and the inferior articular process of the superior vertebra goes down. This is responsible of a loss of lordosis. For restoring the sagittal balance the patient needs more extension of the spine. Above and below the considered level the degenerative disease carries on extending to the whole spine. At the level considered, because of local extension, the inferior facet moves forward, the disc bulges, the ligamentum flavum is shortened and the stenosis is increased. This situation is improved by local kyphosis: the inferior facet moves backward, the disc and the ligamentum flavum are stretched with a quite normal posterior disc height and most often there is no more stenosis. Myelograms show this very well with a quite normal appearance lying, clear compression standing, worse in extension and improved, indeed disappeared in flexion. CT scan and MRI don't show that because they are done lying. The expression of the clinical situation is the same, mute lying and maximum standing with restriction of walking. For us lumbar stenosis is operated with lumbar reconstruction without opening the canal. The patient is in moderate kyphosis on the operating table. Pedicle screws rotated to match a bent rod allow reduction of the spine. The posterior disc height is respected and not distracted, and the anterior part of the disc is stretched in lordosis. The inferior facet is cut for the arthrodesis and no longer compresses the dura. The canal is well enlarged and the lumbar segment in lordosis is the best protection of the adjacent levels at follow-up. This behaviour responds to the same analysis as the ≪recalibrage≫ (enlargement). The mobile segment is damaged by the degenerative disease, the stenosis is a consequence of this damage. It's logical to treat the instability and to restore the normal static anatomy; thus bone resection is not necessary. At the present time all the lumbar stenoses with reduction in flexion are instrumented with spinal reduction and arthrodesis without opening the canal. The laminoarthrectomy and the enlargement are done when there is a fixed arthrosis which is rare in our practice and found in an older population. The follow-up shows a loss of reduction in some cases after reduction-instrumentation-arthrodesis and poses the question of an interbody fusion. We don't open the canal only for fusion (PLIF) if this is not necessary for the treatment of the stenosis. We think that, in such a situation, the future is ALIF with endoscopical approach. The problem is to determine which disc demanding this anterior fusion, is able to regenerate or not.

Morphometric analysis of the relationships between intervertebral disc and vertebral body heights: an anatomical and radiographic study of the human thoracic spine

PubMed Central

Kunkel, Maria E; Herkommer, Andrea; Reinehr, Michael; Böckers, Tobias M; Wilke, Hans-Joachim

2011-01-01

The main aim of this study was to provide anatomical data on the heights of the human intervertebral discs for all levels of the thoracic spine by direct and radiographic measurements. Additionally, the heights of the neighboring vertebral bodies were measured, and the prediction of the disc heights based only on the size of the vertebral bodies was investigated. The anterior (ADH), middle (MDH) and posterior heights (PDH) of the discs were measured directly and on radiographs of 72 spine segments from 30 donors (age 57.43 ± 11.27 years). The radiographic measurement error and the reliability of the measurements were calculated. Linear and non-linear regression analyses were employed for investigation of statistical correlations between the heights of the thoracic disc and vertebrae. Radiographic measurements displayed lower repeatability and were shorter than the anatomical ones (approximately 9% for ADH and 37% for PDH). The thickness of the discs varied from 4.5 to 7.2 mm, with the MDH approximately 22.7% greater. The disc heights showed good correlations with the vertebral body heights (R2, 0.659–0.835, P-values < 0.005; anova), allowing the generation of 10 prediction equations. New data on thoracic disc morphometry were provided in this study. The generated set of regression equations could be used to predict thoracic disc heights from radiographic measurement of the vertebral body height posterior. For the creation of parameterized models of the human thoracic discs, the use of the prediction equations could eliminate the need for direct measurement on intervertebral discs. Moreover, the error produced by radiographic measurements could be reduced at least for the PDH. PMID:21615399

Human and bovine spinal disc mechanics subsequent to trypsin injection.

PubMed

Alsup, Jeremy; Bishop, Timothy; Eggett, Dennis; Bowden, Anton E

2017-10-01

To investigate the biomechanical effects of injections of a protease on the characteristics of bovine coccygeal and human lumbar disc motion segments. Mechanics of treated tissues were measured immediately after injection and 3 h after injection. Motion segments underwent axial rotation and flexion-extension loading. Stiffness and neutral zone parameters experienced significant changes over time, with bovine tissues more strongly affected than human cadaver tissues. This was true in both axial rotation and flexion-extension. The treatment type significantly affected the neutral zone measurements in axial rotation. Hysteresis parameters were impacted by control injections. The extrapolation of bovine coccygeal motion testing results to human lumbar disc mechanics is not yet practical. The injected treatment may have a smaller impact on disc mechanics than time in testing. Viscoelasticity of human lumbar discs may be impacted by any damage to the annulus fibrosis induced by needlestick. Preclinical testing of novel spinal devices is essential to the design validation and regulatory processes, but current testing techniques rely on cadaveric testing of primarily older spines with essentially random amounts of disc degeneration. The present work investigates the viability of using trypsin injections to create a more uniform preclinical model of disc degeneration from a mechanics perspective, for the purpose of testing spinal devices. Such a model would facilitate translation of new spinal technologies to clinical practice.

Transcript Levels of Major Interleukins in Relation to the Clinicopathological Profile of Patients with Tuberculous Intervertebral Discs and Healthy Controls

PubMed Central

Liu, Chong; Zhan, Xinli; Xiao, Zengming; Fan, Qie; Deng, Li; Cui, Mingxing; Xiong, Chunxiang; Xue, Jingbo; Xie, Xiangtao

2014-01-01

Objectives The purpose of the present study was to simultaneously examine the transcript levels of a large number of interleukins (ILs; IL-9, IL-10, IL-12, IL-13, IL-16, IL-17, IL-18, IL-26, and IL-27) and investigate their correlation with the clinicopathological profiles of patients with tuberculous intervertebral discs. Methods Clinical data were collected from 150 patients participating in the study from January 2013 to December 2013. mRNA expression levels in 70 tuberculous, 70 herniated, and 10 control intervertebral disc specimens were determined by real-time polymerase chain reaction. Results IL-10, IL-16, IL-17, IL-18, and IL-27 displayed stronger expression in tuberculous spinal disc tissue than in normal intervertebral disc tissue (P<0.05). Our results illustrated multiple correlations among IL-10, IL-16, IL-17, IL-18, and IL-27 mRNA expression in tuberculous samples. Smoking habits were found to have a positive correlation with IL-17 transcript levels and a negative correlation with IL-10 transcript levels (P<0.05). Pain intensity, symptom duration, C-reactive protein levels, and the erythrocyte sedimentation rate exhibited multiple correlations with the transcript levels of several ILs (P<0.05). Conclusions The experimental data imply a double-sided effect on the activity of ILs in tuberculous spinal intervertebral discs, suggesting that they may be involved in intervertebral discs destruction. Our findings also suggest that smoking may affect the intervertebral discs destruction process of spinal tuberculosis. However, further studies are necessary to elucidate the exact role of ILs in the intervertebral discs destruction process of spinal tuberculosis. PMID:24971599

Altered Helical Axis Patterns of the Lumbar Spine Indicate Increased Instability with Disc Degeneration

PubMed Central

Ellingson, Arin M.; Nuckley, David J.

2014-01-01

Although the causes of low back pain are poorly defined and indistinct, degeneration of the intervertebral disc is most often implicated as the origin of pain. The biochemical and mechanical changes associated with degeneration result in the discs’ inability to maintain structure and function, leading to spinal instability and ultimately pain. Traditionally, a clinical exam assessing functional range-of-motion coupled with T2-weighted MRI revealing disc morphology are used to evaluate spinal health; however, these subjective measures fail to correlate well with pain or provide useful patient stratification. Therefore, improved quantification of spinal motion and objective MRI measures of disc health are necessary. An instantaneous helical axis (IHA) approach provides rich temporal three-dimensional data describing the pathway of motion, which is easily visualized. Eighteen cadaveric osteoligamentous lumbar spines (L4-5) from throughout the degenerative spectrum were tested in a pure moment fashion. IHA were calculated for flexion-extension and lateral bending. A correlational study design was used to determine the relationship between disc measurements from quantitative T2* MRI and IHA metrics. Increased instability and out-of-plane rotation with diminished disc health was observed during lateral bending, but not flexion-extension. This new analysis strategy examines the entire pathway of motion, rather than simplifying spinal kinematics to its terminal ends of motion and provides a more sensitive kinematic measurement of disc health. Ultimately, through the use of 3D dynamic fluoroscopy or similar methods, a patient's functional IHA in lateral bending may be measured and used to assess their disc health for diagnosis, progression tracking, and treatment evaluation. PMID:25481221

Outcome of transforaminal lumbar interbody fusion in spondylolisthesis-A clinico-radiological correlation.

PubMed

Balasubramanian, Vijay Anand; Douraiswami, Balaji; Subramani, Suresh

2018-06-01

Lumbar spondylolisthesis is a common cause of morbidity in middle aged individuals. Spinal fusion with instrumentation has become the gold standard for lumbar segmental instability. Studies which correlate the improvement in radiology postoperatively with functional outcome show contrasting reports. This study is aimed at finding the correlation between clinical and radiological outcomes after surgery with transforaminal lumbar interbody fusion. A retrospective study in 35 patients who underwent transforaminal lumbar interbody fusion in a period of 1 year was done. Preoperative pain (VAS Score), functional ability (ODI), radiological parameters (slip angle, slip grade, disc height, foraminal height, lumbar lordosis) were compared with postoperative recordings at the last followup. Functional improvement (Macnab's criteria) and fusion (Lee's fusion criteria) were assessed. Statistical analysis was done with student's paired t -test and Pearson's correlation coefficient. VAS score, ODI improved from 8 to 2 and 70 to 15 respectively. Slip angle improved from 23°to 5° on an average. 80% patients showed fusion and 85% showed good clinical outcome at 1 year followup. Analyzing with Pearson correlation coefficient showed no significant relation between pain scores and radiological parameters. But there was statistically significant relation between radiological fusion and the final clinical outcome. TLIF produces spinal fusion in most individuals. Strong spinal fusion is essential for good clinical outcome in spondylolisthesis patients who undergo TLIF. Reduction in slip is not necessary for all patients with listhesis.

Sudden quadriplegia after acute cervical disc herniation.

PubMed

Sadanand, Venkatraman; Kelly, Michael; Varughese, George; Fourney, Daryl R

2005-08-01

Acute neurological deterioration secondary to cervical disc herniation not related to external trauma is very rare, with only six published reports to date. In most cases, acute symptoms were due to progression of disc herniation in the presence of pre-existing spinal canal stenosis. A 42-year-old man developed weakness and numbness in his arms and legs immediately following a sneeze. On physical examination he had upper motor neuron signs that progressed over a few hours to a complete C5 quadriplegia. An emergent magnetic resonance imaging study revealed a massive C4/5 disc herniation. He underwent emergency anterior cervical discectomy and fusion. Postoperatively, the patient remained quadriplegic. Eighteen days later, while receiving rehabilitation therapy, he expired secondary to a pulmonary embolus. Autopsy confirmed complete surgical decompression of the spinal cord. Our case demonstrates that acute quadriplegia secondary to cervical disc herniation may occur without a history of myelopathy or spinal canal stenosis after an event as benign as a sneeze.

A potential role for cell-based therapeutics in the treatment of intervertebral disc herniation.

PubMed

Ganey, Timothy M; Meisel, Hans Joerg

2002-10-01

Lower back pain and disc degeneration negatively affect quality of life and impose an enormous financial burden. An extensive body of scientific work has evolved that characterizes the disc, demonstrating spinal anatomy and morphology that contribute to risk and likely promote failure. Ultimately, matrix failure is responsible for mechanical failure, which in turn results in spinal compromise anatomically and subsequent pain. One intervening approach to breaking this sequence has been to repopulate the anatomy with autologous disc chondrocytes--cells capable of restoring the matrix and retaining the mechanical balance by which the disc functions. This strategy has been implemented both in patients and in animal models, and early results, although preliminary, support the premise as a positive approach.

Clinical and radiological outcomes of endoscopic partial facetectomy for degenerative lumbar foraminal stenosis.

PubMed

Youn, Myung Soo; Shin, Jong Ki; Goh, Tae Sik; Lee, Jung Sub

2017-06-01

Several different techniques exist to treat degenerative lumbar foraminal stenosis. Failure to adequately decompress the lumbar foramen may lead to failed back surgery syndrome. However, wide decompression often causes spinal instabilities or may require an additional fusion surgery. The aim of this study was to report the outcomes of endoscopic partial facetectomy (EPF) performed on patients with degenerative lumbar foraminal stenosis. Between 2012 and 2014, 25 consecutive patients (12 women and 13 men) who underwent EPF were included in the study. The patients were assessed before surgery and followed-up regularly during outpatient visits (preoperatively and 1, 3, 6, 12, and 24 months postoperatively). The clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) outcome questionnaire. The radiological outcome was measured using the lumbar Cobb angle, disc wedging angle, lumbar lordosis (LL), slip percentage, and disc height index (DHI) in plain standing radiographs. The VAS, ODI, and SF-36 scores significantly improved at 1 month of follow-up compared with the baseline mean values and were maintained within the 2-year follow-up period. There was no radiologic progression in the lumbar Cobb's angle, disc wedging angle, LL, slip percentage, and DHI between preoperatively and 2 years postoperatively. In addition, the EPF with discectomy group and the EPF group were not significantly different in terms of clinical and radiological outcomes. EPF is an effective option in decompressing the lumbar exiting nerve root without causing spinal instabilities for the treatment of patients with lumbar foraminal stenosis.

Does disc space height of fused segment affect adjacent degeneration in ALIF? A finite element study.

PubMed

Tang, Shujie; Meng, Xueying

2011-01-01

The restoration of disc space height of fused segment is essential in anterior lumbar interbody fusion, while the disc space height in many cases decreased postoperatively, which may adversely aggravate the adjacent segmental degeneration. However, no literature available focused on the issue. A normal healthy finite element model of L3-5 and four anterior lumbar interbody fusion models with different disc space height of fused segment were developed. 800 N compressive loading plus 10 Nm moments simulating flexion, extension, lateral bending and axial rotation were imposed on L3 superior endplate. The intradiscal pressure, the intersegmental rotation, the tresca stress and contact force of facet joints in L3-4 were investigated. Anterior lumbar interbody fusion with severely decreased disc space height presented with the highest values of the four parameters, and the normal healthy model presented with the lowest values except, under extension, the contact force of facet joints in normal healthy model is higher than that in normal anterior lumbar interbody fusion model. With disc space height decrease, the values of parameters in each anterior lumbar interbody fusion model increase gradually. Anterior lumbar interbody fusion with decreased disc space height aggravate the adjacent segmental degeneration more adversely.

A Systematic Review of Mesenchymal Stem Cells in Spinal Cord Injury, Intervertebral Disc Repair and Spinal Fusion.

PubMed

Khan, Shujhat; Mafi, Pouya; Mafi, Reza; Khan, Wasim

2018-01-01

Spinal surgery presents a challenge for both neurosurgery and orthopaedic surgery. Due to the heterogeneous differentiation potential of mesenchymal stem cells, there is much interest in the treatment of spine surgery. Animal and human trials focussing on the efficacy of mesenchymal stem cells in spinal cord injury, spine fusion and disc degeneration were included in this systematic review. Published articles up to January 2016 from MEDLINE, PubMed and Ovid were used by searching for specific terms. Of the 2595 articles found, 53 met the selection criteria and were included for analysis (16 on spinal cord injury, 28 on intervertebral disc repair and 9 on spinal fusion). Numerous studies reported better results when the mesenchymal stem cells were used in co-culture with other cells or used in scaffolds. Mesenchymal stem cells were also found to have an immune-modulatory role, which can improve surgical outcome. This systematic review suggests that mesenchymal stem cells can be used safely and effectively for these spinal surgery treatments. Whilst, in certain studies, mesenchymal stem cells did not necessarily show improved results from existing treatments, they provide an alternative option. This can reduce morbidity that arises from current surgical treatment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Evaluation of a new approach to compute intervertebral disc height measurements from lateral radiographic views of the spine.

PubMed

Allaire, Brett T; DePaolis Kaluza, M Clara; Bruno, Alexander G; Samelson, Elizabeth J; Kiel, Douglas P; Anderson, Dennis E; Bouxsein, Mary L

2017-01-01

Current standard methods to quantify disc height, namely distortion compensated Roentgen analysis (DCRA), have been mostly utilized in the lumbar and cervical spine and have strict exclusion criteria. Specifically, discs adjacent to a vertebral fracture are excluded from measurement, thus limiting the use of DCRA in studies that include older populations with a high prevalence of vertebral fractures. Thus, we developed and tested a modified DCRA algorithm that does not depend on vertebral shape. Participants included 1186 men and women from the Framingham Heart Study Offspring and Third Generation Multidetector CT Study. Lateral CT scout images were used to place 6 morphometry points around each vertebra at 13 vertebral levels in each participant. Disc heights were calculated utilizing these morphometry points using DCRA methodology and our modified version of DCRA, which requires information from fewer morphometry points than the standard DCRA. Modified DCRA and standard DCRA measures of disc height are highly correlated, with concordance correlation coefficients above 0.999. Both measures demonstrate good inter- and intra-operator reproducibility. 13.9 % of available disc heights were not evaluable or excluded using the standard DCRA algorithm, while only 3.3 % of disc heights were not evaluable using our modified DCRA algorithm. Using our modified DCRA algorithm, it is not necessary to exclude vertebrae with fracture or other deformity from disc height measurements as in the standard DCRA. Modified DCRA also yields identical measurements to the standard DCRA. Thus, the use of modified DCRA for quantitative assessment of disc height will lead to less missing data without any loss of accuracy, making it a preferred alternative to the current standard methodology.

Are spinal or paraspinal anatomic markers helpful for vertebral numbering and diagnosing lumbosacral transitional vertebrae?

PubMed

Tokgoz, Nil; Ucar, Murat; Erdogan, Aylin Billur; Kilic, Koray; Ozcan, Cahide

2014-01-01

To evaluate the value of spinal and paraspinal anatomic markers in both the diagnosis of lumbosacral transitional vertebrae (LSTVs) and identification of vertebral levels on lumbar MRI. Lumbar MRI from 1049 adult patients were studied. By comparing with the whole-spine localizer, the diagnostic errors in numbering vertebral segments on lumbar MRI were evaluated. The morphology of S1-2 disc, L5 and S1 body, and lumbar spinous processes (SPs) were evaluated by using sagittal MRI. The positions of right renal artery (RRA), superior mesenteric artery, aortic bifurcation (AB) and conus medullaris (CM) were described. The diagnostic error for evaluation of vertebral segmentation on lumbar MRI alone was 14.1%. In lumbarization, all patients revealed a well-formed S1-2 disc with squared S1 body. A rhombus-shaped L5 body in sacralization and a rectangular-shaped S1 body in lumbarization were found. The L3 had the longest SP. The most common sites of spinal and paraspinal structures were: RRA at L1 body (53.6%) and L1-2 disc (34.1%), superior mesenteric artery at L1 body (55.1%) and T12-L1 disc (31.6%), and AB at L4 body (71.1%). CM had variable locations, changing from the T12-L1 disc to L2 body. They were located at higher sacralization and lower lumbarization. The spinal morphologic features and locations of the spinal and paraspinal structures on lumbar MRI are not completely reliable for the diagnosis of LSTVs and identification on the vertebral levels.

Injectable hydrogels with high fixed charge density and swelling pressure for nucleus pulposus repair: biomimetic glycosaminoglycan analogues.

PubMed

Sivan, S S; Roberts, S; Urban, J P G; Menage, J; Bramhill, J; Campbell, D; Franklin, V J; Lydon, F; Merkher, Y; Maroudas, A; Tighe, B J

2014-03-01

The load-bearing biomechanical role of the intervertebral disc is governed by the composition and organization of its major macromolecular components, collagen and aggrecan. The major function of aggrecan is to maintain tissue hydration, and hence disc height, under the high loads imposed by muscle activity and body weight. Key to this role is the high negative fixed charge of its glycosaminoglycan side chains, which impart a high osmotic pressure to the tissue, thus regulating and maintaining tissue hydration and hence disc height under load. In degenerate discs, aggrecan degrades and is lost from the disc, particularly centrally from the nucleus pulposus. This loss of fixed charge results in reduced hydration and loss of disc height; such changes are closely associated with low back pain. The present authors developed biomimetic glycosaminoglycan analogues based on sulphonate-containing polymers. These biomimetics are deliverable via injection into the disc where they polymerize in situ, forming a non-degradable, nuclear "implant" aimed at restoring disc height to degenerate discs, thereby relieving back pain. In vitro, these glycosaminoglycan analogues possess appropriate fixed charge density, hydration and osmotic responsiveness, thereby displaying the capacity to restore disc height and function. Preliminary biomechanical tests using a degenerate explant model showed that the implant adapts to the space into which it is injected and restores stiffness. These hydrogels mimic the role taken by glycosaminoglycans in vivo and, unlike other hydrogels, provide an intrinsic swelling pressure, which can maintain disc hydration and height under the high and variable compressive loads encountered in vivo. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Posterior epidural disc fragment masquerading as spinal tumor: Review of the literature.

PubMed

Park, Taejune; Lee, Ho Jun; Kim, Jae Seong; Nam, Kiyeun

2018-03-09

Posterior epidural lumbar disc fragment is infrequent because of anatomical barriers, and it is difficult to diagnose posterior epidural lumbar disc fragment because of its rare incidence and the ambiguity of radiologic evaluations. And it is difficult to differentiate it from other diseases such as spinal tumors. Differential diagnosis of posterior epidural lumbar disc fragment is clinically important because its diagnosis can affect treatment and prognosis. To investigate the incidence, anatomical concern, etiology, symptom, diagnostic tool, management and prognosis of posterior epidural lumbar disc fragment, we reviewed articles including case report. We performed a search of all clinical studies of posterior epidural lumbar disc fragment published to date. The following keywords were searched: Posterior epidural lumbar disc fragment, disc migration, posterior epidural disc, extradural migration, dorsal epidural migration, sequestrated disc, and disc fragment. We identified 40 patients of posterior epidural lumbar disc fragment from 28 studies. The most common presentation of posterior epidural lumbar disc fragment was sudden onset radiculopathy (70.0%), followed by cauda equina syndrome (27.5%). The most frequently used diagnostic modality was magnetic resonance imaging (MRI), conducted in 36 cases (90.0%), and followed by computed tomography in 14 cases (35.0%). After the imaging studies, the preoperative diagnoses were 45.0% masses, 20.0% lesions, and 12.5% tumors. Characteristic MRI findings in posterior epidural lumbar disc fragment are helpful for diagnosis; it typically displays low signals on T1-weighted images and high signals on T2-weighted images with respect to the parent disc. In addition, most of the disc fragments show peripheral rim enhancement on MRI with gadolinium administration. Electrodiagnostic testing is useful for verifying nerve damage. Surgical treatment was performed in all cases, and neurologic complications were observed in 12.5%. As posterior epidural lumbar disc fragment could be masqueraded as spinal tumor, if rim enhancement is observed in MRI scans with sudden symptoms of radiculopathy or cauda equina syndrome, it should be taken into consideration. Early diagnosis can lead to early surgery, which can reduce complications.

Are Spinal or Paraspinal Anatomic Markers Helpful for Vertebral Numbering and Diagnosing Lumbosacral Transitional Vertebrae?

PubMed Central

Ucar, Murat; Erdogan, Aylin Billur; Kilic, Koray; Ozcan, Cahide

2014-01-01

Objective To evaluate the value of spinal and paraspinal anatomic markers in both the diagnosis of lumbosacral transitional vertebrae (LSTVs) and identification of vertebral levels on lumbar MRI. Materials and Methods Lumbar MRI from 1049 adult patients were studied. By comparing with the whole-spine localizer, the diagnostic errors in numbering vertebral segments on lumbar MRI were evaluated. The morphology of S1-2 disc, L5 and S1 body, and lumbar spinous processes (SPs) were evaluated by using sagittal MRI. The positions of right renal artery (RRA), superior mesenteric artery, aortic bifurcation (AB) and conus medullaris (CM) were described. Results The diagnostic error for evaluation of vertebral segmentation on lumbar MRI alone was 14.1%. In lumbarization, all patients revealed a well-formed S1-2 disc with squared S1 body. A rhombus-shaped L5 body in sacralization and a rectangular-shaped S1 body in lumbarization were found. The L3 had the longest SP. The most common sites of spinal and paraspinal structures were: RRA at L1 body (53.6%) and L1-2 disc (34.1%), superior mesenteric artery at L1 body (55.1%) and T12-L1 disc (31.6%), and AB at L4 body (71.1%). CM had variable locations, changing from the T12-L1 disc to L2 body. They were located at higher sacralization and lower lumbarization. Conclusion The spinal morphologic features and locations of the spinal and paraspinal structures on lumbar MRI are not completely reliable for the diagnosis of LSTVs and identification on the vertebral levels. PMID:24644411

[Radiological study on the n-HA/PA66 cage used in the transforaminal lumbar interbody fusion].

PubMed

Sang, Pei-ming; Zhang, Ming; Chen, Bin-hui; Cai, Chang; Gu, Shi-rong; Zhou, Min

2014-08-01

To explore the effects of nano-hydroxyapatite/polyamide 66 (n-HA/PA66) cage on recovering and maintaining lumbar curvature, lumbar heights and fusion rate when used in the transforaminal lumbar interbody fusion. From February to July 2012, 50 patients with degenerative lumbar disease(lumbar disc herniation in 32 cases and lumbar spondylolisthesis in 18 cases) were treated with transforaminal lumbar interbody fusion using the n-HA/PA66 cage, and their preoperative and postoperative clinical outcomes were analyzed. The patients were followed up for 2, 4, 6 and 8 months after operation, during which the CR and CT film of lumbar vertebra were checked to get relative height of vertebral space, Taillard index,index of lumbar spinal curvature,angle of segmental and full lumbar lordosis. The data were analyzed respectively with pair t-test, analysis of variance or LSD-t-test. All the patients were followed up, and the duraion ranged from 8 to 13 months, with a mean of 11.32 months. There were significant differences in relative height of vertebral space, Taillard index, index of lumbar spinal curvature, angle of segmental and full lumbar lordosis after surgery, but there were no significant differences in different periods after operation. The fusion time of lumbar ranged from 4 to 8 months. The n-HA/PA66 cage can recover and maintain lumbar normal stability with higher rate of fusion and less complications.

Finite Element Analysis of the Effect of Epidural Adhesions.

PubMed

Lee, Nam; Ji, Gyu Yeul; Yi, Seong; Yoon, Do Heum; Shin, Dong Ah; Kim, Keung Nyun; Ha, Yoon; Oh, Chang Hyun

2016-07-01

It is well documented that epidural adhesion is associated with spinal pain. However, the underlying mechanism of spinal pain generation by epidural adhesion has not yet been elucidated. To elucidate the underlying mechanism of spinal pain generation by epidural adhesion using a two-dimensional (2D) non-linear finite element (FE) analysis. A finite element analysis. A two-dimensional nonlinear FE model of the herniated lumbar disc on L4/5 with epidural adhesion. A two-dimensional nonlinear FE model of the lumbar spine was developed, consisting of intervertebral discs, dura, spinal nerve, and lamina. The annulus fibrosus and nucleus pulpous were modeled as hyperelastic using the Mooney-Rivlin equation. The FE mesh was generated and analyzed using Abaqus (ABAQUS 6.13.; Hibbitt, Karlsson & Sorenson, Inc., Providence, RI, USA). Epidural adhesion was simulated as rough contact, in which no slip occurred once two surfaces were in contact, between the dura mater and posterior annulus fibrosus. The FE model of adhesion showed significant stress concentration in the spinal nerves, especially on the dorsal root ganglion (DRG). The stress concentration was caused by the lack of adaptive displacement between the dura mater and posterior annulus fibrosus. The peak von Mises stress was higher in the epidural adhesion model (Adhesion, 0.67 vs. Control, 0.46). In the control model, adaptive displacement was observed with decreased stress in the spinal nerve and DRG (with adhesion, 2.59 vs. without adhesion, 3.58, P < 0.00). This study used a 2D non-linear FE model, which simplifies the 3D nature of the human intervertebral disc. In addition, this 2D non-linear FE model has not yet been validated. The current study clearly demonstrated that epidural adhesion causes significantly increased stress in the spinal nerves, especially at the DRG. We believe that the increased stress on the spinal nerve might elicit more pain under similar magnitudes of lumbar disc protrusion.

Spinal disabilities in military and civil aviators.

PubMed

Taneja, Narinder

2008-12-01

The purpose of this study was to analyze the nature and cause of spinal disabilities among military and civil aircrew in India. Studies suggest that military aircrew may be more prone than nonaviators to develop spinal disabilities. An in-depth analysis of such disabilities can enable policy makers to develop data-driven preventive health programs. Extensive literature search did not reveal even a single study focusing on spinal disabilities in symptomatic aircrew. A case record of each aircrew is maintained at the Institute of Aerospace Medicine, Indian Air Force, Bangalore, India These records were accessed for all aircrew evaluated for spinal disabilities from the year 2000 to 2006. The total data comprises of 239 military and 11 civil aircrew. Most of the military aircrew were from the fighter stream. The spectrum of causes for spinal disabilities ranged from ejection, aircraft accidents to road traffic accidents, and falls. Degenerative disc disease was the leading cause in helicopter and transport pilots, whereas fractures were the predominant category in fighter pilots. A total of 153 vertebral fractures and 190 intervertebral discs were involved. There were significant differences in the age and distribution of this aircrew. Spinal disabilities assume significance for variety of reasons. Firstly, a large number of spinal disabilities caused by vehicular trauma are preventable. Second, they generally entail a prolonged course of recovery. Third, they can result in loss of trained human resources, especially when the individual cannot return to his or her original workspace. This study provides insights into the nature of spinal disabilities in civil and military aviation. Ejection and aircraft accidents remain the leading cause of vertebral fractures. Disc degenerative disease is a cause of concern. Physical conditioning and regular physical exercise may possibly minimize spinal disabilities in susceptible aircrew.

Baastrup's Disease Is Associated with Recurrent of Sciatica after Posterior Lumbar Spinal Decompressions Utilizing Floating Spinous Process Procedures

PubMed Central

Mannoji, Chikato; Murakami, Masazumi; Kinoshita, Tomoaki; Hirayama, Jiro; Miyashita, Tomohiro; Eguchi, Yawara; Yamazaki, Masashi; Suzuki, Takane; Aramomi, Masaaki; Ota, Mitsutoshi; Maki, Satoshi; Takahashi, Kazuhisa; Furuya, Takeo

2016-01-01

Study Design Retrospective case-control study. Purpose To determine whether kissing spine is a risk factor for recurrence of sciatica after lumbar posterior decompression using a spinous process floating approach. Overview of Literature Kissing spine is defined by apposition and sclerotic change of the facing spinous processes as shown in X-ray images, and is often accompanied by marked disc degeneration and decrement of disc height. If kissing spine significantly contributes to weight bearing and the stability of the lumbar spine, trauma to the spinous process might induce a breakdown of lumbar spine stability after posterior decompression surgery in cases of kissing spine. Methods The present study included 161 patients who had undergone posterior decompression surgery for lumbar canal stenosis using a spinous process floating approaches. We defined recurrence of sciatica as that resolved after initial surgery and then recurred. Kissing spine was defined as sclerotic change and the apposition of the spinous process in a plain radiogram. Preoperative foraminal stenosis was determined by the decrease of perineural fat intensity detected by parasagittal T1-weighted magnetic resonance imaging. Preoperative percentage slip, segmental range of motion, and segmental scoliosis were analyzed in preoperative radiographs. Univariate analysis followed by stepwise logistic regression analysis determined factors independently associated with recurrence of sciatica. Results Stepwise logistic regression revealed kissing spine (p=0.024; odds ratio, 3.80) and foraminal stenosis (p<0.01; odds ratio, 17.89) as independent risk factors for the recurrence of sciatica after posterior lumbar spinal decompression with spinous process floating procedures for lumbar spinal canal stenosis. Conclusions When a patient shows kissing spine and concomitant subclinical foraminal stenosis at the affected level, we should sufficiently discuss the selection of an appropriate surgical procedure. PMID:27994785

Baastrup's Disease Is Associated with Recurrent of Sciatica after Posterior Lumbar Spinal Decompressions Utilizing Floating Spinous Process Procedures.

PubMed

Koda, Masao; Mannoji, Chikato; Murakami, Masazumi; Kinoshita, Tomoaki; Hirayama, Jiro; Miyashita, Tomohiro; Eguchi, Yawara; Yamazaki, Masashi; Suzuki, Takane; Aramomi, Masaaki; Ota, Mitsutoshi; Maki, Satoshi; Takahashi, Kazuhisa; Furuya, Takeo

2016-12-01

Retrospective case-control study. To determine whether kissing spine is a risk factor for recurrence of sciatica after lumbar posterior decompression using a spinous process floating approach. Kissing spine is defined by apposition and sclerotic change of the facing spinous processes as shown in X-ray images, and is often accompanied by marked disc degeneration and decrement of disc height. If kissing spine significantly contributes to weight bearing and the stability of the lumbar spine, trauma to the spinous process might induce a breakdown of lumbar spine stability after posterior decompression surgery in cases of kissing spine. The present study included 161 patients who had undergone posterior decompression surgery for lumbar canal stenosis using a spinous process floating approaches. We defined recurrence of sciatica as that resolved after initial surgery and then recurred. Kissing spine was defined as sclerotic change and the apposition of the spinous process in a plain radiogram. Preoperative foraminal stenosis was determined by the decrease of perineural fat intensity detected by parasagittal T1-weighted magnetic resonance imaging. Preoperative percentage slip, segmental range of motion, and segmental scoliosis were analyzed in preoperative radiographs. Univariate analysis followed by stepwise logistic regression analysis determined factors independently associated with recurrence of sciatica. Stepwise logistic regression revealed kissing spine ( p =0.024; odds ratio, 3.80) and foraminal stenosis ( p <0.01; odds ratio, 17.89) as independent risk factors for the recurrence of sciatica after posterior lumbar spinal decompression with spinous process floating procedures for lumbar spinal canal stenosis. When a patient shows kissing spine and concomitant subclinical foraminal stenosis at the affected level, we should sufficiently discuss the selection of an appropriate surgical procedure.

Understanding how axial loads on the spine influence segmental biomechanics for idiopathic scoliosis patients: A magnetic resonance imaging study.

PubMed

Little, J P; Pearcy, M J; Izatt, M T; Boom, K; Labrom, R D; Askin, G N; Adam, C J

2016-02-01

Segmental biomechanics of the scoliotic spine are important since the overall spinal deformity is comprised of the cumulative coronal and axial rotations of individual joints. This study investigates the coronal plane segmental biomechanics for adolescent idiopathic scoliosis patients in response to physiologically relevant axial compression. Individual spinal joint compliance in the coronal plane was measured for a series of 15 idiopathic scoliosis patients using axially loaded magnetic resonance imaging. Each patient was first imaged in the supine position with no axial load, and then again following application of an axial compressive load. Coronal plane disc wedge angles in the unloaded and loaded configurations were measured. Joint moments exerted by the axial compressive load were used to derive estimates of individual joint compliance. The mean standing major Cobb angle for this patient series was 46°. Mean intra-observer measurement error for endplate inclination was 1.6°. Following loading, initially highly wedged discs demonstrated a smaller change in wedge angle, than less wedged discs for certain spinal levels (+2,+1,-2 relative to the apex, (p<0.05)). Highly wedged discs were observed near the apex of the curve, which corresponded to lower joint compliance in the apical region. While individual patients exhibit substantial variability in disc wedge angles and joint compliance, overall there is a pattern of increased disc wedging near the curve apex, and reduced joint compliance in this region. Approaches such as this can provide valuable biomechanical data on in vivo spinal biomechanics of the scoliotic spine, for analysis of deformity progression and surgical planning. Copyright © 2015 Elsevier Ltd. All rights reserved.

78 FR 24426 - Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-25

... application for the Kineflex/C Cervical Artificial Disc sponsored by SpinalMotion. The Kineflex/C is a metal-on-metal (cobalt chrome molybdenum alloy) cervical total disc replacement device. The Kineflex/C is... degenerative disc disease (DDD) where DDD is defined as discogenic back pain with degeneration of the disc as...

Radiographic and MRI characteristics of lumbar disseminated idiopathic spinal hyperostosis and spondylosis deformans in dogs.

PubMed

Togni, A; Kranenburg, H J C; Morgan, J P; Steffen, F

2014-07-01

To evaluate clinical signs, describe lesions and differences in the magnetic resonance imaging appearance of spinal new bone formations classified as disseminated idiopathic spinal hyperostosis and/or spondylosis deformans on radiographs and compare degeneration status of the intervertebral discs using the Pfirrmann scale. Retrospective analysis of 18 dogs presented with spinal disorders using information from radiographic and magnetic resonance imaging examinations. All dogs were found to be affected with both disseminated idiopathic spinal hyperostosis and spondylosis deformans. Neurological signs due to foraminal stenosis associated with disseminated idiopathic spinal hyperostosis were found in two dogs. Spondylosis deformans was associated with foraminal stenosis and/or disc protrusion in 15 cases. The Pfirrmann score on magnetic resonance imaging was significantly higher in spondylosis deformans compared with disseminated idiopathic spinal hyperostosis and signal intensity of new bone due to disseminated idiopathic spinal hyperostosis was significantly higher compared to spondylosis deformans. Differences between disseminated idiopathic spinal hyperostosis and spondylosis deformans found on magnetic resonance imaging contribute to an increased differentiation between the two entities. Clinically relevant lesions in association with disseminated idiopathic spinal hyperostosis were rare compared to those seen with spondylosis deformans. © 2014 British Small Animal Veterinary Association.

MRI evaluation of spontaneous intervertebral disc degeneration in the alpaca cervical spine.

PubMed

Stolworthy, Dean K; Bowden, Anton E; Roeder, Beverly L; Robinson, Todd F; Holland, Jacob G; Christensen, S Loyd; Beatty, Amanda M; Bridgewater, Laura C; Eggett, Dennis L; Wendel, John D; Stieger-Vanegas, Susanne M; Taylor, Meredith D

2015-12-01

Animal models have historically provided an appropriate benchmark for understanding human pathology, treatment, and healing, but few animals are known to naturally develop intervertebral disc degeneration. The study of degenerative disc disease and its treatment would greatly benefit from a more comprehensive, and comparable animal model. Alpacas have recently been presented as a potential large animal model of intervertebral disc degeneration due to similarities in spinal posture, disc size, biomechanical flexibility, and natural disc pathology. This research further investigated alpacas by determining the prevalence of intervertebral disc degeneration among an aging alpaca population. Twenty healthy female alpacas comprised two age subgroups (5 young: 2-6 years; and 15 older: 10+ years) and were rated according to the Pfirrmann-grade for degeneration of the cervical intervertebral discs. Incidence rates of degeneration showed strong correlations with age and spinal level: younger alpacas were nearly immune to developing disc degeneration, and in older animals, disc degeneration had an increased incidence rate and severity at lower cervical levels. Advanced disc degeneration was present in at least one of the cervical intervertebral discs of 47% of the older alpacas, and it was most common at the two lowest cervical intervertebral discs. The prevalence of intervertebral disc degeneration encourages further investigation and application of the lower cervical spine of alpacas and similar camelids as a large animal model of intervertebral disc degeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

The effect of simulated microgravity on lumbar spine biomechanics: an in vitro study.

PubMed

Laws, Cory J; Berg-Johansen, Britta; Hargens, Alan R; Lotz, Jeffrey C

2016-09-01

Disc herniation risk is quadrupled following spaceflight. This study tested the hypothesis that swelling-induced disc height increases (comparable to those reported in spaceflight) stiffen the spine and elevate annular strain and nuclear pressure during forward bending. Eight human lumbar motion segments were secured to custom-designed testing jigs and subjected to baseline flexion and compression and pure moment flexibility tests. Discs were then free-swelled in saline to varying supraphysiologic heights consistent with prolonged weightlessness and re-tested to assess biomechanical changes. Swelling-induced disc height changes correlated positively with intradiscal pressure (p < 0.01) and stiffening in flexion (p < 0.01), and negatively with flexion range of motion (p < 0.05). Swelling-induced increases in disc height also led to increased annular surface strain under combined flexion with compression. Disc wedge angle decreased with swelling (p < 0.05); this loss of wedge angle correlated with decreased flexion range of motion (R (2) = 0.94, p < 0.0001) and decreased stiffness fold change in extension (p < 0.05). Swelling-induced increases in disc height decrease flexibility and increase annular strain and nuclear pressure during forward bending. These changes, in combination with the measured loss of lordotic curvature with disc swelling, may contribute toward increased herniation risk. This is consistent with clinical observations of increased disc herniation rates after microgravity exposure and may provide the basis for future countermeasure development.

The effect of simulated microgravity on lumbar spine biomechanics: an in vitro study

PubMed Central

Laws, Cory J.; Berg-Johansen, Britta; Hargens, Alan R.; Lotz, Jeffrey C.

2015-01-01

Purpose Disc herniation risk is quadrupled following spaceflight. This study tested the hypothesis that swelling-induced disc height increases (comparable to those reported in spaceflight) stiffen the spine and elevate annular strain and nuclear pressure during forward bending. Methods Eight human lumbar motion segments were secured to custom-designed testing jigs and subjected to baseline flexion and compression and pure moment flexibility tests. Discs were then free-swelled in saline to varying supraphysiologic heights consistent with prolonged weightlessness and re-tested to assess biomechanical changes. Results Swelling-induced disc height changes correlated positively with intradiscal pressure (p < 0.01) and stiffening in flexion (p < 0.01), and negatively with flexion range of motion (p < 0.05). Swelling-induced increases in disc height also led to increased annular surface strain under combined flexion with compression. Disc wedge angle decreased with swelling (p < 0.05); this loss of wedge angle correlated with decreased flexion range of motion (R2 = 0.94, p < 0.0001) and decreased stiffness fold change in extension (p < 0.05). Conclusion Swelling-induced increases in disc height decrease flexibility and increase annular strain and nuclear pressure during forward bending. These changes, in combination with the measured loss of lordotic curvature with disc swelling, may contribute toward increased herniation risk. This is consistent with clinical observations of increased disc herniation rates after microgravity exposure and may provide the basis for future countermeasure development. PMID:26403291

Resolving the disc-halo degeneracy - I: a look at NGC 628

NASA Astrophysics Data System (ADS)

Aniyan, S.; Freeman, K. C.; Arnaboldi, M.; Gerhard, O. E.; Coccato, L.; Fabricius, M.; Kuijken, K.; Merrifield, M.; Ponomareva, A. A.

2018-05-01

The decomposition of the rotation curve of galaxies into contribution from the disc and dark halo remains uncertain and depends on the adopted mass-to-light ratio (M/L) of the disc. Given the vertical velocity dispersion of stars and disc scale height, the disc surface mass density and hence the M/L can be estimated. We address a conceptual problem with previous measurements of the scale height and dispersion. When using this method, the dispersion and scale height must refer to the same population of stars. The scale height is obtained from near-infrared (IR) studies of edge-on galaxies and is weighted towards older kinematically hotter stars, whereas the dispersion obtained from integrated light in the optical bands includes stars of all ages. We aim to extract the dispersion for the hotter stars, so that it can then be used with the correct scale height to obtain the disc surface mass density. We use a sample of planetary nebulae (PNe) as dynamical tracers in the face-on galaxy NGC 628. We extract two different dispersions from its velocity histogram - representing the older and younger PNe. We also present complementary stellar absorption spectra in the inner regions of this galaxy and use a direct pixel fitting technique to extract the two components. Our analysis concludes that previous studies, which do not take account of the young disc, underestimate the disc surface mass density by a factor of ˜2. This is sufficient to make a maximal disc for NGC 628 appear like a submaximal disc.

Influence of height, weight, and body mass index on optic disc parameters.

PubMed

Zheng, Yingfeng; Cheung, Carol Y L; Wong, Tien Y; Mitchell, Paul; Aung, Tin

2010-06-01

To examine the influence of body height, body weight, and body mass index (BMI) on optic disc parameters in a population-based study. The Singapore Malay Eye Study examined 3280 persons of Malay ethnicity, aged 40 to 80 years, of whom 2329 (71.0%) had reliable retinal scanning confocal laser tomography images for analyses. Intraocular pressure (IOP) was ascertained by Goldmann applanation tonometry. Body height and weight were measured with standardized protocols; BMI was calculated as weight (kilograms)/height squared (meters). Sociodemographic information was collected in an interviewer-administered questionnaire. In univariate analyses, body height, weight, and BMI were significantly associated with optic cup area, rim area, and cup-to-disc area ratio (all with P < 0.05) but none of the anthropometric parameters was significantly associated with optic disc area (all with P > 0.05). In multiple regression analyses after adjustment for age, sex, optic disc size, axial length, education, family income, and IOP, each SD increase in body height was associated with a 0.042-mm(2) decrease in optic rim area and a 0.020 increase in optic cup-to-disc area ratio; each SD decrease in body weight was associated with a 0.013-mm(2) decrease in optic rim area and a 0.010 increase in optic cup-to-disc ratio; and each SD decrease in BMI was associated with a 0.021-mm(2) decrease in optic rim area and a 0.010 increase in optic cup-to-disc ratio. Persons who are taller or have lower BMI have a smaller neuroretinal rim area and a larger optic cup-to-disc area ratio.

Effects of a Belt on Intra-Abdominal Pressure during Weight Lifting.

DTIC Science & Technology

1988-03-01

potentially injurious b compressive forces on spinal discs during lifting. To investigate the effects of a standard lifting belt on lAP and lifting mechanics... injurious compressive forces on spinal discs during lifting. To investigate the effects of a standard lifting belt on IAP and lifting ! mechanics... weightlifting (7,9). Both olympic and power lifters have used lifting belts for many years, yet virtually no research has been reported which examines

Slow deformation of intervertebral discs.

PubMed

Broberg, K B

1993-01-01

Intervertebral discs exhibit pronounced time-dependent deformations when subjected to load variations. These deformations are caused by fluid flow to and from the disc and by viscoelastic deformation of annulus fibres. The fluid flow is caused by differences between mechanical and osmotic pressure. A mechanical model of lumbar disc functions allows one to calculate both the extent of fluid flow and its implications for disc height as well as the role played by viscoelastic deformation of annulus fibres. From such calculations changes in body height are estimated. Experimental results already documented in the literature offer bases for the determination of the parameters involved. Body height variations are studied, both those related to normal diurnal rhythmicity and those related to somewhat exceptional circumstances. The normal diurnal fluid flow is found to be about +/- 40% of the disc fluid content late in the evening. Viscoelastic deformation of annulus fibres contributes approximately one quarter of the height change obtained after several hours normal activity, but dominates during the first hour.

Spaceflight-Induced Bone Loss Alters Failure Mode and Reduces Bending Strength in Murine Spinal Segments

PubMed Central

Berg-Johansen, Britta; Liebenberg, Ellen C.; Li, Alfred; Macias, Brandon R.; Hargens, Alan R.; Lotz, Jeffrey C.

2017-01-01

Intervertebral disc herniation rates are quadrupled in astronauts following spaceflight. While bending motions are main contributors to herniation, the effects of microgravity on the bending properties of spinal discs are unknown. Consequently, the goal of this study was to quantify the bending properties of tail discs from mice with or without microgravity exposure. Caudal motion segments from six mice returned from a 30-day Bion M1 mission and eight vivarium controls were loaded to failure in four-point bending. After testing, specimens were processed using histology to determine the location of failure, and adjacent motion segments were scanned with micro-computed tomography (μCT) to quantify bone properties. We observed that spaceflight significantly shortened the nonlinear toe region of the force-displacement curve by 32% and reduced the bending strength by 17%. Flight mouse spinal segments tended to fail within the growth plate and epiphyseal bone, while controls tended to fail at the disc-vertebra junction. Spaceflight significantly reduced vertebral bone volume fraction, bone mineral density, and trabecular thickness, which may explain the tendency of flight specimens to fail within the epiphyseal bone. Together, these results indicate that vertebral bone loss during spaceflight may degrade spine bending properties and contribute to increased disc herniation risk in astronauts. PMID:26285046

Is mandibular asymmetry more frequent and severe with unilateral disc displacement?

PubMed

Xie, Qianyang; Yang, Chi; He, Dongmei; Cai, Xieyi; Ma, Zhigui

2015-01-01

To investigate the prevalence of mandibular asymmetry (MA) within the symptomatic unilateral anterior disc displacement (ADD) patients, and analyze the influence TMJ factors of the MA severity. Patients aged under 20 years old with symptomatic unilateral ADD and asymptomatic volunteers with normal disc-condyle relationship diagnosed by magnetic resonance imaging (MRI) were included in this study. Posteroanterior cephalometric radiographs were taken to measure MA. Condylar height, disc length and disc displacement were measured by MRI. The prevalence and severity of MA were compared between the ADD and the control groups. The correlation between the severity of MA with the amount of condylar height shortage, disc deformity and distance of disc displacement were also evaluated within the ADD group. There were 165 cases in the unilateral ADD group, and 156 cases in the control group. One hundred and nineteen cases had MA which accounted 72.12% (119/165) in the ADD group; while in the control group, only 25.64% (40/156) exhibited MA. The mean horizontal menton deviation and condylar height shortage in the unilateral ADD group were significantly larger than that in the control group (5.62 mm vs. 4.19 mm; 3.14 mm vs. 1.32 mm, p < 0.01). The severity of MA was significantly correlated with the amount of disc displacement, disc deformity and condylar height shortage (correlation coefficient: 0.80, 0.70, and 0.82). MA is much more common and severe in young unilateral ADD patients. The severity of MA is correlated with the height of condyle and the status of the disc. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Choice of surgical approach for ossification of the posterior longitudinal ligament in combination with cervical disc hernia.

PubMed

Yang, Hai-song; Chen, De-yu; Lu, Xu-hua; Yang, Li-li; Yan, Wang-jun; Yuan, Wen; Chen, Yu

2010-03-01

Ossification of the posterior longitudinal ligament (OPLL) is a common spinal disorder that presents with or without cervical myelopathy. Furthermore, there is evidence suggesting that OPLL often coexists with cervical disc hernia (CDH), and that the latter is the more important compression factor. To raise the awareness of CDH in OPLL for spinal surgeons, we performed a retrospective study on 142 patients with radiologically proven OPLL who had received surgery between January 2004 and January 2008 in our hospital. Plain radiograph, three-dimensional computed tomography construction (3D CT), and magnetic resonance imaging (MRI) of the cervical spine were all performed. Twenty-six patients with obvious CDH (15 of segmental-type, nine of mixed-type, two of continuous-type) were selected via clinical and radiographic features, and intraoperative findings. By MRI, the most commonly involved level was C5/6, followed by C3/4, C4/5, and C6/7. The areas of greatest spinal cord compression were at the disc levels because of herniated cervical discs. Eight patients were decompressed via anterior cervical discectomy and fusion (ACDF), 13 patients via anterior cervical corpectomy and fusion (ACCF), and five patients via ACDF combined with posterior laminectomy and fusion. The outcomes were all favorable. In conclusion, surgeons should consider the potential for CDH when performing spinal cord decompression and deciding the surgical approach in patients presenting with OPLL.

Relevant Anatomic and Morphological Measurements of the Rat Spine: Considerations for Rodent Models of Human Spine Trauma.

PubMed

Jaumard, Nicolas V; Leung, Jennifer; Gokhale, Akhilesh J; Guarino, Benjamin B; Welch, William C; Winkelstein, Beth A

2015-10-15

Basic science study measuring anatomical features of the cervical and lumbar spine in rat with normalized comparison with the human. The goal of this study is to comprehensively compare the rat and human cervical and lumbar spines to investigate whether the rat is an appropriate model for spine biomechanics investigations. Animal models have been used for a long time to investigate the effects of trauma, degenerative changes, and mechanical loading on the structure and function of the spine. Comparative studies have reported some mechanical properties and/or anatomical dimensions of the spine to be similar between various species. However, those studies are largely limited to the lumbar spine, and a comprehensive comparison of the rat and human spines is lacking. Spines were harvested from male Holtzman rats (n = 5) and were scanned using micro- computed tomography and digitally rendered in 3 dimensions to quantify the spinal bony anatomy, including the lateral width and anteroposterior depth of the vertebra, vertebral body, and spinal canal, as well as the vertebral body and intervertebral disc heights. Normalized measurements of the vertebra, vertebral body, and spinal canal of the rat were computed and compared with corresponding measurements from the literature for the human in the cervical and lumbar spinal regions. The vertebral dimensions of the rat spine vary more between spinal levels than in humans. Rat vertebrae are more slender than human vertebrae, but the width-to-depth axial aspect ratios are very similar in both species in both the cervical and lumbar regions, especially for the spinal canal. The similar spinal morphology in the axial plane between rats and humans supports using the rat spine as an appropriate surrogate for modeling axial and shear loading of the human spine.

Sitting biomechanics, part II: optimal car driver's seat and optimal driver's spinal model.

PubMed

Harrison, D D; Harrison, S O; Croft, A C; Harrison, D E; Troyanovich, S J

2000-01-01

Driving has been associated with signs and symptoms caused by vibrations. Sitting causes the pelvis to rotate backwards and the lumbar lordosis to reduce. Lumbar support and armrests reduce disc pressure and electromyographically recorded values. However, the ideal driver's seat and an optimal seated spinal model have not been described. To determine an optimal automobile seat and an ideal spinal model of a driver. Information was obtained from peer-reviewed scientific journals and texts, automotive engineering reports, and the National Library of Medicine. Driving predisposes vehicle operators to low-back pain and degeneration. The optimal seat would have an adjustable seat back incline of 100 degrees from horizontal, a changeable depth of seat back to front edge of seat bottom, adjustable height, an adjustable seat bottom incline, firm (dense) foam in the seat bottom cushion, horizontally and vertically adjustable lumbar support, adjustable bilateral arm rests, adjustable head restraint with lordosis pad, seat shock absorbers to dampen frequencies in the 1 to 20 Hz range, and linear front-back travel of the seat enabling drivers of all sizes to reach the pedals. The lumbar support should be pulsating in depth to reduce static load. The seat back should be damped to reduce rebounding of the torso in rear-end impacts. The optimal driver's spinal model would be the average Harrison model in a 10 degrees posterior inclining seat back angle.

Mechanical Characterization of the Human Lumbar Intervertebral Disc Subjected to Impact Loading Conditions

NASA Astrophysics Data System (ADS)

Jamison, David, IV

Low back pain is a large and costly problem in the United States. Several working populations, such as miners, construction workers, forklift operators, and military personnel, have an increased risk and prevalence of low back pain compared to the general population. This is due to exposure to repeated, transient impact shocks, particularly while operating vehicles or other machinery. These shocks typically do not cause acute injury, but rather lead to pain and injury over time. The major focus in low back pain is often the intervertebral disc, due to its role as the major primary load-bearing component along the spinal column. The formation of a reliable standard for human lumbar disc exposure to repeated transient shock could potentially reduce injury risk for these working populations. The objective of this project, therefore, is to characterize the mechanical response of the lumbar intervertebral disc subjected to sub-traumatic impact loading conditions using both cadaveric and computational models, and to investigate the possible implications of this type of loading environment for low back pain. Axial, compressive impact loading events on Naval high speed boats were simulated in the laboratory and applied to human cadaveric specimen. Disc stiffness was higher and hysteresis was lower than quasi-static loading conditions. This indicates a shift in mechanical response when the disc is under impact loads and this behavior could be contributing to long-term back pain. Interstitial fluid loss and disc height changes were shown to affect disc impact mechanics in a creep study. Neutral zone increased, while energy dissipation and low-strain region stiffness decreased. This suggests that the disc has greater clinical instability during impact loading with progressive creep and fluid loss, indicating that time of day should be considered for working populations subjected to impact loads. A finite element model was developed and validated against cadaver specimen subjected to impacts in the laboratory. Analysis showed greater total von Mises stress and pore pressure in the components of the disc under transient shocks compared to static or quasi-static loading. These findings support the idea that impact shocks cause a change in mechanical response and are potentially damaging to the disc in the long term.

Ulf Fernström (1915-1985) and his Contributions to the Development of Artificial Disc Replacements.

PubMed

Fisahn, Christian; Burgess, Brittni; Iwanaga, Joe; Chapman, Jens R; Oskouian, Rod J; Tubbs, R Shane

2017-02-01

Artificial disc replacements, which serve the function of separating vertebrae to allow for proper spinal alignment, can help treat debilitating low back pain in patients who have failed other conservative methods of treatment. A Swedish surgeon, Ulf Fernström, was the pioneer of artificial disc replacement, and his contribution in the form of Fernström balls dramatically altered spinal surgery and technique by showing the proper technique and implant that should be used for areas requiring motion in many planes. Ulf Fernström created his artificial disc inspired by the movement of the hip and knee joints. His implants attempted to restore disc spacing and articulation in patients who had failed conservative measures of treatment. Fernström balls were the first implants of their kind and represent the first attempt at artificial disc replacement. However, many surgeons and researchers questioned Fernström balls, claiming that their lack of elastic properties could damage patients. Of the wide range of implants on the market for the intervertebral disc space, all designs and applications of products stem from the initial discovery made by Fernström, thus making him a pioneer in disc replacement. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of noxious electrical stimulation of the peroneal nerve on stretch reflex activity of the hamstring muscle in rats: possible implications of neuronal mechanisms in the development of tight hamstrings in lumbar disc herniation.

PubMed

Hirayama, Jiro; Yamagata, Masatsune; Takahashi, Kazuhisa; Moriya, Hideshige

2005-05-01

The effect of noxious electrical stimulation of the peroneal nerve on the stretch reflex electromyogram activity of the hamstring muscle (semitendinous) was studied. To verify the following hypothetical mechanisms underlying tight hamstrings in lumbar disc herniation: stretch reflex muscle activity of hamstrings is increased by painful inputs from an injured spinal nerve root and the increased stretch reflex muscle activity is maintained by central sensitization. It is reported that stretch reflex activity of the trunk muscles is induced by noxious stimulation of the sciatic nerve and maintained by central sensitization. In spinalized rats (transected spinal cord), the peroneal nerve was stimulated electrically as a conditioning stimulus. Stretch reflex electromyogram activity of the semitendinous muscle was recorded before and after the conditioning stimulus. Even after electrical stimulation was terminated, an increased stretch reflex activity of the hamstring muscle was observed. It is likely that a central sensitization mechanism at the spinal cord level was involved in the increased reflex activity. Central sensitization may play a part in the neuronal mechanisms of tight hamstrings in lumbar disc herniation.

Lumbar spinal stenosis CAD from clinical MRM and MRI based on inter- and intra-context features with a two-level classifier

NASA Astrophysics Data System (ADS)

Koh, Jaehan; Alomari, Raja S.; Chaudhary, Vipin; Dhillon, Gurmeet

2011-03-01

An imaging test has an important role in the diagnosis of lumbar abnormalities since it allows to examine the internal structure of soft tissues and bony elements without the need of an unnecessary surgery and recovery time. For the past decade, among various imaging modalities, magnetic resonance imaging (MRI) has taken the significant part of the clinical evaluation of the lumbar spine. This is mainly due to technological advancements that lead to the improvement of imaging devices in spatial resolution, contrast resolution, and multi-planar capabilities. In addition, noninvasive nature of MRI makes it easy to diagnose many common causes of low back pain such as disc herniation, spinal stenosis, and degenerative disc diseases. In this paper, we propose a method to diagnose lumbar spinal stenosis (LSS), a narrowing of the spinal canal, from magnetic resonance myelography (MRM) images. Our method segments the thecal sac in the preprocessing stage, generates the features based on inter- and intra-context information, and diagnoses lumbar disc stenosis. Experiments with 55 subjects show that our method achieves 91.3% diagnostic accuracy. In the future, we plan to test our method on more subjects.

Self-reported hard physical work combined with heavy smoking or overweight may result in so-called Modic changes.

PubMed

Leboeuf-Yde, Charlotte; Kjaer, Per; Bendix, Tom; Manniche, Claus

2008-01-14

Recently, the MRI finding of "Modic changes" has been identified as pathologic spinal condition that probably reflects a vertebral inflammatory process (VIP), which coincides with spinal pain in most. We hypothesized that heavy smoking in combination with macro- or repeated microtrauma could lead to VIP. The objectives were to investigate if combinations of self-reported heavy smoking, hard physical work, and overweight would be more strongly linked with VIP than with other spinal conditions, such as degenerated discs and non-specific low back pain (LBP). Secondary analysis was made of a data base pertaining to a population-based cross-sectional study. A population-generated cohort of 412 40-yr old Danes provided questionnaire information on smoking, weight, height, type of work, and LBP. MRI was used to determine the presence/absence of disc degeneration and of VIP. Associations were tested between three explanatory variables (type of work, smoking, and body mass index) and four outcome variables (LBP in the past year, more persistent LBP in the past year, disc degeneration, and VIP). Associations with these four outcome variables were studied for each single explanatory variable and for combinations of two at a time, and, finally, in a multivariable analysis including all three explanatory variables. There were no significant associations between the single explanatory variables and the two pain variables or with disc degeneration. However, VIP was found in 15% of non-smokers vs. 26% of heavy smokers. Similarly, VIP was noted in 11% of those in sedentary jobs vs. 31% of those with hard physical work. Further, the prevalence of VIP in those, who neither smoked heavily nor had a hard physical job was 13%, 25% in those who either smoked heavily or had a hard physical job, and 41% in those who both smoked heavily and worked hard. The odds ratio was 4.9 (1.6-13.0) for those who were both heavy smokers and had a hard physical job as compared to those who were classified as "neither". Similar but weaker findings were noted for the combination of overweight and hard physical work but not for the combination of smoking and overweight. Hard physical work in combination with either heavy smoking or overweight is strongly associated with VIP. If this finding can be reproduced in other studies, it may have consequences in relation to both primary and secondary prevention of LBP, because blue collar workers, who are most likely to experience the consequences of LBP, also are those who are most likely to smoke.

Radiative transfer calculations of the diffuse ionized gas in disc galaxies with cosmic ray feedback

NASA Astrophysics Data System (ADS)

Vandenbroucke, Bert; Wood, Kenneth; Girichidis, Philipp; Hill, Alex S.; Peters, Thomas

2018-05-01

The large vertical scale heights of the diffuse ionized gas (DIG) in disc galaxies are challenging to model, as hydrodynamical models including only thermal feedback seem to be unable to support gas at these heights. In this paper, we use a three-dimensional Monte Carlo radiation transfer code to post-process disc simulations of the Simulating the Life-Cycle of Molecular Clouds project that include feedback by cosmic rays. We show that the more extended discs in simulations including cosmic ray feedback naturally lead to larger scale heights for the DIG which are more in line with observed scale heights. We also show that including a fiducial cosmic ray heating term in our model can help to increase the temperature as a function of disc scale height, but fails to reproduce observed DIG nitrogen and sulphur forbidden line intensities. We show that, to reproduce these line emissions, we require a heating mechanism that affects gas over a larger density range than is achieved by cosmic ray heating, which can be achieved by fine tuning the total luminosity of ionizing sources to get an appropriate ionizing spectrum as a function of scale height. This result sheds a new light on the relation between forbidden line emissions and temperature profiles for realistic DIG gas distributions.

Effect of ligamenta flava hypertrophy on lumbar disc herniation with contralateral symptoms and signs: a clinical and morphometric study

PubMed Central

Yildizhan, Ahmet; Atar, Elmas K.; Yaycioglu, Soner; Gocmen-Mas, Nuket; Yazici, Canan

2010-01-01

Introduction The purpose of this study was to determine whether ligamentum flavum hypertrophy among disc herniated patients causes contralateral pain symptoms. For this reason we measured the thickness of the ligament in disc herniated patients with ipsilateral or contralateral symptoms. Material and methods Two hundred disc herniated patients with ipsilateral symptoms as group I were compared with five disc herniated patients with only contralateral symptoms as group II. Ligamenta flava thicknesses and spinal canal diameters of both groups were measured on magnetic resonance imaging (MRI) with a micro-caliper. Results Both groups underwent surgery only on the disc herniated side. The total thicknesses of the ligamenta flava in group II was thicker than in group I. There was no spinal stenosis in either group and no significance difference between the groups. Statistically significant differences were found for both ipsilateral and contralateral thickness of the ligament flava in both groups. We also compared thickness of the ligamenta flava for each level of disc herniation in group I; ligamenta flava hypertrophy was more common at L3-L4 and L4-L5 levels of vertebrae in females. Conclusions Aetiology of contralateral sciatica among disc herniated patients may be related to hypertrophy of the ligamenta flava, especially on the opposite side. Surgical approaches of the disc herniated side alone may be sufficient for a good outcome. PMID:22371809

Choice of surgical approach for ossification of the posterior longitudinal ligament in combination with cervical disc hernia

PubMed Central

Yang, Hai-song; Lu, Xu-hua; Yang, Li–li; Yan, Wang-jun; Yuan, Wen; Chen, Yu

2009-01-01

Ossification of the posterior longitudinal ligament (OPLL) is a common spinal disorder that presents with or without cervical myelopathy. Furthermore, there is evidence suggesting that OPLL often coexists with cervical disc hernia (CDH), and that the latter is the more important compression factor. To raise the awareness of CDH in OPLL for spinal surgeons, we performed a retrospective study on 142 patients with radiologically proven OPLL who had received surgery between January 2004 and January 2008 in our hospital. Plain radiograph, three-dimensional computed tomography construction (3D CT), and magnetic resonance imaging (MRI) of the cervical spine were all performed. Twenty-six patients with obvious CDH (15 of segmental-type, nine of mixed-type, two of continuous-type) were selected via clinical and radiographic features, and intraoperative findings. By MRI, the most commonly involved level was C5/6, followed by C3/4, C4/5, and C6/7. The areas of greatest spinal cord compression were at the disc levels because of herniated cervical discs. Eight patients were decompressed via anterior cervical discectomy and fusion (ACDF), 13 patients via anterior cervical corpectomy and fusion (ACCF), and five patients via ACDF combined with posterior laminectomy and fusion. The outcomes were all favorable. In conclusion, surgeons should consider the potential for CDH when performing spinal cord decompression and deciding the surgical approach in patients presenting with OPLL. PMID:20012451

Dysuria due to discospondylitis and intervertebral disc herniation in a male alpaca (Vicugna pacos).

PubMed

Sickinger, Marlene; Hirz, Manuela; Schmidt, Martin J; Reinacher, Manfred

2016-05-31

Dysuria in camelids is usually associated with the presence of lower urinary tract disease such as urolithiasis. As another differential diagnosis, urine retention may be caused by neurological disturbances resulting from infections of the spinal cord, discospondylitis or trauma. A 2.5-year-old male Huacaya alpaca (Vicugna pacos) presented with dysuria due to damage of the lumbosacral intumescence of the spinal cord. On presentation the alpaca was recumbent. Clinical examination revealed abdominal pain, oliguria, leucopenia with neutrophilia, and slightly elevated creatinine kinase. Ultrasonography of the abdomen showed an irregularly shaped, dilated urinary bladder with hyperechoic serosa. Magnetic resonance imaging revealed discospondylitis of the fourth and fifth lumbar vertebrae and herniation of the intervertebral disc between these vertebrae and the spinal cord. Postmortem examination confirmed severe chronic purulent discospondylitis with ventral spondylosis and narrowing of the spinal canal. Urolithiasis could not be verified. Although rare, diseases of the spinal cord should be considered as a differential diagnosis for impaired micturition in camelids.

Thoracolumbar Intervertebral Disc Area Morphometry in Elderly Chinese Men and Women: Radiographic Quantifications at Baseline and Changes at Year-4 Follow-up.

PubMed

Wáng, Jùn-Qīng; Káplár, Zoltán; Deng, Min; Griffith, James F; Leung, Jason C S; Kwok, Anthony W L; Kwok, Timothy; Leung, Ping Chung; Wáng, Yì Xiáng J

2018-05-15

A population-based radiographic study with longitudinal follow-up. To develop a quantitative index for lumbar disc space narrowing (DSN) evaluation in elderly subjects; to determine how DSN in the elderly is influenced by osteoporosis and sex. There is paucity of research on quantitative classification of lumbar DSN based on disc areal morphometry. With the database of Osteoporotic Fractures in Men (Hong Kong) and Osteoporotic Fractures in Women (Hong Kong) Studies and those who attended the year-4 follow-up (n = 1519 for men and n = 1546 for women), data of 491 women and 592 men were randomly selected. The anterior, middle, and posterior heights; anteroposterior diameter; and area of intervertebral discs (T4T5 to L4L5) were measured on lateral radiographs. Disc area index for lumbar spine (DAIL, disc area divided by the mean of the sum of square of the adjacent upper and lower vertebrae mid-height anterior-posterior diameter) was developed and compared with semiquantitative DSN expert grading. DAIL correlated with semiquantitative grading, with sensitivity and specificity varying from 87.3% to 96.8% for grade 1 DSN (<30% reduction in disc height), and 92.9% to 100% for grade 3 DSN (>60% reduction in disc height). The thoracolumbar disc area loss among men and women during 4-years' follow-up period varied between 1.32% and 3.56%, and it was greater for women (mean: 2.44%) than for men (mean: 1.90%, P = 0.044). Majority of lumbar DSN progressions during 72 to 76 years old were progression from normal disc space to grade 1 DSN. Osteoporosis was associated with greater disc area decrease, both for thoracic and lumbar discs. Lumbar DSN can be quantified using DAIL. In elderly Chinese, intervertebral disc narrowing over a 4-year period was greater in women than men, and associated with the presence of osteoporosis. 3.

Fortifying the Bone-Implant Interface Part 1: An In Vitro Evaluation of 3D-Printed and TPS Porous Surfaces.

PubMed

MacBarb, Regina F; Lindsey, Derek P; Bahney, Chelsea S; Woods, Shane A; Wolfe, Mark L; Yerby, Scott A

2017-01-01

An aging society and concomitant rise in the incidence of impaired bone health have led to the need for advanced osteoconductive spinal implant surfaces that promote greater biological fixation ( e.g. for interbody fusion cages, sacroiliac joint fusion implants, and artificial disc replacements). Additive manufacturing, i.e. 3D-printing, may improve bone integration by generating biomimetic spinal implant surfaces that mimic bone morphology. Such surfaces may foster an enhanced cellular response compared to traditional implant surfacing processes. This study investigated the response of human osteoblasts to additive manufactured (AM) trabecular-like titanium implant surfaces compared to traditionally machined base material with titanium plasma spray (TPS) coated surfaces, with and without a nanocrystalline hydroxyapatite (HA) coating. For TPS-coated discs, wrought Ti6Al4V ELI was machined and TPS-coating was applied. For AM discs, Ti6Al4V ELI powder was 3D-printed to form a solid base and trabecular-like porous surface. The HA-coating was applied via a precipitation dip-spin method. Surface porosity, pore size, thickness, and hydrophilicity were characterized. Initial cell attachment, proliferation, alkaline phosphatase (ALP) activity, and calcium production of hFOB cells ( n =5 per group) were measured. Cells on AM discs exhibited expedited proliferative activity. While there were no differences in mean ALP expression and calcium production between TPS and AM discs, calcium production on the AM discs trended 48% higher than on TPS discs ( p =0.07). Overall, HA-coating did not further enhance results compared to uncoated TPS and AM discs. Results demonstrate that additive manufacturing allows for controlled trabecular-like surfaces that promote earlier cell proliferation and trends toward higher calcium production than TPS coating. Results further showed that nanocrystalline HA may not provide an advantage on porous titanium surfaces. Additive manufactured porous titanium surfaces may induce a more osteogenic environment compared to traditional TPS, and thus present as an attractive alternative to TPS-coating for orthopedic spinal implants.

Development of a Detailed Volumetric Finite Element Model of the Spine to Simulate Surgical Correction of Spinal Deformities

PubMed Central

Driscoll, Mark; Mac-Thiong, Jean-Marc; Labelle, Hubert; Parent, Stefan

2013-01-01

A large spectrum of medical devices exists; it aims to correct deformities associated with spinal disorders. The development of a detailed volumetric finite element model of the osteoligamentous spine would serve as a valuable tool to assess, compare, and optimize spinal devices. Thus the purpose of the study was to develop and initiate validation of a detailed osteoligamentous finite element model of the spine with simulated correction from spinal instrumentation. A finite element of the spine from T1 to L5 was developed using properties and geometry from the published literature and patient data. Spinal instrumentation, consisting of segmental translation of a scoliotic spine, was emulated. Postoperative patient and relevant published data of intervertebral disc stress, screw/vertebra pullout forces, and spinal profiles was used to evaluate the models validity. Intervertebral disc and vertebral reaction stresses respected published in vivo, ex vivo, and in silico values. Screw/vertebra reaction forces agreed with accepted pullout threshold values. Cobb angle measurements of spinal deformity following simulated surgical instrumentation corroborated with patient data. This computational biomechanical analysis validated a detailed volumetric spine model. Future studies seek to exploit the model to explore the performance of corrective spinal devices. PMID:23991426

Spinal infections: clinical and imaging features.

PubMed

Arbelaez, Andres; Restrepo, Feliza; Castillo, Mauricio

2014-10-01

Spinal infections represent a group of rare conditions affecting vertebral bodies, intervertebral discs, paraspinal soft tissues, epidural space, meninges, and spinal cord. The causal factors, clinical presentations, and imaging features are a challenge because the difficulty to differentiate them from other conditions, such as degenerative and inflammatory disorders and spinal neoplasm. They require early recognition because delay diagnosis, imaging, and intervention may have devastating consequences especially in children and the elderly. This article reviews the most common spinal infections, their pathophysiologic, clinical manifestation, and their imaging findings.

Spinal Elongation and its Effects on Seated Height in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Rajulu, Sudhakar; Young, Karen

2009-01-01

Objectives: 1. To collect spinal elongation induced seated height data for subjects exposed to microgravity environments. 2. To provide information relating to the seated height rate of change over time for astronauts subjected to microgravity. We will collect: Seated Height measurement (ground & flight) and digital still photograph (ground and flight).

Kinematic relationship between missed ligamentum flavum bulge and degenerative factors in the cervical spine.

PubMed

Zhong, Guibin; Buser, Zorica; Lao, Lifeng; Yin, Ruofeng; Wang, Jeffrey C

2015-10-01

Bulging of ligamentum flavum can happen with the aging process and can lead to compression of the spinal cord and nerves. However, the distribution and the risk factors associated with a missed ligamentum flavum bulge (LFB) are unknown. The aim was to evaluate the distribution and risk factors associated with missed LFB in the cervical spine. This was a retrospective analysis of kinematic magnetic resonance images (kMRI). Patients diagnosed with symptomatic neck pain or radiculopathy between March 2011 and October 2012 were included. The outcome measures were missed LFB and degenerative factors. A total of 200 patients (1,000 cervical segments) underwent upright kMRI in neutral, flexion, and extension postures. The LFB, sagittal cervical angles, disc herniation, disc degeneration, disc height, angular motion, translational motion, age, and gender were recorded. After excluding segments with LFB in neutral and flexion position, Pearson and Spearman correlation coefficients were used to evaluate the relation between the risk factors and missed LFB in the extension position. The average depth of LFB was 0.24±0.71 mm at C2-C3, 1.02±1.42 mm at C3-C4, 1.65±1.48 mm at C4-C5, 2.13±1.37 mm at C5-C6, and 1.05±1.54 mm at C6-C7. The distribution of LFB was the most frequent at C5-C6 level (76.58%) followed by C4-C5 (63.06%). Disc herniation, disc degeneration, angular variation, and translational motion were significantly correlated with missed LFB at C4-C5 andC5-C6. Disc degeneration was the only factor significantly correlated with missed LFB at all cervical segments. Occurrence and depth of missed LFB was the highest at C4-C5 and C5-C6 compared with other cervical levels. Disc degeneration, disc herniation, angular variation, and translational motion could play a role in the development of LFB at C4-C5 andC5-C6. Copyright © 2015 Elsevier Inc. All rights reserved.

Comparison of radiographic changes after ACDF versus Bryan disc arthroplasty in single and bi-level cases

PubMed Central

Limson, Marc Anthony; Kim, Soo-Bum; Arbatin, Jose Joefrey F.; Chang, Kee-Young; Park, Moon-Soo; Shin, Jae-hyuk; Ju, Yeong-Su

2009-01-01

The object of this study is to compare radiographic outcomes of anterior cervical decompression and fusion (ACDF) versus cervical disc replacement using the Bryan Cervical Disc Prosthesis (Medtronic Sofamor Danek, Memphis, TN) in terms of range of motion (ROM), Functional spinal unit (FSU), overall sagittal alignment (C2–C7), anterior intervertebral height (AIH), posterior intervertebral height (PIH) and radiographic changes at the implanted and adjacent levels. The study consisted of 105 patients. A total of 63 Bryan disc were placed in 51 patients. A single level procedure was performed in 39 patients and a two-level procedure in the other 12. Fifty-four patients underwent ACDF, 26 single level cases and 28 double level cases. The Bryan group had a mean follow-up 19 months (12–38). Mean follow-up for the ACDF group was 20 months (12–40 months). All patients were evaluated using static and dynamic cervical spine radiographs as well as MR imaging. All patients underwent anterior cervical discectomy followed by autogenous bone graft with plate (or implantation of a cage) or the Bryan artificial disc prosthesis. Clinical evaluation included the visual analogue scale (VAS), and neck disability index (NDI). Radiographic evaluation included static and dynamic flexion-extension radiographs using the computer software (Infinitt PiviewSTAR 5051) program. ROM, disc space angle, intervertebral height were measured at the operative site and adjacent levels. FSU and overall sagittal alignment (C2–C7) were also measured pre-operatively, postoperatively and at final follow-up. Radiological change was analyzed using χ2 test (95% confidence interval). Other data were analyzed using the mixed model (SAS enterprises guide 4.1 versions). There was clinical improvement within each group in terms of VAS and NDI scores from pre-op to final follow-up but not significantly between the two groups for both single (VAS p = 0.8371, NDI p = 0.2872) and double (VAS p = 0.2938, NDI p = 0.6753) level surgeries. Overall, ROM and intervertebral height was relatively well maintained during the follow-up in the Bryan group compared to ACDF. Regardless of the number of levels operated on, significant differences were noted for overall ROM of the cervical spine (p < 0.0001) and all other levels except at the upper adjacent level for single level surgeries (p = 0.2872). Statistically significant (p < 0.0001 and p = 0.0172) differences in the trend of intervertebral height measurements between the two groups were noted at all levels except for the AIH of single level surgeries at the upper (p = 0.1264) and lower (p = 0.7598) adjacent levels as well as PIH for double level surgeries at the upper (p = 0.8363) adjacent level. Radiological change was 3.5 times more observed for the ACDF group. Clinical status of both groups, regardless of the number of levels, showed improvement. Although clinical outcomes between the two groups were not significantly different at final follow-up, radiographic parameters, namely ROM and intervertebral heights at the operated site, some adjacent levels as well as FSU and overall sagittal alignment of the cervical spine were relatively well maintained in Bryan group compared to ACDF group. We surmise that to a certain degree, the maintenance of these parameters could contribute to reduce development of adjacent level change. Noteworthy is that radiographic change was 3.5 times more observed for ACDF surgeries. A longer period of evaluation is needed, to see if all these radiographic changes will translate to symptomatic adjacent level disease. PMID:19127374

Indications for spine surgery: validation of an administrative coding algorithm to classify degenerative diagnoses

PubMed Central

Lurie, Jon D.; Tosteson, Anna N.A.; Deyo, Richard A.; Tosteson, Tor; Weinstein, James; Mirza, Sohail K.

2014-01-01

Study Design Retrospective analysis of Medicare claims linked to a multi-center clinical trial. Objective The Spine Patient Outcomes Research Trial (SPORT) provided a unique opportunity to examine the validity of a claims-based algorithm for grouping patients by surgical indication. SPORT enrolled patients for lumbar disc herniation, spinal stenosis, and degenerative spondylolisthesis. We compared the surgical indication derived from Medicare claims to that provided by SPORT surgeons, the “gold standard”. Summary of Background Data Administrative data are frequently used to report procedure rates, surgical safety outcomes, and costs in the management of spinal surgery. However, the accuracy of using diagnosis codes to classify patients by surgical indication has not been examined. Methods Medicare claims were link to beneficiaries enrolled in SPORT. The sensitivity and specificity of three claims-based approaches to group patients based on surgical indications were examined: 1) using the first listed diagnosis; 2) using all diagnoses independently; and 3) using a diagnosis hierarchy based on the support for fusion surgery. Results Medicare claims were obtained from 376 SPORT participants, including 21 with disc herniation, 183 with spinal stenosis, and 172 with degenerative spondylolisthesis. The hierarchical coding algorithm was the most accurate approach for classifying patients by surgical indication, with sensitivities of 76.2%, 88.1%, and 84.3% for disc herniation, spinal stenosis, and degenerative spondylolisthesis cohorts, respectively. The specificity was 98.3% for disc herniation, 83.2% for spinal stenosis, and 90.7% for degenerative spondylolisthesis. Misclassifications were primarily due to codes attributing more complex pathology to the case. Conclusion Standardized approaches for using claims data to accurately group patients by surgical indications has widespread interest. We found that a hierarchical coding approach correctly classified over 90% of spine patients into their respective SPORT cohorts. Therefore, claims data appears to be a reasonably valid approach to classifying patients by surgical indication. PMID:24525995

Posture-related distribution of hyperbaric bupivacaine in cerebro-spinal fluid is influenced by spinal needle characteristics.

PubMed

Mardirosoff, C; Dumont, L; Deyaert, M; Leconte, M

2001-07-01

No studies have evaluated the relationship between duration of time sitting and spinal needle type on the maximal spread of local anaesthetics. The few trials available have studied the influence of time spent sitting on the spread of anaesthesia without standardising spinal needle types, and have not found any effect. In this randomised, blinded study, 60 patients scheduled for elective orthopaedic surgery of the lower limbs were divided into 4 groups. With the patient sitting erect, 15 mg hyperbaric bupivacaine were injected in a standard manner through a 24G Sprotte or a 27G Whitacre needle and patients were placed supine after 1 min (24G/1 group and 27G/1 group) or 4 min (24G/4 group and 27G/4 group). Time to achieve maximum block height after injection was similar in all groups. Block height levels were significantly lower at all time points for the 24G/4 group. Maximum block heights were Th4 in the 24G/1, 27G/1 and 27G/4 groups, and Th6 in the 24G/4 group (P<0.0001). In a standard spinal anaesthesia procedure, when different lengths of time spent sitting are compared, spinal needle characteristics influence the maximum spread of hyperbaric bupivacaine. However, within the limits of our study, a two-segment difference in block height is too small to consider using spinal needles as valuable tools to control block height during spinal anaesthesia in our daily practice.

Biomarkers of Spontaneous Recovery from Traumatic Spinal Cord Injury

DTIC Science & Technology

2017-10-01

this was continued challenges with recruitment and retention, which we hope will be mitigated by our inclusion of additional sites of excellence from...Disc. Disability and pain from degenerated intervertebral discs (IVD) affects >40% of U.S adults, costs >$100 billion annually and the etiology is

The Kinematics and Spondylosis of the Lumbar Spine Vary Depending on the Levels of Motion Segments in Individuals With Low Back Pain.

PubMed

Basques, Bryce A; Espinoza Orías, Alejandro A; Shifflett, Grant D; Fice, Michael P; Andersson, Gunnar B; An, Howard S; Inoue, Nozomu

2017-07-01

A prospective cohort study. The aim of this study was to identify associations of spondylotic and kinematic changes with low back pain (LBP). The ability to characterize and differentiate the biomechanics of both the symptomatic and asymptomatic lumbar spine is crucial to alleviate the sparse literature on the association of lumbar spine biomechanics and LBP. Lumbar dynamic plain radiographs (flexion-extension), dynamic computed tomography (CT) scanning (axial rotation, disc height), and magnetic resonance imaging (MRI, disc and facet degeneration grades) were obtained for each subject. These parameters were compared between symptomatic and control groups using Student t test and multivariate logistic regression, which controlled for patient age and sex and identified spinal parameters that were independently associated with symptomatic LBP. Disc grade and mean segmental motion by level were tested by one-way analysis of variance (ANOVA). Ninety-nine volunteers (64 asymptomatic/35 LBP) were prospectively recruited. Mean age was 37.3 ± 10.1 years and 55% were male. LBP showed association with increased L5/S1 translation [odds ratio (OR) 1.63 per mm, P = 0.005], decreased flexion-extension motion at L1/L2 (OR 0.87 per degree, P = 0.036), L2/L3 (OR 0.88 per degree, P = 0.036), and L4/L5 (OR 0.87 per degree, P = 0.020), increased axial rotation at L4/L5 (OR 2.11 per degree, P = 0.032), decreased disc height at L3/L4 (OR 0.52 per mm, P = 0.008) and L4/L5 (OR 0.37 per mm, p < 0.001), increased disc grade at all levels (ORs 2.01-12.33 per grade, P = 0.001-0.026), and increased facet grade at L4/L5 (OR 4.99 per grade, P = 0.001) and L5/S1 (OR 3.52 per grade, P = 0.004). Significant associations were found between disc grade and kinematic parameters (flexion-extension motion, axial rotation, and translation) at L4/L5 (P = 0.001) and L5/S1 (P < 0.001), but not at other levels (P > 0.05). In symptomatic individuals, L4/L5 and L5/S1 levels were affected by spondylosis and kinematic changes. This study clarifies the relationships between kinematic alterations and LBP, mostly observed at the above-mentioned segments. N/A.

Dwarfism and age-associated spinal degeneration of heterozygote cmd mice defective in aggrecan

PubMed Central

Watanabe, Hideto; Nakata, Ken; Kimata, Koji; Nakanishi, Isao; Yamada, Yoshihiko

1997-01-01

Mouse cartilage matrix deficiency (cmd) is an autosomal recessive disorder caused by a genetic defect of aggrecan, a large chondroitin sulfate proteoglycan in cartilage. The homozygotes (−/−) are characterized by cleft palate and short limbs, tail, and snout. They die just after birth because of respiratory failure, and the heterozygotes (+/−) appear normal at birth. Here we report that the heterozygotes show dwarfism and develop spinal misalignment with age. Within 19 months of age, they exhibit spastic gait caused by misalignment of the cervical spine and die because of starvation. Histological examination revealed a high incidence of herniation and degeneration of vertebral discs. Electron microscopy showed a degeneration of disc chondrocytes in the heterozygotes. These findings may facilitate the identification of mutations in humans predisposed to spinal degeneration. PMID:9192671

Fortifying the Bone-Implant Interface Part 1: An In Vitro Evaluation of 3D-Printed and TPS Porous Surfaces

PubMed Central

Lindsey, Derek P.; Bahney, Chelsea S.; Woods, Shane A.; Wolfe, Mark L.; Yerby, Scott A.

2017-01-01

Background An aging society and concomitant rise in the incidence of impaired bone health have led to the need for advanced osteoconductive spinal implant surfaces that promote greater biological fixation (e.g. for interbody fusion cages, sacroiliac joint fusion implants, and artificial disc replacements). Additive manufacturing, i.e. 3D-printing, may improve bone integration by generating biomimetic spinal implant surfaces that mimic bone morphology. Such surfaces may foster an enhanced cellular response compared to traditional implant surfacing processes. Methods This study investigated the response of human osteoblasts to additive manufactured (AM) trabecular-like titanium implant surfaces compared to traditionally machined base material with titanium plasma spray (TPS) coated surfaces, with and without a nanocrystalline hydroxyapatite (HA) coating. For TPS-coated discs, wrought Ti6Al4V ELI was machined and TPS-coating was applied. For AM discs, Ti6Al4V ELI powder was 3D-printed to form a solid base and trabecular-like porous surface. The HA-coating was applied via a precipitation dip-spin method. Surface porosity, pore size, thickness, and hydrophilicity were characterized. Initial cell attachment, proliferation, alkaline phosphatase (ALP) activity, and calcium production of hFOB cells (n=5 per group) were measured. Results Cells on AM discs exhibited expedited proliferative activity. While there were no differences in mean ALP expression and calcium production between TPS and AM discs, calcium production on the AM discs trended 48% higher than on TPS discs (p=0.07). Overall, HA-coating did not further enhance results compared to uncoated TPS and AM discs. Conclusions Results demonstrate that additive manufacturing allows for controlled trabecular-like surfaces that promote earlier cell proliferation and trends toward higher calcium production than TPS coating. Results further showed that nanocrystalline HA may not provide an advantage on porous titanium surfaces. Clinical Relevance Additive manufactured porous titanium surfaces may induce a more osteogenic environment compared to traditional TPS, and thus present as an attractive alternative to TPS-coating for orthopedic spinal implants. PMID:28765799

Which iodinated contrast media is the least cytotoxic to human disc cells?

PubMed

Kim, Kyung-Hyun; Park, Jeong-Yoon; Park, Hyo-Suk; Kuh, Sung-Uk; Chin, Dong-Kyu; Kim, Keun-Su; Cho, Yong-Eun

2015-05-01

Iodinated contrast media (CM) is commonly used for various intradiscal injections such as in discography and endoscopic spinal surgery. However, CM has been shown to be toxic to renal tissue due to its ionic strength and osmolarity and as a result of iodine-induced cytotoxicity, which has raised concern over whether there are similar negative effects on disc cells. This in vitro study was designed to identify the least cytotoxic iodinated CM to the human disc cell among four different physiochemical iodinated contrast dyes. In vitro laboratory study. Intervertebral disc tissue was obtained by discectomy from a total of 10 lumbar disc patients undergoing surgery and disc cells were isolated. The human disc cells were grown in 3D alginate bead culture with 0, 0.1, 10, and 100 mg/mL CM solutions (ionic dimer, ionic monomer, non-ionic dimer, and non-ionic monomer) and mannitol as a control for 2 days. The living cells were analyzed with trypan blue staining. Fluorescence-activated cell sorting analysis was performed using Annexin V and propidium iodide (PI) and 3D alginate bead immunostaining to identify live, apoptotic, and necrotic cells. Human disc cell death was time- and dose-dependent in response to CM and more necrosis was observed than apoptosis. In addition, non-ionic dimeric CM (iodixanol) showed the least toxic effect on human disc cells, followed by non-ionic monomeric (iopromide), ionic dimeric (ioxaglate), and ionic monomeric CM (ioxithalamate). Contrast media is cytotoxic to human disc cells in a dose- and time-dependent manner. This in vitro study revealed that, among four different CM preparations, non-ionic dimeric CM is the least detrimental to human disc cell viability. Careful attention should be paid to the type of CM chosen for discography and endoscopic spinal surgery. It is also necessary to investigate the detrimental effects of CM on disc cells and disc degeneration in further in vivo studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Osmosis and viscoelasticity both contribute to time-dependent behaviour of the intervertebral disc under compressive load: A caprine in vitro study.

PubMed

Emanuel, Kaj S; van der Veen, Albert J; Rustenburg, Christine M E; Smit, Theodoor H; Kingma, Idsart

2018-03-21

The mechanical behaviour of the intervertebral disc highly depends on the content and transport of interstitial fluid. It is unknown, however, to what extent the time-dependent behaviour can be attributed to osmosis. Here we investigate the effect of both mechanical and osmotic loading on water content, nucleus pressure and disc height. Eight goat intervertebral discs, immersed in physiological saline, were subjected to a compressive force with a pressure needle inserted in the nucleus. The loading protocol was: 10 N (6 h); 150 N (42 h); 10 N (24 h). Half-way the 150 N-phase (24 h), we eliminated the osmotic gradient by adding 26% poly-ethylene glycol to the surrounding fluid. For 62 additional discs, we determined the water content of both nucleus and annulus after 6, 24, 48, or 72 h. The compressive load was initially counterbalanced by the hydrostatic pressure in the nucleus. The load forced 4.3% of the water out of the nucleus, which reduced nucleus pressure by 44(±6)%. Reduction of the osmotic gradient disturbed the equilibrium disc height, and a significant loss of annulus water content was found. Remarkably, pressure and water content of the nucleus pulposus remained unchanged. This shows that annulus water content is important in the response to axial loading. After unloading, in the absence of an osmotic gradient, there was substantial viscoelastic recovery of 53(±11)% of the disc height, without a change in water content. However, for restoration of the nucleus pressure and for full restoration of disc height, restoration of the osmotic gradient was needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of a weightlifting belt on spinal shrinkage.

PubMed

Bourne, N D; Reilly, T

1991-12-01

Spinal loading during weightlifting results in a loss of stature which has been attributed to a decrease in height of the intervertebral discs--so-called 'spinal shrinkage'. Belts are often used during the lifting of heavy weights, purportedly to support, stabilize and thereby attenuate the load on the spine. The purpose of this study was to examine the effects of a standard weightlifting belt in attenuating spinal shrinkage. Eight male subjects with a mean age of 24.8 years performed two sequences of circuit weight-training, one without a belt and on a separate occasion with a belt. The circuit training regimen consisted of six common weight-training exercises. These were performed in three sets of ten with a change of exercise after each set of ten repetitions. A stadiometer sensitive to within 0.01 mm was used to record alterations in stature. Measurements of stature were taken before and after completion of the circuit. The absolute visual analogue scale (AVAS) was used to measure the discomfort and pain intensity resulting from each of the two conditions. The circuit weight-training caused stature losses of 3.59mm without the belt and 2.87 mm with the belt (P greater than 0.05). The subjects complained of significantly less discomfort when the belt was worn (P less than 0.05). The degree of shrinkage was significantly correlated (r = 0.752, P less than 0.05) with perceived discomfort but only when the belt was not worn. These results suggest the potential benefits of wearing a weightlifting belt and support the hypothesis that the belt can help in stabilizing the trunk.

[Dynamic stabilisation and compression without fusion using Dynesys for the treatment of degenerative lumbar spondylolisthesis: a prospective series of 25 cases].

PubMed

Ricart, O; Serwier, J-M

2008-11-01

We used the Dynesys stabilization to treat degenerative lumber spondylolysis by decompression without fusion with the objective of decreasing the morbidity related to instrumented arthrodesis in older patients yet preventing progression of the displacement. This was a prospective study of 25 patients with symptomatic degenerative lumber spondylolysis associated with degenerative spinal canal stenosis documented by saccoradiculography. For inclusion, static anteroposterior intervertebral displacement had to be at least 3mm in the upright position, irrespective of the displacement on the stress films. The series included 19 women and six men, mean age 71 years (range 53-83). The level was L4-L5 in all 25 cases. Instrumentations involved a single level (L4-L5) or two levels (L3-L5). All patients were explored with computed tomography and saccoradiculography. An MRI was obtained in 12 patients. Pre- and postoperative stress images and views of the entire spinal column in the upright position were used to study pelvic parameters and sagittal spinal balance before and after surgery. Lumbar incidence and lordosis was used to divide the patients into three groups. Outcome was assessed with the Beaujon classification at minimal follow-up of 24 months, mean 34, range 24-72 months. Very good results were obtained in 72% of patients (relative gain greater than 70%) and good results in 28% (relative gain 40-70%). There were not outcomes considered fair or poor. There were two complications: aggravation of preoperative crural paresia with complete recovery and replacement of one neuroaggressive pedicular screw with no consequence thereafter. The stress films confirmed the residual mobility of the instrumented level when the preserved disc was of sufficient height. Postoperative pelvic parameters after Dynesys instrumentation showed improvement in sagittal tilt for T9 by accentuated suprajacent lordosis, even in the event of anterior spinal imbalance preoperatively. Theoretically, solicitation of the pedicular anchors of a rigid instrumentation on a poorly balanced spine would rapidly lead to failure, while fibrous non-union on a globally well balanced spine would be tolerated much longer or even definitively without development of clinical symptoms. In our opinion, the Dynesys instrumentation enables a real restabilization of the spine by adapting to the patients particular spinal balance intra-operatively and postoperatively without imposing a definitive curvature as would a rigid fixation. The ultimate objective is to accompany the aging spine without brutally changing the stress forces. This semi-rigid instrumentation without fusion enables an adapted evolution of the overall spinal degeneration without imposing excessive local forces, which could be sources of stenosis or junctional instability. The most logical indication for this instrumentation is the older subject aged at least 65 years with degenerative lumber spondylolysis and a predominantly self-reducible angular displacement and satisfactory disc height. This context (group 3 in our series) occurs in patients with a weak sacral slope and incidence, as well as minimal lordosis adapted to the pelvic parameters. The Dynesys instrumentation can be a palliative alternative to fusion for more advanced degenerative lumber spondylolysis occurring on spines with anterior imbalance where fusion would be technically difficult in terms of correction of the kyphosis or because of the general risk factors.

Development of Methodology to Gather Seated Anthropometry Data in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Rajulu, Sudhakar; Young, Karen; Mesloh, Miranda

2010-01-01

The Constellation Program is designing a new vehicle based off of new anthropometric requirements. These requirements specify the need to account for a spinal elongation factor for anthropometric measurements involving the spine, such as eye height and seated height. However, to date there is no data relating spinal elongation to a seated posture. Only data relating spinal elongation to stature has been collected in microgravity. Therefore, it was proposed to collect seated height in microgravity to provide the Constellation designers appropriate data for their analyses. This document will describe the process in which the best method to collect seated height in microgravity was developed.

Surgical results of dynamic nonfusion stabilization with the Segmental Spinal Correction System for degenerative lumbar spinal diseases with instability: Minimum 2-year follow-up

PubMed Central

Ohta, Hideki; Matsumoto, Yoshiyuki; Morishita, Yuichirou; Sakai, Tsubasa; Huang, George; Kida, Hirotaka; Takemitsu, Yoshiharu

2011-01-01

Background When spinal fusion is applied to degenerative lumbar spinal disease with instability, adjacent segment disorder will be an issue in the future. However, decompression alone could cause recurrence of spinal canal stenosis because of increased instability on operated segments and lead to revision surgery. Covering the disadvantages of both procedures, we applied nonfusion stabilization with the Segmental Spinal Correction System (Ulrich Medical, Ulm, Germany) and decompression. Methods The surgical results of 52 patients (35 men and 17 women) with a minimum 2-year follow-up were analyzed: 10 patients with lumbar spinal canal stenosis, 15 with lumbar canal stenosis with disc herniation, 20 with degenerative spondylolisthesis, 6 with disc herniation, and 1 with lumbar discopathy. Results The Japanese Orthopaedic Association score was improved, from 14.4 ± 5.3 to 25.5 ± 2.8. The improvement rate was 76%. Range of motion of the operated segments was significantly decreased, from 9.6° ± 4.2° to 2.0° ± 1.8°. Only 1 patient had adjacent segment disease that required revision surgery. There was only 1 screw breakage, but the patient was asymptomatic. Conclusions Over a minimum 2-year follow-up, the results of nonfusion stabilization with the Segmental Spinal Correction System for unstable degenerative lumbar disease were good. It is necessary to follow up the cases with a focus on adjacent segment disorders in the future. PMID:25802671

Altered disc pressure profile after an osteoporotic vertebral fracture is a risk factor for adjacent vertebral body fracture

PubMed Central

Tzermiadianos, Michael N.; Renner, Susan M.; Phillips, Frank M.; Hadjipavlou, Alexander G.; Zindrick, Michael R.; Havey, Robert M.; Voronov, Michael

2008-01-01

This study investigated the effect of endplate deformity after an osteoporotic vertebral fracture in increasing the risk for adjacent vertebral fractures. Eight human lower thoracic or thoracolumbar specimens, each consisting of five vertebrae were used. To selectively fracture one of the endplates of the middle VB of each specimen a void was created under the target endplate and the specimen was flexed and compressed until failure. The fractured vertebra was subjected to spinal extension under 150 N preload that restored the anterior wall height and vertebral kyphosis, while the fractured endplate remained significantly depressed. The VB was filled with cement to stabilize the fracture, after complete evacuation of its trabecular content to ensure similar cement distribution under both the endplates. Specimens were tested in flexion-extension under 400 N preload while pressure in the discs and strain at the anterior wall of the adjacent vertebrae were recorded. Disc pressure in the intact specimens increased during flexion by 26 ± 14%. After cementation, disc pressure increased during flexion by 15 ± 11% in the discs with un-fractured endplates, while decreased by 19 ± 26.7% in the discs with the fractured endplates. During flexion, the compressive strain at the anterior wall of the vertebra next to the fractured endplate increased by 94 ± 23% compared to intact status (p < 0.05), while it did not significantly change at the vertebra next to the un-fractured endplate (18.2 ± 7.1%, p > 0.05). Subsequent flexion with compression to failure resulted in adjacent fracture close to the fractured endplate in six specimens and in a non-adjacent fracture in one specimen, while one specimen had no adjacent fractures. Depression of the fractured endplate alters the pressure profile of the damaged disc resulting in increased compressive loading of the anterior wall of adjacent vertebra that predisposes it to wedge fracture. This data suggests that correction of endplate deformity may play a role in reducing the risk of adjacent fractures. PMID:18795344

Swespine: the Swedish spine register : the 2012 report.

PubMed

Strömqvist, Björn; Fritzell, Peter; Hägg, Olle; Jönsson, Bo; Sandén, Bengt

2013-04-01

Swespine, the Swedish National Spine Register, has existed for 20 years and is in general use within the country since over 10 years regarding degenerative lumbar spine disorders. Today there are protocols for registering all disorders of the entire spinal column. Patient-based pre- and postoperative questionnaires, completed before surgery and at 1, 2, 5 and 10 years postoperatively. Among patient-based data are VAS pain, ODI, SF-36 and EQ-5D. Postoperatively evaluation of leg and back pain as compared to preoperatively ("global assessment"), overall satisfaction with outcome and working conditions are registered in addition to the same parameters as preoperatively evaluation. A yearly report is produced including an analytic part of a certain topic, in this issue disc prosthesis surgery. More than 75,000 surgically treated patients are registered to date with an increasing number yearly. The present report includes 7,285 patients; 1-, 2- and 5-year follow-up data of previously operated patients are also included for lumbar disorders as well as for disc prosthesis surgery. For the degenerative lumbar spine disorders (disc herniation, spinal stenosis, spondylolisthesis and DDD) significant improvements are seen in all aspects as exemplified by pronounced improvement regarding EQ-5D and ODI. Results seem to be stable over time. Spinal stenosis is the most common indication for spine surgery. Disc prosthesis surgery yields results on a par with fusion surgery in disc degenerative pain. The utility of spine surgery is well documented by the results. Results of spine surgery as documented on a national basis can be utilized for quality assurance and quality improvement as well as for research purposes, documenting changes over time and bench marking when introducing new surgical techniques. A basis for international comparisons is also laid.

Cervical spondylosis anatomy: pathophysiology and biomechanics.

PubMed

Shedid, Daniel; Benzel, Edward C

2007-01-01

Cervical spondylosis is the most common progressive disorder in the aging cervical spine. It results from the process of degeneration of the intervertebral discs and facet joints of the cervical spine. Biomechanically, the disc and the facets are the connecting structures between the vertebrae for the transmission of external forces. They also facilitate cervical spine mobility. Symptoms related to myelopathy and radiculopathy are caused by the formation of osteophytes, which compromise the diameter of the spinal canal. This compromise may also be partially developmental. The developmental process, together with the degenerative process, may cause mechanical pressure on the spinal cord at one or multiple levels. This pressure may produce direct neurological damage or ischemic changes and, thus, lead to spinal cord disturbances. A thorough understanding of the biomechanics, the pathology, the clinical presentation, the radiological evaluation, as well as the surgical indications of cervical spondylosis, is essential for the management of patients with cervical spondylosis.

Change of Lumbar Ligamentum Flavum after Indirect Decompression Using Anterior Lumbar Interbody Fusion.

PubMed

Ohtori, Seiji; Orita, Sumihisa; Yamauchi, Kazuyo; Eguchi, Yawara; Aoki, Yasuchika; Nakamura, Junichi; Miyagi, Masayuki; Suzuki, Miyako; Kubota, Gou; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Shiga, Yasuhiro; Abe, Koki; Kanamoto, Hiroto; Inoue, Gen; Takahashi, Kazuhisa; Furuya, Takeo; Koda, Masao

2017-02-01

Retrospective case series. The purpose of this study was to examine changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a 10-year follow-up. Extreme lateral interbody fusion provides minimally invasive treatment of the lumbar spine; this anterior fusion without direct posterior decompression, so-called indirect decompression, can achieve pain relief. Anterior fusion may restore disc height, stretch the flexure of the ligamentum flavum, and increase the spinal canal diameter. However, changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a long follow-up have not yet been reported. We evaluated 10 patients with L4 spondylolisthesis who underwent stand-alone anterior interbody fusion using the iliac crest bone. Magnetic resonance imaging was performed 10 years after surgery. The cross-sectional area (CSA) of the dural sac and the ligamentum flavum at L1-2 to L5-S1 was calculated using a Picture Archiving and Communication System. Spinal fusion with correction loss (average, 4.75 mm anterior slip) was achieved in all patients 10 years postsurgery. The average CSAs of the dural sac and the ligamentum flavum at L1-2 to L5-S1 were 150 mm 2 and 78 mm 2 , respectively. The average CSA of the ligamentum flavum at L4-5 (30 mm 2 ) (fusion level) was significantly less than that at L1-2 to L3-4 or L5-S1. Although patients had an average anterior slip of 4.75 mm, the average CSA of the dural sac at L4-5 was significantly larger than at the other levels. Spinal stability induced a lumbar ligamentum flavum change and a sustained remodeling of the spinal canal, which may explain the long-term pain relief after indirect decompression fusion surgery.

Lumbar intervertebral disc allograft transplantation: long-term mobility and impact on the adjacent segments.

PubMed

Huang, Yong-Can; Xiao, Jun; Lu, William W; Leung, Victor Y L; Hu, Yong; Luk, Keith D K

2017-03-01

Fresh-frozen intervertebral disc (IVD) allograft transplantation has been successfully performed in the human cervical spine. Whether this non-fusion technology could truly decrease adjacent segment disease is still unknown. This study evaluated the long-term mobility of the IVD-transplanted segment and the impact on the adjacent spinal segments in a goat model. Twelve goats were used. IVD allograft transplantation was performed at lumbar L4/L5 in 5 goats; the other 7 goats were used as the untreated control (5) and for the supply of allografts (2). Post-operation lateral radiographs of the lumbar spine in the neutral, full-flexion and full-extension positions were taken at 1, 3, 6, 9 and 12 months. Disc height (DH) of the allograft and the adjacent levels was calculated and range of motion (ROM) was measured using the Cobb's method. The anatomy of the adjacent discs was observed histologically. DH of the transplanted segment was decreased significantly after 3 months but no further reduction was recorded until the final follow-up. No obvious alteration was seen in the ROM of the transplanted segment at different time points with the ROM at 12 months being comparable to that of the untreated control. The DH and ROM in the adjacent segments were well maintained during the whole observation period. At post-operative 12 months, the ROM of the adjacent levels was similar to that of the untreated control and the anatomical morphology was well preserved. Lumbar IVD allograft transplantation in goats could restore the segmental mobility and did not negatively affect the adjacent segments after 12 months.

Whole-body vibration of mice induces progressive degeneration of intervertebral discs associated with increased expression of Il-1β and multiple matrix degrading enzymes.

PubMed

McCann, Matthew R; Veras, Matthew A; Yeung, Cynthia; Lalli, Gurkeet; Patel, Priya; Leitch, Kristyn M; Holdsworth, David W; Dixon, S Jeffrey; Séguin, Cheryle A

2017-05-01

Whole-body vibration (WBV) is a popular fitness trend based on claims of increased muscle mass, weight loss and reduced joint pain. Following its original implementation as a treatment to increase bone mass in patients with osteoporosis, WBV has been incorporated into clinical practice for musculoskeletal disorders, including back pain. However, our recent studies revealed damaging effects of WBV on joint health in a murine model. In this report, we examined potential mechanisms underlying disc degeneration following exposure of mice to WBV. Ten-week-old male mice were exposed to WBV (45 Hz, 0.3 g peak acceleration, 30 min/day, 5 days/week) for 4 weeks, 8 weeks, or 4 weeks WBV followed by 4 weeks recovery. Micro-computed tomography (micro-CT), histological, and gene expression analyses were used to assess the effects of WBV on spinal tissues. Exposure of mice to 4 or 8 weeks of WBV did not alter total body composition or induce significant changes in vertebral bone density. On the other hand, WBV-induced intervertebral disc (IVD) degeneration, associated with decreased disc height and degenerative changes in the annulus fibrosus (AF) that did not recover within 4 weeks after cessation of WBV. Gene expression analysis showed that WBV for 8 weeks induced expression of Mmp3, Mmp13, and Adamts5 in IVD tissues, changes preceded by increased expression of Il-1β. Progressive IVD degeneration induced by WBV was associated with increased expression of Il-1β within the IVD that preceded Mmp and Adamts gene induction. Moreover, WBV-induced IVD degeneration is not reversed following cessation of vibration. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Circadian factors BMAL1 and RORα control HIF-1α transcriptional activity in nucleus pulposus cells: implications in maintenance of intervertebral disc health

PubMed Central

Suyama, Kaori; Silagi, Elizabeth S.; Choi, Hyowon; Sakabe, Kou; Mochida, Joji; Shapiro, Irving M.; Risbud, Makarand V.

2016-01-01

BMAL1 and RORα are major regulators of the circadian molecular oscillator. Since previous work in other cell types has shown cross talk between circadian rhythm genes and hypoxic signaling, we investigated the role of BMAL1 and RORα in controlling HIF-1-dependent transcriptional responses in NP cells that exist in the physiologically hypoxic intervertebral disc. HIF-1-dependent HRE reporter activity was further promoted by co-transfection with either BMAL1 or RORα. In addition, stable silencing of BMAL1 or inhibition of RORα activity resulted in decreased HRE activation. Inhibition of RORα also modulated HIF1α-TAD activity. Interestingly, immunoprecipitation studies showed no evidence of BMAL1, CLOCK or RORα binding to HIF-1α in NP cells. Noteworthy, stable silencing of BMAL1 as well as inhibition of RORα decreased expression of select HIF-1 target genes including VEGF, PFKFB3 and Eno1. To delineate if BMAL1 plays a role in maintenance of disc health, we studied the spinal phenotype of BMAL1-null mice. The lumbar discs of null mice evidenced decreased height, and several parameters associated with vertebral trabecular bone quality were also affected in nulls. In addition, null animals showed a higher ratio of cells to matrix in NP tissue and hyperplasia of the annulus fibrosus. Taken together, our results indicate that BMAL1 and RORα form a regulatory loop in the NP and control HIF-1 activity without direct interaction. Importantly, activities of these circadian rhythm molecules may play a role in the adaptation of NP cells to their unique niche. PMID:27049729

How Long and Low Can You Go? Effect of Conformation on the Risk of Thoracolumbar Intervertebral Disc Extrusion in Domestic Dogs

PubMed Central

Packer, Rowena M. A.; Hendricks, Anke; Volk, Holger A.; Shihab, Nadia K.; Burn, Charlotte C.

2013-01-01

Intervertebral disc extrusion (IVDE) is a common neurological disorder in certain dog breeds, resulting in spinal cord compression and injury that can cause pain and neurological deficits. Most disc extrusions are reported in chondrodystrophic breeds (e.g. Dachshunds, Basset Hounds, Pekingese), where selection for ‘long and low’ morphologies is linked with intervertebral discs abnormalities that predispose dogs to IVDE. The aim of this study was to quantify the relationship between relative thoracolumbar vertebral column length and IVDE risk in diverse breeds. A 14 month cross-sectional study of dogs entering a UK small animal referral hospital for diverse disorders including IVDE was carried out. Dogs were measured on breed-defining morphometrics, including back length (BL) and height at the withers (HW). Of 700 dogs recruited from this referral population, measured and clinically examined, 79 were diagnosed with thoracolumbar IVDE following diagnostic imaging ± surgery. The BL:HW ratio was positively associated with IVDE risk, indicating that relatively longer dogs were at increased risk, e.g. the probability of IVDE was 0.30 for Miniature Dachshunds when BL:HW ratio equalled 1.1, compared to 0.68 when BL:HW ratio equalled 1.5. Additionally, both being overweight and skeletally smaller significantly increased IVDE risk. Therefore, selection for longer backs and miniaturisation should be discouraged in high-risk breeds to reduce IVDE risk. In higher risk individuals, maintaining a lean body shape is particularly important to reduce the risk of IVDE. Results are reported as probabilities to aid decision-making regarding breed standards and screening programmes reflecting the degree of risk acceptable to stakeholders. PMID:23894518

How long and low can you go? Effect of conformation on the risk of thoracolumbar intervertebral disc extrusion in domestic dogs.

PubMed

Packer, Rowena M A; Hendricks, Anke; Volk, Holger A; Shihab, Nadia K; Burn, Charlotte C

2013-01-01

Intervertebral disc extrusion (IVDE) is a common neurological disorder in certain dog breeds, resulting in spinal cord compression and injury that can cause pain and neurological deficits. Most disc extrusions are reported in chondrodystrophic breeds (e.g. Dachshunds, Basset Hounds, Pekingese), where selection for 'long and low' morphologies is linked with intervertebral discs abnormalities that predispose dogs to IVDE. The aim of this study was to quantify the relationship between relative thoracolumbar vertebral column length and IVDE risk in diverse breeds. A 14 month cross-sectional study of dogs entering a UK small animal referral hospital for diverse disorders including IVDE was carried out. Dogs were measured on breed-defining morphometrics, including back length (BL) and height at the withers (HW). Of 700 dogs recruited from this referral population, measured and clinically examined, 79 were diagnosed with thoracolumbar IVDE following diagnostic imaging ± surgery. The BL:HW ratio was positively associated with IVDE risk, indicating that relatively longer dogs were at increased risk, e.g. the probability of IVDE was 0.30 for Miniature Dachshunds when BL:HW ratio equalled 1.1, compared to 0.68 when BL:HW ratio equalled 1.5. Additionally, both being overweight and skeletally smaller significantly increased IVDE risk. Therefore, selection for longer backs and miniaturisation should be discouraged in high-risk breeds to reduce IVDE risk. In higher risk individuals, maintaining a lean body shape is particularly important to reduce the risk of IVDE. Results are reported as probabilities to aid decision-making regarding breed standards and screening programmes reflecting the degree of risk acceptable to stakeholders.

Hybrid Surgery Combined with Dynamic Stabilization System and Fusion for the Multilevel Degenerative Disease of the Lumbosacral Spine.

PubMed

Lee, Soo Eon; Jahng, Tae-Ahn; Kim, Hyun Jib

2015-01-01

As motion-preserving technique has been developed, the concept of hybrid surgery involves simultaneous application of two different kinds of devices, dynamic stabilization system and fusion technique. In the present study, the application of hybrid surgery for lumbosacral degenerative disease involving two-segments and its long-term outcome were investigated. Fifteen patients with hybrid surgery (Hybrid group) and 10 patients with two-segment fusion (Fusion group) were retrospectively compared. Preoperative grade for disc degeneration was not different between the two groups, and the most common operated segment had the most degenerated disc grade in both groups; L4-5 and L5-S1 in the Hybrid group, and L3-4 and L4-5 in Fusion group. Over 48 months of follow-up, lumbar lordosis and range of motion (ROM) at the T12-S1 global segment were preserved in the Hybrid group, and the segmental ROM at the dynamic stabilized segment maintained at final follow-up. The Fusion group had a significantly decreased global ROM and a decreased segmental ROM with larger angles compared to the Hybrid group. Defining a 2-mm decrease in posterior disc height (PDH) as radiologic adjacent segment pathology (ASP), these changes were observed in 6 and 7 patients in the Hybrid and Fusion group, respectively. However, the last PDH at the above adjacent segment had statistically higher value in Hybrid group. Pain score for back and legs was much reduced in both groups. Functional outcome measured by Oswestry disability index (ODI), however, had better improvement in Hybrid group. Hybrid surgery, combined dynamic stabilization system and fusion, can be effective surgical treatment for multilevel degenerative lumbosacral spinal disease, maintaining lumbar motion and delaying disc degeneration.

Hybrid Surgery Combined with Dynamic Stabilization System and Fusion for the Multilevel Degenerative Disease of the Lumbosacral Spine

PubMed Central

Lee, Soo Eon; Kim, Hyun Jib

2015-01-01

Background As motion-preserving technique has been developed, the concept of hybrid surgery involves simultaneous application of two different kinds of devices, dynamic stabilization system and fusion technique. In the present study, the application of hybrid surgery for lumbosacral degenerative disease involving two-segments and its long-term outcome were investigated. Methods Fifteen patients with hybrid surgery (Hybrid group) and 10 patients with two-segment fusion (Fusion group) were retrospectively compared. Results Preoperative grade for disc degeneration was not different between the two groups, and the most common operated segment had the most degenerated disc grade in both groups; L4-5 and L5-S1 in the Hybrid group, and L3-4 and L4-5 in Fusion group. Over 48 months of follow-up, lumbar lordosis and range of motion (ROM) at the T12-S1 global segment were preserved in the Hybrid group, and the segmental ROM at the dynamic stabilized segment maintained at final follow-up. The Fusion group had a significantly decreased global ROM and a decreased segmental ROM with larger angles compared to the Hybrid group. Defining a 2-mm decrease in posterior disc height (PDH) as radiologic adjacent segment pathology (ASP), these changes were observed in 6 and 7 patients in the Hybrid and Fusion group, respectively. However, the last PDH at the above adjacent segment had statistically higher value in Hybrid group. Pain score for back and legs was much reduced in both groups. Functional outcome measured by Oswestry disability index (ODI), however, had better improvement in Hybrid group. Conclusion Hybrid surgery, combined dynamic stabilization system and fusion, can be effective surgical treatment for multilevel degenerative lumbosacral spinal disease, maintaining lumbar motion and delaying disc degeneration. PMID:26484008

Chemonucleolysis for relief of sciatica due to a herniated intervertebral disc.

PubMed Central

McCulloch, J A

1981-01-01

Chemonucleolysis is the nonoperative chemical removal of displaced lumbar disc material. The enzyme chymopapain, which has a wide margin of safety between its effective therapeutic and toxic doses, is effective in the management of sciatica due to a herniated intervertebral disc. The patient will have leg pain as the dominant symptom and a 50% reduction in straight-leg raising with or without bowstring discomfort and crossover pain. Neurologic symptoms and signs are usual, as are abnormal results of contrast studies, which will verify the level of involvement. In 220 randomly selected patients who met criteria for the diagnosis of sciatica due to a herniated intervertebral disc and did not have psychogenic or nonorganic spinal pain, a spinal stenosis or a history of a previous, unsuccessful operation to relieve the sciatica, chemonucleolysis had a success rate of 80%. The only complications were a severe anaphylactic reaction in two patients and lesser, delayed reactions in five others. All of the reactions were successfully treated. Of the 45 patients in whom chemonucleolysis was unsuccessful, 38 underwent a laminectomy. In 3 of the 38 the results of chemonucleolysis were initially good, but later the disc herniation recurred; thus, the long-term treatment failure rate was 1.4%. PMID:7011530

Cervical Intradural Disc Herniation Causing Progressive Quadriparesis After Spinal Manipulation Therapy: A Case Report and Literature Review.

PubMed

Yang, Hwan-Seo; Oh, Young-Min; Eun, Jong-Pil

2016-02-01

Cervical intradural disc herniation (IDH) is an extremely rare condition, comprising only 0.27% of all disc herniations. Three percent of IDHs occur in the cervical, 5% in the thoracic, and over 92% in the lumbar spinal canal. There have been a total of 31 cervical IDHs reported in the literature. The pathogenesis and imaging characteristics of IDH are not fully understood. A preoperative diagnosis is key to facilitating prompt intradural exploration in patients with ambivalent findings, as well as in preventing reoperation. The purpose of reporting our case is to remind clinicians to consider the possibility of cervical IDH during spinal manipulation therapy in patient with chronic neck pain.The patient signed informed consent for publication of this case report and any accompanying image. The ethical approval of this study was waived by the ethics committee of Chonbuk National University Hospital, because this study was case report and the number of patients was <3.A 32-year-old man was transferred our emergency department with progressive quadriparesis. He had no history of trauma, but had received physical therapy with spinal manipulation for chronic neck pain over the course of a month. The day prior, he had noticed neck pain and tingling in the bilateral upper and lower extremities during the manipulation procedure. The following day, he presented with bilateral weakness of all 4 extremities, which rendered him unable to walk. Neurological examination demonstrated a positive Hoffmann sign and ankle clonus bilaterally, hypoesthesia below the C5 dermatome, 3/5 strength in the bilateral upper extremities, and 2/5 strength in the lower extremities. This motor weakness was progressive, and he further complained of voiding difficulty.Urgent magnetic resonance imaging (MRI) of the cervical spine revealed large, central disc herniations at C4-C5 and C5-C6 that caused severe spinal cord compression and surrounding edema. We performed C4-C5-C6 anterior cervical discectomy and fusion.The patient's limb weakness improved rapidly within 1 day postoperatively, and he was discharged 4 weeks later. At his 12-month follow-up, the patient had recovered nearly full muscle power.We presented an extremely rare case of cervical IDH causing progressive quadriparesis after excessive spinal manipulation therapy. The presence of a "halo" and "Y-sign" were useful MRI markers for cervical IDH in this case.

Spine and axial skeleton injuries in the National Football League.

PubMed

Mall, Nathan A; Buchowski, Jacob; Zebala, Lukas; Brophy, Robert H; Wright, Rick W; Matava, Matthew J

2012-08-01

The majority of previous literature focusing on spinal injuries in American football players is centered around catastrophic injuries; however, this may underestimate the true number of these injuries in this athletic cohort. The goals of this study were to (1) report the incidence of spinal and axial skeleton injuries, both minor and severe, in the National Football League (NFL) over an 11-year period; (2) determine the incidence of spinal injury by injury type, anatomic location, player position, mechanism of injury, and type of exposure (practice vs game); and (3) determine the average number of practices and days missed because of injury for each injury type. Descriptive epidemiological study. All documented injuries to the cervical, thoracic, and lumbar spine; pelvis; ribs; and spinal cord were retrospectively analyzed using the NFL's injury surveillance database over a period of 11 seasons from 2000 through 2010. The data were analyzed by the number of injuries per athlete-exposure, the anatomic location and type of injury, player position, mechanism of injury, and number of days missed per injury. A total of 2208 injuries occurred to the spine or axial skeleton over an 11-season interval in the NFL, with a mean loss of 25.7 days per injury. This represented 7% of the total injuries during this time period. Of these 2208 injuries, 987 (44.7%) occurred in the cervical spine. Time missed from play was greatest for thoracic disc herniations (189 days/injury). Other injuries that had a mean time missed greater than 30 days included (in descending order) cervical fracture (120 days/injury), cervical disc degeneration/herniation (85 days/injury), spinal cord injury (77 days/injury), lumbar disc degeneration/herniation (52 days/injury), thoracic fracture (34 days/injury), and thoracic nerve injury (30 days/injury). Offensive linemen were the most likely to suffer a spinal injury, followed by defensive backs, defensive linemen, and linebackers. Blocking and tackling were the 2 most frequent injury mechanisms reported. Spinal and axial skeleton injuries occur frequently in the NFL and can result in significant time missed from practices and games. Tackling and blocking result in the greatest number of injuries, and players performing these activities are the most likely to sustain a spinal injury. The results of this study may be used as an impetus to formulate strategies to prevent spinal injuries in American football players.

The use of polyurethane materials in the surgery of the spine: a review.

PubMed

St John, Kenneth R

2014-12-01

The spine contains intervertebral discs and the interspinous and longitudinal ligaments. These structures are elastomeric or viscoelastic in their mechanical properties and serve to allow and control the movement of the bony elements of the spine. The use of metallic or hard polymeric devices to replace the intervertebral discs and the creation of fusion masses to replace discs and/or vertebral bodies changes the load transfer characteristics of the spine and the range of motion of segments of the spine. The purpose of the study was to survey the literature, regulatory information available on the Web, and industry-reported device development found on the Web to ascertain the usage and outcomes of the use of polyurethane polymers in the design and clinical use of devices for spine surgery. A systematic review of the available information from all sources concerning the subject materials' usage in spinal devices was conducted. A search of the peer-reviewed literature combining spinal surgery with polyurethane or specific types and trade names of medical polyurethanes was performed. Additionally, information available on the Food and Drug Administration Web site and for corporate Web sites was reviewed in an attempt to identify pertinent information. The review captured devices that are in testing or have entered clinical practice that use elastomeric polyurethane polymers as disc replacements, dynamic stabilization of spinal movement, or motion limitation to relieve nerve root compression and pain and as complete a listing as possible of such devices that have been designed or tested but appear to no longer be pursued. This review summarizes the available information about the uses to which polyurethanes have been tested or are being used in spinal surgery. The use of polyurethanes in medicine has expanded as modifications to the stability of the polymers in the physiological environment have been improved. The potential for the use of elastomeric materials to more closely match the mechanical properties of the structures being replaced and to maintain motion between spinal segments appears to hold promise. The published results from the use of the devices that are discussed show early success with these applications of elastomeric materials. Copyright © 2014 Elsevier Inc. All rights reserved.

The Application of Fiber-Reinforced Materials in Disc Repair

PubMed Central

Pei, Bao-Qing; Li, Hui; Zhu, Gang; Li, De-Yu; Fan, Yu-Bo; Wu, Shu-Qin

2013-01-01

The intervertebral disc degeneration and injury are the most common spinal diseases with tremendous financial and social implications. Regenerative therapies for disc repair are promising treatments. Fiber-reinforced materials (FRMs) are a kind of composites by embedding the fibers into the matrix materials. FRMs can maintain the original properties of the matrix and enhance the mechanical properties. By now, there are still some problems for disc repair such as the unsatisfied static strength and dynamic properties for disc implants. The application of FRMs may resolve these problems to some extent. In this review, six parts such as background of FRMs in tissue repair, the comparison of mechanical properties between natural disc and some typical FRMs, the repair standard and FRMs applications in disc repair, and the possible research directions for FRMs' in the future are stated. PMID:24383057

Semiautomatic computer-aided classification of degenerative lumbar spine disease in magnetic resonance imaging.

PubMed

Ruiz-España, Silvia; Arana, Estanislao; Moratal, David

2015-07-01

Computer-aided diagnosis (CAD) methods for detecting and classifying lumbar spine disease in Magnetic Resonance imaging (MRI) can assist radiologists to perform their decision-making tasks. In this paper, a CAD software has been developed able to classify and quantify spine disease (disc degeneration, herniation and spinal stenosis) in two-dimensional MRI. A set of 52 lumbar discs from 14 patients was used for training and 243 lumbar discs from 53 patients for testing in conventional two-dimensional MRI of the lumbar spine. To classify disc degeneration according to the gold standard, Pfirrmann classification, a method based on the measurement of disc signal intensity and structure was developed. A gradient Vector Flow algorithm was used to extract disc shape features and for detecting contour abnormalities. Also, a signal intensity method was used for segmenting and detecting spinal stenosis. Novel algorithms have also been developed to quantify the severity of these pathologies. Variability was evaluated by kappa (k) and intra-class correlation (ICC) statistics. Segmentation inaccuracy was below 1%. Almost perfect agreement, as measured by the k and ICC statistics, was obtained for all the analyzed pathologies: disc degeneration (k=0.81 with 95% CI=[0.75..0.88]) with a sensitivity of 95.8% and a specificity of 92.6%, disc herniation (k=0.94 with 95% CI=[0.87..1]) with a sensitivity of 60% and a specificity of 87.1%, categorical stenosis (k=0.94 with 95% CI=[0.90..0.98]) and quantitative stenosis (ICC=0.98 with 95% CI=[0.97..0.98]) with a sensitivity of 70% and a specificity of 81.7%. The proposed methods are reproducible and should be considered as a possible alternative when compared to reference standards. Copyright © 2015 Elsevier Ltd. All rights reserved.

Size matters: Perceived depth magnitude varies with stimulus height.

PubMed

Tsirlin, Inna; Wilcox, Laurie M; Allison, Robert S

2016-06-01

Both the upper and lower disparity limits for stereopsis vary with the size of the targets. Recently, Tsirlin, Wilcox, and Allison (2012) suggested that perceived depth magnitude from stereopsis might also depend on the vertical extent of a stimulus. To test this hypothesis we compared apparent depth in small discs to depth in long bars with equivalent width and disparity. We used three estimation techniques: a virtual ruler, a touch-sensor (for haptic estimates) and a disparity probe. We found that depth estimates were significantly larger for the bar stimuli than for the disc stimuli for all methods of estimation and different configurations. In a second experiment, we measured perceived depth as a function of the height of the bar and the radius of the disc. Perceived depth increased with increasing bar height and disc radius suggesting that disparity is integrated along the vertical edges. We discuss size-disparity correlation and inter-neural excitatory connections as potential mechanisms that could account for these results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Functional anatomy of the spine.

PubMed

Bogduk, Nikolai

2016-01-01

Among other important features of the functional anatomy of the spine, described in this chapter, is the remarkable difference between the design and function of the cervical spine and that of the lumbar spine. In the cervical spine, the atlas serves to transmit the load of the head to the typical cervical vertebrae. The axis adapts the suboccipital region to the typical cervical spine. In cervical intervertebrtal discs the anulus fibrosus is not circumferential but is crescentic, and serves as an interosseous ligament in the saddle joint between vertebral bodies. Cervical vertebrae rotate and translate in the sagittal plane, and rotate in the manner of an inverted cone, across an oblique coronal plane. The cervical zygapophysial joints are the most common source of chronic neck pain. By contrast, lumbar discs are well designed to sustain compression loads, but rely on posterior elements to limit axial rotation. Internal disc disruption is the most common basis for chronic low-back pain. Spinal muscles are arranged systematically in prevertebral and postvertebral groups. The intrinsic elements of the spine are innervated by the dorsal rami of the spinal nerves, and by the sinuvertebral nerves. Little modern research has been conducted into the structure of the thoracic spine, or the causes of thoracic spinal pain. © 2016 Elsevier B.V. All rights reserved.

Back pain in space and post-flight spine injury: Mechanisms and countermeasure development

NASA Astrophysics Data System (ADS)

Sayson, Jojo V.; Lotz, Jeffrey; Parazynski, Scott; Hargens, Alan R.

2013-05-01

During spaceflight many astronauts experience moderate to severe lumbar pain and deconditioning of paraspinal muscles. There is also a significant incidence of herniated nucleus pulposus (HNP) in astronauts post-flight being most prevalent in cervical discs. Relief of in-flight lumbar back pain is facilitated by assuming a knee-to-chest position. The pathogenesis of lumbar back pain during spaceflight is most likely discogenic and somatic referred (from the sinuvertebral nerves) due to supra-physiologic swelling of the lumbar intervertebral discs (IVDs) due to removal of gravitational compressive loads in microgravity. The knee-to-chest position may reduce lumbar back pain by redistributing stresses through compressive loading to the IVDs, possibly reducing disc volume by fluid outflow across IVD endplates. IVD stress redistribution may reduce Type IV mechanoreceptor nerve impulse propagation in the annulus fibrosus and vertebral endplate resulting in centrally mediated pain inhibition during spinal flexion. Countermeasures for lumbar back pain may include in-flight use of: (1) an axial compression harness to prevent excessive IVD expansion and spinal column elongation; (2) the use of an adjustable pulley exercise developed to prevent atrophy of spine muscle stabilisers; and (3) other exercises that provide Earth-like annular stress with low-load repetitive active spine rotation movements. The overall objective of these countermeasures is to promote IVD health and to prevent degenerative changes that may lead to HNPs post-flight. In response to "NASA's Critical Path Roadmap Risks and Questions" regarding disc injury and higher incidence of HNPs after space flight (Integrated Research Plan Gap-B4), future studies will incorporate pre- and post-flight imaging of International Space Station long-duration crew members to investigate mechanisms of lumbar back pain as well as degeneration and damage to spinal structures. Quantitative results on morphological, biochemical, metabolic, and kinematic spinal changes in the lumbar spine may aid further development of countermeasures to prevent lumbar back pain in microgravity and reduce the incidence of HNPs post-flight.

Effect of a weightlifting belt on spinal shrinkage.

PubMed Central

Bourne, N D; Reilly, T

1991-01-01

Spinal loading during weightlifting results in a loss of stature which has been attributed to a decrease in height of the intervertebral discs--so-called 'spinal shrinkage'. Belts are often used during the lifting of heavy weights, purportedly to support, stabilize and thereby attenuate the load on the spine. The purpose of this study was to examine the effects of a standard weightlifting belt in attenuating spinal shrinkage. Eight male subjects with a mean age of 24.8 years performed two sequences of circuit weight-training, one without a belt and on a separate occasion with a belt. The circuit training regimen consisted of six common weight-training exercises. These were performed in three sets of ten with a change of exercise after each set of ten repetitions. A stadiometer sensitive to within 0.01 mm was used to record alterations in stature. Measurements of stature were taken before and after completion of the circuit. The absolute visual analogue scale (AVAS) was used to measure the discomfort and pain intensity resulting from each of the two conditions. The circuit weight-training caused stature losses of 3.59mm without the belt and 2.87 mm with the belt (P greater than 0.05). The subjects complained of significantly less discomfort when the belt was worn (P less than 0.05). The degree of shrinkage was significantly correlated (r = 0.752, P less than 0.05) with perceived discomfort but only when the belt was not worn. These results suggest the potential benefits of wearing a weightlifting belt and support the hypothesis that the belt can help in stabilizing the trunk. Images Figure 1 PMID:1810615

Less invasive reduction and fusion of fresh A2 and A 3 traumatic L 1-L 4 fractures with a novel vertebral body augmentation implant and short pedicle screw fixation and fusion.

PubMed

Korovessis, Panagiotis; Vardakastanis, Konstantinos; Repantis, Thomas; Vitsas, Vasilios

2014-04-01

The aim of this clinical study was to report on the efficacy in reduction and safety in PMMA leakage of a novel vertebral augmentation technique with PEEK and PMMA, together with pedicle screws in the treatment of fresh vertebral fractures in young adults. Twenty consecutive young adults aged 45 ± 11 years with fresh burst A3/AO or severely compressed A2/AO fractures underwent via a less invasive posterior approach one-staged reduction with a novel augmentation implant and PMMA plus 3-vertebrae pedicle screw fixation and fusion. Radiologic parameters as segmental kyphosis (SKA), anterior (AVBHr) and posterior vertebral body height ratio (PVBHr), spinal canal encroachment (SCE), cement leakage and functional parameters as VAS, SF-36 were measured pre- and post-operatively. Hybrid construct restored AVBHr (P < 0.000), PVBHr (P = 0.02), SKA (P = 0.015), SCE (P = 0.002) without loss of correction at an average follow-up of 17 months. PMMA leakage occurred in 3 patients (3 vertebrae) either anteriorly to the fractured vertebral body or to the adjacent disc, but in no case to the spinal canal. Two pedicle screws were malpositioned (one medially, one laterally to the pedicle at the fracture level) without neurologic sequelae. Solid posterolateral spinal fusion occurred 8-10 months post-operatively. Pre-operative VAS and SF-36 scores improved post-operatively significantly. This study showed that this novel vertebral augmentation technique using PEEK implant and PMMA reduces and stabilizes via less invasive technique A2 and A3 vertebral fractures without loss of correction and leakage to the spinal canal.

Heidelberg retina tomograph measurements of the optic disc and parapapillary retina for detecting glaucoma analyzed by machine learning classifiers.

PubMed

Zangwill, Linda M; Chan, Kwokleung; Bowd, Christopher; Hao, Jicuang; Lee, Te-Won; Weinreb, Robert N; Sejnowski, Terrence J; Goldbaum, Michael H

2004-09-01

To determine whether topographical measurements of the parapapillary region analyzed by machine learning classifiers can detect early to moderate glaucoma better than similarly processed measurements obtained within the disc margin and to improve methods for optimization of machine learning classifier feature selection. One eye of each of 95 patients with early to moderate glaucomatous visual field damage and of each of 135 normal subjects older than 40 years participating in the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS) were included. Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Dossenheim, Germany) mean height contour was measured in 36 equal sectors, both along the disc margin and in the parapapillary region (at a mean contour line radius of 1.7 mm). Each sector was evaluated individually and in combination with other sectors. Gaussian support vector machine (SVM) learning classifiers were used to interpret HRT sector measurements along the disc margin and in the parapapillary region, to differentiate between eyes with normal and glaucomatous visual fields and to compare the results with global and regional HRT parameter measurements. The area under the receiver operating characteristic (ROC) curve was used to measure diagnostic performance of the HRT parameters and to evaluate the cross-validation strategies and forward selection and backward elimination optimization techniques that were used to generate the reduced feature sets. The area under the ROC curve for mean height contour of the 36 sectors along the disc margin was larger than that for the mean height contour in the parapapillary region (0.97 and 0.85, respectively). Of the 36 individual sectors along the disc margin, those in the inferior region between 240 degrees and 300 degrees, had the largest area under the ROC curve (0.85-0.91). With SVM Gaussian techniques, the regional parameters showed the best ability to discriminate between normal eyes and eyes with glaucomatous visual field damage, followed by the global parameters, mean height contour measures along the disc margin, and mean height contour measures in the parapapillary region. The area under the ROC curve was 0.98, 0.94, 0.93, and 0.85, respectively. Cross-validation and optimization techniques demonstrated that good discrimination (99% of peak area under the ROC curve) can be obtained with a reduced number of HRT parameters. Mean height contour measurements along the disc margin discriminated between normal and glaucomatous eyes better than measurements obtained in the parapapillary region. Copyright Association for Research in Vision and Ophthalmology

Heidelberg Retina Tomograph Measurements of the Optic Disc and Parapapillary Retina for Detecting Glaucoma Analyzed by Machine Learning Classifiers

PubMed Central

Zangwill, Linda M.; Chan, Kwokleung; Bowd, Christopher; Hao, Jicuang; Lee, Te-Won; Weinreb, Robert N.; Sejnowski, Terrence J.; Goldbaum, Michael H.

2010-01-01

Purpose To determine whether topographical measurements of the parapapillary region analyzed by machine learning classifiers can detect early to moderate glaucoma better than similarly processed measurements obtained within the disc margin and to improve methods for optimization of machine learning classifier feature selection. Methods One eye of each of 95 patients with early to moderate glaucomatous visual field damage and of each of 135 normal subjects older than 40 years participating in the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS) were included. Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Dossenheim, Germany) mean height contour was measured in 36 equal sectors, both along the disc margin and in the parapapillary region (at a mean contour line radius of 1.7 mm). Each sector was evaluated individually and in combination with other sectors. Gaussian support vector machine (SVM) learning classifiers were used to interpret HRT sector measurements along the disc margin and in the parapapillary region, to differentiate between eyes with normal and glaucomatous visual fields and to compare the results with global and regional HRT parameter measurements. The area under the receiver operating characteristic (ROC) curve was used to measure diagnostic performance of the HRT parameters and to evaluate the cross-validation strategies and forward selection and backward elimination optimization techniques that were used to generate the reduced feature sets. Results The area under the ROC curve for mean height contour of the 36 sectors along the disc margin was larger than that for the mean height contour in the parapapillary region (0.97 and 0.85, respectively). Of the 36 individual sectors along the disc margin, those in the inferior region between 240° and 300°, had the largest area under the ROC curve (0.85–0.91). With SVM Gaussian techniques, the regional parameters showed the best ability to discriminate between normal eyes and eyes with glaucomatous visual field damage, followed by the global parameters, mean height contour measures along the disc margin, and mean height contour measures in the parapapillary region. The area under the ROC curve was 0.98, 0.94, 0.93, and 0.85, respectively. Cross-validation and optimization techniques demonstrated that good discrimination (99% of peak area under the ROC curve) can be obtained with a reduced number of HRT parameters. Conclusions Mean height contour measurements along the disc margin discriminated between normal and glaucomatous eyes better than measurements obtained in the parapapillary region. PMID:15326133

The Effects of Microgravity on Seated Height (Spinal Elongation)

NASA Technical Reports Server (NTRS)

Young, K. S.; Rajulu, S.

2011-01-01

ABSTRACT Many physiological factors, such as spinal elongation, fluid shifts, bone atrophy, and muscle loss, occur during an exposure to a microgravity environment. Spinal elongation is just one of the factors that can also affect the safety and performance of a crewmember while in space. Spinal elongation occurs due to the lack of gravity/compression on the spinal column. This allows for the straightening of the natural spinal curve. There is a possible fluid shift in the inter-vertebral disks that may also result in changes in height. This study aims at collecting the overall change in seated height for crewmembers exposed to a microgravity environment. During previous Programs, Apollo-Soyuz Test Project (ASTP) and Skylab, spinal elongation data was collected from a small number of subjects in a standing posture but were limited in scope. Data from these studies indicated a quick increase in stature during the first few days of weightlessness, after which stature growth reached a plateau resulting in up to a 3% increase of the original measurement [1-5]. However, this data was collected only for crewmembers in standing posture and not in a seated posture. Seated height may have a different effect than standing height due to a change in posture as well as due to a compounded effect of wearing restraints and a potential compression of the gluteal area. Seated height was deemed as a critical measurement in the design of the Constellation Program s (CxP) Crew Exploration Vehicle (CEV), called Orion which is now the point-of-departure vehicle for the Multi-Purpose Crew Vehicle (MPCV) Program; therefore a better understanding of the effects of microgravity on seated height is necessary. Potential changes in seated height that may not have impacted crew accommodation in previous Programs will have significant effects on crew accommodation due to the layout of seats in the Orion.. The current and existing configuration is such that the four crewmembers are stacked two by two with the commander and pilot seats on the top and the two remaining seats underneath, thereby limiting the amount of clearance for the crewmembers seated in the bottom seat. The inner mold line of these types of vehicles are fixed due to other design constraints; therefore, it is essential that all seats incorporate additional clearance to account for adequate spinal growth thereby ensuring that the crew can safely ingress the seat and be strapped in prior to its return to earth. If there is not enough clearance to account for spinal growth deltas between seats then there is the potential that crewmembers will not be able to comfortably and safely fit into their seats. The crewmember in the bottom stacked seat may even have negative clearance with the seat above him or her which could lead to potential ingress/egress issues or potentially injury of the crewmember during landing. These impacts are specific to these types of vehicles with stacked seat configuration. Without proper knowledge of the amount of spinal elongation, or growth, which occurs due to microgravity and space flight, the design of future vehicle(s) or suits may cause injury, discomfort, and limit crew accommodation and crew complements. The experiment primarily aimed to collect seated height data for subjects exposed to microgravity environments, and feed new information regarding the effect of elongation of the spine forward into the design of the Orion. The data collected during the experiment included, two seated height measurement and two digital pictures of seated height pre-, in-, and post-flight. In addition to seated height, crewmembers had an optional task of collecting stature , standing height. Seated height data was obtained from 29 crewmembers that included 8 ISS increment crew (2 females and 6 males) and 21 Shuttle crew (1 female, 20 males), and whose mean age was 48 years ( 4 years). This study utilized the last six Shuttle flights, STS-128 to STS-134. The results show that partipating crewmembers experienced growth up to 6% in seated height and up to 3% in stature. Based on the worst case statistical analysis of the subject data, the recommended seated height growth of 6% will be provided to the designers as the necessary seated height adjustment.

Evaluation of spine MRIs in athletes participating in the Rio de Janeiro 2016 Summer Olympic Games.

PubMed

Wasserman, Michael S; Guermazi, Ali; Jarraya, Mohamed; Engbretsen, Lars; AbdelKader, Mohamad; Roemer, Frank W; Hayashi, Daichi; Crema, Michel D; Mian, Asim Z

2018-01-01

In high-level Olympic athletes, many spinal pathologies arise from overuse, while others are the result of acute injury. Our aim is to analyse the epidemiology of spinal pathologies detected on MRI in athletes participating in the 2016 Rio de Janeiro Summer Olympics. In this retrospective study, all spine MRIs performed during the 2016 Rio Games were analysed. Descriptive data from the MRIs were tabulated and analysed for disc degeneration, spinal canal and/or neural foraminal narrowing, and acute/chronic fractures. Data were analysed by sport, continent of origin, age and sex. Of 11 274 athletes participating in the Olympic games, 100 received spine MRI. Fifty-two of the 100 (52%) athletes who received cervical, thoracic and/or lumbar spine MRI showed moderate to severe spinal disease. The highest sport-specific incidence of moderate to severe spine disease was seen in aquatic diving athletes (67%, 3 per 100 divers). Weightlifting had the second highest sport-specific incidence of spine disease (67%, 1.5 per 100 weightlifters). Athletics used the most spine MRIs (31 of 107 MRIs, 29%). European athletes had more spine MRIs than all other continents combined (55 of 107 MRIs, 51%). Athletes over 30 years old had the highest rate of moderate to severe spine disease on MRI (24 of 37 athletes >30 years old, 65%). A high number of the world's premier athletes demonstrated moderate to severe spine disease on MRI during the 2016 Summer Olympics, including moderate/severe degenerative disc changes with varying degrees of disc bulges and herniations.

Evaluation of spine MRIs in athletes participating in the Rio de Janeiro 2016 Summer Olympic Games

PubMed Central

Wasserman, Michael S; Guermazi, Ali; Engbretsen, Lars; AbdelKader, Mohamad; Roemer, Frank W; Hayashi, Daichi; Mian, Asim Z

2018-01-01

Background/aim In high-level Olympic athletes, many spinal pathologies arise from overuse, while others are the result of acute injury. Our aim is to analyse the epidemiology of spinal pathologies detected on MRI in athletes participating in the 2016 Rio de Janeiro Summer Olympics. Methods In this retrospective study, all spine MRIs performed during the 2016 Rio Games were analysed. Descriptive data from the MRIs were tabulated and analysed for disc degeneration, spinal canal and/or neural foraminal narrowing, and acute/chronic fractures. Data were analysed by sport, continent of origin, age and sex. Results Of 11 274 athletes participating in the Olympic games, 100 received spine MRI. Fifty-two of the 100 (52%) athletes who received cervical, thoracic and/or lumbar spine MRI showed moderate to severe spinal disease. The highest sport-specific incidence of moderate to severe spine disease was seen in aquatic diving athletes (67%, 3 per 100 divers). Weightlifting had the second highest sport-specific incidence of spine disease (67%, 1.5 per 100 weightlifters). Athletics used the most spine MRIs (31 of 107 MRIs, 29%). European athletes had more spine MRIs than all other continents combined (55 of 107 MRIs, 51%). Athletes over 30 years old had the highest rate of moderate to severe spine disease on MRI (24 of 37 athletes >30 years old, 65%). Conclusions A high number of the world’s premier athletes demonstrated moderate to severe spine disease on MRI during the 2016 Summer Olympics, including moderate/severe degenerative disc changes with varying degrees of disc bulges and herniations. PMID:29629185

Lumbar Spinal Stenosis: Who Should Be Fused? An Updated Review

PubMed Central

Hasankhani, Ebrahim Ghayem; Ashjazadeh, Amir

2014-01-01

Lumbar spinal stenosis (LSS) is mostly caused by osteoarthritis (spondylosis). Clinically, the symptoms of patients with LSS can be categorized into two groups; regional (low back pain, stiffness, and so on) or radicular (spinal stenosis mainly presenting as neurogenic claudication). Both of these symptoms usually improve with appropriate conservative treatment, but in refractory cases, surgical intervention is occasionally indicated. In the patients who primarily complain of radiculopathy with an underlying biomechanically stable spine, a decompression surgery alone using a less invasive technique may be sufficient. Preoperatively, with the presence of indicators such as failed back surgery syndrome (revision surgery), degenerative instability, considerable essential deformity, symptomatic spondylolysis, refractory degenerative disc disease, and adjacent segment disease, lumbar fusion is probably recommended. Intraoperatively, in cases with extensive decompression associated with a wide disc space or insufficient bone stock, fusion is preferred. Instrumentation improves the fusion rate, but it is not necessarily associated with improved recovery rate and better functional outcome. PMID:25187873

Changes in muscle activity and stature recovery after active rehabilitation for chronic low back pain.

PubMed

Lewis, Sandra; Holmes, Paul; Woby, Steve; Hindle, Jackie; Fowler, Neil

2014-06-01

Patients with low back pain often demonstrate elevated paraspinal muscle activity compared to asymptomatic controls. This hyperactivity has been associated with a delayed rate of stature recovery following spinal loading tasks. The aim of this study was to investigate the changes in muscle activity and stature recovery in patients with chronic low back pain following an active rehabilitation programme. The body height recovery over a 40-min unloading period was assessed via stadiometry and surface electromyograms were recorded from the paraspinal muscles during standing. The measurements were repeated after patients had attended the rehabilitation programme and again at a six-month follow-up. Analysis was based on 17 patients who completed the post-treatment analysis and 12 of these who also participated in the follow-up. By the end of the six months, patients recovered significantly more height during the unloading session than at their initial visit (ES = 1.18; P < 0.01). Greater stature recovery immediately following the programme was associated with decreased pain (r = -0.55; P = 0.01). The increased height gain after six months suggests that delayed rates of recovery are not primarily caused by disc degeneration. Muscle activity did not decrease after treatment, perhaps reflecting a period of adaptation or altered patterns of motor control. Copyright © 2014 Elsevier Ltd. All rights reserved.

Efficient radiative transfer techniques in hydrodynamic simulations

NASA Astrophysics Data System (ADS)

Mercer, A.; Stamatellos, D.; Dunhill, A.

2018-05-01

Radiative transfer is an important component of hydrodynamic simulations as it determines the thermal properties of a physical system. It is especially important in cases where heating and cooling regulate significant processes, such as in the collapse of molecular clouds, the development of gravitational instabilities in protostellar discs, disc-planet interactions, and planet migration. We compare two approximate radiative transfer methods which indirectly estimate optical depths within hydrodynamic simulations using two different metrics: (i) the gravitational potential and density of the gas (Stamatellos et al.), and (ii) the pressure scale-height (Lombardi et al.). We find that both methods are accurate for spherical configurations e.g. in collapsing molecular clouds and within clumps that form in protostellar discs. However, the pressure scale-height approach is more accurate in protostellar discs (low and high-mass discs, discs with spiral features, discs with embedded planets). We also investigate the β-cooling approximation which is commonly used when simulating protostellar discs, and in which the cooling time is proportional to the orbital period of the gas. We demonstrate that the use of a constant β cannot capture the wide range of spatial and temporal variations of cooling in protostellar discs, which may affect the development of gravitational instabilities, planet migration, planet mass growth, and the orbital properties of planets.

[Current status of thoracoscopic surgery for thoracic and lumbar spine. Part 2: treatment of the thoracic disc hernia, spinal deformities, spinal tumors, infections and miscellaneous].

PubMed

Verdú-López, Francisco; Beisse, Rudolf

2014-01-01

Thoracoscopic surgery or video-assisted thoracic surgery (VATS) of the thoracic and lumbar spine has evolved greatly since it appeared less than 20 years ago. It is currently used in a large number of processes and injuries. The aim of this article, in its two parts, is to review the current status of VATS of the thoracic and lumbar spine in its entire spectrum. After reviewing the current literature, we developed each of the large groups of indications where VATS takes place, one by one. This second part reviews and discusses the management, treatment and specific thoracoscopic technique in thoracic disc herniation, spinal deformities, tumour pathology, infections of the spine and other possible indications for VATS. Thoracoscopic surgery is in many cases an alternative to conventional open surgery. The transdiaphragmatic approach has made endoscopic treatment of many thoracolumbar junction processes possible, thus widening the spectrum of therapeutic indications. These include the treatment of spinal deformities, spinal tumours, infections and other pathological processes, as well as the reconstruction of injured spinal segments and decompression of the spinal canal if lesion placement is favourable to antero-lateral approach. Good clinical results of thoracoscopic surgery are supported by growing experience reflected in a large number of articles. The degree of complications in thoracoscopic surgery is comparable to open surgery, with benefits in regard to morbidity of the approach and subsequent patient recovery. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Qualitative and quantitative assessment of degeneration of cervical intervertebral discs and facet joints.

PubMed

Walraevens, Joris; Liu, Baoge; Meersschaert, Joke; Demaerel, Philippe; Delye, Hans; Depreitere, Bart; Vander Sloten, Jos; Goffin, Jan

2009-03-01

Degeneration of intervertebral discs and facet joints is one of the most frequently encountered spinal disorders. In order to describe and quantify degeneration and evaluate a possible relationship between degeneration and biomechanical parameters, e.g., the intervertebral range of motion and intradiscal pressure, a scoring system for degeneration is mandatory. However, few scoring systems for the assessment of degeneration of the cervical spine exist. Therefore, two separate objective scoring systems to qualitatively and quantitatively assess the degree of cervical intervertebral disc and facet joint degeneration were developed and validated. The scoring system for cervical disc degeneration consists of three variables which are individually scored on neutral lateral radiographs: "height loss" (0-4 points), "anterior osteophytes" (0-3 points) and "endplate sclerosis" (0-2 points). The scoring system for facet joint degeneration consists of four variables which are individually scored on neutral computed tomography scans: "hypertrophy" (0-2 points), "osteophytes" (0-1 point), "irregularity" on the articular surface (0-1 point) and "joint space narrowing" (0-1 point). Each variable contributes with varying importance to the overall degeneration score (max 9 points for the scoring system of cervical disc degeneration and max 5 points for facet joint degeneration). Degeneration of 20 discs and facet joints of 20 patients was blindly assessed by four raters: two neurosurgeons (one senior and one junior) and two radiologists (one senior and one junior), firstly based on first subjective impression and secondly using the scoring systems. Measurement errors and inter- and intra-rater agreement were determined. The measurement error of the scoring system for cervical disc degeneration was 11.1 versus 17.9% of the subjective impression results. This scoring system showed excellent intra-rater agreement (ICC = 0.86, 0.75-0.93) and excellent inter-rater agreement (ICC = 0.78, 0.64-0.88). Surgeons as well as radiologists and seniors as well as juniors obtained excellent inter- and intra-rater agreement. The measurement error of the scoring system for cervical facet joint degeneration was 20.1 versus 24.2% of the subjective impression results. This scoring system showed good intra-rater agreement (ICC = 0.71, 0.42-0.89) and fair inter-rater agreement (ICC = 0.49, 0.26-0.74). Both scoring systems fulfilled the criteria for recommendation proposed by Kettler and Wilke. Our scoring systems can be reliable and objective tools for assessing cervical disc and facet joint degeneration. Moreover, the scoring system of cervical disc degeneration was shown to be experience- and discipline-independent.

Hybrid Method of Transvertebral Foraminotomy Combined with Anterior Cervical Decompression and Fusion for Multilevel Cervical Disease.

PubMed

Yamamoto, Yu; Hara, Masahito; Nishimura, Yusuke; Haimoto, Shoichi; Wakabayashi, Toshihiko

2018-03-15

Transvertebral foraminotomy (TVF) combined with anterior cervical decompression and fusion (ACDF) can be used to treat multilevel cervical spondylotic myelopathy and radiculopathy; however, the radiological outcomes and effectiveness of this hybrid procedure are unknown. We retrospectively assessed 22 consecutive patients treated with combined TVF and ACDF between January 2007 and May 2016. The Japanese Orthopedic Association (JOA) score and Odom's criteria were analyzed. Radiological assessment included the C2-7 sagittal Cobb angle (CA) and range of motion (ROM). The tilting angle (TA), TA ROM, and disc height (DH) of segments adjacent to the ACDF were also measured. Adjacent segment degeneration, which includes disc degeneration, was evaluated. The mean postoperative follow-up was 41.7 months. All surgeries were performed at two adjacent segments, with ACDF and TVF of the upper and lower segments, respectively. The JOA scores significantly improved. There were no significant differences in the C2-7 CA, C2-7 ROM, TA, and TA ROM, but there was a statistically significant decrease in DH of the lower adjacent segment to ACDF. Progression of disc degeneration was identified in two patients, with no progression in the criterion of adjacent segment degeneration over the follow-up. The TVF combined with ACDF produced excellent clinical results and maintained spinal alignment, albeit with a reduction in DH. TVF was safely performed at the lower segment adjacent to the ACDF, although this might result in earlier degeneration. In conclusion, this hybrid method is less invasive and beneficial for reduction of the number of fused levels.

Anterior transcorporeal approach of percutaneous endoscopic cervical discectomy for disc herniation at the C4-C5 levels: a technical note.

PubMed

Deng, Zhong-Liang; Chu, Lei; Chen, Liang; Yang, Jun-Song

2016-05-01

With the continuous development of the spinal endoscopic technique in recent years, percutaneous endoscopic cervical discectomy (PECD) has emerged, which bridges the gap between conservative therapy and traditional surgery and has been mainly divided into the anterior transdiscal approach and the posterior interlaminar access. Because of the relatively greater violation to the anterior nucleus pulposus, there is a higher potential of postoperative intervertebral space decrease in the anterior transdiscal approach than in the posterior interlaminar access. In addition, when the herniated lesion is migrated upward or downward behind the vertebral body, both approaches, and even anterior cervical discectomy and fusion, are impractical, and corpectomy is commonly considered as the only efficacious treatment. Anterior transcorporeal approach under endoscopy could enable an individual and adjustable trajectory within the vertebral body under different conditions of disc herniation preserving the motion of adjacent segment, especially in a migrated or sequestered lesion. This report aimed to first describe a novel anterior transcorporeal approach under endoscopy in which we addressed a migrated disc herniation at the C4-C5 levels. A technical report was carried out. A 37-year-old woman presented with posterior neck pain and weakness of extremities for 9 months. On neurologic examination, tingling sensation and numbness were not obvious. However, the power of extremities was dramatically decreased at a level of 3. Hoffmann sign was positive in the bilateral hand. Magnetic resonance imaging (MRI) showed a huge herniation of the C4-C5 disc compressing the median area of the spinal cord. Besides the C4-C5 disc herniation, preoperative computer tomography (CT) also detected that the herniated disc had partial calcification. A novel anterior transcorporeal approach of PECD, through the vertebral body of C5, was performed to address a migrated disc herniation at the C4-C5 levels. The posterior neck pain was measured using the visual analog scale (VAS). A novel anterior transcorporeal approach under endoscopy was performed to address a migrated disc herniation at the C4-C5 levels. This operation was accomplished in 75 minutes. Postoperatively, the drainage tube was retained into the drilling hole for 24 hours to avoid the possibility of hematoma. The patient was advised to wear a neck collar for 3 weeks. Immediately after the operation, the posterior neck pain improved from VAS 7/10 preoperatively to 3/10, and the myodynamia of extremities improved stepwise. At 12 hours postoperatively, the range of motion was also improved. In the further follow-up, the patient has completely recovered from the preoperative symptoms, whose myodynamia of extremities is normal. Besides the postoperative MRI, a total removal of the herniated disc and the transcorporeal drilling tunnel are observed in CT. At postoperative 3-month follow-up, neither disc space narrowing nor instability was observed on CT, in which the bone defect after drilling tunnelwas partially decreased, indicating bone healing. There were no surgery-related complications, such as dysphagia, Horner syndrome, recurrent laryngeal nerve palsy, vagus nerve injury, tracheoesophageal injury, or cervical hematocele. As a supplement to the described surgical approach of PECD, the transcorporeal approach is a novel access for the treatment of cervical intervertebral disc herniation. Among the advantages of this approach are providing a clear visual field during microendoscopic surgery and decreasing the intraoperative iatrogenic injury to, as well as avoiding violation to the discal tissue. Theoretically, the potential of secondary decline of intervertebral height is low. However, as the limitation of one case shows, whether this transcorporeal approach is efficacious and reliable should be verified in a further comparative cohort study with a large volume of patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Lumbar Disc Replacement for Junctional Decompensation After Fusion Surgery: Clinical and Radiological Outcome at an Average Follow-Up of 33 Months

PubMed Central

Sliwa, Karen; Weinberg, Ian R.; Sweet, Barry MBE; de Villiers, Malan; Candy, Geoffrey P.

2007-01-01

Background Failed fusion surgery remains difficult to treat. Few published data on disc replacement surgery after failed fusion procedures exist. Our objective was to evaluate outcomes of junctional lumbar disc replacement after previous fusion surgery and to correlate outcome with radiological changes to parameters of sagittal balance. Methods Out of a single-center prospective registry of 290 patients with 404 lumbar disc replacements, 27 patients had had a previous lumbar fusion operation on 1 to 4 lumbar segments and had completed a mean follow- up of 33 months (range: 18–56). We correlated the clinical outcome measures (patient satisfaction, 10-point pain score, and Oswestry Disability Index [ODI] score) to parameters of spinal sagittal alignment (sacral tilt, pelvic tilt, pelvic incidence, and lumbar lordosis). Results Postoperative hospital stay averaged 3.3 days (range: 2–8). Previously-employed patients went back to their jobs with a mean of 32 days (range: 21–42) after the procedure. At the latest follow-up, 1 of the patients considered the outcome to be poor, 3 fair, 8 good, and 15 excellent. Twenty-four patients “would undergo the operation again.” Average pain score decreased from 9.1 ± 1.0 (SD) to 3.2 ± 2.1 (P < .01). Average ODI decreased from 50.2 ± 9.9 preoperatively to 21.7 ± 14.2 (P ≤ .01). We found the change in pelvic tilt to be an independent predictor of better clinical outcome by multivariate analysis (P < .05). Conclusions In patients with junctional failure adjacent to a previous posterolateral fusion, disc replacement at the junctional level(s), compared with osteotomy and fusion surgery, offers the advantage of maintaining segmental mobility and correcting the flat-back deformity through a single approach with less operative time and blood loss. Early- to intermediate-term results are promising. The influence of changes in spinal sagittal alignment on clinical outcome needs to be addressed in future research. Clinical Relevance This is the first study on “junctional disc replacement patients” correlating clinical outcome to changes in spinal/pelvic alignment. PMID:25802584

Biomechanical testing of a polymer-based biomaterial for the restoration of spinal stability after nucleotomy

PubMed Central

Hegewald, Aldemar A; Knecht, Sven; Baumgartner, Daniel; Gerber, Hans; Endres, Michaela; Kaps, Christian; Stüssi, Edgar; Thomé, Claudius

2009-01-01

Background Surgery for disc herniations can be complicated by two major problems: painful degeneration of the spinal segment and re-herniation. Therefore, we examined an absorbable poly-glycolic acid (PGA) biomaterial, which was lyophilized with hyaluronic acid (HA), for its utility to (a) re-establish spinal stability and to (b) seal annulus fibrosus defects. The biomechanical properties range of motion (ROM), neutral zone (NZ) and a potential annulus sealing capacity were investigated. Methods Seven bovine, lumbar spinal units were tested in vitro for ROM and NZ in three consecutive stages: (a) intact, (b) following nucleotomy and (c) after insertion of a PGA/HA nucleus-implant. For biomechanical testing, spinal units were mounted on a loading-simulator for spines. In three cycles, axial loading was applied in an excentric mode with 0.5 Nm steps until an applied moment of ± 7.5 Nm was achieved in flexion/extension. ROM and NZ were assessed. These tests were performed without and with annulus sealing by sewing a PGA/HA annulus-implant into the annulus defect. Results Spinal stability was significantly impaired after nucleotomy (p < 0.001). Intradiscal implantation of a PGA-HA nucleus-implant, however, restored spinal stability (p < 0.003). There was no statistical difference between the stability provided by the nucleus-implant and the intact stage regarding flexion/extension movements (p = 0.209). During the testing sequences, herniation of biomaterial through the annulus defect into the spinal canal regularly occurred, resulting in compression of neural elements. Sewing a PGA/HA annulus-implant into the annulus defect, however, effectively prevented herniation. Conclusion PGA/HA biomaterial seems to be well suited for cell-free and cell-based regenerative treatment strategies in spinal surgery. Its abilities to restore spinal stability and potentially close annulus defects open up new vistas for regenerative approaches to treat intervertebral disc degeneration and for preventing implant herniation. PMID:19604373

Radiologic study of disc behavior following compression fracture of the thoracolumbar hinge managed by kyphoplasty: A 52-case series.

PubMed

Teyssédou, S; Saget, M; Gayet, L E; Pries, P; Brèque, C; Vendeuvre, T

2016-02-01

Kyphoplasty has proved effective for durable correction of traumatic vertebral deformity following Magerl A fracture, but subsequent behavior of the adjacent discs is unclear. The objective of the present study was to analyze evolution according to severity of initial kyphosis and quality of fracture reduction. A single-center prospective study included cases of single compression fracture of the thoracolumbar hinge managed by Kyphon Balloon Kyphoplasty with polymethylmethacrylate bone cement. Radiology focused on traumatic vertebral kyphosis (VK), disc angulation (DA) and disc height index (DHI) in the adjacent discs. Linear regression assessed the correlation between superior disc height index (SupDHI) and postoperative VK on the one hand and correction gain on the other, using the Student t test for matched pairs and Pearson correlation coefficient. Fifty-two young patients were included, with mean follow-up of 18.6 months. VK fell from 13.9° preoperatively to 8.2° at last follow-up. DHI found significant superior disc subsidence (P=0.0001) and non-significant inferior disc subsidence (P=0.116). DA showed significantly reduced superior disc lordosis (P=4*10(-5)). SupDHI correlated with VK correction (r=0.32). Preoperative VK did not correlate with radiologic degeneration of the adjacent discs. Correction of traumatic vertebral deformity avoids subsidence and loss of mechanical function in the superior adjacent disc. The underlying disc compensates for residual deformity. Balloon kyphoplasty is useful in compression fracture, providing significant reduction of traumatic vertebral deformity while conserving free and healthy adjacent discs. IV. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Cohort study of lumbar percutaneous chemonucleolysis using ethanol gel in sciatica refractory to conservative treatment.

PubMed

Touraine, Sébastien; Damiano, Joël; Tran, Olivia; Laredo, Jean-Denis

2015-11-01

To investigate the efficacy of percutaneous chemonucleolysis using ethanol gel (PCEG) in alleviating radicular pain due to disc herniation after failure of conservative treatment. After failure of conservative treatment, PCEG was performed under fluoroscopic guidance in 42 patients with sciatica >4/10 on a Visual Analog Scale (VAS) for at least 6 weeks and consistent disc herniation on MRI or CT <3 months. The VAS pain score was determined at baseline, then after 1 and 3 months. We assessed the influence of patient-related factors (age, gender, pain duration) and disc herniation-related factors (level, migration pattern, disc herniation-related spinal stenosis) on outcome of PCEG. Mean pain duration was 6.7 months. Pain intensity decreased by 44% and 62.6% after 1 and 3 months, respectively, versus baseline (P = 0.007). A mild improvement was noted by the rheumatologist in 30/42 (71.4%) and 36/42 (85.7%) patients after 1 and 3 months, respectively, and in 31/42 (73.8%) and 33/42 (78.6%) patients by self-evaluation. Patients who failed PCEG were significantly older (49.8 vs. 37.3 years, P = 0.03). None of the other variables studied were significantly associated with pain relief. PCEG may significantly improve disc-related radicular pain refractory to conservative treatment. • Percutaneous chemonucleolysis using ethanol gel (PCEG) is feasible on an outpatient basis. • PCEG improves disc-related radicular pain refractory to conservative treatment. • PCEG is feasible on an outpatient basis. • Failure of PCEG does not interfere with subsequent spinal surgery.

MRI features of cervical articular process degenerative joint disease in Great Dane dogs with cervical spondylomyelopathy.

PubMed

Gutierrez-Quintana, Rodrigo; Penderis, Jacques

2012-01-01

Cervical spondylomyelopathy or Wobbler syndrome commonly affects the cervical vertebral column of Great Dane dogs. Degenerative changes affecting the articular process joints are a frequent finding in these patients; however, the correlation between these changes and other features of cervical spondylomyelopathy are uncertain. We described and graded the degenerative changes evident in the cervical articular process joints from 13 Great Danes dogs with cervical spondylomyelopathy using MR imaging, and evaluated the relationship between individual features of cervical articular process joint degeneration and the presence of spinal cord compression, vertebral foraminal stenosis, intramedullary spinal cord changes, and intervertebral disc degenerative changes. Degenerative changes affecting the articular process joints were common, with only 13 of 94 (14%) having no degenerative changes. The most severe changes were evident between C4-C5 and C7-T1 intervertebral spaces. Reduction or loss of the hyperintense synovial fluid signal on T2-weighted MR images was the most frequent feature associated with articular process joint degenerative changes. Degenerative changes of the articular process joints affecting the synovial fluid or articular surface, or causing lateral hypertrophic tissue, were positively correlated with lateral spinal cord compression and vertebral foraminal stenosis. Dorsal hypertrophic tissue was positively correlated with dorsal spinal cord compression. Disc-associated spinal cord compression was recognized less frequently. © 2011 Veterinary Radiology & Ultrasound.

Heritability of Thoracic Spine Curvature and Genetic Correlations With Other Spine Traits: The Framingham Study

PubMed Central

Yau, Michelle S; Demissie, Serkalem; Zhou, Yanhua; Anderson, Dennis E; Lorbergs, Amanda L; Kiel, Douglas P; Allaire, Brett T; Yang, Laiji; Cupples, L Adrienne; Travison, Thomas G; Bouxsein, Mary L; Karasik, David; Samelson, Elizabeth J

2017-01-01

Hyperkyphosis is a common spinal disorder in older adults, characterized by excessive forward curvature of the thoracic spine and adverse health outcomes. The etiology of hyperkyphosis has not been firmly established, but may be related to changes that occur with aging in the vertebrae, discs, joints, and muscles, which function as a unit to support the spine. Determining the contribution of genetics to thoracic spine curvature and the degree of genetic sharing among co-occurring measures of spine health may provide insight into the etiology of hyperkyphosis. The purpose of our study was to estimate heritability of thoracic spine curvature using T4–T12 kyphosis (Cobb) angle and genetic correlations between thoracic spine curvature and vertebral fracture, intervertebral disc height narrowing, facet joint osteoarthritis (OA), lumbar spine volumetric bone mineral density (vBMD), and paraspinal muscle area and density, which were all assessed from computed tomography (CT) images. Participants included 2063 women and men in the second and third generation offspring of the original cohort of the Framingham Study. Heritability of kyphosis angle, adjusted for age, sex, and weight, was 54% (95% confidence interval [CI], 43% to 64%). We found moderate genetic correlations between kyphosis angle and paraspinal muscle area ( ρ^G, −0.46; 95% CI, −0.67 to −0.26), vertebral fracture ( ρ^G, 0.39; 95% CI, 0.18 to 0.61), vBMD ( ρ^G,−0.23; 95% CI, −0.41 to −0.04), and paraspinal muscle density ( ρ^G,−0.22; 95% CI, −0.48 to 0.03). Genetic correlations between kyphosis angle and disc height narrowing ( ρ^G, 0.17; 95% CI, −0.05 to 0.38) and facet joint OA ( ρ^G, 0.05; 95% CI, −0.15 to 0.24) were low. Thoracic spine curvature may be heritable and share genetic factors with other age-related spine traits including trunk muscle size, vertebral fracture, and bone mineral density. PMID:27455046

A Randomized Controlled Trial to Assess Pain and Magnetic Resonance Imaging-Based (MRI-Based) Structural Spine Changes in Low Back Pain Patients After Yoga Practice

PubMed Central

Telles, Shirley; Bhardwaj, Abhishek K.; Gupta, Ram K.; Sharma, Sachin K.; Monro, Robin; Balkrishna, Acharya

2016-01-01

Background The present study aimed at determining whether 12 weeks of yoga practice in patients with chronic LBP and MRI-based degenerative changes would result in differences in: (i) self-reported pain, anxiety, and spinal flexibility; and (ii) the structure of the discs or vertebrae. Material/Methods Sixty-two persons with MRI-proven degenerative intervertebral discs (group mean ±S.D., 36.2±6.4 years; 30 females) were randomly assigned to yoga and control groups. However, testing was conducted on only 40 subjects, so only their data are included in this study. The assessments were: self-reported pain, state anxiety, spinal flexibility, and MRI of the lumbosacral spine, performed using a 1.5 Tesla system with a spinal surface column. The yoga group was taught light exercises, physical postures, breathing techniques, and yoga relaxation techniques for 1 hour daily for 3 months. No intervention was given to the control group except for routine medical care. A repeated-measures analysis of variance (ANOVA) with post hoc analyses (which was Bonferroni-adjusted) was used. The Ethics Committee of Patanjali Research Foundation had approved the study which had been registered in the Clinical Trials Registry of India (CTRI/2012/11/003094). Results The yoga group showed a significant reduction in self-reported pain and state anxiety in a before/after comparison at 12 weeks. A few patients in both groups showed changes in the discs and vertebrae at post-intervention assessment. Conclusions Within 12 weeks, yoga practice reduced pain and state anxiety but did not alter MRI-proven changes in the intervertebral discs and in the vertebrae.

Cervical Laminoplasty

MedlinePlus

... Medicine Acupuncture Herbal Supplements Surgical Options Anterior Cervical Fusion Artifical Disc Replacement (ADR) Bone Graft Alternatives Bone ... Percutaneous Vertebral Augmentation (PVA) Posterior Cervical Foraminotomy Spinal ... Nonsurgical Treatments Activity Modification Chiropractic – A Conversation with ...

Morphometric Study of the Lumbar Posterior Longitudinal Ligament

PubMed Central

Lee, Sang Beom; Chang, Jae Chil; Lee, Gwang Soo; Hwang, Jae Chan; Bae, Hack Gun; Doh, Jae Won

2018-01-01

Objective Morphometric data for the lumbar posterior longitudinal ligament (PLL) was investigated to identify whether there is a difference in the morphometry of the PLL of the lumbar spine at each level with respect to the pattern of intervertebral disc displacement. Methods In 14 formalin-fixed adult cadavers (12 males and 2 females), from L1 to L5, the authors measured the width and height of the PLL and compared them with other landmarks such as the disc and the pedicle. Results Horizontally, at the upper margin of the disc, the central portion of the superficial PLL covered 17.8–36.9% of the disc width and the fan-like portion of the PLL covered 63.9–76.7% of the disc width. At the level of the median portion of the disc, the PLL covered 69.1–74.5% of the disc width. Vertically, at the level of the medial margin of the pedicle, the fan-like portion of the PLL covered 23.5–29.9% of the disc height. In general, a significant difference in length was not found in the right-left and male-female comparisons. Conclusion This study presents the morphometric data on the pattern of intervertebral disc displacement and helps to improve the knowledge of the surgical anatomy of the lumbar PLL. PMID:29354240

[Diagnostic imaging of spinal diseases].

PubMed

Miyasaka, Kazuo

2005-11-01

With the advent of magnetic resonance imaging, diagnostic accuracy of spinal disorders has been much improved regarding their localization and histological prediction. The location of herniated disc materials is well appreciated on MR images without using contrast materials. MRI can predict the posterior longitudinal ligament is perforated or not. Kinematics of the spinal axis and CSF flow movement is evaluated on MRI with fast imaging. MR angiography with 3D reconstruction depicts the Adamkiewicz's artery and anterior spinal artery. Neuritis and neuropathy can be diagnosed by post-contrast T1 weighted image since inflammatory nerves are thick and enhance. Some intramedullary deseases tend to involve the peripheral area of the spinal cord; others are central. Edema extends longitudinally within the spinal cord by sparing the peripheral margin of the spinal cord and it is well appreciated with the T2- and proton- weighted images. The lateral and posterior funiculi are more frequently involved in multiple sclerosis.

Birth weight and optic nerve head parameters.

PubMed

Samarawickrama, Chameen; Huynh, Son C; Liew, Gerald; Burlutsky, George; Mitchell, Paul

2009-06-01

To assess the relationship of birth weight, birth length, and head circumference as proxy markers of intrauterine growth, cup/disc ratio, and other optic disc parameters measured using optical coherence tomography (OCT). Population-based cross sectional analysis. The Sydney Childhood Eye Study examined 2353 primarily 12-year-old children from 21 randomly selected secondary schools during 2003 to 2005. Of 2353 children examined, 2134 (90.7%) had OCT scans (Zeiss Stratus OCT, Carl Zeiss Meditec, Dublin, CA) and are included in this study. The "fast" optic disc scan protocol was used. Birth weight, birth length, and head circumference were ascertained from health records. Height and weight were measured using standardized protocols, body mass index (BMI) was defined as weight (kilograms)/ height squared (meters), and sociodemographic information was collected in a questionnaire completed by parents. Low birth weight was defined as birth weight

Pediatric Return to Sports After Spinal Surgery.

PubMed

Christman, Tyler; Li, Ying

2016-07-01

Pediatric patients who undergo spinal surgery are frequently involved in sporting activities. Return to play is often an important postoperative concern for the patient and family. A PubMed search was conducted for articles in the English language on return to play after treatment of pediatric acute disc herniation, degenerative disc disease, spondylolysis, spondylolisthesis, and scoliosis from 1980 to 2015. Reference lists were reviewed for additional pertinent articles. We included articles that focused on return to sports after surgical treatment of these conditions in this review. Clinical review. Level 4. There are no published guidelines, and most of the literature in this area has focused on return to play after spinal injury rather than after spinal surgery. Most children and adolescents have excellent outcomes with minimal pain at 1 year after lumbar discectomy. The majority of surgeons allow return to full activity once pain-free range of motion and strength are regained, typically at 8 to 12 weeks postoperatively. Pediatric patients with spondylolysis have good outcomes after direct pars repair. Satisfactory outcomes have been demonstrated after fusion for low- and high-grade spondylolisthesis. Most surgeons allow return to noncontact sports by 6 months after surgical treatment of spondylolysis and spondylolisthesis. Return to contact and collision sports is controversial. After posterior spinal fusion for scoliosis, most surgeons allow return to noncontact sports by 3 months and return to contact sports between 6 months and 1 year. Return to collision sports is controversial. There is little evidence to guide practitioners on return to sports after pediatric spinal surgery. Ultimately, the decision to allow any young athlete to resume sports participation after spinal injury or surgery must be individualized. © 2016 The Author(s).

Pediatric Return to Sports After Spinal Surgery

PubMed Central

Christman, Tyler; Li, Ying

2016-01-01

Context: Pediatric patients who undergo spinal surgery are frequently involved in sporting activities. Return to play is often an important postoperative concern for the patient and family. Evidence Acquisition: A PubMed search was conducted for articles in the English language on return to play after treatment of pediatric acute disc herniation, degenerative disc disease, spondylolysis, spondylolisthesis, and scoliosis from 1980 to 2015. Reference lists were reviewed for additional pertinent articles. We included articles that focused on return to sports after surgical treatment of these conditions in this review. Study Design: Clinical review. Level of Evidence: Level 4. Results: There are no published guidelines, and most of the literature in this area has focused on return to play after spinal injury rather than after spinal surgery. Most children and adolescents have excellent outcomes with minimal pain at 1 year after lumbar discectomy. The majority of surgeons allow return to full activity once pain-free range of motion and strength are regained, typically at 8 to 12 weeks postoperatively. Pediatric patients with spondylolysis have good outcomes after direct pars repair. Satisfactory outcomes have been demonstrated after fusion for low- and high-grade spondylolisthesis. Most surgeons allow return to noncontact sports by 6 months after surgical treatment of spondylolysis and spondylolisthesis. Return to contact and collision sports is controversial. After posterior spinal fusion for scoliosis, most surgeons allow return to noncontact sports by 3 months and return to contact sports between 6 months and 1 year. Return to collision sports is controversial. Conclusion: There is little evidence to guide practitioners on return to sports after pediatric spinal surgery. Ultimately, the decision to allow any young athlete to resume sports participation after spinal injury or surgery must be individualized. PMID:26920125

Changes in intervertebral disc cross-sectional area with bed rest and space flight

NASA Technical Reports Server (NTRS)

LeBlanc, A. D.; Evans, H. J.; Schneider, V. S.; Wendt, R. E. 3rd; Hedrick, T. D.

1994-01-01

STUDY DESIGN. We measured the cross-sectional area of the intervertebral discs of normal volunteers after an overnight rest; before, during, and after 5 or 17 weeks of bed rest; and before and after 8 days of weightlessness. OBJECTIVES. This study sought to determine the degree of expansion of the lumbar discs resulting from bed rest and space flight. SUMMARY OF BACKGROUND DATA. Weightlessness and bed rest, an analog for weightlessness, reduce the mechanical loading on the musculoskeletal system. When unloaded, intervertebral discs will expand, increasing the nutritional diffusion distance and altering the mechanical properties of the spine. METHODS. Magnetic resonance imaging was used to measure the cross-sectional area and transverse relaxation time (T2) of the intervertebral discs. RESULTS. Overnight or longer bed rest causes expansion of the disc area, which reaches an equilibrium value of about 22% (range 10-40%) above baseline within 4 days. Increases in disc area were associated with modest increases in disc T2. During bed rest, disc height increased approximately 1 mm, about one-half of previous estimates based on body height measurements. After 5 weeks of bed rest, disc area returned to baseline within a few days of ambulation, whereas after 17 weeks, disc area remained above baseline 6 weeks after reambulation. After 8 days of weightlessness, T2, disc area, and lumbar length were not significantly different from baseline values 24 hours after landing. CONCLUSIONS. Significant adaptive changes in the intervertebral discs can be expected during weightlessness. These changes, which are rapidly reversible after short-duration flights, may be an important factor during and after long-duration missions.

The impact of computer display height and desk design on muscle activity during information technology work by young adults.

PubMed

Straker, L; Pollock, C; Burgess-Limerick, R; Skoss, R; Coleman, J

2008-08-01

Computer display height and desk design are believed to be important workstation features and are included in international standards and guidelines. However, the evidence base for these guidelines is lacking a comparison of neck/shoulder muscle activity during computer and paper tasks and whether forearm support can be provided by desk design. This study measured the spinal and upper limb muscle activity in 36 young adults whilst they worked in different computer display, book and desk conditions. Display height affected spinal muscle activity with paper tasks resulting in greater mean spinal and upper limb muscle activity. A curved desk resulted in increased proximal muscle activity. There was no substantial interaction between display and desk.

Artificial Disc Replacement

MedlinePlus

... Cervical Foraminotomy Spinal Fusion Nonsurgical Treatments Activity Modification Chiropractic – A Conversation with Dr. Jordan Gliedt, DC Directional ... with non-operative care such as medication, injections, chiropractic care and/or physical therapy. Typically, you will ...

Spinal epidural abscess due to Aspergillus infection of the vertebrae: report of 3 cases.

PubMed

Dubbeld, P; van Oostenbrugge, R J; Twinjstra, A; Schouten, H C

1996-01-01

Aspergillus infection of the vertebral bodies and intervertebral disc spaces with consequent formation of a spinal epidural abscess was diagnosed in 3 patients with acute leukaemia. Medical therapy consisted of high-dose amphotericin-B with good local control of disease in one patient. The second patient underwent surgical drainage. The third patient had stabilisation of the disease. The clinical features, diagnosis and treatment are discussed.

Applications of 3D printing in the management of severe spinal conditions.

PubMed

Provaggi, Elena; Leong, Julian J H; Kalaskar, Deepak M

2017-06-01

The latest and fastest-growing innovation in the medical field has been the advent of three-dimensional printing technologies, which have recently seen applications in the production of low-cost, patient-specific medical implants. While a wide range of three-dimensional printing systems has been explored in manufacturing anatomical models and devices for the medical setting, their applications are cutting-edge in the field of spinal surgery. This review aims to provide a comprehensive overview and classification of the current applications of three-dimensional printing technologies in spine care. Although three-dimensional printing technology has been widely used for the construction of patient-specific anatomical models of the spine and intraoperative guide templates to provide personalized surgical planning and increase pedicle screw placement accuracy, only few studies have been focused on the manufacturing of spinal implants. Therefore, three-dimensional printed custom-designed intervertebral fusion devices, artificial vertebral bodies and disc substitutes for total disc replacement, along with tissue engineering strategies focused on scaffold constructs for bone and cartilage regeneration, represent a set of promising applications towards the trend of individualized patient care.

[Analysis of the results of total cervical disc arthroplasty using a M6-C prosthesis: a multicenter study].

PubMed

Byval'tsev, V A; Kalinin, A A; Stepanov, I A; Pestryakov, Yu Ya; Shepelev, V V

Cervical spondylosis and intervertebral disc (IVD) degeneration are the most common cause for compression of the spinal cord and/or its roots. Total IVD arthroplasty, as a modern alternative to surgical treatment of IVD degeneration, is gaining popularity in many neurosurgical clinics around the world. Aim - the study aim was to conduct a multicenter analysis of cervical spine arthroplasty with an IVD prosthesis M6-C ('Spinal Kinetics', USA). The study included 112 patients (77 males and 35 females). All patients underwent single-level discectomy with implantation of the artificial IVD prosthesis M6-C. The follow-up period was up to 36 months. Dynamic assessment of the prosthesis was based on clinical parameters (pain intensity in the cervical spine and upper extremities (visual analog scale - VAS); quality of life (Neck Disability Index - NDI)); and subjective satisfaction with the results of surgical treatment (Macnab scale) and instrumental data (range of motion in the operated spinal motion segment, degree of heterotopic ossification (McAfee-Suchomel classification), and time course of degenerative changes in the adjacent segments).

[Development and application of artificial vertebral body].

PubMed

Liu, Jian-Tao; Zhang, Feng; Gao, Zheng-Chao; Niu, Bin-Bin; Li, Yu-Huan; He, Xi-Jing

2017-12-25

Artificial vertebral body has achieved good results in treating spinal tumors, tuberculosis, fracture and other diseases. Currently, artificial vertebral body with variety of kinds and pros and cons, is generally divided into two types: fusion type and movable type. The former according to whether the height could be adjusted and strength of self-stability is divided into three types: support-fixed type, adjust-fixed type and self-fixed type. Whether the height of self-fixed type could be adjusted is dependent on structure of collar thread rotation. The latter is due to mobile device of ball-and-socket joints or hollow structures instead of the disc which retains the activity of the spine to some extent. Materials of artificial vertebral body include metals, ceramics, biomaterials, polymer composites and other materials. Titanium with a dominant role in the metal has developed to the third generation, but there are still defects such as poor surface bioactivity; ceramics with the representative of hydroxyapatite composite, magnetic bioceramics, polycrystalline alumina ceramics and so on, which have the defects of processing complex and uneven mechanical properties; biological material is mainly dominated by xenogeneic bone, which is closest to human bone in structure and properties, but has defects of low toughness and complex production; polymer composites according to biological characteristics in general consists of biodegradable type and non-biodegradable type which are respectively represented by poly-lactide and polyethylene, each with advantages and disadvantages. Although the design and materials of prosthesis have made great progress, it is difficult to fully meet requirements of spinal implants and they need be further optimized. 3D printing technology makes process of the complex structure of prosthesis and individual customization possible and has broad development prospects. However, long production cycles and high cost of defect should be overcome. Although artificial vertebral body has achieved curative effect in treating spinal disease, there were reports of implant loosening or displacement. Combining with evaluation standards not unified, short follow-up time, its exact effect needs further observation. Copyright© 2017 by the China Journal of Orthopaedics and Traumatology Press.

A Baseline Historical Analysis of Neck and Back-Related Morbidity in the U.S. Army: Occupational Risks Potentially Related to Head-Supported Mass

DTIC Science & Technology

2005-09-01

disorder with myelopathy, unspecified region 722.73 Intervertebral disc disorder w/ myelopathy, lumbar region 721.3 Lumbosacral spondylosis without...Disc disorder, lumbar region 721.42 Spondylosis with myelopathy, lumbar region 724.6 Disorders of sacrum 738.4 Acquired spondylolisthesis...particular, increases risk for spondylosis and accentuates age-related decreases in spinal lordosis(20). In addition to the ballistic protection

Comparison of Clinical and Radiologic Results of Mini-Open Transforaminal Lumbar Interbody Fusion and Extreme Lateral Interbody Fusion Indirect Decompression for Degenerative Lumbar Spondylolisthesis

PubMed Central

Gen, Hogaku; Sakuma, Yoshio; Koshika, Yasuhide

2018-01-01

Study Design Retrospective study. Purpose In this study, we compared the postoperative outcomes of extreme lateral interbody fusion (XLIF) indirect decompression with that of mini-open transforaminal lumbar interbody fusion (TLIF) in patients with lumbar degenerative spondylolisthesis. Overview of Literature There are very few reports examining postoperative results of XLIF and minimally invasive TLIF for degenerative lumbar spondylolisthesis, and no reports comparing XLIF and mini-open TLIF. Methods Forty patients who underwent 1-level spinal fusion, either by XLIF indirect decompression (X group, 20 patients) or by mini-open TLIF (T group, 20 patients), for treatment of lumbar degenerative spondylolisthesis were included in this study. Invasiveness of surgery was evaluated on the basis of surgery time, blood loss, hospitalization period, and perioperative complications. The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ), disc angle (DA), disc height (DH), and slipping length (SL) were evaluated before surgery, immediately after surgery, and at 12 months after surgery. Cross-sectional spinal canal area (CSA) was also measured before surgery and at 1 month after surgery. Results There was no significant difference between the groups in terms of surgery time or hospitalization period; however, X group showed a significant decrease in blood loss (p<0.001). Serious complications were not observed in either group. In clinical assessment, no significant differences were observed between the groups with regard to the JOABPEQ results. The change in DH at 12 months after surgery increased significantly in the X group (p<0.05), and the changes in DA and SL were not significantly different between the two groups. The change in CSA was significantly greater in the T group (p<0.001). Conclusions Postoperative clinical results were equally favorable for both procedures; however, in comparison with mini-open TLIF, less blood loss and greater correction of DH were observed in XLIF. PMID:29713419

Comparison of Clinical and Radiologic Results of Mini-Open Transforaminal Lumbar Interbody Fusion and Extreme Lateral Interbody Fusion Indirect Decompression for Degenerative Lumbar Spondylolisthesis.

PubMed

Kono, Yutaka; Gen, Hogaku; Sakuma, Yoshio; Koshika, Yasuhide

2018-04-01

Retrospective study. In this study, we compared the postoperative outcomes of extreme lateral interbody fusion (XLIF) indirect decompression with that of mini-open transforaminal lumbar interbody fusion (TLIF) in patients with lumbar degenerative spondylolisthesis. There are very few reports examining postoperative results of XLIF and minimally invasive TLIF for degenerative lumbar spondylolisthesis, and no reports comparing XLIF and mini-open TLIF. Forty patients who underwent 1-level spinal fusion, either by XLIF indirect decompression (X group, 20 patients) or by mini-open TLIF (T group, 20 patients), for treatment of lumbar degenerative spondylolisthesis were included in this study. Invasiveness of surgery was evaluated on the basis of surgery time, blood loss, hospitalization period, and perioperative complications. The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ), disc angle (DA), disc height (DH), and slipping length (SL) were evaluated before surgery, immediately after surgery, and at 12 months after surgery. Cross-sectional spinal canal area (CSA) was also measured before surgery and at 1 month after surgery. There was no significant difference between the groups in terms of surgery time or hospitalization period; however, X group showed a significant decrease in blood loss ( p <0.001). Serious complications were not observed in either group. In clinical assessment, no significant differences were observed between the groups with regard to the JOABPEQ results. The change in DH at 12 months after surgery increased significantly in the X group ( p <0.05), and the changes in DA and SL were not significantly different between the two groups. The change in CSA was significantly greater in the T group ( p <0.001). Postoperative clinical results were equally favorable for both procedures; however, in comparison with mini-open TLIF, less blood loss and greater correction of DH were observed in XLIF.

A Novel, Minimally-Invasive Approach to Repair Degenerative Disk Disease in an Ovine Model Using Injectable Polymethyl-Methacrylate and Bovine Collagen (PMMA/BC)

PubMed Central

Feldman, Erica; Narayan, Anisha; Taylor, William

2016-01-01

Background : The natural, inflammatory repair processes of an injured intervertebral degenerative disc can propagate further injury and destruction. While there are many different treatment modalities of the pain related to degenerative disc disease, none are actually reparative in nature. Treatment strategies to repair a degenerative disc without inducing a destructive inflammatory milieu have been elusive.  Purpose: The purpose of this experiment is to discover the feasibility of reconstructing an injured intervertebral disc using an injected, inert polymer as the foundation for endogenous collagen growth. Study Design: In this ovine model of six subjects in total, we introduce a modality where a large inert polymer, polymethyl methacrylate (PMMA), in conjunction bovine collagen (BC) is injected into the intervertebral disc. Following six months of observation, histologic specimens were evaluated macroscopically and microscopically for evidence of a benefit of the injectable PMMA/BC. Methods: We obtained six merino sheep for this study. Concentric injuries were made to four of their lumbar intervertebral discs. Two of those levels were treated with a percutaneous injection of 0.3 cc of PMMA/BC. The remaining lumbar levels were left untreated and were our controls. After six months, all subjects were sacrificed. Their four levels were extracted and were examined macroscopically and microscopically. Results: All subjects tolerated the lumbar injury and percutaneous injection of PMMA/BC well. After the six month interval, all subjects have demonstrated an intact architecture of their lumbar disc height at the macroscopic and microscopic level. Microscopically, there was no evidence of external migration of the PMMA/BC microspheres, nor was there any evidence of an inflammatory response by its presence. Notably, the PMMA/BC microspheres were well-incorporated into the concentric disc tears and had undergone endogenous collagen formation in its environment. Treatment levels were revealing for maintenance of disc height without evidence of an ongoing degeneration. The controlled levels were revealing for continued disc degeneration with loss of disc height and evolving injury at the level of the concentric tear. Conclusions: This ovine model demonstrates a novel and promising technique for prevention and arrest of lumbar intervertebral disc degeneration. PMID:27630802

A Large Animal Model that Recapitulates the Spectrum of Human Intervertebral Disc Degeneration

PubMed Central

Gullbrand, Sarah E.; Malhotra, Neil R.; Schaer, Thomas P.; Zawacki, Zosia; Martin, John T.; Bendigo, Justin R.; Milby, Andrew H.; Dodge, George R.; Vresilovic, Edward J.; Elliott, Dawn M.; Mauck, Robert L.; Smith, Lachlan J.

2016-01-01

Objective The objective of this study was to establish a large animal model that recapitulates the spectrum of intervertebral disc degeneration that occurs in humans and which is suitable for pre-clinical evaluation of a wide range of experimental therapeutics. Design Degeneration was induced in the lumbar intervertebral discs of large frame goats by either intradiscal injection of chondroitinase ABC (ChABC) over a range of dosages (0.1U, 1U or 5U) or subtotal nucleotomy. Radiographs were used to assess disc height changes over 12 weeks. Degenerative changes to the discs and endplates were assessed via magnetic resonance imaging (MRI), semi-quantitative histological grading, micro-computed tomography (µCT), and measurement of disc biomechanical properties. Results Degenerative changes were observed for all interventions that ranged from mild (0.1U ChABC) to moderate (1U ChABC and nucleotomy) to severe (5U ChABC). All groups showed progressive reductions in disc height over 12 weeks. Histological scores were significantly increased in the 1U and 5U ChABC groups. Reductions in T2 and T1ρ, and increased Pfirrmann grade were observed on MRI. Resorption and remodeling of the cortical boney endplate adjacent to ChABC injected discs also occurred. Spine segment range of motion was greater and compressive modulus was lower in 1U ChABC and nucleotomy discs compared to intact. Conclusions A large animal model of disc degeneration was established that recapitulates the spectrum of structural, compositional and biomechanical features of human disc degeneration. This model may serve as a robust platform for evaluating the efficacy of therapeutics targeted towards varying degrees of disc degeneration. PMID:27568573

Cost utility analysis of caudal epidural injections in the treatment of lumbar disc herniation, axial or discogenic low back pain, central spinal stenosis, and post lumbar surgery syndrome.

PubMed

Manchikanti, Laxmaiah; Falco, Frank J E; Pampati, Vidyasagar; Cash, Kimberly A; Benyamin, Ramsin M; Hirsch, Joshua A

2013-01-01

In this era of escalating health care costs and the questionable effectiveness of multiple interventions, cost effectiveness or cost utility analysis has become the cornerstone of evidence-based medicine, and has an influence coverage decisions. Even though multiple cost effectiveness analysis studies have been performed over the years, extensive literature is lacking for interventional techniques. Cost utility analysis studies of epidural injections for managing chronic low back pain demonstrated highly variable results including a lack of cost utility in randomized trials and contrasting results in observational studies. There has not been any cost utility analysis studies of epidural injections in large randomized trials performed in interventional pain management settings. To assess the cost utility of caudal epidural injections in managing chronic low back pain secondary to lumbar disc herniation, axial or discogenic low back pain, lumbar central spinal stenosis, and lumbar post surgery syndrome. This analysis is based on 4 previously published randomized trials. A private, specialty referral interventional pain management center in the United States. Four randomized trials were conducted assessing the clinical effectiveness of caudal epidural injections with or without steroids for lumbar disc herniation, lumbar discogenic or axial low back pain, lumbar central spinal stenosis, and post surgery syndrome. A cost utility analysis was performed with direct payment data for a total of 480 patients over a period of 2 years from these 4 trials. Outcome included various measures with significant improvement defined as at least a 50% improvement in pain reduction and disability status. The results of 4 randomized controlled trials of low back pain with 480 patients with a 2 year follow-up with the actual reimbursement data showed cost utility for one year of quality-adjusted life year (QALY) of $2,206 for disc herniation, $2,136 for axial or discogenic pain without disc herniation, $2,155 for central spinal stenosis, and $2,191 for post surgery syndrome. All patients showed significant improvement clinically and showed positive results in the cost utility analysis with an average cost per one year QALY of $2,172.50 for all patients and $1,966.03 for patients judged to be successful. The results of this assessment show a better cost utility or lower cost of managing chronic, intractable low back pain with caudal epidural injections at a QALY that is similar or lower in price than medical therapy only, physical therapy, manipulation, and surgery in most cases. The limitations of this cost utility analysis include that it is a single center evaluation, even though 480 patients were included in the analysis. Further, only the costs of interventional procedures and physician visits were included. The benefits of returning to work were not assessed.   This cost utility analysis of caudal epidural injections in the treatment of disc herniation, axial or discogenic low back pain, central spinal stenosis, and post surgery syndrome in the lumbar spine shows the clinical effectiveness and cost utility of these injections at less than $2,200 per one year of QALY.

Association between CT-evaluated lumbar lordosis and features of spinal degeneration, evaluated in supine position

PubMed Central

Kalichman, Leonid; Li, Ling; Hunter, David; Been, Ella

2013-01-01

Background Context Few studies have directly evaluated the association of lumbar lordosis and segmental wedging of the vertebral bodies and intervertebral disks with prevalence of spinal degenerative features. Purpose To evaluate the association of CT-evaluated lumbar lordosis, segmental wedging of the vertebral bodies and that of the intervertebral disks with various spinal degeneration features. Study design This cross-sectional study was a nested project to the Framingham Heart Study. Sample A random consecutive subset of 191 participants chosen from the 3590 participants enrolled in the Framingham Heart Study who underwent multi-detector CT to assess aortic calcification. Outcome Measures Physiologic Measures Dichotomous variables indicating the presence of intervertebral disc narrowing, facet joint osteoarthritis, spondylolysis, spondylolisthesis and spinal stenosis and density (in Hounsfield units) of multifidus and erector spinae muscles were evaluated on supine CT, as well as the lordosis angle (LA) and the wedging of the vertebral bodies and intervertebral disks. Sum of vertebral bodies wedging (ΣB) and sum of intervertebral discs wedging (ΣD) were used in analyses. Methods Mean values (±SD) of LA, ΣB and ΣD were calculated in males and females and compared using the t-test. Mean values (±SD) of LA, ΣB and ΣD in 4 age groups: <40, 40–49, 50–59 and 60+ years were calculated. We tested the linear relationship between LA, ΣB and ΣD and age groups. We evaluated the association between each spinal degeneration feature and LA, ΣB and ΣD using multiple logistic regression analysis where studied degeneration features were the dependent variable and all LA, ΣB and ΣD (separately) as well as age, sex, and BMI were independent predictors. Results LA was slightly lower than the normal range for standing individuals, and no difference was found between males and females (p=0.4107). However, the sex differences in sum of vertebral bodies wedging (ΣB) and sum of intervertebral discs wedging (ΣD) were statistically significant (0.0001 and 0.001, respectively). Females exhibit more dorsal wedging of the vertebral bodies and less dorsal wedging of the intervertebral discs than do males. All these parameters showed no association (p>0.05) with increasing age. LA showed statistically significant association with presence of spondylolysis (OR(95%CI): 1.08(1.02–1.14)) and with density of multifidus (1.06 (1.01–1.11). as well as a marginally significant association with isthmic spondylolisthesis (1.07(1.00–1.14). ΣB showed a positive association with degenerative spondylolisthesis and disc narrowing ((1.14(1.06–1.23) and 1.04 (1.00–1.08), correspondingly), whereas ΣD showed negative one (0.93(0.87–0.98) and (0.93(0.89–0.97), correspondingly). Conclusions Significant associations were found between lumbar lordosis evaluated in supine position and segmental wedging of the vertebral bodies and intervertebral disks and prevalence of spondylolysis and spondylolisthesis. Additional studies are needed, to evaluate the association between spondylolysis, isthmic and degenerative spondylolisthesis and vertebral and disc wedging at segmental level. PMID:21474082

New lumbar disc endoprosthesis applied to the patient's anatomic features.

PubMed

Mróz, Adrian; Skalski, Konstanty; Walczyk, Wojciech

2015-01-01

The paper describes the process of designing, manufacturing and design verification of the intervertebral of a new structure of lumbar disc endoprosthesis - INOP/LSP.1101. Modern and noninvasive medical imagining techniques, make it possible to record results of tests in a digital form, which creates opportunities for further processing. Mimics Innovation Suite software generates three-dimensional virtual models reflecting the real shape and measurements of components of L4-L5 spinal motion segment. With the use of 3D Print technique, physical models of bone structures of the mobile segment of the spine as well as the INOP/LSP.1101 endoprosthesis model were generated. A simplified FEA analysis of stresses in the endoprosthesis was performed to evaluate the designed geometries and materials of the new structure. The endoprosthesis prototype was made of Co28Cr6Mo alloy with the use of selective laser technology. The prototypes were subject to tribological verification with the use of the SBT-03.1 spine simulator. The structure of the endoprosthesis ensures a full reflection of its kinematics, full range of mobility of the motion segment in all anatomical planes as well as restoration of a normal height of the intervertebral space and curvature of the lordosis. The results of the tribological tests confirmed that SLM technology has the potential for production of the human bone and jointendoprostheses.

Towards an affordable deep learning system: automated intervertebral disc detection in x-ray images

NASA Astrophysics Data System (ADS)

Sa, Ruhan; Owens, William; Wiegand, Raymond; Chaudhary, Vipin

2017-03-01

Adult Spinal Deformity is a prominent medical issue with about 68% of the elderly population suffering from the disease.1 Detailed biomechanical assessment is needed both in the presurgical planning of structural spinal deformity as well as in early functional biomechanical compensation in ambulatory spinal pain patients. When considering automation of this process, we have to look at photographic intervertebral disc detection technique as a way to produce a detailed model of the spine with appropriate measurements required to make efficient and accurate decisions on patient care. Deep convolutional neural network (CNN) has given remarkable results in object recognition tasks in recent years. However, massive training data, computational resources and long training time is needed for both training a deep network from scratch or finetuning a network. Using pretrained model as feature extractor has shown promising result for moderate sized medical data.2 However, most work have extracted features from the last layer and little has been explored in terms of the number of convolutional layers needed for best performance. In this work we trained Support Vector Machine (SVM) classifiers on different layers of CaffeNet3 features to show that deeper the better concept does not hold for task such as intervertebral disc detection. Furthermore, our experimental results show the potential of using very small training data, such as 15 annotated medical images in our experiment, to yield satisfactory classification performance with accuracy up to 97.2%.

Ventral Dural Injury After Oblique Lumbar Interbody Fusion.

PubMed

Chang, JaeChil; Kim, Jin-Sung; Jo, Hyunjin

2017-02-01

Oblique lumbar interbody fusion (OLIF) through the oblique corridor between the aorta and anterior border of psoas muscle is favored among spinal surgeons who employ minimally invasive techniques. We report a case of ventral dural tear after OLIF that was associated with the inaccurate trajectory direction of endplate preparation. This is the first report to our knowledge of ventral dural tear associated with OLIF. A 72-year-old woman presented with right leg pain and numbness. X-rays showed degenerative spondylolisthesis and loss of disc height at L4-L5 and L5-S1 levels. Magnetic resonance imaging revealed right-sided paracentral disc herniation at the L3-L4 level and foraminal disc herniation at L4-L5. The initial surgical plan was OLIF of L3-L4 and L4-L5 after percutaneous screw fixation without laminectomy. With the patient in the lateral position, discectomy and endplate preparation were done successfully at the L3-L4 level, and the same procedure was done at the L4-L5 level for OLIF. A sharp Cobbs elevator for endplate preparation triggered a ventral dural defect at the L4-L5 level. We changed the patient's position to attempt dural repair. The ventral dural defect could not be repaired because it was too large. After the herniated rootlets were repositioned, TachoComb was patched over the defect site. Postoperatively, the patient has no definite neurologic deficits. When a surgeon performs OLIF, ventral dural injury should be avoided during the procedure of endplate preparation and contralateral annular release. Copyright © 2016 Elsevier Inc. All rights reserved.

Hollow-organ perforation following thoracolumbar spinal injuries of fall from height

PubMed Central

Yudoyono, Farid; Dahlan, Rully Hanafi; Tjahjono, Firman Priguna; Imron, Akhmad; Arifin, Muhammad Zafrullah

2015-01-01

Introduction Spinal trauma is the cause of high mortality and morbidity, the fall from height as mechanism that can cause a wide variety of lesions, associated both with the direct impact on the ground and with the deceleration. In such fall cases greater heights and higher mortality are involved. Presentation of case We report the successful management of life-threatening hollow-organ perforation following thoracolumbar spinal injury. Discussion Perforation of the hollow-organ in the setting of thoracolumbar trauma may delay the diagnosis and can have devastating consequences. Conclusions This case supports the recommendation for neurosurgeon in the setting of thoracolumbar injury that perforation of the hollow-organ can have devastating consequences. It is vital to achieve an early diagnosis to improve survival rate. PMID:25967553

A Structurally and Functionally Biomimetic Biphasic Scaffold for Intervertebral Disc Tissue Engineering

PubMed Central

Choy, Andrew Tsz Hang; Chan, Barbara Pui

2015-01-01

Tissue engineering offers high hopes for the treatment of intervertebral disc (IVD) degeneration. Whereas scaffolds of the disc nucleus and annulus have been extensively studied, a truly biomimetic and mechanically functional biphasic scaffold using naturally occurring extracellular matrix is yet to be developed. Here, a biphasic scaffold was fabricated with collagen and glycosaminoglycans (GAGs), two of the most abundant extracellular matrix components in the IVD. Following fabrication, the scaffold was characterized and benchmarked against native disc. The biphasic scaffold was composed of a collagen-GAG co-precipitate making up the nucleus pulposus-like core, and this was encapsulated in multiple lamellae of photochemically crosslinked collagen membranes comprising the annulus fibrosus-like lamellae. On mechanical testing, the height of our engineered disc recovered by ~82-89% in an annulus-independent manner, when compared with the 99% recovery exhibited by native disc. The annulus-independent nature of disc height recovery suggests that the fluid replacement function of the engineered nucleus pulposus core might mimic this hitherto unique feature of native disc. Biphasic scaffolds comprised of 10 annulus fibrosus-like lamellae had the best overall mechanical performance among the various designs owing to their similarity to native disc in most aspects, including elastic compliance during creep and recovery, and viscous compliance during recovery. However, the dynamic mechanical performance (including dynamic stiffness and damping factor) of all the biphasic scaffolds was similar to that of the native discs. This study contributes to the rationalized design and development of a biomimetic and mechanically viable biphasic scaffold for IVD tissue engineering. PMID:26115332

Vertebral growth modulation by hemicircumferential electrocoagulation: an experimental study in pigs.

PubMed

Caballero, Alberto; Barrios, Carlos; Burgos, Jesús; Hevia, Eduardo; Correa, Carlos

2011-08-01

This experimental study in pigs was aimed at evaluating spinal growth disorders after partial arrest of the vertebral epiphyseal plates (EP) and neurocentral cartilages (NCC). Unilateral and multisegmental single or combined lesions of the physeal structures were performed by electrocoagulation throughout a video-assisted thoracoscopical approach. Thirty 4-week-old domestic pigs (mean weight 16 kg) were included in the experiments. The superior and inferior epiphyseal plates of T5 to T9 vertebra were damaged in ten animals by hemicircumferential electrocoagulation (group I). In other ten pigs (group II), right NCC at the same T5-T9 levels were damaged. Ten other animals underwent combined lesions of the ipsilateral hemiepiphyseal plates and NCC at the T5-T9 levels. A total of 26 animals could be evaluated after 12 weeks of follow-up using conventional X-rays, CT scans and histology. The pigs with hemicircumferential EP damage developed very slight concave non-structured scoliotic deformities without vertebral rotation.(mean 12° Cobb; range10-16°). Some of the damaged vertebra showed a marked wedgening with unilateral development alteration of the vertebral body, including the adjacent discs The animals with damage of the NCC developed mild scoliotic curves (mean 19° Cobb; range 16-24°) with convexity opposite to the damaged side and loss of physiological kyphosis. The injured segments showed an asymmetric growth with hypoplasia of the pedicle and costovertebral joints at the damaged side. The pigs undergoing combined EP and NCC lesions developed minimal non-structured curves, ranging from 10 to 12° Cobb. In these animals there was a lack of growth of a vertebral hemibody and disc hypoplasia at the damaged segments. Both damage of the NCC and the EP affect the height of the vertebral body. No spinal stenosis was found in any case. In most cases, the adjacent superior and inferior vertebral EP to damaged segments had a compensatory growth that maintained the straight spinal shape. In summary, unilateral direct lesion of the EP by hemicircumferential thoracoscopic electrocoagulation modifies vertebral growth, but is not able to induce true scoliostic curves in pigs. Only animals with damaged NCC developed mild scoliotic curves of lordotic type. This work rediscovers and emphasizes the decisive role of the neurocentral cartilage in the ethiopatogeny of idiopathic scoliosis.

[The assessment of the impact of rehabilitation on the pain intensity level in patients with herniated nucleus pulposus of the intervertebral disc].

PubMed

Koszela, Kamil; Krukowska, Sylwia; Woldańska-Okońska, Marta

2017-05-23

Back pain may be caused by many factors. In many cases it is difficult to unambiguously determine a cause of the pathology, which can involve various structures in the spine. In this paper we will discuss the symptoms associated with the degenerative changes of the intervertebral disc, which involve, among others, its bulging, dislocation and pressure on the surrounding structures. These problems require an adequate clinical and imaging diagnostics in order to implement an appropriate treatment. In the first place, it should be based on the conservative methods (such as: pharmacotherapy, rehabilitation and lifestyle changes). Only in the absence of improvement it is recommended to consider a surgical treatment. The aim of the study is to assess the impact of rehabilitation on the pain intensity level in patients with herniated nucleus pulposus of the intervertebral disc. The study was performed in 46 patients (age range: 19-85), including 26 women and 20 men. On the basis of imaging, all patients showed the presence of a slipped disc with disc herniation. The patients were treated conservatively. For pain assessment was used the The Laitinen Modified Questionnaire Indicators of Pain and The Visual- Analogue Scale. The results were statistically analyzed. The results clearly demonstrate the analgesic efficacy of specialized rehabilitation in the spinal pain syndrome in a discopathy with a spinal disc herniation of an intervertebral disc. The rehabilitation of patients with a back pain due to the presence of herniated nucleus pulposus has a significant analgesic effect. In the case of a presence of the herniated nucleus pulposus, the rehabilitation should be considered in a first place. If no improvement, a possible surgery should be considered. An important element of a conservative treatment is an effective rehabilitation, which is of vital economic importance, because a therapy including surgery usually requires subsequent rehabilitation and is much more expensive.

The structure of protoplanetary discs around evolving young stars

NASA Astrophysics Data System (ADS)

Bitsch, Bertram; Johansen, Anders; Lambrechts, Michiel; Morbidelli, Alessandro

2015-03-01

The formation of planets with gaseous envelopes takes place in protoplanetary accretion discs on time scales of several million years. Small dust particles stick to each other to form pebbles, pebbles concentrate in the turbulent flow to form planetesimals and planetary embryos and grow to planets, which undergo substantial radial migration. All these processes are influenced by the underlying structure of the protoplanetary disc, specifically the profiles of temperature, gas scale height, and density. The commonly used disc structure of the minimum mass solar nebula (MMSN) is a simple power law in all these quantities. However, protoplanetary disc models with both viscous and stellar heating show several bumps and dips in temperature, scale height, and density caused by transitions in opacity, which are missing in the MMSN model. These play an important role in the formation of planets, since they can act as sweet spots for forming planetesimals via the streaming instability and affect the direction and magnitude of type-I migration. We present 2D simulations of accretion discs that feature radiative cooling and viscous and stellar heating, and they are linked to the observed evolutionary stages of protoplanetary discs and their host stars. These models allow us to identify preferred planetesimal and planet formation regions in the protoplanetary disc as a function of the disc's metallicity, accretion rate, and lifetime. We derive simple fitting formulae that feature all structural characteristics of protoplanetary discs during the evolution of several Myr. These fits are straightforward for applying to modelling any growth stage of planets where detailed knowledge of the underlying disc structure is required. Appendix A is available in electronic form at http://www.aanda.org

Mild (not severe) disc degeneration is implicated in the progression of bilateral L5 spondylolysis to spondylolisthesis.

PubMed

Ramakrishna, Vivek A S; Chamoli, Uphar; Viglione, Luke L; Tsafnat, Naomi; Diwan, Ashish D

2018-04-02

Spondylolytic (or lytic) spondylolisthesis is often associated with disc degeneration at the index-level; however, it is not clear if disc degeneration is the cause or the consequence of lytic spondylolisthesis. The main objective of this computed tomography based finite element modelling study was to examine the role of different grades of disc degeneration in the progression of a bilateral L5-lytic defect to spondylolisthesis. High-resolution computed tomography data of the lumbosacral spine from an anonymised healthy male subject (26 years old) were segmented to build a 3D-computational model of an INTACT L1-S1 spine. The INTACT model was manipulated to generate four more models representing a bilateral L5-lytic defect and the following states of the L5-S1 disc: nil degeneration (NOR LYTIC), mild degeneration (M-DEG LYTIC), mild degeneration with 50% disc height collapse (M-DEG-COL LYTIC), and severe degeneration with 50% disc height collapse(S-COL LYTIC). The models were imported into a finite element modelling software for pre-processing, running nonlinear-static solves, and post-processing of the results. Compared with the baseline INTACT model, M-DEG LYTIC model experienced the greatest increase in kinematics (Fx range of motion: 73% ↑, Fx intervertebral translation: 53%↑), shear stresses in the annulus (Fx anteroposterior: 163%↑, Fx posteroanterior: 31%↑), and strain in the iliolumbar ligament (Fx: 90%↑). The S-COL LYTIC model experienced a decrease in mobility (Fx range of motion: 48%↓, Fx intervertebral translation: 69%↓) and an increase in normal stresses in the annulus (Fx Tensile: 170%↑; Fx Compressive: 397%↑). No significant difference in results was noted between M-DEG-COL LYTIC and S-COL LYTIC models. In the presence of a bilateral L5 spondylolytic defect, a mildly degenerate index-level disc experienced greater intervertebral motions and shear stresses compared with a severely degenerate index-level disc in flexion and extension bending motions. Disc height collapse, with or without degenerative changes in the stiffness properties of the disc, is one of the plausible re-stabilisation mechanisms available to the L5-S1 motion segment to mitigate increased intervertebral motions and shear stresses due to a bilateral L5 lytic defect.

Prognosis of intervertebral disc loss from diagnosis of degenerative disc disease

NASA Astrophysics Data System (ADS)

Li, S.; Lin, A.; Tay, K.; Romano, W.; Osman, Said

2015-03-01

Degenerative Disc Disease (DDD) is one of the most common causes of low back pain, and is a major factor in limiting the quality of life of an individual usually as they enter older stages of life, the disc degeneration reduces the shock absorption available which in turn causes pain. Disc loss is one of the central processes in the pathogenesis of DDD. In this study, we investigated whether the image texture features quantified from magnetic resonance imaging (MRI) could be appropriate markers for diagnosis of DDD and prognosis of inter-vertebral disc loss. The main objective is to use simple image based biomarkers to perform prognosis of spinal diseases using non-invasive procedures. Our results from 65 subjects proved the higher success rates of the combination marker compared to the individual markers and in the future, we will extend the study to other spine regions to allow prognosis and diagnosis of DDD for a wider region.

Factors favoring regain of the lost vertical spinal height through posterior spinal fusion in adolescent idiopathic scoliosis.

PubMed

Shi, Benlong; Mao, Saihu; Xu, Leilei; Sun, Xu; Liu, Zhen; Zhu, Zezhang; Lam, Tsz Ping; Cheng, Jack Cy; Ng, Bobby; Qiu, Yong

2016-07-04

Height gain is a common beneficial consequence following correction surgery in adolescent idiopathic scoliosis (AIS), yet little is known concerning factors favoring regain of the lost vertical spinal height (SH) through posterior spinal fusion. A consecutive series of AIS patients from February 2013 to August 2015 were reviewed. Surgical changes in SH (ΔSH), as well as the multiple coronal and sagittal deformity parameters were measured and correlated. Factors associated with ΔSH were identified through Pearson correlation analysis and multivariate regression analysis. A total of 172 single curve and 104 double curve patients were reviewed. The ΔSH averaged 2.5 ± 0.9 cm in single curve group and 2.9 ± 1.0 cm in double curve group. The multivariate regression analysis revealed the following pre-operative variables contributed significantly to ΔSH: pre-op Cobb angle, pre-op TK (single curve group only), pre-op GK (double curve group only) and pre-op LL (double curve group only) (p < 0.05). Thus change in height (in cm) = 0.044 × (pre-op Cobb angle) + 0.012 × (pre-op TK) (Single curve, adjusted R(2) = 0.549) or 0.923 + 0.021 × (pre-op Cobb angle1) + 0.028 × (pre-op Cobb angle2) + 0.015 × (pre-op GK)-0.012 × (pre-op LL) (Double curve, adjusted R(2) = 0.563). Severer pre-operative coronal Cobb angle and greater sagittal curves were beneficial factors favoring more contribution to the surgical lengthening effect in vertical spinal height in AIS.

[The Relation between the Height of Radiographic Table and Workloads of Radiologic Technologist in General X-ray Examinations].

PubMed

Hattori, Akiko; Mizoguchi, Noriko; Arimura, Hisao; Fukano, Yuuichi; Umezu, Yoshiyuki; Yabuuchi, Hidetake

2015-12-01

Workloads of radiological technologists under different conditions of heights of radiographic table and/or X-ray tube assembly were calculated using a software for preventing musculoskeletal complaint to investigate optimal working environment for general X-ray examinations. In the patient positioning, compressive force of lumbar disc decreased at higher radiographic table within the range of 45-90 cm. On the other hand, workload of the shoulder joint increased with increase in the height of radiographic table. Load of the shoulder joint similarly increased as the height of the X-ray tube assembly increased. Compressive force of lumbar disc reduced by approximately 10-30% as the height ratio of the radiographic table to body height increased by approximately 40%, compared to the lowest table of 45 cm. Muscle load of a 50-years-old woman was approximately double compared to a 30-year-old man, even in the same workload. It is important to keep suitable height of radiographic table for reduction of the workloads of lumbar rather than shoulder joint, because floating-type radiographic table is generally used.

Abdominal girth, vertebral column length, and spread of spinal anesthesia in 30 minutes after plain bupivacaine 5 mg/mL.

PubMed

Zhou, Qing-he; Xiao, Wang-pin; Shen, Ying-yan

2014-07-01

The spread of spinal anesthesia is highly unpredictable. In patients with increased abdominal girth and short stature, a greater cephalad spread after a fixed amount of subarachnoidally administered plain bupivacaine is often observed. We hypothesized that there is a strong correlation between abdominal girth/vertebral column length and cephalad spread. Age, weight, height, body mass index, abdominal girth, and vertebral column length were recorded for 114 patients. The L3-L4 interspace was entered, and 3 mL of 0.5% plain bupivacaine was injected into the subarachnoid space. The cephalad spread (loss of temperature sensation and loss of pinprick discrimination) was assessed 30 minutes after intrathecal injection. Linear regression analysis was performed for age, weight, height, body mass index, abdominal girth, vertebral column length, and the spread of spinal anesthesia, and the combined linear contribution of age up to 55 years, weight, height, abdominal girth, and vertebral column length was tested by multiple regression analysis. Linear regression analysis showed that there was a significant univariate correlation among all 6 patient characteristics evaluated and the spread of spinal anesthesia (all P < 0.039) except for age and loss of temperature sensation (P > 0.068). Multiple regression analysis showed that abdominal girth and the vertebral column length were the key determinants for spinal anesthesia spread (both P < 0.0001), whereas age, weight, and height could be omitted without changing the results (all P > 0.059, all 95% confidence limits < 0.372). Multiple regression analysis revealed that the combination of a patient's 5 general characteristics, especially abdominal girth and vertebral column length, had a high predictive value for the spread of spinal anesthesia after a given dose of plain bupivacaine.

Factors affecting the sensitivity and specificity of the Heidelberg Retina Tomograph parameters to glaucomatous progression in disc photographs.

PubMed

Saarela, Ville; Falck, Aura; Airaksinen, P Juhani; Tuulonen, Anja

2012-03-01

To evaluate the factors affecting the sensitivity and specificity of the stereometric optic nerve head (ONH) parameters of the Heidelberg Retina Tomograph (HRT) to glaucomatous progression in stereoscopic ONH photographs. The factors affecting the sensitivity and specificity of the vertical cup : disc ratio, the cup : disc area ratio, the cup volume, the rim area and a linear discriminant function to progression were analysed. These parameters were the best indicators of progression in a retrospective study of 476 eyes. The reference standard for progression was the masked evaluation of stereoscopic ONH photographs. The factors having the most significant effect on the sensitivity and specificity of the stereometric ONH parameters were the reference height difference and the mean topography standard deviation (TSD), indicating image quality. Also, the change in the TSD and age showed consistent, but variably significant, influence on all parameters tested. The sensitivity and specificity improved when there was little change in the reference height, the image quality was good and stable, and the patients were younger. The sensitivity and specificity of the vertical cup : disc ratio was improved by a large disc area and high baseline cup : disc area ratio. The rim area showed a better sensitivity and specificity for progression with a small disc area and low baseline cup : disc area ratio. The factors affecting the sensitivity and specificity of the stereometric ONH parameters to glaucomatous progression in disc photographs are essentially the same as those affecting the measurement variability of the HRT. © 2010 The Authors. Acta Ophthalmologica © 2010 Acta Ophthalmologica Scandinavica Foundation.

AxiaLIF system: minimally invasive device for presacral lumbar interbody spinal fusion

PubMed Central

Rapp, Steven M; Miller, Larry E; Block, Jon E

2011-01-01

Lumbar fusion is commonly performed to alleviate chronic low back and leg pain secondary to disc degeneration, spondylolisthesis with or without concomitant lumbar spinal stenosis, or chronic lumbar instability. However, the risk of iatrogenic injury during traditional anterior, posterior, and transforaminal open fusion surgery is significant. The axial lumbar interbody fusion (AxiaLIF) system is a minimally invasive fusion device that accesses the lumbar (L4–S1) intervertebral disc spaces via a reproducible presacral approach that avoids critical neurovascular and musculoligamentous structures. Since the AxiaLIF system received marketing clearance from the US Food and Drug Administration in 2004, clinical studies of this device have reported high fusion rates without implant subsidence, significant improvements in pain and function, and low complication rates. This paper describes the design and approach of this lumbar fusion system, details the indications for use, and summarizes the clinical experience with the AxiaLIF system to date. PMID:22915939

AxiaLIF system: minimally invasive device for presacral lumbar interbody spinal fusion.

PubMed

Rapp, Steven M; Miller, Larry E; Block, Jon E

2011-01-01

Lumbar fusion is commonly performed to alleviate chronic low back and leg pain secondary to disc degeneration, spondylolisthesis with or without concomitant lumbar spinal stenosis, or chronic lumbar instability. However, the risk of iatrogenic injury during traditional anterior, posterior, and transforaminal open fusion surgery is significant. The axial lumbar interbody fusion (AxiaLIF) system is a minimally invasive fusion device that accesses the lumbar (L4-S1) intervertebral disc spaces via a reproducible presacral approach that avoids critical neurovascular and musculoligamentous structures. Since the AxiaLIF system received marketing clearance from the US Food and Drug Administration in 2004, clinical studies of this device have reported high fusion rates without implant subsidence, significant improvements in pain and function, and low complication rates. This paper describes the design and approach of this lumbar fusion system, details the indications for use, and summarizes the clinical experience with the AxiaLIF system to date.

Examination of a lumbar spine biomechanical model for assessing axial compression, shear, and bending moment using selected Olympic lifts.

PubMed

Eltoukhy, Moataz; Travascio, Francesco; Asfour, Shihab; Elmasry, Shady; Heredia-Vargas, Hector; Signorile, Joseph

2016-09-01

Loading during concurrent bending and compression associated with deadlift, hang clean and hang snatch lifts carries the potential for injury to the intervertebral discs, muscles and ligaments. This study examined the capacity of a newly developed spinal model to compute shear and compressive forces, and bending moments in lumbar spine for each lift. Five male subjects participated in the study. The spine was modeled as a chain of rigid bodies (vertebrae) connected via the intervertebral discs. Each vertebral reference frame was centered in the center of mass of the vertebral body, and its principal directions were axial, anterior-posterior, and medial-lateral. The results demonstrated the capacity of this spinal model to assess forces and bending moments at and about the lumbar vertebrae by showing the variations among these variables with different lifting techniques. These results show the model's potential as a diagnostic tool.

A case of an 18-year-old male rugby union forward with a C5/C6 central disc herniation.

PubMed

Broughton, Henare Renata

2009-01-01

The patient was an 18-year-old front row forward rugby player who had a history of episodic neck pain for over 2 years following playing games of rugby. The initial event of April 2005 for which the symptoms manifested was a scrum collapse; he continued playing until a front-on tackle occurred when the symptoms dictated that he leave the field and be taken to the local hospital. A diagnosis of a cervical sprain was made and conservative management ensued. During the selections held on January 2008, a medical assessment was made and an MRI found that he had a central disc herniation at C5/C6. He was referred to a spinal orthopaedic surgeon for further treatment. The risks to cervical spinal injuries are illustrated in this case, in a scrum and in the tackle. The prevention of such an injury is discussed.

The Degenerative Spine.

PubMed

Clarençon, Frédéric; Law-Ye, Bruno; Bienvenot, Peggy; Cormier, Évelyne; Chiras, Jacques

2016-08-01

Degenerative disease of the spine is a leading cause of back pain and radiculopathy, and is a frequent indication for spine MR imaging. Disc degeneration, disc protrusion/herniation, discarhtrosis, spinal canal stenosis, and facet joint arthrosis, as well as interspinous processes arthrosis, may require an MR imaging workup. This review presents the MR imaging patterns of these diseases and describes the benefit of the MR imaging in these indications compared with the other imaging modalities like plain radiographs or computed tomography scan. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of Neonatal Enzyme Replacement Therapy and Simvastatin Treatment on Cervical Spine Disease in Mucopolysaccharidosis I Dogs

PubMed Central

Chiaro, Joseph A; O’Donnell, Patricia; Shore, Eileen M; Malhotra, Neil R; Ponder, Katherine P; Haskins, Mark E; Smith, Lachlan J

2014-01-01

Mucopolysaccharidosis I (MPS I) is a lysosomal storage disease characterized by deficient α-L-iduronidase activity, leading to the accumulation of poorly degraded glycosaminoglycans (GAGs). Children with MPS I exhibit high incidence of spine disease, including accelerated disc degeneration and vertebral dysplasia, which in turn lead to spinal cord compression and kypho-scoliosis. In this study we investigated the efficacy of neonatal enzyme replacement therapy (ERT), alone or in combination with oral simvastatin (ERT+SIM) for attenuating cervical spine disease progression in MPS I, using a canine model. Four groups were studied: normal controls; MPS I untreated; MPS I ERT treated; and MPS I ERT+SIM treated. Animals were euthanized at one year-of-age. Intervertebral disc condition and spinal cord compression were evaluated from MRIs and plain radiographs, vertebral bone condition and odontoid hypoplasia were evaluated using microcomputed tomography, and epiphyseal cartilage to bone conversion was evaluated histologically. Untreated MPS I animals exhibited more advanced disc degeneration and more severe spinal cord compression than normal animals. Both treatment groups resulted in partial preservation of disc condition and cord compression, with ERT+SIM not significantly better than ERT alone. Untreated MPS I animals had significantly lower vertebral trabecular bone volume and mineral density, while ERT treatment resulted in partial preservation of these properties. ERT+SIM treatment demonstrated similar, but not greater, efficacy. Both treatment groups partially normalized endochondral ossification in the vertebral epiphyses (as indicated by absence of persistent growth plate cartilage), and odontoid process size and morphology. These results indicate that ERT begun from a very early age attenuates the severity of cervical spine disease in MPS I, particularly for the vertebral bone and odontoid process, and that additional treatment with simvastatin does not provide a significant additional benefit over ERT alone. PMID:24898323

Do cervical epidural injections provide long-term relief in neck and upper extremity pain? A systematic review.

PubMed

Manchikanti, Laxmaiah; Nampiaparampil, Devi E; Candido, Kenneth D; Bakshi, Sanjay; Grider, Jay S; Falco, Frank J E; Sehgal, Nalini; Hirsch, Joshua A

2015-01-01

The high prevalence of chronic persistent neck pain not only leads to disability but also has a significant economic, societal, and health impact. Among multiple modalities of treatments prescribed in the management of neck and upper extremity pain, surgical, interventional and conservative modalities have been described. Cervical epidural injections are also common modalities of treatments provided in managing neck and upper extremity pain. They are administered by either an interlaminar approach or transforaminal approach. To determine the long-term efficacy of cervical interlaminar and transforaminal epidural injections in the treatment of cervical disc herniation, spinal stenosis, discogenic pain without facet joint pain, and post surgery syndrome. The literature search was performed from 1966 to October 2014 utilizing data from PubMed, Cochrane Library, US National Guideline Clearinghouse, previous systematic reviews, and cross-references. The evidence was assessed based on best evidence synthesis with Level I to Level V. There were 7 manuscripts meeting inclusion criteria. Of these, 4 assessed the role of interlaminar epidural injections for managing disc herniation or radiculitis, and 3 assessed these injections for managing central spinal stenosis, discogenic pain without facet joint pain, and post surgery syndrome. There were 4 high quality manuscripts. A qualitative synthesis of evidence showed there is Level II evidence for each etiology category. The evidence is based on one relevant, high quality trial supporting the efficacy of cervical interlaminar epidural injections for each particular etiology. There were no randomized trials available assessing the efficacy of cervical transforaminal epidural injections. Paucity of available literature, specifically conditions other than disc herniation. This systematic review with qualitative best evidence synthesis shows Level II evidence for the efficacy of cervical interlaminar epidural injections with local anesthetic with or without steroids, based on at least one high-quality relevant randomized control trial in each category for disc herniation, discogenic pain without facet joint pain, central spinal stenosis, and post surgery syndrome.

Cerebrospinal fluid leaks following spinal surgery: use of fat grafts for prevention and repair. Technical note.

PubMed

Black, Perry

2002-03-01

Cerebrospinal fluid (CSF) leaks are relatively common following spinal surgery. A midline dural tear in the spine is readily repaired by direct application of sutures; however, far-lateral or ventral dural tears are problematic. Fat is an ideal sealant because it is impermeable to water. In this paper the author reports his experience with using fat grafts for the prevention or repair of CSF leaks and proposes a technique in which a large sheet of fat, harvested from the patient's subcutaneous layer, is used to cover not only the dural tear(s) but all of the exposed dura and is tucked into the lateral recess. This procedure prevents CSF from seeping around the fat, which may be tacked to the dura with a few sutures. Fibrin glue is spread on the surface of the fat and is further covered with Surgicel or Gelfoam. For ventral dural tears (associated with procedures in which disc material is excised), fat is packed into the disc space to seal off the ventral dural leak. Dural suture lines following spinal intradural exploration are prophylatically protected from CSF leakage in the same manner. With one exception, 27 dural tears noted during 1650 spinal procedures were successfully repaired using this technique. There was one case of postoperative CSF leakage in 140 cases in which intradural exploration for tumor or other lesions was undertaken. Both postoperative CSF leaks were controlled by applying additional skin sutures. The use of a fat graft is recommended as a rapid, effective means of prevention and repair of CSF leaks following spinal surgery.

The lamppost model: effects of photon trapping, the bottom lamp and disc truncation

NASA Astrophysics Data System (ADS)

Niedźwiecki, Andrzej; Zdziarski, Andrzej A.

2018-04-01

We study the lamppost model, in which the primary X-ray sources in accreting black-hole systems are located symmetrically on the rotation axis on both sides of the black hole surrounded by an accretion disc. We show the importance of the emission of the source on the opposite side to the observer. Due to gravitational light bending, its emission can increase the direct (i.e., not re-emitted by the disc) flux by as much as an order of magnitude. This happens for near to face-on observers when the disc is even moderately truncated. For truncated discs, we also consider effects of emission of the top source gravitationally bent around the black hole. We also present results for the attenuation of the observed radiation with respect to that emitted by the lamppost as functions of the lamppost height, black-hole spin and the degree of disc truncation. This attenuation, which is due to the time dilation, gravitational redshift and the loss of photons crossing the black-hole horizon, can be as severe as by several orders of magnitude for low lamppost heights. We also consider the contribution to the observed flux due to re-emission by optically-thick matter within the innermost stable circular orbit.

Changes in lumbosacral spinal nerve roots on diffusion tensor imaging in spinal stenosis.

PubMed

Hou, Zhong-Jun; Huang, Yong; Fan, Zi-Wen; Li, Xin-Chun; Cao, Bing-Yi

2015-11-01

Lumbosacral degenerative disc disease is a common cause of lower back and leg pain. Conventional T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI) scans are commonly used to image spinal cord degeneration. However, these modalities are unable to image the entire lumbosacral spinal nerve roots. Thus, in the present study, we assessed the potential of diffusion tensor imaging (DTI) for quantitative assessment of compressed lumbosacral spinal nerve roots. Subjects were 20 young healthy volunteers and 31 patients with lumbosacral stenosis. T2WI showed that the residual dural sac area was less than two-thirds that of the corresponding normal area in patients from L3 to S1 stenosis. On T1WI and T2WI, 74 lumbosacral spinal nerve roots from 31 patients showed compression changes. DTI showed thinning and distortion in 36 lumbosacral spinal nerve roots (49%) and abruption in 17 lumbosacral spinal nerve roots (23%). Moreover, fractional anisotropy values were reduced in the lumbosacral spinal nerve roots of patients with lumbosacral stenosis. These findings suggest that DTI can objectively and quantitatively evaluate the severity of lumbosacral spinal nerve root compression.

Clinical Guideline for Treatment of Symptomatic Thoracic Spinal Stenosis.

PubMed

Chen, Zhong-qiang; Sun, Chui-guo

2015-08-01

Thoracic spinal stenosis is a relatively common disorder causing paraplegia in the population of China. Until nowadays, the clinical management of thoracic spinal stenosis is still demanding and challenging with lots of questions remaining to be answered. A clinical guideline for the treatment of symptomatic thoracic spinal stenosis has been created by reaching the consensus of Chinese specialists using the best available evidence as a tool to aid practitioners involved with the care of this disease. In this guideline, many fundamental questions about thoracic spinal stenosis which were controversial have been explained clearly, including the definition of thoracic spinal stenosis, the standard procedure for diagnosing symptomatic thoracic spinal stenosis, indications for surgery, and so on. According to the consensus on the definition of thoracic spinal stenosis, the soft herniation of thoracic discs has been excluded from the pathological factors causing thoracic spinal stenosis. The procedure for diagnosing thoracic spinal stenosis has been quite mature, while the principles for selecting operative procedures remain to be improved. This guideline will be updated on a timely schedule and adhering to its recommendations should not be mandatory because it does not have the force of law. © 2015 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

Feasibility of the runt cow for in vivo testing of a spinal interbody prosthesis with preliminary results.

PubMed

Buttermann, Glenn R; Mendenhall, H Vincent

2012-04-01

The optimal lumbar spinal disc prosthesis has yet to be developed. Failures of clinical device studies may be minimized by appropriate large animal preclinical studies. The lumbar spine of the mature "runt" cow, Corrientes breed, has been shown to have a number of desirable characteristics to the human. This study assessed the feasibility of the "runt" cow for in vivo testing of human-sized lumbar interbody implants and the ability to perform common analyses of explants. Eight cows (four experimental and four controls) were compared. The experimental animals had transosseous implantation of the disc prosthesis at L4-L5, and their spines were harvested at four or six months. They were evaluated for the ease of surgical access and healing, motion segment mobility, ability to remove the implant nondestructively, and microradiography and histomorphology. All animals had successful implantation. All explantations were performed without alteration to the devices. All animals had surgical healing and intended device motion, and histology found device stability by demonstrating bone ingrowth into the device's porous plates. There was a significant 46% increase in the amount of trabecular bone adjacent to the implants. The mature runt cow allows for implantation of human-sized interbody and intrabody spinal prostheses. This animal model allowed for macro- and histological analysis of the implant and surrounding tissues. In vivo stability was demonstrated for the disc prosthesis while also allowing for evaluation of intended mobility. Additionally, this is the first study to suggest increased bone density supporting an interbody prosthesis.

Precision of lumbar intervertebral measurements: does a computer-assisted technique improve reliability?

PubMed

Pearson, Adam M; Spratt, Kevin F; Genuario, James; McGough, William; Kosman, Katherine; Lurie, Jon; Sengupta, Dilip K

2011-04-01

Comparison of intra- and interobserver reliability of digitized manual and computer-assisted intervertebral motion measurements and classification of "instability." To determine if computer-assisted measurement of lumbar intervertebral motion on flexion-extension radiographs improves reliability compared with digitized manual measurements. Many studies have questioned the reliability of manual intervertebral measurements, although few have compared the reliability of computer-assisted and manual measurements on lumbar flexion-extension radiographs. Intervertebral rotation, anterior-posterior (AP) translation, and change in anterior and posterior disc height were measured with a digitized manual technique by three physicians and by three other observers using computer-assisted quantitative motion analysis (QMA) software. Each observer measured 30 sets of digital flexion-extension radiographs (L1-S1) twice. Shrout-Fleiss intraclass correlation coefficients for intra- and interobserver reliabilities were computed. The stability of each level was also classified (instability defined as >4 mm AP translation or 10° rotation), and the intra- and interobserver reliabilities of the two methods were compared using adjusted percent agreement (APA). Intraobserver reliability intraclass correlation coefficients were substantially higher for the QMA technique THAN the digitized manual technique across all measurements: rotation 0.997 versus 0.870, AP translation 0.959 versus 0.557, change in anterior disc height 0.962 versus 0.770, and change in posterior disc height 0.951 versus 0.283. The same pattern was observed for interobserver reliability (rotation 0.962 vs. 0.693, AP translation 0.862 vs. 0.151, change in anterior disc height 0.862 vs. 0.373, and change in posterior disc height 0.730 vs. 0.300). The QMA technique was also more reliable for the classification of "instability." Intraobserver APAs ranged from 87 to 97% for QMA versus 60% to 73% for digitized manual measurements, while interobserver APAs ranged from 91% to 96% for QMA versus 57% to 63% for digitized manual measurements. The use of QMA software substantially improved the reliability of lumbar intervertebral measurements and the classification of instability based on flexion-extension radiographs.

Kinematic Evaluation of Association between Disc Bulge Migration, Lumbar Segmental Mobility, and Disc Degeneration in the Lumbar Spine Using Positional Magnetic Resonance Imaging

PubMed Central

Hu, Jonathan K.; Morishita, Yuichiro; Montgomery, Scott R.; Hymanson, Henry; Taghavi, Cyrus E.; Do, Duc; Wang, Jeff C.

2011-01-01

Degenerative disc disease and disc bulge in the lumbar spine are common sources of lower back pain. Little is known regarding disc bulge migration and lumbar segmental mobility as the lumbar spine moves from flexion to extension. In this study, 329 symptomatic (low back pain with or without neurological symptoms) patients with an average age of 43.5 years with varying degrees of disc degeneration were examined to characterize the kinematics of the lumbar intervertebral discs through flexion, neutral, and extension weight-bearing positions. In this population, disc bulge migration associated with dynamic motion of the lumbar spine significantly increased with increased grade of disk degeneration. Although no obvious trends relating the migration of disc bulge and angular segmental mobility were seen, translational segmental mobility tended to increase with disc bulge migration in all of the degenerative disc states. It appears that many factors, both static (intervertebral disc degeneration or disc height) and dynamic (lumbar segmental mobility), affect the mechanisms of lumbar disc bulge migration. PMID:24353937

Surgical treatment of aspergillus spondylodiscitis.

PubMed

van Ooij, A; Beckers, J M; Herpers, M J; Walenkamp, G H

2000-02-01

Four cases of aspergillus spondylodiscitis were treated with operative debridement and fusion. In this rarely encountered mycotic infection of the spine in immunocompromised patients rapid destruction of the intervertebral disc and vertebral bodies can occur. In advanced cases antimycotic drug therapy is thought to be ineffective and a forcing indication for surgery exists when the destruction is progressive and spinal cord compression is imminent or manifest. Spinal instrumentation can be of help in maintaining or restoring spinal stability and maintaining spinal alignment. In our four patients the aspergillus spondylodiscitis was successfully eradicated and fusion achieved. In two of three patients with a neurologic deficit, this deficit disappeared. Two patients died within 6 months after the operative treatment, due to complications related to the underlying illness. One patient was left with a subtotal paraplegia.

Diagnosis and Incidence of Spondylosis and Cervical Disc Disorders in the University Clinical Hospital in Olsztyn, in Years 2011–2015

PubMed Central

Włodarczyk, Andrzej; Wojtkiewicz, Joanna

2018-01-01

Background Disorders connected with the musculoskeletal and central nervous system dysfunction are the most significant clinical problem worldwide. Our earlier research has shown that back and spinal disorders and lumbar disc disorders were most frequently diagnosed using MRI scanner at the University Clinical Hospital (UCH) in Olsztyn in years 2011–2015. We have also observed that another two diseases of spinal column, spondylosis and cervical disc disorders, were also very prevalent. The main objective of this work was to analyze the prevalence of spondylosis and cervical disc disorders in the study population diagnosed at UCH in years 2011–2015. Methods The digital database including patients' diagnostic and demographic information was generated based on MRI reports from years 2011–2015 and analyzed using SPSS software. Results Within the study group (n = 13298) the most frequently MRI-diagnosed diseases were musculoskeletal group (M00–M99; n = 7711; 57,98%) and cervical disc disorders (M50; n = 1659; 12,47%) and spondylosis (M47, n = 611; 4,59%). More women (67%) than men (33%) were enrolled in the study, and the largest fraction of the study population was in the range of 51–60 years, with about 1/3 of cases of both diseases diagnosed in early age range of 31–40 years. Conclusion Significant number of patients presenting with either of the spine disorders at the young age of 31–40 years points to the necessity of introducing methods preventing disorders of the vertebral column at younger age, preferably at school age. PMID:29770333

[Constitutional narrowing of the cervical spinal canal. Radiological and clinical findings].

PubMed

Ritter, G; Rittmeyer, K; Hopf, H C

1975-02-21

A constitutional narrowing of the cervical spinal canal was seen in 31 patients with neurological disorders. The ratio of the inner diameter of the spinal canal to the diameter of the vertebral body was smaller than 1 (normal greater than 1). Clinical signs were observed from 45 years upwards where reactivedegenerative changes cause additional narrowing. The majority of patients were male, predominantly heavy manual labourers. There is often a trauma preceding. On myelography multilocular deformations of the spinal subarachnoid space and nerve roots are seen. On the mechanical narrowing of the spinal canal a vascular factor supervenes, caused by exostoses, intervertebral disc protrusions, and fibrosing processes. Clinically a chronic progressive spinal transection syndrome (cervical myelopathy) dominates besides a multilocular root involvement. Posterior column sensibility is predominantly lost. Pain in the extemities and the cervical column is an early symptom. Non-specific CSF changes occur frequently. In case of root involvement the electromyogram is pathological. The prognosis is bad. Operation can only remove reactive processes but not the constitutional anomaly.

Giant Comets, Evolution and Civilization

DTIC Science & Technology

1998-01-01

Depending on the assumed scale height of dark matter in the Galactic disc, the periodic modulations may easily attain amplitudes of 3:1 or more...an in-plane density pz - 0.18 M® p- 3 for the ambient Galactic disc [18], im- 4 plying the presence of dark matter in the disc with an extreme...poles and equator, broadly in accordance with the Galactic tide [19] complemented by individ- ual (stellar and dark matter ) perturbers. In addition

Safety of intraoperative electrophysiological monitoring (TES and EMG) for spinal and cranial lesions.

PubMed

Gazzeri, Roberto; Faiola, Andrea; Neroni, Massimiliano; Fiore, Claudio; Callovini, Giorgio; Pischedda, Mauro; Galarza, Marcelo

2013-09-01

Intraoperative motor evoked potentials (MEP) and electromyography (EMG) monitoring in patients with spinal and cranial lesions is a valuable tool for prevention of postoperative motor deficits. The purpose of this study was to determine whether electrophysiological monitoring during skull base, spinal cord, and spinal surgery might be useful for predicting postoperative motor deterioration. From January 2012 to March 2013, thirty-three consecutive patients were studied using intraoperative monitoring (Nuvasive NV-M5 System) to check the integrity of brainstem, spinal cord, and nerve roots, recording transcranial motor evoked potentials (TcMEPs) and electromyography. Changes in MEPs and EMGs were related to postoperative deficits. Preoperative diagnosis included skull base and brainstem lesions (6 patients), spinal tumors (11 patients), spinal deformity (16 cases). Using TcMEPs and EMG is a practicable and safe method. MEPs are useful in any surgery in which the brainstem and spinal cord are at risk. EMG stimulation helps to identify an optimal trans-psoas entry point for an extreme lateral lumbar interbody fusion (XLIF) approach to protect against potential nerve injury. This neural navigation technique via a surgeon-interpreted interface assists the surgical team in safely removing lesions and accessing the intervertebral disc space for minimally invasive spinal procedures.

The GALAH survey: properties of the Galactic disc(s) in the solar neighbourhood

NASA Astrophysics Data System (ADS)

Duong, L.; Freeman, K. C.; Asplund, M.; Casagrande, L.; Buder, S.; Lind, K.; Ness, M.; Bland-Hawthorn, J.; De Silva, G. M.; D'Orazi, V.; Kos, J.; Lewis, G. F.; Lin, J.; Martell, S. L.; Schlesinger, K.; Sharma, S.; Simpson, J. D.; Zucker, D. B.; Zwitter, T.; Anguiano, B.; Da Costa, G. S.; Hyde, E.; Horner, J.; Kafle, P. R.; Nataf, D. M.; Reid, W.; Stello, D.; Ting, Y.-S.; Wyse, R. F. G.

2018-06-01

Using data from the GALAH pilot survey, we determine properties of the Galactic thin and thick discs near the solar neighbourhood. The data cover a small range of Galactocentric radius (7.9 ≲ R_GC ≲ 9.5 kpc), but extend up to 4 kpc in height from the Galactic plane, and several kpc in the direction of Galactic anti-rotation (at longitude 260° ≤ ℓ ≤ 280°). This allows us to reliably measure the vertical density and abundance profiles of the chemically and kinematically defined `thick' and `thin' discs of the Galaxy. The thin disc (low-α population) exhibits a steep negative vertical metallicity gradient, at d[M/H]/dz = -0.18 ± 0.01 dex kpc-1, which is broadly consistent with previous studies. In contrast, its vertical α-abundance profile is almost flat, with a gradient of d[α/M]/dz = 0.008 ± 0.002 dex kpc-1. The steep vertical metallicity gradient of the low-α population is in agreement with models where radial migration has a major role in the evolution of the thin disc. The thick disc (high-α population) has a weaker vertical metallicity gradient d[M/H]/dz = -0.058 ± 0.003 dex kpc-1. The α-abundance of the thick disc is nearly constant with height, d[α/M]/dz = 0.007 ± 0.002 dex kpc-1. The negative gradient in metallicity and the small gradient in [α/M] indicate that the high-α population experienced a settling phase, but also formed prior to the onset of major Type Ia supernova enrichment. We explore the implications of the distinct α-enrichments and narrow [α/M] range of the sub-populations in the context of thick disc formation.

In vitro and in silico investigations of disc nucleus replacement

PubMed Central

Reitmaier, Sandra; Shirazi-Adl, Aboulfazl; Bashkuev, Maxim; Wilke, Hans-Joachim; Gloria, Antonio; Schmidt, Hendrik

2012-01-01

Currently, numerous hydrogels are under examination as potential nucleus replacements. The clinical success, however, depends on how well the mechanical function of the host structure is restored. This study aimed to evaluate the extent to and mechanisms by which surgery for nucleus replacements influence the mechanical behaviour of the disc. The effects of an annulus defect with and without nucleus replacement on disc height and nucleus pressure were measured using 24 ovine motion segments. The following cases were considered: intact; annulus incision repaired by suture and glue; annulus incision with removal and re-implantation of nucleus tissue repaired by suture and glue or plug. To identify the likely mechanisms observed in vitro, a finite-element model of a human disc (L4–L5) was employed. Both studies were subjected to physiological cycles of compression and recovery. A repaired annulus defect did not influence the disc behaviour in vitro, whereas additional nucleus removal and replacement substantially decreased disc stiffness and nucleus pressure. Model predictions demonstrated the substantial effects of reductions in replaced nucleus water content, bulk modulus and osmotic potential on disc height loss and pressure, similar to measurements. In these events, the compression load transfer in the disc markedly altered by substantially increasing the load on the annulus when compared with the nucleus. The success of hydrogels for nucleus replacements is not only dependent on the implant material itself but also on the restoration of the environment perturbed during surgery. The substantial effects on the disc response of disruptions owing to nucleus replacements can be simulated by reduced nucleus water content, elastic modulus and osmotic potential. PMID:22337630

Endogenous-lesioned cervical disc herniation: a retrospective review of 9 cases.

PubMed

Zhang, Zifeng; Bai, Yushu; Hou, Tiesheng

2011-01-01

The purpose of this study was to analyze the pathogenic mechanisms, clinical presentation, and surgical treatment of cervical disc herniation without external trauma. Between 2004 and 2008, 9 patients with cervical disc herniation and no antecedent history of trauma were diagnosed with cervical disc herniation and underwent surgical decompression. Pathogenic mechanisms, clinical presentation, surgical treatment, and prognosis were analyzed retrospectively. In 6 patients, herniation resulted from excessive neck motion rather than from external trauma. An injury from this source is termed an endogenous-lesioned injury. Patients exhibited neurologic symptoms of compression of the cervical spinal cord or nerve roots. In the other 3 patients, no clear cause for the herniation was recorded, but all patients had a desk job with long periods of head-down neck flexion posture. After surgery, all patients experienced a reduction in their symptoms and an uneventful recovery. Cervical disc herniation can occur in the absence of trauma. Surgical decompression is effective at reducing symptoms in these patients, similar to other patients with cervical disc herniation. Surgical treatment may be considered for this disorder when the herniation becomes symptomatic.

Analysis of radiological parameters associated with decreased fractional anisotropy values on diffusion tensor imaging in patients with lumbar spinal stenosis.

PubMed

Wang, Xiandi; Wang, Hongli; Sun, Chi; Zhou, Shuyi; Meng, Tao; Lv, Feizhou; Ma, Xiaosheng; Xia, Xinlei; Jiang, Jianyuan

2018-04-26

Previous studies have indicated that decreased fractional anisotropy (FA) values on diffusion tensor imaging (DTI) are well correlated with the symptoms of nerve root compression. The aim of our study is to determine primary radiological parameters associated with decreased FA values in patients with lumbar spinal stenosis involving single L5 nerve root. Patients confirmed with single L5 nerve root compression by transforaminal nerve root blocks were included in this study. FA values of L5 nerve roots on both symptomatic and asymptomatic side were obtained. Conventional radiological parameters, such as disc height, degenerative scoliosis, dural sac cross-sectional area (DSCSA), foraminal height (FH), hypertrophic facet joint degeneration (HFJD), sagittal rotation (SR), sedimentation sign, sagittal translation and traction spur were measured. Correlation and regression analyses were performed between the radiological parameters and FA values of the symptomatic L5 nerve roots. A predictive regression equation was established. Twenty-one patients were included in this study. FA values were significantly lower at the symptomatic side comparing to the asymptomatic side (0.263 ± 0.069 vs. 0.334 ± 0.080, P = 0.038). DSCSA, FH, HFJD, and SR were significantly correlated with the decreased FA values, with r = 0.518, 0.443, 0.472 and - 0.910, respectively (P < 0.05). DSCSA and SR were found to be the primary radiological parameters related to the decreased FA values, and the regression equation is FA = - 0.012 × SR + 0.002 × DSCSA. DSCSA and SR were primary contributors to decreased FA values in LSS patients involving single L5 nerve root, indicating that central canal decompression and segmental stability should be the first considerations in preoperative planning of these patients. These slides can be retrieved under Electronic Supplementary Material.

Cervical Spinal Injury from Repeated Exposures to Sustained Acceleration.

DTIC Science & Technology

1999-02-01

68 13 9 58 (64) 45 (59) n.s. Mean 1. . . ... 68 57 2. . . . 10 ..3. . . 22 . 4. 53 33 height (0-2); and, (6) foraminal ...height was graded 0-2; 0 meant no or < 25% reduction, 1 was 25-50% reduction and 2 meant >50% reduction. • Foraminal stenosis due to degenerative...found. In grade 0 no foraminal stenosis was found. Each spinal evaluation criterion (shown above) for each experimental group was compared between

Biomechanical comparison of a two-level Maverick disc replacement with a hybrid one-level disc replacement and one-level anterior lumbar interbody fusion.

PubMed

Erkan, Serkan; Rivera, Yamil; Wu, Chunhui; Mehbod, Amir A; Transfeldt, Ensor E

2009-10-01

Multilevel lumbar disc disease (MLDD) is a common finding in many patients. Surgical solutions for MLDD include fusion or disc replacement. The hybrid model, combining fusion and disc replacement, is a potential alternative for patients who require surgical intervention at both L5-S1 and L4-L5. The indications for this hybrid model could be posterior element insufficiency, severe facet pathology, calcified ligamentum flavum, and subarticular disease confirming spinal stenosis at L5-S1 level, or previous fusion surgery at L5-S1 and new symptomatic pathology at L4-L5. Biomechanical data of the hybrid model with the Maverick disc and anterior fusion are not available in the literature. To compare the biomechanical properties of a two-level Maverick disc replacement at L4-L5, L5-S1, and a hybrid model consisting of an L4-L5 Maverick disc replacement with an L5-S1 anterior lumbar interbody fusion using multidirectional flexibility test. An in vitro human cadaveric biomechanical study. Six fresh human cadaveric lumbar specimens (L4-S1) were subjected to unconstrained load in axial torsion (AT), lateral bending (LB), flexion (F), extension (E), and flexion-extension (FE) using multidirectional flexibility test. Four surgical treatments-intact, one-level Maverick at L5-S1, two-level Maverick between L4 and S1, and the hybrid model (anterior fusion at L5-S1 and Maverick at L4-L5) were tested in sequential order. The range of motion of each treatment was calculated. The Maverick disc replacement slightly reduced intact motion in AT and LB at both levels. The total FE motion was similar to the intact motion. However, the E motion is significantly increased (approximately 50% higher) and F motion is significantly decreased (30%-50% lower). The anterior fusion using a cage and anterior plate significantly reduced spinal motion compared with the condition (p<.05). No significant differences were found between two-level Maverick disc prosthesis and the hybrid model in terms of all motion types at L4-L5 level (p>.05). The Maverick disc preserved total motion but altered the motion pattern of the intact condition. This result is similar to unconstrained devices such as Charité. The motion at L4-L5 of the hybrid model is similar to that of two-level Maverick disc replacement. The fusion procedure using an anterior plate significantly reduced intact motion. Clinical studies are recommended to validate the efficacy of the hybrid model.

Immediate changes in spinal height and pain after aquatic vertical traction in patients with persistent low back symptoms: a crossover clinical trial.

PubMed

Simmerman, Susanne M; Sizer, Phillip S; Dedrick, Gregory S; Apte, Gail G; Brismée, Jean-Michel

2011-05-01

To investigate the effect of aquatic vertical traction on spinal height, pain intensity, and centralization response compared with a land-based supine flexion position for patients with low back pain and signs of nerve root compression. Single-blind, repeated-measures crossover design. Outpatient physical therapy clinic. Ninety-eight subjects were recruited using consecutive sampling, with 28 men and 32 women of a mean ± standard deviation (SD) age of 59.6 ± 11.6 years completing testing. Each subject participated in 2 sessions that consisted of loaded walking for 15 minutes, followed by either 15 minutes of land-based supine position or 15 minutes of aquatic vertical traction. Spinal height change, measured using a commercial stadiometer, was determined after completing loaded walking and after each intervention. The mean ± SD height change of 4.99 ± 2.88 mm after aquatic vertical traction was similar to that of 4.21 ± 2.53 mm after the land-based supine flexion (P = .0969). Paired t-test indicated that both interventions resulted in significant increased height (P < .0001). Decreases in pain after aquatic intervention (2.7 ± 2.1 cm) were significantly greater than decreases after land intervention (1.7 ± 1.7 cm; P = .0034), and centralization of symptoms was more pronounced after aquatic vertical suspension compared with the supine land-based flexion condition (P < .0001). A significant correlation between height change and both pain reduction (r = 0.39; P = .001) and centralization (r = 0.29; P = .013) was observed for the aquatic intervention only. Although both the aquatic and land interventions produced significant increases in overall spinal height, the aquatic intervention produced greater pain relief and centralization response in subjects with low back pain and signs of nerve root compression. Copyright © 2011 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Temporary Segmental Distraction in a Dog with Degenerative Lumbosacral Stenosis.

PubMed

Willems, Nicole; Kersten, Roel F M R; van Gaalen, Steven M; Öner, F Cumhur; Strijkers, Gustav J; Veraa, Stefanie; Beukers, Martijn; Tryfonidou, Marianna A; Meij, Björn P

2018-06-02

 Degenerative lumbosacral stenosis (DLSS) is characterized by intervertebral disc degeneration and causes lower back pain in dogs. Temporary distraction in rabbit models with induced intervertebral disc degeneration showed signs of intervertebral disc repair. In the present study, we assessed safety and efficacy of temporary segmental distraction in a dog with clinical signs of DLSS.  Distraction of the lumbosacral junction by pedicle screw-rod fixation was applied in a 5-year-old Greyhound with DLSS and evaluated by radiography, magnetic resonance imaging, and force plate analysis before and after distraction.  Safe distraction of the lumbosacral junction was demonstrated, with improvement of clinical signs after removal of the distraction device. Signal intensity of the intervertebral disc showed no changes over time. T2 value was highest directly after removal of the distraction device but decreased by 10% of the preoperative value at 9 months of follow-up. Disc height decreased (8%) immediately after removal of the distraction device, but recovered to the initial value. A decrease in the pelvic/thoracic propulsive force during pedicle screw-rod fixation and distraction was demonstrated, which slowly increased by 4% compared with the initial value.  Temporary pedicle screw-rod fixation in combination with distraction in a dog with DLSS was safe, improved clinical signs and retained disc height at 9 months of follow-up. Schattauer GmbH Stuttgart.

Multifocal Aspergillus terreus discospondylitis in two German shepherd dogs.

PubMed

Berry, W L; Leisewitz, A L

1996-12-01

Multifocal fungal (Aspergillus terreus) discospondylitis was diagnosed in 2 German shepherd dogs. In one dog, the aetiology was established by means of fluoroscopic-guided disc aspiration, cytology and culture of disc material and urine. Disseminated aspergillosis was confirmed at necropsy and A. terreus cultured from numerous organs in this dog. The aetiology in the other dog was not established until therapeutic failure forced surgical curettage of disc material from which the fungus was cultured. Ketoconazole therapy failed to effect an improvement, and at necropsy, disease was localised to the spinal column, with A. terreus cultured from the affected discs and associated vertebrae. Immunodeficiency was suspected in both cases. In the case of disseminated disease a reduced lymphocyte blastogenic response was demonstrated. Reduced IgA was shown in both cases. The German shepherd breed seems to be predisposed to Aspergillus infections and IgA deficiency.

The effects of flexion-distraction and drop techniques on disorders and Ferguson’s angle in female patients with lumbar intervertebral disc herniation

PubMed Central

Oh, Hyunju; Lee, Sangyong; Lee, Kwansub; Jeong, Mugeun

2018-01-01

[Purpose] This study examines the effects of the flexion-distraction technique and the drop technique on disorders and on Ferguson’s angle in female patients with lumbar intervertebral disc herniation. [Subjects and Methods] Thirty female patients with lumbar intervertebral disc herniation were divided into an experimental group (n=15) treated with flexion-distraction and drop techniques and a control group (n=15) treated with spinal decompression therapy. Both groups were treated three times a week over an eight-week period. [Results] In the comparison of changes within each group after treatment, both groups showed statistically significant decreases in disorders and in Ferguson’s angle. [Conclusion] Flexion-distraction and drop techniques may be an effective intervention to improve disorders and Ferguson’s angle in female patients with lumbar intervertebral disc herniation. PMID:29706701

Biotribological evaluation of artificial disc arthroplasty devices: influence of loading and kinematic patterns during in vitro wear simulation.

PubMed

Grupp, Thomas M; Yue, James J; Garcia, Rolando; Basson, Janet; Schwiesau, Jens; Fritz, Bernhard; Blömer, Wilhelm

2009-01-01

Wear simulation is an essential pre-clinical method to predict the mid- and long-term clinical wear behavior of newly introduced devices for total disc arthroplasty. The main requirement of a suitable method for spinal wear simulation has to be the ability to distinguish between design concepts and allow for a direct comparison of predicate devices. The objective of our study was to investigate the influence of loading and kinematic patterns based on two different protocols for spinal wear simulation (ISO/FDIS 18192-1 (2006) and ASTM F2423-05). In vitro wear simulation was performed with six activ L lumbar artificial disc devices (Aesculap Tuttlingen, Germany). The applied kinematic pattern of movement was multidirectional for ISO (elliptic track) and unidirectional with a curvilinear shape for ASTM. Testing was done for 10 million cycles in the ISO loading mode and afterwards with the same specimens for 5 million cycles according to the ASTM protocol with a customized six-station servohydraulic spinal wear simulator (EndoLab Thansau, Germany). Gravimetrical and geometrical wear assessment, a slide track analysis correlated to an optical surface characterization, and an estimation of particle size and morphology were performed. The gravimetric wear rate for the first 10 million cycles was ISO(initial) = 2.7 +/- 0.3 mg/million cycles. During the ASTM test period (10-15 million cycles) a gravimetric wear rate of 0.14 +/- 0.06 mg/million cycles was estimated. The wear rates between the ISO and ASTM driven simulations differ substantially (approximately 20-fold) and statistical analysis demonstrates a significant difference (p < 0.001) between the test groups. The main explanation of divergency between ISO and ASTM driven wear simulations is the multidirectional pattern of movement described in the ISO document resulting in a cross-shear stress on the polyethylene material. Due to previous retrieval observations, it seems to be very unlikely that a lumbar artificial disc is loaded with a linear wear path.Testing according to ASTM F2423-05 with pure unidirectional motion does not reflect the kinematics of TDA patients' daily activities. Based on our findings it seems to be more reliable to predict the clinical wear behavior of an artificial disc replacement using the ISO/FDIS 18192-1 method.

Biotribological evaluation of artificial disc arthroplasty devices: influence of loading and kinematic patterns during in vitro wear simulation

PubMed Central

Yue, James J.; Garcia, Rolando; Basson, Janet; Schwiesau, Jens; Fritz, Bernhard; Blömer, Wilhelm

2008-01-01

Wear simulation is an essential pre-clinical method to predict the mid- and long-term clinical wear behavior of newly introduced devices for total disc arthroplasty. The main requirement of a suitable method for spinal wear simulation has to be the ability to distinguish between design concepts and allow for a direct comparison of predicate devices. The objective of our study was to investigate the influence of loading and kinematic patterns based on two different protocols for spinal wear simulation (ISO/FDIS 18192-1 (2006) and ASTM F2423-05). In vitro wear simulation was performed with six activ® L lumbar artificial disc devices (Aesculap Tuttlingen, Germany). The applied kinematic pattern of movement was multidirectional for ISO (elliptic track) and unidirectional with a curvilinear shape for ASTM. Testing was done for 10 million cycles in the ISO loading mode and afterwards with the same specimens for 5 million cycles according to the ASTM protocol with a customized six-station servohydraulic spinal wear simulator (EndoLab Thansau, Germany). Gravimetrical and geometrical wear assessment, a slide track analysis correlated to an optical surface characterization, and an estimation of particle size and morphology were performed. The gravimetric wear rate for the first 10 million cycles was ISOinitial = 2.7 ± 0.3 mg/million cycles. During the ASTM test period (10–15 million cycles) a gravimetric wear rate of 0.14 ± 0.06 mg/million cycles was estimated. The wear rates between the ISO and ASTM driven simulations differ substantially (approximately 20-fold) and statistical analysis demonstrates a significant difference (p < 0.001) between the test groups. The main explanation of divergency between ISO and ASTM driven wear simulations is the multidirectional pattern of movement described in the ISO document resulting in a cross-shear stress on the polyethylene material. Due to previous retrieval observations, it seems to be very unlikely that a lumbar artificial disc is loaded with a linear wear path.Testing according to ASTM F2423-05 with pure unidirectional motion does not reflect the kinematics of TDA patients‘ daily activities. Based on our findings it seems to be more reliable to predict the clinical wear behavior of an artificial disc replacement using the ISO/FDIS 18192-1 method. PMID:19050942

49 CFR 399.207 - Truck and truck-tractor access requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... requirements: (1) Vertical height. All measurements of vertical height shall be made from ground level with the... vertical height of the first step shall be no more than 609 millimeters (24 inches) from ground level. (3... requirement. The step need not retain the disc at rest. (5) Step strength. Each step must withstand a vertical...

49 CFR 399.207 - Truck and truck-tractor access requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... requirements: (1) Vertical height. All measurements of vertical height shall be made from ground level with the... vertical height of the first step shall be no more than 609 millimeters (24 inches) from ground level. (3... requirement. The step need not retain the disc at rest. (5) Step strength. Each step must withstand a vertical...

49 CFR 399.207 - Truck and truck-tractor access requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... requirements: (1) Vertical height. All measurements of vertical height shall be made from ground level with the... vertical height of the first step shall be no more than 609 millimeters (24 inches) from ground level. (3... requirement. The step need not retain the disc at rest. (5) Step strength. Each step must withstand a vertical...

49 CFR 399.207 - Truck and truck-tractor access requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... requirements: (1) Vertical height. All measurements of vertical height shall be made from ground level with the... vertical height of the first step shall be no more than 609 millimeters (24 inches) from ground level. (3... requirement. The step need not retain the disc at rest. (5) Step strength. Each step must withstand a vertical...

Cerebrospinal fluid leaks following spinal or posterior fossa surgery: use of fat grafts for prevention and repair.

PubMed

Black, P

2000-01-01

Cerebrospinal fluid (CSF) leaks are relatively common following spinal or posterior fossa surgery. A midline dural tear in the spine is readily repaired by direct application of a suture. However, far-lateral or ventral dural tears are problematic. Fat is an ideal sealant because it is impermeable to water. In this paper the author reports his experience with using fat grafts for the prevention or repair of CSF leaks and proposes a technique in which a large sheet of fat, harvested from the patient's subcutaneous layer, is used to cover not only the dural tear(s) but all of the exposed dura and is tucked into the lateral recess. This procedure prevents CSF from seeping around the fat, which may be tacked to the dura with a few sutures. Fibrin glue is spread on the surface of the fat and is further covered with Surgicel or Gelfoam. For ventral dural tears (associated with procedures in which disc material is excised), fat is packed into the disc space to seal off the ventral dural leak. Leaks in the posterior fossa are managed similarly to those in the spine. Dural suture lines, following suboccipital or spinal intradural exploration, are prophylactically protected from CSF leakage in the same manner. With one exception, 27 dural tears noted during 1650 spinal procedures were successfully repaired using this technique. There was one case of postoperative CSF leakage in 150 cases in which intradural exploration for tumor or other lesions was undertaken. Both postoperative CSF leaks were controlled by applying additional skin sutures. The use of a fat graft is recommended as a rapid, effective means of prevention and repair of CSF leaks following posterior fossa and spinal surgery.

Effects of inter-individual lumbar spine geometry variation on load-sharing: Geometrically personalized Finite Element study.

PubMed

Naserkhaki, Sadegh; Jaremko, Jacob L; El-Rich, Marwan

2016-09-06

There is a large, at times contradictory, body of research relating spinal curvature to Low Back Pain (LBP). Mechanical load is considered as important factor in LBP etiology. Geometry of the spinal structures and sagittal curvature of the lumbar spine govern its mechanical behavior. Thus, understanding how inter-individual geometry particularly sagittal curvature variation affects the spinal load-sharing becomes of high importance in LBP assessment. This study calculated and compared kinematics and load-sharing in three ligamentous lumbosacral spines: one hypo-lordotic (Hypo-L) with low lordosis, one normal-lordotic (Norm-L) with normal lordosis, and one hyper-lordotic (Hyper-L) with high lordosis in flexed and extended postures using 3D nonlinear Finite Element (FE) modeling. These postures were simulated by applying Follower Load (FL) combined with flexion or extension moment. The Hypo-L spine demonstrated stiffer behavior in flexion but more flexible response to extension compared to the Norm-L spine. The excessive lordosis stiffened response of the Hyper-L spine to extension but did not affect its resistance to flexion compared to the Norm-L spine. Despite the different resisting actions of the posterior ligaments to flexion moment, the increase of disc compression was similar in all the spines leading to similar load-sharing. However, resistance of the facet joints to extension was more important in the Norm- and Hyper-L spines which reduced the disc compression. The spinal curvature strongly influenced the magnitude and location of load on the spinal components and also altered the kinematics and load-sharing particularly in extension. Consideration of the subject-specific geometry and sagittal curvature should be an integral part of mechanical analysis of the lumbar spine. Copyright © 2016 Elsevier Ltd. All rights reserved.

Expression of growth differentiation factor 6 in the human developing fetal spine retreats from vertebral ossifying regions and is restricted to cartilaginous tissues.

PubMed

Wei, Aiqun; Shen, Bojiang; Williams, Lisa A; Bhargav, Divya; Gulati, Twishi; Fang, Zhimin; Pathmanandavel, Sarennya; Diwan, Ashish D

2016-02-01

During embryogenesis vertebral segmentation is initiated by sclerotomal cell migration and condensation around the notochord, forming anlagen of vertebral bodies and intervertebral discs. The factors that govern the segmentation are not clear. Previous research demonstrated that mutations in growth differentiation factor 6 resulted in congenital vertebral fusion, suggesting this factor plays a role in development of vertebral column. In this study, we detected expression and localization of growth differentiation factor 6 in human fetal spinal column, especially in the period of early ossification of vertebrae and the developing intervertebral discs. The extracellular matrix proteins were also examined. Results showed that high levels of growth differentiation factor 6 were expressed in the nucleus pulposus of intervertebral discs and the hypertrophic chondrocytes adjacent to the ossification centre in vertebral bodies, where strong expression of proteoglycan and collagens was also detected. As fetal age increased, the expression of growth differentiation factor 6 was decreased correspondingly with the progress of ossification in vertebral bodies and restricted to cartilaginous regions. This expression pattern and the genetic link to vertebral fusion suggest that growth differentiation factor 6 may play an important role in suppression of ossification to ensure proper vertebral segmentation during spinal development. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Bertolotti's syndrome revisited. Transitional vertebrae of the lumbar spine.

PubMed

Elster, A D

1989-12-01

Bertolotti's syndrome refers to the association of back pain with lumbosacral transitional vertebrae. Such vertebrae were observed in 140 of 2,000 adults with back pain over a 4-year period of study. Each patient had radiographic evaluation of the lumbar spine by plain films as well as a sectional imaging modality (magnetic resonance [MR] or computed tomography [CT]). The overall incidence of structural pathology (eg, spinal stenosis and disc protrusion) detected by CT or MR was not apparently higher in patients with transitional vertebrae, but the distribution of these lesions was significantly different. Disc bulge or herniation, when it occurred, was nearly nine times more common at the interspace immediately above the transitional vertebra than at any other level. Spinal stenosis and nerve root canal stenosis were more common at or near the interspace above the transitional vertebra than at any other level. Degenerative change at the articulation between the transverse process of the transitional vertebra and the pelvis was an uncommon occurrence; when seen there was no significant correlation with the reported side of pain. It is postulated that hypermobility and altered stresses become concentrated in the spine at the level immediately above a lumbar transitional vertebra. Accelerated disc and facet joint degeneration at this level may then result.

Multilevel magnetic resonance imaging analysis of multifidus-longissimus cleavage planes in the lumbar spine and potential clinical applications to Wiltse's paraspinal approach.

PubMed

Palmer, Daniel Kyle; Allen, Jonathan L; Williams, Paul A; Voss, Ashley Elizabeth; Jadhav, Vikram; Wu, David S; Cheng, Wayne K

2011-07-15

Retrospective magnetic resonance imaging (MRI)-based study. Our goal was to develop Wiltse's paraspinal surgical approach by determining the precise anatomic locations of the intermuscular cleavage planes formed by the multifidus and longissimus muscles. The primary objective was to measure the distances between the midline and the intermuscular planes, bilaterally, on MRI scans at each of the five disc levels between L1 and S1. Secondary objectives included identifying the existence of any correlations between patient demographics and the measured outcomes. In 1968, Wiltse described an approach to the spine using the natural cleavage plane of the multifidus and longissimus muscles as an entry to the posterior spinal elements. The small direct incisions lessened bleeding, tissue violation, and muscle retraction, which popularized Wiltse's approach among surgeons. A detailed description of the locations of the intermuscular cleavage planes at each lumbar disc level, however, is not available. MRI scans of 200 patients taken during routine care (2007-2009) were retrospectively reviewed to gather measurements of the distances from the intermuscular cleavage planes to the midline, bilaterally, at each disc level from L1 to S1. Age, sex, and BMI (body mass index) were obtained to determine correlations. Mean measurements significantly differed between all disc levels. At L5-S1, the mean distance was 37.8 mm; at L4-L5, 28.4 mm; at L3-L4, 16.2 mm; at L2-L3, 10.4 mm; and at L1-L2, 7.9 mm. The mean female distances were significantly greater than males (2 mm) on both sides of L5-S1 only. No correlation was discovered between BMI, age, height (N = 50), or weight (N = 50) with respect to measured distances. In the absence of any significant clinical correlation between patient demographics and the entry site in Wiltse's approach, the spine surgeon may use distances described in this paper to apply to a broad base of spine patients regardless of BMI, sex, or age.

[Virtual clinical diagnosis support system of degenerative stenosis of the lumbar spinal canal].

PubMed

Shevelev, I N; Konovalov, N A; Cherkashov, A M; Molodchenkov, A A; Sharamko, T G; Asiutin, D S; Nazarenko, A G

2013-01-01

The aim of the study was to develop a virtual clinical diagnostic support system of degenerative lumbar spinal stenosis on database of spine registry. Choice of criteria's for diagnostic system was made on symptom analysis of 298 patients with lumbar spinal stenosis. Also was analysed a group of patient with disc herniation's for sensitivity and specify assessment of developed diagnostic support system. Represented clinical diagnostic support system allows identifying patients with degenerative lumbar spinal stenosis on stage of patient's primary visit. System sensitivity and specify are 90 and 71% respectively. "Online" mode of diagnostic system in structure of spine registry provides maximal availability for specialists, regardless of their locations. Development of tools "medicine 2.0" is the actual direction for carrying out further researches with which carrying out the centralized baea collection by means of specialized registers helps.

Assessment of block height for satisfactory spinal anaesthesia for caesarean section.

PubMed

Ousley, R; Egan, C; Dowling, K; Cyna, A M

2012-12-01

We investigated block heights that anaesthetists considered adequate for caesarean section to proceed under spinal anaesthesia. During 3 months, 15 obstetric anaesthetists recorded block height to touch, pinprick or cold when spinal anaesthesia was considered satisfactory for caesarean section to proceed. Median (IQR [range]) block height for touch, pinprick, first cold and icy were: T10 (T7-T12 [T3-L1]); T5 (T4-T6 [C7-L1]); T5 (T4-T6 [C7-L1]); and T3 (T2-T4 [C7-L1]), respectively. Modalities were significantly correlated for: touch and cold, p = 0.0001; touch and icy, p = 0.0007; touch and pinprick, p = 0.0018; cold and icy, p < 0.0001; cold and pinprick, p = 0.0001; icy and pinprick, p < 0.0001. Pairwise comparisons showed differences between all modalities (p < 0.001) apart from pinprick and first cold (p = 0.94). All women had satisfactory anaesthesia despite 76 (81%) having a block to touch below T6. Single modality assessment of block height, particularly using touch, may erroneously indicate inadequate anaesthesia for caesarean section. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.

A comparative study of American football helmet removal techniques using a cadaveric model of cervical spine injury.

PubMed

Anderson, Andrew; Tollefson, Brian; Cohen, Rob; Johnson, Jeremy; Summers, Richard L

2011-04-01

American football is the source of a significant number of cervical spine injuries. Removal of the helmets from these individuals is often problematic and presents a potential for exacerbation of the injury. There are two widely recognized helmet removal techniques that are currently in practice. In this study, the two methods are compared for cervical movement and potential for cord injury to determine their relative efficiency and clinical utility. A single cadaver with a simulated cervical injury was used to compare the National Athletic Trainers' Association (NATA) and cast saw techniques of helmet removal. Directed lateral fluoroscopy was used to measure the relative changes in angulation, translation, distraction, and space available to the spinal cord during helmet removal using the two techniques as performed by medical personnel with limited training in the methods. By radiologists' reports, there were no detectable changes in disc height, translation or space available for the spinal cord during helmet removal with either of the studied techniques. Operators noted that the noise of the cast saw would probably be significantly uncomfortable for any live subject inside of a helmet. Both the NATA and cast saw methods appear effective for the safe removal of a football helmet and with little risk of further injury to the cervical spine. Considering the simplicity and efficiency of the NATA helmet removal technique, the authors conclude that the NATA technique should be the preferred helmet removal method.

The adult spinal cord injury without radiographic abnormalities syndrome: magnetic resonance imaging and clinical findings in adults with spinal cord injuries having normal radiographs and computed tomography studies.

PubMed

Kasimatis, Georgios B; Panagiotopoulos, Elias; Megas, Panagiotis; Matzaroglou, Charalambos; Gliatis, John; Tyllianakis, Minos; Lambiris, Elias

2008-07-01

Spinal cord injury without radiographic abnormalities (SCIWORA) is thought to represent mostly a pediatric entity and its incidence in adults is rather underreported. Some authors have also proposed the term spinal cord injury without radiologic evidence of trauma, as more precisely describing the condition of adult SCIWORA in the setting of cervical spondylosis. The purpose of the present study was to evaluate adult patients with cervical spine injuries and radiological-clinical examination discrepancy, and to discuss their characteristics and current management. During a 16-year period, 166 patients with a cervical spine injury were admitted in our institution (Level I trauma center). Upper cervical spine injuries (occiput to C2, 54 patients) were treated mainly by a Halo vest, whereas lower cervical spine injuries (C3-T1, 112 patients) were treated surgically either with an anterior, or posterior procedure, or both. Seven of these 166 patients (4.2%) had a radiologic-clinical mismatch, i.e., they presented with frank spinal cord injury with no signs of trauma, and were included in the study. Magnetic resonance imaging was available for 6 of 7 patients, showing intramedullary signal changes in 5 of 6 patients with varying degrees of compression from the disc and/or the ligamentum flavum, whereas the remaining patient had only traumatic herniation of the intervertebral disc and ligamentum flavum bulging. Follow-up period was 6.4 years on average (1-10 years). This retrospective chart review provides information on adult patients with cervical spinal cord injuries whose radiographs and computed tomography studies were normal. It furthers reinforces the pathologic background of SCIWORA in an adult population, when evaluated by magnetic resonance imaging. Particularly for patients with cervical spondylosis, special attention should be paid with regard to vascular compromise by predisposing factors such as smoking or vascular disease, since they probably contribute in the development of SCIWORA.

Discrepancies in anthropometric parameters between different models affect intervertebral rotations when loading finite element models with muscle forces from inverse static analyses.

PubMed

Zhu, Rui; Rohlmann, Antonius

2014-06-01

In only a few published finite element (FE) simulations have muscle forces been applied to the spine. Recently, muscle forces determined using an inverse static (IS) model of the spine were transferred to a spinal FE model, and the effect of methodical parameters was investigated. However, the sensitivity of anthropometric differences between FE and IS models, such as body height and spinal orientation, was not considered. The aim of this sensitivity study was to determine the influence of those differences on the intervertebral rotations (IVRs) following the transfer of muscle forces from an IS model to a FE model. Muscle forces were estimated for 20° flexion and 10° extension of the upper body using an inverse static musculoskeletal model. These forces were subsequently transferred to a nonlinear FE model of the spino-pelvic complex, which includes 243 muscle fascicles. Deviations of body height (±10 cm), spinal orientation in the sagittal plane (±10°), and body weight (±10 kg) between both models were intentionally generated, and their influences on IVRs were determined. The changes in each factor relative to their corresponding reference value of the IS model were calculated. Deviations in body height, spinal orientation, and body weight resulted in maximum changes in the IVR of 19.2%, 26% and 4.2%, respectively, relative to T12-S1 IVR. When transferring muscle forces from an IS to a FE model, it is crucial that both models have the same spinal orientation and height. Additionally, the body weight should be equal in both models.

Reduction in nerve root compression by the nucleus pulposus after Feng's Spinal Manipulation☆

PubMed Central

Feng, Yu; Gao, Yan; Yang, Wendong; Feng, Tianyou

2013-01-01

Ninety-four patients with lumbar intervertebral disc herniation were enrolled in this study. Of these, 48 were treated with Feng's Spinal Manipulation, hot fomentation, and bed rest (treatment group). The remaining 46 patients were treated with hot fomentation and bed rest only (control group). After 3 weeks of treatment, clinical parameters including the angle of straight-leg raising, visual analogue scale pain score, and Japanese Orthopaedic Association score for low back pain were improved. The treatment group had significantly better improvement in scores than the control group. Magnetic resonance myelography three-dimensional reconstruction imaging of the vertebral canal demonstrated that filling of the compressed nerve root sleeve with cerebrospinal fluid increased significantly in the treatment group. The diameter of the nerve root sleeve was significantly larger in the treatment group than in the control group. However, the sagittal diameter index of the herniated nucleus pulposus and the angle between the nerve root sleeve and the thecal sac did not change significantly in either the treatment or control groups. The effectiveness of Feng's Spinal Manipulation for the treatment of symptoms associated with lumbar intervertebral disc herniation may be attributable to the relief of nerve root compression, without affecting the herniated nucleus pulposus or changing the morphology or position of the nerve root. PMID:25206408

Urinary 3-hydroxypropyl mercapturic acid (3-HPMA) concentrations in dogs with acute spinal cord injury due to intervertebral disc herniation.

PubMed

Sangster, A M; Zheng, L; Bentley, R T; Shi, R; Packer, R A

2017-01-01

The aim of this study was to investigate urinary 3-hydroxypropyl mercapturic acid (3-HPMA), a metabolite of acrolein, as a novel biomarker in acute spinal cord injury (ASCI) due to intervertebral disc herniation in dogs. Urine from 10 client-owned dogs with ASCI collected at presentation and 10 control dogs was analyzed for 3-HPMA. The median urinary 3-HPMA concentration in ASCI dogs was significantly higher than in control dogs, but was not correlated with the severity of ASCI. The median urinary 3-HPMA concentration in intact dogs was higher than in neutered dogs. Higher urinary 3-HPMA concentrations in dogs after ASCI support a role for acrolein, a cytotoxic by-product of lipid peroxidation, in canine ASCI. Urinary 3-HPMA could be used as a biomarker in future clinical trials to measure the effect of therapeutic intervention of reducing acrolein after ASCI. Copyright © 2016. Published by Elsevier Ltd.

[Neurosurgical treatment of complications of intra-disk injections of triamcinolone hexacetonide. Value of a radio-clinical classification].

PubMed

Privat, J M; Finiels, P J

1997-01-01

Epidural granulomas following intra-discal injection of triamcinolone hexacetonide are a well-known complication of this procedure, which is still encountered, even if its utilization was discontinued several years ago. According to the results of their experience, the authors propose a new radio-clinical grading system: grade I: disc calcification with aspect of "sub-ligamentar hernia" on CT scan; grade II: ascendant or descendant retrosomatic migration of distal content; grade III: pseudotumoral epidural infiltrate producing progressive narrowing of the spinal canal with neurological disturbance. Surgical indications in these cases can be drawn from their evolution: posterior approach can be used, with or without laminectomy, for excision as complete as possible of the involved disc (grades I and II); anterior approach should be preferred in cases of multiples recurrences after medical treatment and failure of classical posterior approach, or in case of necrotico-inflammatory proliferation with narrowing of the spinal canal (grade III).

A case of an 18-year-old male rugby union forward with a C5/C6 central disc herniation

PubMed Central

Broughton, Henare Renata

2009-01-01

The patient was an 18-year-old front row forward rugby player who had a history of episodic neck pain for over 2 years following playing games of rugby. The initial event of April 2005 for which the symptoms manifested was a scrum collapse; he continued playing until a front-on tackle occurred when the symptoms dictated that he leave the field and be taken to the local hospital. A diagnosis of a cervical sprain was made and conservative management ensued. During the selections held on January 2008, a medical assessment was made and an MRI found that he had a central disc herniation at C5/C6. He was referred to a spinal orthopaedic surgeon for further treatment. The risks to cervical spinal injuries are illustrated in this case, in a scrum and in the tackle. The prevention of such an injury is discussed. PMID:21686741

Intradiscal pressure study of percutaneous disc decompression with nucleoplasty in human cadavers.

PubMed

Chen, Yung C; Lee, Sang-heon; Chen, Darwin

2003-04-01

Intradiscal pressure was measured after percutaneous disc decompression by nucleoplasty in human cadavers with different degrees of disc degeneration. To assess intradiscal pressure change after disc decompression, and to analyze the influence of degeneration on the intradiscal pressure change. Partial removal of the nucleus has been shown to decompress herniated discs, relieving pressure on nerve roots and, in some cases, offering relief from disc pain. Nucleoplasty, a new minimally invasive procedure using patented Coblation technology, combines coagulation and ablation for partial removal of the nucleus. Coblated channels remove the tissue volume and may decrease the disc pressure. Three fresh human cadaver spinal specimens (T8-L5; age, 54-84 years; mean age, 70.7 years) were used in this investigation. The intradiscal pressure was measured at three points: before treatment, after each channel was created, and after treatment using a 25-guage 6-inch needle connected to a Merit Medical Systems Intellisystem Inflation Monitor. The needles were calibrated initially to approximately 30 pounds per square inch. For the control, the change in disc pressure was recorded by the same procedure without using Coblation energy. To evaluate the effectiveness of nucleoplasty, disc pressure changes were compared between treatment with and without Coblation energy. Intradiscal pressure was markedly reduced in the younger, healthy disc cadaver. In the older, degenerative disc cadavers, the change in intradiscal pressure after nucleoplasty was very small. There was an inverse correlation between the degree of disc degeneration and the change in intradiscal pressure. Pressure reduction through nucleoplasty is highly dependent on the degree of spine degeneration. Nucleoplasty markedly reduced intradiscal pressure in nondegenerative discs, but had a negligible effect on highly degenerative discs.

Segmental hyperhidrosis as a manifestation of spinal and paraspinal disease.

PubMed

Schulz, V; Ward, D; Moulin, D E

1998-11-01

Segmental hyperhidrosis is an uncommon finding which is usually associated with irritation or infiltration of pre-ganglionic sympathetic fibres or the sympathetic chain. We report two cases of segmental hyperhidrosis with striking clinical features. In one case, a mesothelioma produced ipsilateral simultaneous underactivity and overactivity of sympathetic outflow and in the other case a thoracic central disc herniation was probably responsible for a band of sweating which clearly extended beyond the segmental level of injury. Segmental hyperhidrosis should trigger a search for structural disease in the spinal and paraspinal region.

Association between menopause and lumbar disc degeneration: an MRI study of 1,566 women and 1,382 men.

PubMed

Lou, Chao; Chen, Hongliang; Mei, Liangwei; Yu, Weiyang; Zhu, Kejun; Liu, Feijun; Chen, Zhenzhong; Xiang, Guangheng; Chen, Minjiang; Weng, Qiaoyou; He, Dengwei

2017-10-01

The aim of this study was to revisit and further investigate the association between menopause and disc degeneration in the lumbar spine using a magnetic resonance imaging-based eight-level grading system. This study cohort comprised of 1,566 women and 1,382 age-matched men who were admitted for low back pain from June 2013 to October 2016. Data on age, weight, height, body mass index, age at natural menopause, and years since menopause (YSM) were obtained. Lumbar disc degeneration was assessed using a magnetic resonance imaging-based eight-level grading system. After adjustment for the confounding factors of age, height, and weight, young age-matched men were more susceptible to disc degeneration than premenopausal women (P < 0.05). However, after menopause, postmenopausal women had a significant tendency to develop more severe disc degeneration than their age-matched men (P < 0.05), and also compared with premenopausal and perimenopausal women (P < 0.01). Postmenopausal women were divided into nine subgroups by every 5 YSM. When YSM was less than 15 years, a positive trend was observed between YSM and severity of disc degeneration, respectively, at L1/L2 (r = 0.241), L2/L3 (r = 0.193), L3/L4 (r = 0.191), L4/L5 (r = 0.165), L5/S1 (r = 0.153), and all lumbar discs (r = 0.237) (P < 0.05 or 0.01). The analysis of covariance indicated a significant difference in each disc level (P < 0.05 or 0.01) between every two groups. When YSM was more than 15 years, the significant difference, however, disappeared in each disc level (P > 0.05). Menopause is associated with lumbar disc degeneration. The association occurred in the first 15 YSM, suggesting estrogen deficiency might be a risk factor of disc degeneration of the lumbar spine. Further studies need to be carried out for deciding whether age or menopause plays a more important role in the progression of disc degeneration in the lumbar spine.

Microbiology and Epidemiology of Infectious Spinal Disease

PubMed Central

Jeong, Se-Jin; Youm, Jin-Young; Kim, Hyun-Woo; Ha, Ho-Gyun; Yi, Jin-Seok

2014-01-01

Objective Infectious spinal disease is regarded as an infection by a specific organism that affects the vertebral body, intervertebral disc and adjacent perivertebral soft tissue. Its incidence seems to be increasing as a result of larger proportion of the older patients with chronic debilitating disease, the rise of intravenous drug abuser, and the increase in spinal procedure and surgery. In Korea, studies assessing infectious spinal disease are rare and have not been addressed in recent times. The objectives of this study are to describe the epidemiology of all kind of spinal infectious disease and their clinical and microbiological characteristics as well as to assess the diagnostic methodology and the parameters related to the outcomes. Methods A retrospective study was performed in all infectious spinal disease cases presenting from January 2005 to April 2010 to three tertiary teaching hospitals within a city of 1.5 million in Korea. Patient demographics, risk factors, clinical features, and outcomes were assessed. Risk factors entailed the presence of diabetes, chronic renal failure, liver cirrhosis, immunosuppressants, remote infection, underlying malignancy and previous spinal surgery or procedure. We comparatively analyzed the results between the groups of pyogenic and tuberculous spinal infection. SPSS version 14 statistical software was used to perform the analyses of the data. The threshold for statistical significance was established at p<0.05. Results Ninety-two cases fulfilled the inclusion criteria and were reviewed. Overall, patients of tuberculous spinal infection (TSI) and pyogenic spinal infection (PSI) entailed 20 (21.7%) and 72 (78.3%) cases, respectively. A previous spinal surgery or procedure was the most commonly noted risk factor (39.1%), followed by diabetes (15.2%). The occurrence of both pyogenic and tuberculous spondylitis was predominant in the lumbar spine. Discs are more easily invaded in PSI. At initial presentation, white cell blood count and C-reactive protein levels were higher in PSI compared to TSI (p<0.05). Etiological agents were identified in 53.3%, and the most effective method for identification of etiological agents was tissue culture (50.0%). Staphyococcus aureus was the most commonly isolated infective agent associated with pyogenic spondylitis, followed by E. coli. Surgical treatment was performed in 31.5% of pyogenic spondylitis and in 35.0% of tuberculous spondylitis cases. Conclusion Many previous studies in Korea usually reported that tuberculous spondylitis is the predominant infection. However, in our study, the number of pyogenic infection was 3 times greater than that of tuberculous spinal disease. Etiological agents were identified in a half of all infectious spinal disease. For better outcomes, we should try to identify the causative microorganism before antibiotic therapy and make every effort to improve the result of culture and biopsy. PMID:25289121

Geometric Structure of 3D Spinal Curves: Plane Regions and Connecting Zones

PubMed Central

Berthonnaud, E.; Hilmi, R.; Dimnet, J.

2012-01-01

This paper presents a new study of the geometric structure of 3D spinal curves. The spine is considered as an heterogeneous beam, compound of vertebrae and intervertebral discs. The spine is modeled as a deformable wire along which vertebrae are beads rotating about the wire. 3D spinal curves are compound of plane regions connected together by zones of transition. The 3D spinal curve is uniquely flexed along the plane regions. The angular offsets between adjacent regions are concentrated at level of the middle zones of transition, so illustrating the heterogeneity of the spinal geometric structure. The plane regions along the 3D spinal curve must satisfy two criteria: (i) a criterion of minimum distance between the curve and the regional plane and (ii) a criterion controlling that the curve is continuously plane at the level of the region. The geometric structure of each 3D spinal curve is characterized by the sizes and orientations of regional planes, by the parameters representing flexed regions and by the sizes and functions of zones of transition. Spinal curves of asymptomatic subjects show three plane regions corresponding to spinal curvatures: lumbar, thoracic and cervical curvatures. In some scoliotic spines, four plane regions may be detected. PMID:25031873

Lumbar spine disc height and curvature responses to an axial load generated by a compression device compatible with magnetic resonance imaging

NASA Technical Reports Server (NTRS)

Kimura, S.; Steinbach, G. C.; Watenpaugh, D. E.; Hargens, A. R.

2001-01-01

STUDY DESIGN: Axial load-dependent changes in the lumbar spine of supine healthy volunteers were examined using a compression device compatible with magnetic resonance imaging. OBJECTIVE: To test two hypotheses: Axial loading of 50% body weight from shoulder to feet in supine posture 1) simulates the upright lumbar spine alignment and 2) decreases disc height significantly. SUMMARY OF BACKGROUND DATA: Axial compression on the lumbar spine has significantly narrowed the lumbar dural sac in patients with sciatica, neurogenic claudication or both. METHODS: Using a device compatible with magnetic resonance imaging, the lumbar spine of eight young volunteers, ages 22 to 36 years, was axially compressed with a force equivalent to 50% of body weight, approximating the normal load on the lumbar spine in upright posture. Sagittal lumbar magnetic resonance imaging was performed to measure intervertebral angle and disc height before and during compression. RESULTS: Each intervertebral angle before and during compression was as follows: T12-L1 (-0.8 degrees +/- 2.5 degrees and -1.5 degrees +/- 2.6 degrees ), L1-L2 (0.7 degrees +/- 1.4 degrees and 3.3 degrees +/- 2.9 degrees ), L2-L3 (4.7 degrees +/- 3.5 degrees and 7.3 degrees +/- 6 degrees ), L3-L4 (7.9 degrees +/- 2.4 degrees and 11.1 degrees +/- 4.6 degrees ), L4-L5 (14.3 degrees +/- 3.3 degrees and 14.9 degrees +/- 1.7 degrees ), L5-S1 (25.8 degrees +/- 5.2 degrees and 20.8 degrees +/- 6 degrees ), and L1-S1 (53.4 degrees +/- 11.9 degrees and 57.3 degrees +/- 16.7 degrees ). Negative values reflect kyphosis, and positive values reflect lordosis. A significant difference between values before and during compression was obtained at L3-L4 and L5-S1. There was a significant decrease in disc height only at L4-L5 during compression. CONCLUSIONS: The axial force of 50% body weight in supine posture simulates the upright lumbar spine morphologically. No change in intervertebral angle occurred at L4-L5. However, disc height at L4-L5 decreased significantly during compression.

Surgery or physical activity in the management of sciatica: a systematic review and meta-analysis.

PubMed

Fernandez, Matthew; Ferreira, Manuela L; Refshauge, Kathryn M; Hartvigsen, Jan; Silva, Isabela R C; Maher, Chris G; Koes, Bart W; Ferreira, Paulo H

2016-11-01

Previous reviews have compared surgical to non-surgical management of sciatica, but have overlooked the specific comparison between surgery and physical activity-based interventions. Systematic review using MEDLINE, CINAHL, Embase and PEDro databases was conducted. Randomised controlled trials comparing surgery to physical activity, where patients were experiencing the three most common causes of sciatica-disc herniation, spondylolisthesis and spinal stenosis. Two independent reviewers extracted pain and disability data (converted to a common 0-100 scale) and assessed methodological quality using the PEDro scale. The size of the effects was estimated for each outcome at three different time points, with a random effects model adopted and the GRADE approach used in summary conclusions. Twelve trials were included. In the short term, surgery provided better outcomes than physical activity for disc herniation: disability [WMD -9.00 (95 % CI -13.73, -4.27)], leg pain [WMD -16.01 (95 % CI -23.00, -9.02)] and back pain [WMD -12.44 (95 % CI -17.76, -7.09)]; for spondylolisthesis: disability [WMD -14.60 (95 % CI -17.12, -12.08)], leg pain [WMD -35.00 (95 % CI -39.66, -30.34)] and back pain [WMD -20.00 (95 % CI -24.66, -15.34)] and spinal stenosis: disability [WMD -11.39 (95 % CI -17.31, -5.46)], leg pain [WMD, -27.17 (95 % CI -35.87, -18.46)] and back pain [WMD -20.80 (95 % CI -25.15, -16.44)]. Long-term and greater than 2-year post-randomisation results favoured surgery for spondylolisthesis and stenosis, although the size of the effects reduced with time. For disc herniation, no significant effect was shown for leg and back pain comparing surgery to physical activity. There are indications that surgery is superior to physical activity-based interventions in reducing pain and disability for disc herniation at short-term follow-up only; but high-quality evidence in this field is lacking (GRADE). For spondylolisthesis and spinal stenosis, surgery is superior to physical activity up to greater than 2 years follow-up. Results should guide clinicians and patients when facing the difficult decision of having surgery or engaging in active care interventions. PROSPERO registration number : CRD42013005746.

Reduction of turbulent skin-friction drag by oscillating discs

NASA Astrophysics Data System (ADS)

Wise, Daniel; Ricco, Pierre

2013-11-01

A new drag-reduction method, based on the active technique proposed by Ricco & Hahn (2013), i.e. steadily rotating flush-mounted discs, is studied by DNS. The effect of sinusoidally oscillating discs on the turbulent channel-flow drag is investigated at Reτ = 180 , based on the friction velocity of the stationary-wall case and the half channel height. A parametric investigation on the disc diameter, tip velocity and oscillation period yielded a maximum drag reduction of 18.5%. Regions of net power saved, calculated by considering the power spent to enforce the disc motion against the viscous resistance of the fluid, are found to reach up to 6.5% for low disc tip velocities. Significantly, the characteristic time-scale for the oscillating disc forcing is double that for the steadily rotating discs, representing a further step towards industrial implementation. The oscillating disc forcing, similar to the steadily rotating disc forcing, creates streamwise-elongated structures between the discs. These structures - largely unaffected by the periodic wall forcing and persisting throughout the entire period of the oscillation - are the main contributor to the additional Reynolds stresses term created by the disc forcing, and are important for the drag reduction mechanism.

Locomotor problems of supersonic aviation and astronautics.

PubMed

Remes, P

1989-04-01

Modern high-speed aviation and space flight are fraught with many problems and require a high standard of health and fitness. Those responsible for the health of pilots must appreciate the importance of early diagnosis even before symptoms appear. This is particularly true in terms of preventing spinal injuries where even a single Schmorl's node may make a pilot unfit for high-speed flying. Spinal fractures are frequent during emergency ejection and landing. Helicopter crews are particularly prone to spinal disc degeneration due to vibration. By effective lowering of vibration by changes in the seats, a reduction in such lesions is possible. The osteoporosis and muscle atrophy occurring among astronauts subjected to prolonged weightlessness can be prevented by regular physical exercises.

Hallucinatory Experience: A Personal Account

ERIC Educational Resources Information Center

Goldstein, Alvin G.

1976-01-01

A nonpsychotic experimental psychologist presents a self-report of several highly organized visual, auditory, and kinesthetic hallucinations that occurred during a 3-day period prior to spinal disc surgery. Probable factors related to the production of the phenomena are described and the relation between hallucination and diagnosis is briefly…

Precise Measurement of Velocity Dependent Friction in Rotational Motion

ERIC Educational Resources Information Center

Alam, Junaid; Hassan, Hafsa; Shamim, Sohaib; Mahmood, Waqas; Anwar, Muhammad Sabieh

2011-01-01

Frictional losses are experimentally determined for a uniform circular disc exhibiting rotational motion. The clockwise and anticlockwise rotations of the disc, that result when a hanger tied to a thread is released from a certain height, give rise to vertical oscillations of the hanger as the thread winds and unwinds over a pulley attached to the…

Why do some intervertebral discs degenerate, when others (in the same spine) do not?

PubMed

Adams, Michael A; Lama, Polly; Zehra, Uruj; Dolan, Patricia

2015-03-01

This review suggests why some discs degenerate rather than age normally. Intervertebral discs are avascular pads of fibrocartilage that allow movement between vertebral bodies. Human discs have a low cell density and a limited ability to adapt to mechanical demands. With increasing age, the matrix becomes yellowed, fibrous, and brittle, but if disc structure remains intact, there is little impairment in function, and minimal ingrowth of blood vessels or nerves. Approximately half of old lumbar discs degenerate in the sense of becoming physically disrupted. The posterior annulus and lower lumbar discs are most affected, presumably because they are most heavily loaded. Age and genetic inheritance can weaken discs to such an extent that they are physically disrupted during everyday activities. Damage to the endplate or annulus typically decompresses the nucleus, concentrates stress within the annulus, and allows ingrowth of nerves and blood vessels. Matrix disruption progresses by mechanical and biological means. The site of initial damage leads to two disc degeneration "phenotypes": endplate-driven degeneration is common in the upper lumbar and thoracic spine, and annulus-driven degeneration is common at L4-S1. Discogenic back pain can be initiated by tissue disruption, and amplified by inflammation and infection. Healing is possible in the outer annulus only, where cell density is highest. We conclude that some discs degenerate because they are disrupted by excessive mechanical loading. This can occur without trauma if tissues are weakened by age and genetic inheritance. Moderate mechanical loading, in contrast, strengthens all spinal tissues, including discs. © 2014 Wiley Periodicals, Inc.

A biomechanical study of artificial cervical discs using computer simulation.

PubMed

Ahn, Hyung Soo; DiAngelo, Denis J

2008-04-15

A virtual simulation model of the subaxial cervical spine was used to study the biomechanical effects of various disc prosthesis designs. To study the biomechanics of different design features of cervical disc arthroplasty devices. Disc arthroplasty is an alternative approach to cervical fusion surgery for restoring and maintaining motion at a diseased spinal segment. Different types of cervical disc arthroplasty devices exist and vary based on their placement and degrees of motion offered. A virtual dynamic model of the subaxial cervical spine was used to study 3 different prosthetic disc designs (PDD): (1) PDD-I: The center of rotation of a spherical joint located at the mid C5-C6 disc, (2) PDD-II: The center of rotation of a spherical joint located 6.5 mm below the mid C5-C6 disc, and (3) PDD-III: The center of rotation of a spherical joint in a plane located at the C5-C6 disc level. A constrained spherical joint placed at the disc level (PDD-I) significantly increased facet loads during extension. Lowering the rotational axis of the spherical joint towards the subjacent body (PDD-II) caused a marginal increase in facet loading during flexion, extension, and lateral bending. Lastly, unconstraining the spherical joint to move freely in a plane (PDD-III) minimized facet load build up during all loading modes. The simulation model showed the impact simple design changes may have on cervical disc dynamics. The predicted facet loads calculated from computer model have to be validated in the experimental study.

The evaluation of lumbar paraspinal muscle quantity and quality using the Goutallier classification and lumbar indentation value.

PubMed

Tamai, Koji; Chen, Jessica; Stone, Michael; Arakelyan, Anush; Paholpak, Permsak; Nakamura, Hiroaki; Buser, Zorica; Wang, Jeffrey C

2018-05-01

The cross-sectional area and fat infiltration are accepted as standard parameters for quantitative and qualitative evaluation of muscle degeneration. However, they are time-consuming, which prevents them from being used in a clinical setting. The aim of this study was to analyze the relationship between lumbar muscle degeneration and spinal degenerative disorders, using lumbar indentation value (LIV) as quantitative and Goutallier classification as qualitative measures. This is a retrospective analysis of kinematic magnetic resonance images (kMRI). Two-hundred and thirty patients with kMRIs taken in weight-bearing positions were selected randomly. The LIV and Goutallier classification were evaluated at L4-5. The correlation of these two parameters with patients' age, gender, lumbar lordosis (LL), range of motion, disc degeneration, disc height, and Modic change were analyzed. There was no significant trend of LIV among the different grades of Goutallier classification (p = 0.943). There was a significant increase in age with higher grades of Goutallier classification (p < 0.001). In contrast, there was no correlation between LIV and age (p = 0.799). The Goutallier classification positively correlated with LL (r = 0.377) and severe disc degeneration (r = 0.249). The LIV positively correlated with LL (r = 0.476) and degenerative spondylolisthesis (r = 0.184). Multinomial logistic regression analysis showed that age (p = 0.026), gender (p = 0.003), and LIV (p < 0.001) were significant predictors for patients with low LL (< 10°). Lumbar muscle quantity and quality showed specific correlation with age and spine disorders. Additionally, LL can be predicted by the muscle quantity, but not the quality. These time-saving evaluation tools potentially accelerate the study of lumbar muscles. These slides can be retrieved under Electronic Supplementary Material.

Speculum lumbar extraforaminal microdiscectomy.

PubMed

Obenchain, T G

2001-01-01

Public interest, monetary pressures and improving diagnostic techniques have placed an increasing emphasis on minimalism in lumbar disc excision. Current techniques include microlumbar discectomy and minimally invasive spinal surgery. Both are good techniques but may be painful, require a hospital stay and/or are not widely used because of difficulty acquiring the necessary skills. The author therefore developed a less invasive microscopic technique that may be performed on a consistent outpatient basis with easily acquired skills. The purpose of this study was to describe a variant of minimally invasive lumbar disc excision, while assessing the effects on a small group of patients. The treatment protocol was a prospective community hospital-based case study designed to evaluate a less invasive method of excising herniated lumbar discs residing in the canal, foraminal or far lateral space. This study is comprised of 50 patients with all anatomic forms of lumbar disc herniations, inside or outside the canal, at all levels except the lumbosacral joint. Clinical results were measured by return to work time, the criteria of MacNab and by Prolo et al.'s economic and functional criteria. Selection criteria included adult patients with intractable low back and leg pain, plus an imaging study revealing a lumbar disc herniation consistent with the patient's clinical presentation. Mean patient age was 48 years. The male:female ratio was approximately 2:1. All patients failed at least 3 weeks of conservative therapy. Herniations occurred from the L2-3 space through L4-5, with 30 herniations being within and 20 outside the spinal canal. Both contained and extruded/sequestered herniations were treated. Excluded from the study were patients with herniations inside the spinal canal at the L5-S1 level. Surgical approach was by microscopic speculum transforaminal route for discs residing both within and outside the lumbar canal. The initial 50 consecutive patients had successful technical operations performed on an outpatient basis by this less invasive technique. By the criteria of MacNab (Table 3), 84% (42 of 50) had an excellent or good result, returning to work at a mean time of 3.5 weeks. Per Prolo et al.'s economic scale, 72% were disabled at levels I and II before surgery. Postoperatively, 92% had improved to levels IV and V. Similarly, on his functional scale, 94% functioned at levels I and II before surgery, whereas 88% achieved levels IV and V after surgery. Eighty percent required no pain medications 1 week after surgery. The only complication was an L3 minor nerve root injury as it exited the L3-4 foramen. The author has described a minimally invasive technique for excising herniated discs that is applicable to all types of lumbar herniations, except for those residing in the canal at L5-S1. Clinical outcomes are comparable to those of other forms of discectomy.

Lumbar disc herniation in young children.

PubMed

Haidar, R; Ghanem, I; Saad, S; Uthman, I

2010-01-01

This article explores lumbar disc herniation in young children through focusing on matters relevant to patient presentation, physical examination, differential diagnosis, imaging and treatment. Major databases were searched for studies that addressed lumbar disc herniation in young children. Diagnosis of lumbar disc herniation in young children is usually delayed because of the rarity and lack of experience with this entity and the difficulty in extracting a reliable medical history. Nevertheless, lumbar disc herniation should be considered in the differential diagnosis of any young child presenting with a chief complaint of back pain and/or radiculopathy, especially in the setting of recent trauma. This should be coupled with a directed physical examination to elicit signs and narrow the differential diagnosis. Imaging studies, mainly magnetic resonance imaging, will help establish a diagnosis; yet radiographs are still required to exclude other spinal lesions. The initial management of lumbar disc herniation in children is the same as that in adults and consists of conservative treatment unless lumbar disc herniation affects the patient's motor and neurological functions in which case, early surgical treatment must be undertaken. Although the latter remains more difficult, current experience suggests a favourable outcome. Awareness of lumbar disc herniation will help the paediatrician extract a relevant medical history, perform a directed physical examination, and order appropriate imaging studies. This will aid in initiating early intervention, be it conservative or operative, and achieving a favourable outcome.

A rare case of spontaneous Aspergillus spondylodiscitis with epidural abscess in a 45-year-old immunocompetent female

PubMed Central

Raj, K. Ambedkar; Srinivasamurthy, Banushree C.; Nagarajan, Krishnan; Sinduja, M. G. Ilavarasi

2013-01-01

Vertebral osteomyelitis and discitis are mainly due to bacterial infections though fungal infections are one of the important causes of morbidity and mortality in immunocompromised patients. Aspergillus involving intervertebral disc space is extremely rare. We report a case of aspergillosis of intervertebral L5-S1 disc space with spinal epidural abscess in an immunocompetent 45-year-old female which can add on to a few case reports described in literature as well as an insight for clinicians regarding this rare spontaneous infection in an immunocompetent patient. PMID:24744568

A rare case of spontaneous Aspergillus spondylodiscitis with epidural abscess in a 45-year-old immunocompetent female.

PubMed

Raj, K Ambedkar; Srinivasamurthy, Banushree C; Nagarajan, Krishnan; Sinduja, M G Ilavarasi

2013-07-01

Vertebral osteomyelitis and discitis are mainly due to bacterial infections though fungal infections are one of the important causes of morbidity and mortality in immunocompromised patients. Aspergillus involving intervertebral disc space is extremely rare. We report a case of aspergillosis of intervertebral L5-S1 disc space with spinal epidural abscess in an immunocompetent 45-year-old female which can add on to a few case reports described in literature as well as an insight for clinicians regarding this rare spontaneous infection in an immunocompetent patient.

A Prospective Study of Clinical and Radiological Outcomes of Zero-Profile Cage Screw Implants for Single-Level Anterior Cervical Discectomy and Fusion: Is Segmental Lordosis Maintained at 2 Years?

PubMed

Basu, Saumyajit; Rathinavelu, Sreeramalingam

2017-04-01

Prospective cohort study. To study clinicoradiological parameters of zero-profile cage screw used for anterior cervical discectomy and fusion (ACDF). Radiological parameters of various implants used for ACDF are available, but those for zero-profile cage are sparse. Patients with unilateral intractable brachialgia due to single-level cervical disc prolapse between April 1, 2011 and March 31, 2014 were included. Clinical assessment included arm and neck pain using visual analogue score (VAS) and neck disability index (NDI) scores. Radiological assessment included motion segment height, adjacent disc height (upper and lower), segmental and cervical lordosis, implant subsidence, and pseudoarthrosis. Follow-ups were scheduled at 1, 3, 6, 12, and 24 months. Thirty-four patients (26 males, 8 females) aged 30-50 years (mean, 42.2) showed excellent clinical improvement based on VAS scores (7.4-0 for arm and 2.0-0.6 for neck pains). Postoperative disc height improved by 11.33% ( p <0.001), but at 2 years, the score deteriorated by 7.03% ( p <0.001). Difference in the adjacent segment disc height at 2 years was 0.08% ( p =0.8) in upper and 0.16% ( p <0.001) in lower disc spaces. Average segmental lordosis achieved was 5.59° ( p <0.001) from a preoperative kyphosis of 0.88°; at 2 years, an average loss of 7.05° ( p <0.001) occurred, resulting in an average segmental kyphosis of 1.38°. Cervical lordosis improved from 11.59° to 14.88° ( p =0.164), and at 2 years, it progressively improved to 22.59° ( p <0.001). Three patients showed bone formation and two mild protrusion of the implant at 2 years without pseudoarthrosis/implant failure. The zero-profile cage screw device provides good fusion and cervical lordosis but is incapable of maintaining the segmental lordosis achieved up to a 2-year follow-up. We also recommend caution when using it in patients with small vertebrae.

Strain on intervertebral discs after anterior cervical decompression and fusion.

PubMed

Matsunaga, S; Kabayama, S; Yamamoto, T; Yone, K; Sakou, T; Nakanishi, K

1999-04-01

An analysis of the change in strain distribution of intervertebral discs present after anterior cervical decompression and fusion by an original method. The analytical results were compared to occurrence of herniation of the intervertebral disc on magnetic resonance imaging. To elucidate the influence of anterior cervical decompression and fusion on the unfused segments of the spine. There is no consensus regarding the exact significance of the biomechanical change in the unfused segment present after surgery. Ninety-six patients subjected to anterior cervical decompression and fusion for herniation of intervertebral discs were examined. Shear strain and longitudinal strain of intervertebral discs were analyzed on pre- and postoperative lateral dynamic routine radiography of the cervical spine. Thirty of the 96 patients were examined by magnetic resonance imaging before and after surgery, and the relation between alteration in strains and postsurgical occurrence of disc herniation was examined. In the cases of double- or triple-level fusion, shear strain of adjacent segments had increased 20% on average 1 year after surgery. Thirteen intervertebral discs that had an abnormally high degree of strain showed an increase in longitudinal strain after surgery. Eleven (85%) of the 13 discs that showed an abnormal increase in longitudinal strain had herniation in the same intervertebral discs with compression of the spinal cord during the follow-up period. Relief of symptoms was significantly poor in the patients with recent herniation. Close attention should be paid to long-term biomechanical changes in the unfused segment.

[Sciatica. From stretch rack to microdiscectomy].

PubMed

Gruber, P; Böni, T

2015-12-01

In ancient times as well as in the Middle Ages treatment options for discogenic nerve compression syndrome were limited and usually not very specific because of low anatomical and pathophysiological knowledge. The stretch rack (scamnum Hippocratis) was particularly prominent but was widely used as a therapeutic device for very different spinal disorders. Since the beginning of the nineteenth century anatomical knowledge increased and the advances in the fields of asepsis, anesthesia and surgery resulted in an increase in surgical interventions on the spine. In 1908 the first successful lumbar discectomy was initiated and performed by the German neurologist Heinrich O. Oppenheim (1858-1919) and the surgeon Fedor Krause (1857-1937); however, neither recognized the true pathological condition of discogenic nerve compression syndrome. With the landmark report in the New England Journal of Medicine in 1934, the two American surgeons William Jason Mixter (1880-1958) and Joseph Seaton Barr (1901-1963) finally clarified the pathomechanism of lumbar disc herniation and furthermore, propagated discectomy as the standard therapy. Since then interventions on intervertebral discs rapidly increased and the treatment options for lumbar disc surgery quickly evolved. The surgical procedures changed over time and were continuously being refined. In the late 1960s the surgical microscope was introduced for spinal surgery by the work of the famous neurosurgeon Mahmut Gazi Yasargil and his colleague Wolfhard Caspar and so-called microdiscectomy was introduced. Besides open discectomy other interventional techniques were developed to overcome the side effects of surgical procedures. In 1964 the American orthopedic surgeon Lyman Smith (1912-1991) introduced chemonucleolysis, a minimally invasive technique consisting only of a cannula and the proteolytic enzyme chymopapain, which is injected into the disc compartment to dissolve the displaced disc material. In 1975 the Japanese orthopedic surgeon Sadahisa Hijikata described percutaneous discectomy for the first time, which was a further minimally invasive surgical technique. Further variants of minimally invasive surgical procedures, such as percutaneous laser discectomy in 1986 and percutaneous endoscopic microdiscectomy in 1997, were also introduced; however, open discectomy, especially microdiscectomy remains the therapeutic gold standard for lumbar disc herniation.

Disc herniations in the national football league.

PubMed

Gray, Benjamin L; Buchowski, Jacob M; Bumpass, David B; Lehman, Ronald A; Mall, Nathan A; Matava, Matthew J

2013-10-15

Retrospective analysis of a prospectively collected database. To determine the overall incidence, location, and type of disc herniations in professional football players to target treatment issues and prevention. Disc herniations represent a common and debilitating injury to the professional athlete. The NFL's (National Football League's) Sports Injury Monitoring System is a surveillance database created to monitor the league for all injuries, including injuries to the cervical, thoracic, and lumbar spine. A retrospective analysis was performed on all disc herniations to the cervical, thoracic, and lumbar spine during a 12-season period (2000-2012) using the NFL's surveillance database. The primary data points included the location of the injury, player position, activity at time of injury, and playing time lost due to injury. During the 12 seasons, 275 disc herniations occurred in the spine. In regard to location, 76% occurred in the lumbar spine and most frequently affected the L5-S1 disc. The offensive linemen were most frequently injured. As expected, blocking was the activity that caused most injuries. Lumbar disc herniations rose in prevalence and had a mean loss of playing time of more than half the season (11 games). Thoracic disc herniations led to the largest mean number of days lost overall, whereas players with cervical disc herniations missed the most practices. Disc herniations represent a significant cause of morbidity in the NFL. Although much attention is placed on spinal cord injuries, preventive measures targeting the cervical, thoracic, and lumbar spine may help to reduce the overall incidence of these debilitating injuries.Level of Evidence: N/A.

Disc herniations in the National Football League.

PubMed

Gray, Benjamin L; Buchowski, Jacob M; Bumpass, David B; Lehman, Ronald A; Mall, Nathan A; Matava, Matthew J

2013-10-15

Retrospective analysis of a prospectively collected database. To determine the overall incidence, location, and type of disc herniations in professional football players to target treatment issues and prevention. Disc herniations represent a common and debilitating injury to the professional athlete. The NFL's (National Football League's) Sports Injury Monitoring System is a surveillance database created to monitor the league for all injuries, including injuries to the cervical, thoracic, and lumbar spine. A retrospective analysis was performed on all disc herniations to the cervical, thoracic, and lumbar spine during a 12-season period (2000–2012) using the NFL's surveillance database. The primary data points included the location of the injury, player position, activity at time of injury, and playing time lost due to injury. During the 12 seasons, 275 disc herniations occurred in the spine. In regard to location, 76% occurred in the lumbar spine and most frequently affected the L5–S1 disc. The offensive linemen were most frequently injured. As expected, blocking was the activity that caused most injuries. Lumbar disc herniations rose in prevalence and had a mean loss of playing time of more than half the season (11 games). Thoracic disc herniations led to the largest mean number of days lost overall, whereas players with cervical disc herniations missed the most practices. Disc herniations represent a significant cause of morbidity in the NFL. Although much attention is placed on spinal cord injuries, preventive measures targeting the cervical, thoracic, and lumbar spine may help to reduce the overall incidence of these debilitating injuries. N/A

Operative and nonoperative treatment of cervical disc herniation in National Football League athletes.

PubMed

Meredith, Dennis S; Jones, Kristofer J; Barnes, Ronnie; Rodeo, Scott A; Cammisa, Frank P; Warren, Russell F

2013-09-01

Limited evidence exists to guide clinical decision making regarding cervical disc herniations in professional athletes playing for the National Football League (NFL) in the United States. To describe the presentation and treatment outcomes of cervical disc herniations in NFL athletes with a focus on safety and return to sport. Case series; Level of evidence, 4. The records of a single NFL team and its consulting physicians were reviewed from 2000 to 2011. Only athletes with magnetic resonance imaging (MRI)-proven disc herniation concordant with the reported symptoms were included. A total of 16 athletes met inclusion criteria. Linemen, linebackers, and defensive backs were the most represented positions (13/16 athletes; 81%). The most common presentation was radiculopathy after a single traumatic event (9/16 athletes; 56%). Three players had transient paresis. Three players underwent one-level anterior cervical discectomy and fusion. These 3 players had failed nonoperative therapy and had evidence of spinal cord compression with signal change on MRI, but only 1 returned to sport. Three players received epidural steroid injections, which provided transient symptomatic relief. Five players were treated nonoperatively and did not return to sport. Two of these 5 athletes had cord compression with signal change and retired rather than undergo surgery. The other 3 were cleared but were released by the team. Eight players were treated nonoperatively and returned to sport. Three of these 8 athletes had evidence of disc material abutting the cord without cord signal change but had a normal examination finding and returned to sport after resolution of their symptoms and repeat MRI that demonstrated no cord compression. Five of the 8 players had evidence of root compression and were treated symptomatically. There were no subsequent traumatic spinal cord injuries at a minimum of 1-year follow-up. Data regarding the treatment of this unique population are limited but suggest that NFL athletes can safely return to sport after the treatment of cervical disc herniations. In the treatment algorithm for this study, cord compression with signal change in the cord on MRI was a consistent operative indication. Discs abutting the cord can be treated nonoperatively but do not allow for return to sport until symptoms have improved and repeat imaging demonstrates no cord compression. Isolated nerve root compression has a more favorable prognosis. It can be treated symptomatically and return to sport allowed when symptoms permit.

Spondylodiscitis revisited

PubMed Central

Mavrogenis, Andreas F.; Megaloikonomos, Panayiotis D.; Igoumenou, Vasileios G.; Panagopoulos, Georgios N.; Giannitsioti, Efthymia; Papadopoulos, Antonios; Papagelopoulos, Panayiotis J.

2017-01-01

Spondylodiscitis may involve the vertebral bodies, intervertebral discs, paravertebral structures and spinal canal, with potentially high morbidity and mortality rates. A rise in the susceptible population and improved diagnosis have increased the reported incidence of the disease in recent years. Blood cultures, appropriate imaging and biopsy are essential for diagnosis and treatment. Most patients are successfully treated by conservative means; however, some patients may require surgical treatment. Surgical indications include doubtful diagnosis, progressive neurological deficits, progressive spinal deformity, failure to respond to treatment, and unresolved pain. Cite this article: EFORT Open Rev 2017;2:447–461. DOI: 10.1302/2058-5241.2.160062 PMID:29218230

The Lumbar Lordosis in Males and Females, Revisited.

PubMed

Hay, Ori; Dar, Gali; Abbas, Janan; Stein, Dan; May, Hila; Masharawi, Youssef; Peled, Nathan; Hershkovitz, Israel

2015-01-01

Whether differences exist in male and female lumbar lordosis has been debated by researchers who are divided as to the nature of variations in the spinal curve, their origin, reasoning, and implications from a morphological, functional and evolutionary perspective. Evaluation of the spinal curvature is constructive in understanding the evolution of the spine, as well as its pathology, planning of surgical procedures, monitoring its progression and treatment of spinal deformities. The aim of the current study was to revisit the nature of lumbar curve in males and females. Our new automated method uses CT imaging of the spine to measure lumbar curvature in males and females. The curves extracted from 158 individuals were based on the spinal canal, thus avoiding traditional pitfalls of using bone features for curve estimation. The model analysis was carried out on the entire curve, whereby both local and global descriptors were examined in a single framework. Six parameters were calculated: segment length, curve length, curvedness, lordosis peak location, lordosis cranial peak height, and lordosis caudal peak height. Compared to males, the female spine manifested a statistically significant greater curvature, a caudally located lordotic peak, and greater cranial peak height. As caudal peak height is similar for males and females, the illusion of deeper lordosis among females is due partially to the fact that the upper part of the female lumbar curve is positioned more dorsally (more backwardly inclined). Males and females manifest different lumbar curve shape, yet similar amount of inward curving (lordosis). The morphological characteristics of the female spine were probably developed to reduce stress on the vertebral elements during pregnancy and nursing.

Clinical and instrumental assessment of herniated discs after nucleoplasty: a preliminary study.

PubMed

Liguori, Alessandro; Galli, Federica; Gurgitano, Martina; Borelli, Anna; Pandolfi, Marco; Caranci, Ferdinando; Magenta Biasina, Alberto M; Pompili, Giovanni G M; Piccolo, Claudia L; Miele, Vittorio; Masciocchi, Carlo; Carrafiello, Giampaolo

2018-01-19

The therapy for low back pain boasts different approaches; one of these is nucleoplasty. We wanted to assess the effectiveness of nucleoplasty both by clinical response both by MR imaging evaluation, including even extrusions larger than one third of the spinal canal. Fifty-seven patients were treated with nucleoplasty in our hospital, 11 of these patients accepted both clinical and MRI evaluation after six months from treatment. The clinical evaluation was performed with Visual Analogue Scale (VAS) of pain, scored before and after the procedure. MRI evaluation consisted of analysing some imaging parameters of disc protrusions before and after the treatment. In 10 out of 11 (91%) patients, VAS was reduced and only 1 out of 11 (9%) had the same pain after procedure. The mean of decrease of VAS score was 64%. In our population 8/11 (72%) patients had a herniation larger than 1/3 of the sagittal diameter of spinal canal and 100% of them had an improvement with a mean VAS reduction value of 75%. With MRI evaluation, the mean percentage of expulsion before and after treatment was respectively 40% and 34%. The expulsion decreased in 7/13 discs, remained equal in 4/13, and increased in 2/13 discs. Among the 9 larger protrusions, 3 didn't change, 6 reduced with a decrease mean value of 13%. Other MRI parameters didn't change significantly. Our preliminary experience supports the success of coblation on pain relief, aiming to show progressively that this treatment is suitable even in case of great extrusions, which are generally treated only with surgical approach. It's not clear the usefulness of MRI control yet, even if in most of cases we could have found a certain reduction of expulsion degree.

Biomechanical analysis of combining head-down tilt traction with vibration for different grades of degeneration of the lumbar spine.

PubMed

Wang, Sicong; Wang, Lizhen; Wang, Yawei; Du, Chengfei; Zhang, Ming; Fan, Yubo

2017-01-01

In recent years, a combination of traction and vibration therapy is usually used to alleviate low back pain (LBP) in clinical settings. Combining head-down tilt (HDT) traction with vibration was demonstrated to be efficacious for LBP patients in our previous study. However, the biomechanics of the lumbar spine during this combined treatment is not well known and need quantitative analysis. In addition, LBP patients have different grades of degeneration of the lumbar spinal structure, which are often age related. Selecting a suitable rehabilitation therapy for different age groups of patients has been challenging. Therefore, a finite element (FE) model of the L1-L5 lumbar spine and a vibration dynamic model are developed in this study in order to investigate the biomechanical effects of the combination of HDT traction and vibration therapy on the age-related degeneration of the lumbar spine. The decrease of intradiscal pressure is more effective when vibration is combined with traction therapy. Moreover, the stresses on the discs are lower in the "traction+vibration" mode than the "traction-only" mode. The stress concentration at the posterior part of nucleus is mitigated after the vibration is combined. The disc deformations especially posterior disc radial retraction is improved in the "traction+vibration" mode. These beneficial effects of this therapy could help decompress the discs and spinal nerves and therefore relieve LBP. Simultaneously, patients with grade 1 degeneration (approximately 41-50 years old) are able to achieve better results compared with other age groups. This study could be used to provide a more effective LBP rehabilitation therapy. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Modeling and optimization of an elastic arthroplastic disc for a degenerated disc

NASA Astrophysics Data System (ADS)

Ghouchani, Azadeh; Ravari, Mohammad; Mahmoudi, Farid

2011-10-01

A three-dimensional finite element model (FEM) of the L3-L4 motion segment using ABAQUS v 6.9 has been developed. The model took into account the material nonlinearities and is imposed different loading conditions. In this study, we validated the model by comparison of its predictions with several sets of experimental data. Disc deformation under compression and segmental rotational motions under moment loads for the normal disc model agreed well with the corresponding in vivo studies. By linking ABAQUS with MATLAB 2010.a, we determined the optimal Young s modulus as well as the Poisson's ratio for the artificial disc under different physiologic loading conditions. The results of the present study confirmed that a well-designed elastic arthroplastic disc preferably has an annulus modulus of 19.1 MPa and 1.24 MPa for nucleus section and Poisson ratio of 0.41 and 0.47 respectively. Elastic artificial disc with such properties can then achieve the goal of restoring the disc height and mechanical function of intact disc under different loading conditions and so can reduce low back pain which is mostly caused due to disc degeneration.

Fragmentation of protoplanetary discs around M-dwarfs

NASA Astrophysics Data System (ADS)

Backus, Isaac; Quinn, Thomas

2016-12-01

We investigate the conditions required for planet formation via gravitational instability (GI) and protoplanetary disc (PPD) fragmentation around M-dwarfs. Using a suite of 64 SPH simulations with 106 particles, the parameter space of disc mass, temperature, and radius is explored, bracketing reasonable values based on theory and observation. Our model consists of an equilibrium, gaseous, and locally isothermal disc orbiting a central star of mass M* = M⊙/3. Discs with a minimum Toomre Q of Qmin ≲ 0.9 will fragment and form gravitationally bound clumps. Some previous literature has found Qmin < 1.3-1.5 to be sufficient for fragmentation. Increasing disc height tends to stabilize discs, and when incorporated into Q as Qeff ∝ Q(H/R)α for α = 0.18 is sufficient to predict fragmentation. Some discrepancies in the literature regarding Qcrit may be due to different methods of generating initial conditions (ICs). A series of 15 simulations demonstrates that perturbing ICs slightly out of equilibrium can cause discs to fragment for higher Q. Our method for generating ICs is presented in detail. We argue that GI likely plays a role in PPDs around M-dwarfs and that disc fragmentation at large radii is a plausible outcome for these discs.

[LOCATION CHANGE OF ROTATION CENTER AFTER SINGLE SEGMENTAL CERVICAL DISC REPLACEMENT WITH ProDisc-C].

PubMed

Lou, Jigang; Liu, Hao; Rong, Xin; Gong, Quan; Song, Yueming; Li, Tao

2015-01-01

To evaluate the effectiveness of the single segmental cervical disc replacement with ProDisc-C, and to explore the location change of the flexion/extension center of rotation (COR) of the target level as well as its clinical significance. Between June 2010 and February 2012, 23 patients underwent single segmental cervical disc replacement with ProDisc-C, and the clinical data were retrospectively analyzed. Of 23 patients, 9 were male, and 14 were female with the age range from 27 to 65 years (mean, 45 years), and the disease duration ranged from 10 to 84 months (mean, 25 months). There were 15 patients with radiculopathy, 5 patients with myelopathy, and 3 patients with mixed cervical spondylosis. The involved segments were C4,5 in 5 cases, C5,6 in 14 cases, and C6,7 in 4 cases. Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) were adopted to evaluate the effectiveness. Preoperative and Postoperative radiographic parameters, such as cervical overall range of motion (ROM), target segmental ROM, the adjacent segmental ROM, and intervertebral height were compared. Besides, the location changes of the COR of the target level were further analyzed by the alteration of its coordinates (COR-X, COR-Y), and the relationships between the location changes of the COR and the effectiveness or the radiographic results were analyzed. All the operations were completed successfully; 1 case had hoarseness after operation, which disappeared at 3 months after operation. All cases were followed up 18.3 months on average (range, 6-36 months). There was no device migration, loosening, subsidence, or fracture at last follow-up. The JOA score increased significantly and the NDI score decreased significantly at last follow-up when compared with preoperative scores (P < 0.05). No difference was found in the cervical overall ROM, target segmental ROM, the adjacent segmental ROM, and the COR-Y of the target level between pre-operation and last follow-up (P > 0.05); while the intervertebral height and the COR-X increased significantly (P < 0.05). The change of the COR-X had no obvious correlation with the postoperative JOA, NDI, and target segmental ROM (P > 0.05). According to whether the difference of the COR-X between pre- and post-operation was less than the average value 1.86 mm or not, the patients were divided into 2 groups; significant difference was shown in the postoperative target segmental ROM between 2 groups (P < 0.05), but no significant difference was found in the postoperative JOA, NDI, cervical overall ROM, adjacent segmental ROM, and the intervertebral height between 2 groups (P > 0.05). Single segmental cervical disc replacement with ProDisc-C can obtain satisfactory outcomes. The cervical overall ROM, target segmental ROM, and adjacent segmental ROM can be effectively maintained, and the intervertebral height is increased. The location of the flexion/extension COR of the target segment shifts forward after insertion of the ProDisc-C prosthesis, and the postoperative target segmental ROM becomes smaller as the distance of the displacement of the COR becomes greater.

Spinal sagittal imbalance in patients with lumbar disc herniation: its spinopelvic characteristics, strength changes of the spinal musculature and natural history after lumbar discectomy.

PubMed

Liang, Chen; Sun, Jianmin; Cui, Xingang; Jiang, Zhensong; Zhang, Wen; Li, Tao

2016-07-22

Spinal sagittal imbalance is a widely acknowledged problem, but there is insufficient knowledge regarding its occurrence. In some patients with lumbar disc herniation (LDH), their symptom is similar to spinal sagittal imbalance. The aim of this study is to illustrate the spinopelvic sagittal characteristics and identity the role of spinal musculature in the mechanism of sagittal imbalance in patients with LDH. Twenty-five adults with spinal sagittal imbalance who initially came to our clinic for treatment of LDH, followed by posterior discectomy were reviewed. The horizontal distance between C7 plumb line-sagittal vertical axis (C7PL-SVA) greater than 5 cm anteriorly with forward bending posture is considered as spinal sagittal imbalance. Radiographic parameters including thoracic kyphotic angle (TK), lumbar lordotic angle (LL), pelvic tilting angle (PT), sacral slope angle (SS) and an electromyography(EMG) index 'the largest recruitment order' were recorded and compared. All patients restored coronal and sagittal balance immediately after lumbar discectomy. The mean C7PL-SVA and trunk shift value decreased from (11.6 ± 6.6 cm, and 2.9 ± 6.1 cm) preoperatively to (-0.5 ± 2.6 cm and 0.2 ± 0.5 cm) postoperatively, while preoperative LL and SS increased from (25.3° ± 14.0° and 25.6° ± 9.5°) to (42.4° ± 10.2° and 30.4° ± 8.7°) after surgery (P < 0.05). The preoperative mean TK and PT (24.7° ± 11.3° and 20.7° ± 7.8°) decreased to (22.0° ± 9.8° and 15.8 ± 5.5°) postoperatively (P < 0.05). The largest recruitment order on the level of T7-T8, T12-L1 and the herniated level all improved compared with before and after surgery (P < 0.05). All patients have been followed up for more than 2 years. The mean ODI was 77.8 % before surgery to 4.2 % at the final follow-up. Spinal sagittal imbalance caused by LDH is one type of compensatory sagittal imbalance. Compensatory mechanism of spinal sagittal imbalance mainly includes a loss of lumbar lordosis, an increase of thoracic kyphosis and pelvis tilt. Spinal musculature plays an important role in spinal sagittal imbalance in patients with LDH.

Percutaneous laser disc decompression versus conventional microdiscectomy for patients with sciatica: Two-year results of a randomised controlled trial.

PubMed

Brouwer, Patrick A; Brand, Ronald; van den Akker-van Marle, M Elske; Jacobs, Wilco Ch; Schenk, Barry; van den Berg-Huijsmans, Annette A; Koes, Bart W; Arts, Mark A; van Buchem, M A; Peul, Wilco C

2017-06-01

Background Percutaneous laser disc decompression is a minimally invasive treatment, for lumbar disc herniation and might serve as an alternative to surgical management of sciatica. In a randomised trial with two-year follow-up we assessed the clinical effectiveness of percutaneous laser disc decompression compared to conventional surgery. Materials and methods This multicentre randomised prospective trial with a non-inferiority design, was carried out according to an intent-to-treat protocol with full institutional review board approval. One hundred and fifteen eligible surgical candidates, with sciatica from a disc herniation smaller than one-third of the spinal canal, were randomly allocated to percutaneous laser disc decompression ( n = 55) or conventional surgery ( n = 57). The main outcome measures for this trial were the Roland-Morris Disability Questionnaire for sciatica, visual analogue scores for back and leg pain and the patient's report of perceived recovery. Results The primary outcome measures showed no significant difference or clinically relevant difference between the two groups at two-year follow-up. The re-operation rate was 21% in the surgery group, which is relatively high, and with an even higher 52% in the percutaneous laser disc decompression group. Conclusion At two-year follow-up, a strategy of percutaneous laser disc decompression, followed by surgery if needed, resulted in non-inferior outcomes compared to a strategy of microdiscectomy. Although the rate of reoperation in the percutaneous laser disc decompression group was higher than expected, surgery could be avoided in 48% of those patients that were originally candidates for surgery. Percutaneous laser disc decompression, as a non-surgical method, could have a place in the treatment arsenal of sciatica caused by contained herniated discs.

Contribution of facet joints, axial compression, and composition to human lumbar disc torsion mechanics.

PubMed

Bezci, Semih E; Eleswarapu, Ananth; Klineberg, Eric O; O'Connell, Grace D

2018-02-12

Stresses applied to the spinal column are distributed between the intervertebral disc and facet joints. Structural and compositional changes alter stress distributions within the disc and between the disc and facet joints. These changes influence the mechanical properties of the disc joint, including its stiffness, range of motion, and energy absorption under quasi-static and dynamic loads. There have been few studies evaluating the role of facet joints in torsion. Furthermore, the relationship between biochemical composition and torsion mechanics is not well understood. Therefore, the first objective of this study was to investigate the role of facet joints in torsion mechanics of healthy and degenerated human lumbar discs under a wide range of compressive preloads. To achieve this, each disc was tested under four different compressive preloads (300-1200 N) with and without facet joints. The second objective was to develop a quantitative structure-function relationship between tissue composition and torsion mechanics. Facet joints have a significant contribution to disc torsional stiffness (∼60%) and viscoelasticity, regardless of the magnitude of axial compression. The findings from this study demonstrate that annulus fibrosus GAG content plays an important role in disc torsion mechanics. A decrease in GAG content with degeneration reduced torsion mechanics by more than an order of magnitude, while collagen content did not significantly influence disc torsion mechanics. The biochemical-mechanical and compression-torsion relationships reported in this study allow for better comparison between studies that use discs of varying levels of degeneration or testing protocols and provide important design criteria for biological repair strategies. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Comparison of animal discs used in disc research to human lumbar disc: torsion mechanics and collagen content.

PubMed

Showalter, Brent L; Beckstein, Jesse C; Martin, John T; Beattie, Elizabeth E; Espinoza Orías, Alejandro A; Schaer, Thomas P; Vresilovic, Edward J; Elliott, Dawn M

2012-07-01

Experimental measurement and normalization of in vitro disc torsion mechanics and collagen content for several animal species used in intervertebral disc research and comparing these with the human disc. To aid in the selection of appropriate animal models for disc research by measuring torsional mechanical properties and collagen content. There is lack of data and variability in testing protocols for comparing animal and human disc torsion mechanics and collagen content. Intervertebral disc torsion mechanics were measured and normalized by disc height and polar moment of inertia for 11 disc types in 8 mammalian species: the calf, pig, baboon, goat, sheep, rabbit, rat, and mouse lumbar discs, and cow, rat, and mouse caudal discs. Collagen content was measured and normalized by dry weight for the same discs except the rat and the mouse. Collagen fiber stretch in torsion was calculated using an analytical model. Measured torsion parameters varied by several orders of magnitude across the different species. After geometric normalization, only the sheep and pig discs were statistically different from human discs. Fiber stretch was found to be highly dependent on the assumed initial fiber angle. The collagen content of the discs was similar, especially in the outer annulus where only the calf and goat discs were statistically different from human. Disc collagen content did not correlate with torsion mechanics. Disc torsion mechanics are comparable with human lumbar discs in 9 of 11 disc types after normalization by geometry. The normalized torsion mechanics and collagen content of the multiple animal discs presented are useful for selecting and interpreting results for animal disc models. Structural organization of the fiber angle may explain the differences that were noted between species after geometric normalization.

Restoring Segmental Biomechanics Through Nucleus Augmentation: An In Vitro Study.

PubMed

Pelletier, Matthew H; Cohen, Charles S; Ducheyne, Paul; Walsh, William R

2016-12-01

In vitro biomechanical laboratory study. The purpose of this study is to evaluate a mechanical treatment to create a degenerative motion segment and the ability of nucleus augmentation to restore biomechanics. In cases with an intact annulus fibrosus, the replacement or augmentation of the nucleus pulposus alone may provide a less invasive option to restore normal biomechanics and disk height when compared with spinal fusion or total disk replacement. Laboratory testing allows these changes to be fully characterized. However, without preexisting pathology, nucleus augmentation therapies are difficult to evaluate in vitro. The present study evaluated pure moment bending and compressive biomechanics in 3 states (n=6): (1) intact, (2) after creep loading and nucleus disruption to induce degenerative biomechanical changes, and (3) after nucleus augmentation through an injectable polymer (DiscCell). Neutral zone and ROM were increased in all modes of bending after the degenerative treatment. The most sensitive mode of bending was lateral bending, with intact ROM (20.0±2.9 degrees) increased to 22.3±2.6 degrees after degenerative treatment and reduced to 18.4±1.6 degrees after injection of the polymer. All bending ROM and NZ changes induced by the degenerative treatment were reversed by nucleus augmentation. This material was shown to be effective at altering motion segment biomechanics and restoring disk height during time zero tests. This technique may provide a model to examine the time zero performance of a nucleus augmentation device/material.

Smartphone apps for spinal surgery: is technology good or evil?

PubMed

Robertson, Greg A J; Wong, Seng Juong; Brady, Richard R; Subramanian, Ashok S

2016-05-01

The increased utilization of smartphones together with their downloadable applications (apps) provides opportunity for doctors, including spinal surgeons, to integrate such technology into clinical practice. However, the clinical reliability of the medical app sector remains questionable. We reviewed available apps themed specifically towards spinal surgery and related conditions and assessed the level of medical professional involvement in their design and content. The most popular smartphone app stores (Android, Apple, Blackberry, Windows, Samsung, Nokia) were searched for spinal surgery-themed apps, using the disease terms Spinal Surgery, Back Surgery, Spine, Disc Prolapse, Sciatica, Radiculopathy, Spinal Stenosis, Scoliosis, Spinal Fracture and Spondylolisthesis. A total of 78 individual spinal surgery themed apps were identified, of which there were six duplicates (N = 72). According to app store classifications, there were 57 (79 %) medical themed apps, 11 (15 %) health and fitness themed apps, 1 (1 %) business and 3 (4 %) education themed apps. Forty-five (63 %) apps were available for download free of charge. For those that charged access, the prices ranged from £0.62 to £47.99. Only 44 % of spinal surgery apps had customer satisfaction ratings and 56 % had named medical professional involvement in their development or content. This is the first study to specifically address the characteristics of apps related to spinal surgery. We found that nearly half of spinal surgery apps had no named medical professional involvement, raising concerns over app content and evidence base for their use. We recommend increased regulation of spinal surgical apps to improve the accountability of app content.

MRI Quantification of Human Spine Cartilage Endplate Geometry: Comparison With Age, Degeneration, Level, and Disc Geometry

PubMed Central

DeLucca, John F.; Peloquin, John M.; Smith, Lachlan J.; Wright, Alexander C.; Vresilovic, Edward J.; Elliott, Dawn M.

2017-01-01

Geometry is an important indicator of disc mechanical function and degeneration. While the geometry and associated degenerative changes in the nucleus pulposus and the annulus fibrosus are well-defined, the geometry of the cartilage endplate (CEP) and its relationship to disc degeneration are unknown. The objectives of this study were to quantify CEP geometry in three dimensions using an MRI FLASH imaging sequence and evaluate relationships between CEP geometry and age, degeneration, spinal level, and overall disc geometry. To do so, we assessed the MRI-based measurements for accuracy and repeatability. Next, we measured CEP geometry across a larger sample set and correlated CEP geometric parameters to age, disc degeneration, level, and disc geometry. The MRI-based measures resulted in thicknesses (0.3–1 mm) that are comparable to prior measurements of CEP thickness. CEP thickness was greatest at the anterior/posterior (A/P) margins and smallest in the center. The CEP A/P thickness, axial area, and lateral width decreased with age but were not related to disc degeneration. Age-related, but not degeneration-related, changes in geometry suggest that the CEP may not follow the progression of disc degeneration. Ultimately, if the CEP undergoes significant geometric changes with aging and if these can be related to low back pain, a clinically feasible translation of the FLASH MRI-based measurement of CEP geometry presented in this study may prove a useful diagnostic tool. PMID:27232974

Geometry of the intervertebral volume and vertebral endplates of the human spine.

PubMed

van der Houwen, E B; Baron, P; Veldhuizen, A G; Burgerhof, J G M; van Ooijen, P M A; Verkerke, G J

2010-01-01

Replacement of a degenerated vertebral disc with an artificial intervertebral disc (AID) is currently possible, but poses problems, mainly in the force distribution through the vertebral column. Data on the intervertebral disc space geometry will provide a better fit of the prosthesis to the vertebrae, but current literature on vertebral disc geometry is very scarce or not suitable. In this study, existing CT-scans of 77 patients were analyzed to measure the intervertebral disc and vertebral endplate geometry of the lumbar spine. Ten adjacent points on both sides of the vertebrae (S1-superior to T12-inferior) and sagittal and transverse diameters were measured to describe the shape of the caudal and cranial vertebral planes of the vertebrae. It was found that the largest endplate depth is located in the middle or posterior regions of the vertebra, that there is a linear relationship between all inferior endplate depths and the endplate location (p < 0.0001) within the spinal column, and that the superior endplate depth increases with age by about 0.01 mm per year (p < 0.02). The wedge angle increases from T12-L1 to L5-S1. The results allow for improvement of the fit of intervertebral disc-prostheses to the vertebrae and optimized force transmission through the vertebral column.

Comparative Analysis between Total Disc Replacement and Posterior Foraminotomy for Posterolateral Soft Disc Herniation with Unilateral Radiculopathy : Clinical and Biomechanical Results of a Minimum 5 Years Follow-up

PubMed Central

Kim, Kyoung-Tae; Cho, Dae-Chul; Sung, Joo-Kyung; Kim, Young-Baeg; Kim, Du Hwan

2017-01-01

Objective To compare the clinical outcomes and biomechanical effects of total disc replacement (TDR) and posterior cervical foraminotomy (PCF) and to propose relative inclusion criteria. Methods Thirty-five patients who underwent surgery between 2006 and 2008 were included. All patients had single-level disease and only radiculopathy. The overall sagittal balance and angle and height of a functional segmental unit (FSU; upper and lower vertebral body of the operative lesion) were assessed by preoperative and follow-up radiographs. C2–7 range of motion (ROM), FSU, and the adjacent segment were also checked. Results The clinical outcome of TDR (group A) was tended to be superior to that of PCF (group B) without statistical significance. In the group A, preoperative and postoperative upper adjacent segment level motion values were 8.6±2.3 and 8.4±2.0, and lower level motion values were 8.4±2.2 and 8.3±1.9. Preoperative and postoperative FSU heights were 37.0±2.1 and 37.1±1.8. In the group B, upper level adjacent segment motion values were 8.1±2.6 and 8.2±2.8, and lower level motion values were 6.5±3.3 and 6.3±3.1. FSU heights were 37.1±2.0 and 36.2±1.8. The postoperative FSU motion and height changes were significant (p<0.05). The patient’s satisfaction rates for surgery were 88.2% in group A and 88.8% in group B. Conclusion TDR and PCF have favorable outcomes in patients with unilateral soft disc herniation. However, patients have different biomechanical backgrounds, so the patient’s biomechanical characteristics and economic status should be understood and treated using the optimal procedure. PMID:28061490

Degenerative lumbar spinal stenosis and lumbar spine configuration

PubMed Central

Hamoud, K.; May, H.; Hay, O.; Medlej, B.; Masharawi, Y.; Peled, N.; Hershkovitz, I.

2010-01-01

As life expectancy increases, degenerative lumbar spinal stenosis (DLSS) becomes a common health problem among the elderly. DLSS is usually caused by degenerative changes in bony and/or soft tissue elements. The poor correlation between radiological manifestations and the clinical picture emphasizes the fact that more studies are required to determine the natural course of this syndrome. Our aim was to reveal the association between lower lumbar spine configuration and DLSS. Two groups were studied: the first included 67 individuals with DLSS (mean age 66 ± 10) and the second 100 individuals (mean age 63.4 ± 13) without DLSS-related symptoms. Both groups underwent CT images (Philips Brilliance 64) and the following measurements were performed: a cross-section area of the dural sac, vertebral body dimensions (height, length and width), AP diameter of the bony spinal canal, lumbar lordosis and sacral slope angles. All measurements were taken at L3 to S1. Vertebral body lengths were significantly greater in the DLSS group at all levels compared to the control, whereas anterior vertebral body heights (L3, L4, L5) and middle vertebral heights (L3, L5) were significantly smaller in the LSS group. Lumbar lordosis, sacral slope and bony spinal canal were significantly smaller in the DLSS compared to the control. We conclude that the size and shape of vertebral bodies and canals significantly differed between the study groups. A tentative model is suggested to explain the association between these characteristics and the development of degenerative spinal stenosis. PMID:20652366

Recurrent Neurological Deterioration after Conservative Treatment for Acute Traumatic Central Cord Syndrome without Bony Injury: Seventeen Operative Case Reports.

PubMed

Jin, Wenjie; Sun, Xin; Shen, Kangping; Wang, Jia; Liu, Xingzhen; Shang, Xiushuai; Tao, Hairong; Zhu, Tong

2017-11-01

The mechanisms of late recurrent neurological deterioration after conservative treatment for acute traumatic central cord syndrome (ATCCS) remain unclear. Seventeen operative cases sustaining late recurrent neurological deterioration after conservative treatment for ATCCS were reviewed to investigate the mechanisms. The assessment of neurological status was based on International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). Gender, age, cause of injury, results of image, conservative treatment and operative data, and neurological status at different time points were recorded. The mean age of 17 patients was 43.8 ± 2.3 years old, and the causes of the cervical injury were 14 vehicle accidents and 3 falls. The neurological deficits of 17 patients on admission were not serious, and patients recovered quickly after conservative treatment. No fractures or dislocation were found in any patient's radiographs or CT scan images. All 17 patients performed first MRI test in 4 days and there was a slight or mild compression on the spinal cord in 16 patients. Eight patients had a second MRI scan ∼6 weeks later, which showed that there was aggravated compression on the spinal cord in six patients. All patients underwent an anterior approach to cervical decompression and internal fixation operation. During the operation, there were loose discs found in all 17 patients, obvious ruptures of disks found in 3 patients, obvious ruptures of anterior longitudinal ligaments (ALLs) found in 8 patients, and obvious ruptures of posterior longitudinal ligaments (PLLs) found in 7 patients. There was serious adhesion between PLLs and cervical disks in 12 patients. In five patients, partial ossification of PLLs was detected. All patients had a good neurological outcome at 6 month follow-up. Ruptures of ALLs, PLLs, and discs resulting in cervical instability and secondary compression on the spinal cord were important causes for recurrent neurological deterioration after conservative treatment for ATCCS. With timely spinal decompression after recurrent neurological deterioration, patients could achieve a good neurological outcome.

Comparison of Animal Discs Used in Disc Research to Human Lumbar Disc: Torsion Mechanics and Collagen Content

PubMed Central

Showalter, Brent L.; Beckstein, Jesse C.; Martin, John T.; Beattie, Elizabeth E.; Orías, Alejandro A. Espinoza; Schaer, Thomas P.; Vresilovic, Edward J.; Elliott, Dawn M.

2012-01-01

Study Design Experimental measurement and normalization of in vitro disc torsion mechanics and collagen content for several animal species used in intervertebral disc research and comparing these to the human disc. Objective To aid in the selection of appropriate animal models for disc research by measuring torsional mechanical properties and collagen content. Summary of Background Data There is lack of data and variability in testing protocols for comparing animal and human disc torsion mechanics and collagen content. Methods Intervertebral disc torsion mechanics were measured and normalized by disc height and polar moment of inertia for 11 disc types in 8 mammalian species: the calf, pig, baboon, goat, sheep, rabbit, rat, and mouse lumbar, and cow, rat, and mouse caudal. Collagen content was measured and normalized by dry weight for the same discs except the rat and mouse. Collagen fiber stretch in torsion was calculated using an analytical model. Results Measured torsion parameters varied by several orders of magnitude across the different species. After geometric normalization, only the sheep and pig discs were statistically different from human. Fiber stretch was found to be highly dependent on the assumed initial fiber angle. The collagen content of the discs was similar, especially in the outer annulus where only the calf and goat discs were statistically different from human. Disc collagen content did not correlate with torsion mechanics. Conclusion Disc torsion mechanics are comparable to human lumbar discs in 9 of 11 disc types after normalization by geometry. The normalized torsion mechanics and collagen content of the multiple animal discs presented is useful for selecting and interpreting results for animal models of the disc. Structural composition of the disc, such as initial fiber angle, may explain the differences that were noted between species after geometric normalization. PMID:22333953

Total disc replacement using a tissue-engineered intervertebral disc in vivo: new animal model and initial results

PubMed Central

Gebhard, Harry; Bowles, Robby; Dyke, Jonathan; Saleh, Tatianna; Doty, Stephen; Bonassar, Lawrence; Härtl, Roger

2010-01-01

Study type: Basic science Introduction: Chronic back pain due to degenerative disc disease (DDD) is among the most important medical conditions causing morbidity and significant health care costs. Surgical treatment options include disc replacement or fusion surgery, but are associated with significant short- and long-term risks.1 Biological tissue-engineering of human intervertebral discs (IVD) could offer an important alternative.2 Recent in vitro data from our group have shown successful engineering and growth of ovine intervertebral disc composites with circumferentially aligned collagen fibrils in the annulus fibrosus (AF) (Figure 1).3 Figure 1 Tissue-engineered composite disc a Experimental steps to generate composite tissue-engineered IVDs3 b Example of different AF formulations on collagen alignment in the AF. Second harmonic generation and two-photon excited fluorescence images of seeded collagen gels (for AF) of 1 and 2.5 mg/ml over time. At seeding, cells and collagen were homogenously distributed in the gels. Over time, AF cells elongated and collagen aligned parallel to cells. Less contraction and less alignment is noted after 3 days in the 2.5 mg/mL gel. c Imaging-based creation of a virtual disc model that will serve as template for the engineered disc. Total disc dimensions (AF and NP) were retrieved from micro-computer tomography (CT) (left images), and nucleus pulposus (NP) dimensions alone were retrieved from T2-weighted MRI images (right images). Merging of MRI and micro-CT models revealed a composite disc model (middle image)—Software: Microview, GE Healthcare Inc., Princeton, NJ; and slicOmatic v4.3, TomoVision, Montreal, Canada. d Flow chart describing the process for generating multi-lamellar tissue engineered IVDs. IVDs are produced by allowing cell-seeded collagen layers to contract around a cell-seeded alginate core (NP) over time Objective: The next step is to investigate if biological disc implants survive, integrate, and restore function to the spine in vivo. A model will be developed that allows efficient in vivo testing of tissue-engineered discs of various compositions and characteristics. Methods: Athymic rats were anesthetized and a dorsal approach was chosen to perform a microsurgical discectomy in the rat caudal spine (Fig. 2,Fig. 3). Control group I (n = 6) underwent discectomy only, Control group II (n = 6) underwent discectomy, followed by reimplantation of the autologous disc. Two treatment groups (group III, n = 6, 1 month survival; group IV, n = 6, 6 months survival) received a tissue-engineered composite disc implant. The rodents were followed clinically for signs of infection, pain level and wound healing. X-rays and magnetic resonance imaging (MRI) were assessed postoperatively and up to 6 months after surgery (Fig. 6,Fig. 7). A 7 Tesla MRI (Bruker) was implemented for assessment of the operated level as well as the adjacent disc (hydration). T2-weighted sequences were interpreted by a semiquantitative score (0 = no signal, 1 = weak signal, 2 = strong signal and anatomical features of a normal disc). Histology was performed with staining for proteoglycans (Alcian blue) and collagen (Picrosirius red) (Fig. 4,Fig. 5). Figure 2 Disc replacement surgery a Operative situs with native disc that has been disassociated from both adjacent vertebrae b Native disc (left) and tissue-engineered implant (right) c Implant in situ before wound closureAF: Annulus fi brosus, nP: nucleus pulposus, eP: endplate, M: Muscle, T: Tendon, s: skin, art: artery, GP: Growth plate, B: Bone Figure 3 Disc replacement surgery. Anatomy of the rat caudal disc space a Pircrosirius red stained axial cut of native disc space b Saffranin-O stained sagittal cut of native disc space Figure 4 Histologies of three separate motion segments from three different rats. Animal one = native IVD, Animal two = status after discectomy, Animal three = tissue-engineered implant (1 month) a–c H&E (overall tissue staining for light micrsocopy) d–f Alcian blue (proteoglycans) g–i Picrosirius red (collagen I and II) Figure 5 Histology from one motion segment four months after implantation of a bio-engineered disc construct a Picrosirius red staining (collagen) b Polarized light microscopy showing collagen staining and collagen organization in AF region c Increased Safranin-O staining (proteoglycans) in NP region of the disc implant d Higher magnification of figure 5c: Integration between implanted tissue-engineered total disc replacement and vertebral body bone Figure 6 MRI a Disc space height measurements in flash/T1 sequence (top: implant (714.0 micrometer), bottom: native disc (823.5 micrometer) b T2 sequence, red circle surrounding the implant NP Figure 7 7 Tesla MRI imaging of rat tail IVDs showing axial images (preliminary pilot data) a Diffusion tensor imaging (DTI) on two explanted rat tail discs in Formalin b Higher magnification of a, showing directional alignment of collagen fibers (red and green) when compared to the color ball on top which maps fibers' directional alignment (eg, fibers directing from left to right: red, from top to bottom: blue) c Native IVD in vivo (successful imaging of top and bottom of the IVD (red) d Gradient echo sequence (GE) showing differentiation between NP (light grey) and AF (dark margin) e GE of reimplanted tail IVD at the explantation level f T1Rho sequence demonstrating the NP (grey) within the AF (dark margin), containing the yellow marked region of interest for value acquisition (preliminary data are consistent with values reported in the literature). g T2 image of native IVD in vivo for monitoring of hydration (white: NP) Results: The model allowed reproducible and complete discectomies as well as disc implantation in the rat tail spine without any surgical or postoperative complications. Discectomy resulted in immediate collapse of the disc space. Preliminary results indicate that disc space height was maintained after disc implantation in groups II, III and IV over time. MRI revealed high resolution images of normal intervertebral discs in vivo. Eight out of twelve animals (groups III and IV) showed a positive signal in T2-weighted images after 1 month (grade 0 = 4, grade 1 = 4, grade 2 = 4). Positive staining was seen for collagen as well as proteoglycans at the site of disc implantation after 1 month in each of the six animals with engineered implants (group III). Analysis of group IV showed positive T2 signal in five out of six animals and disc-height preservation in all animals after 6 months. Conclusions: This study demonstrates for the first time that tissue-engineered composite IVDs with circumferentially aligned collagen fibrils survive and integrate with surrounding vertebral bodies when placed in the rat spine for up to 6 months. Tissue-engineered composite IVDs restored function to the rat spine as indicated by maintenance of disc height and vertebral alignment. A significant finding was that maintenance of the composite structure in group III was observed, with increased proteoglycan staining in the nucleus pulposus region (Figure 4d–f). Proteoglycan and collagen matrix as well as disc height preservation and positive T2 signals in MRI are promising parameters and indicate functionality of the implants. PMID:23637671

Total disc replacement using a tissue-engineered intervertebral disc in vivo: new animal model and initial results.

PubMed

Gebhard, Harry; Bowles, Robby; Dyke, Jonathan; Saleh, Tatianna; Doty, Stephen; Bonassar, Lawrence; Härtl, Roger

2010-08-01

 Basic science Introduction:  Chronic back pain due to degenerative disc disease (DDD) is among the most important medical conditions causing morbidity and significant health care costs. Surgical treatment options include disc replacement or fusion surgery, but are associated with significant short- and long-term risks.1 Biological tissue-engineering of human intervertebral discs (IVD) could offer an important alternative.2 Recent in vitro data from our group have shown successful engineering and growth of ovine intervertebral disc composites with circumferentially aligned collagen fibrils in the annulus fibrosus (AF) (Figure 1).3 Figure 1 Tissue-engineered composite disc a Experimental steps to generate composite tissue-engineered IVDs3b Example of different AF formulations on collagen alignment in the AF. Second harmonic generation and two-photon excited fluorescence images of seeded collagen gels (for AF) of 1 and 2.5 mg/ml over time. At seeding, cells and collagen were homogenously distributed in the gels. Over time, AF cells elongated and collagen aligned parallel to cells. Less contraction and less alignment is noted after 3 days in the 2.5 mg/mL gel. c Imaging-based creation of a virtual disc model that will serve as template for the engineered disc. Total disc dimensions (AF and NP) were retrieved from micro-computer tomography (CT) (left images), and nucleus pulposus (NP) dimensions alone were retrieved from T2-weighted MRI images (right images). Merging of MRI and micro-CT models revealed a composite disc model (middle image)-Software: Microview, GE Healthcare Inc., Princeton, NJ; and slicOmatic v4.3, TomoVision, Montreal, Canada. d Flow chart describing the process for generating multi-lamellar tissue engineered IVDs. IVDs are produced by allowing cell-seeded collagen layers to contract around a cell-seeded alginate core (NP) over time Objective:  The next step is to investigate if biological disc implants survive, integrate, and restore function to the spine in vivo. A model will be developed that allows efficient in vivo testing of tissue-engineered discs of various compositions and characteristics.  Athymic rats were anesthetized and a dorsal approach was chosen to perform a microsurgical discectomy in the rat caudal spine (Fig. 2,Fig. 3). Control group I (n = 6) underwent discectomy only, Control group II (n = 6) underwent discectomy, followed by reimplantation of the autologous disc. Two treatment groups (group III, n = 6, 1 month survival; group IV, n = 6, 6 months survival) received a tissue-engineered composite disc implant. The rodents were followed clinically for signs of infection, pain level and wound healing. X-rays and magnetic resonance imaging (MRI) were assessed postoperatively and up to 6 months after surgery (Fig. 6,Fig. 7). A 7 Tesla MRI (Bruker) was implemented for assessment of the operated level as well as the adjacent disc (hydration). T2-weighted sequences were interpreted by a semiquantitative score (0 = no signal, 1 = weak signal, 2 = strong signal and anatomical features of a normal disc). Histology was performed with staining for proteoglycans (Alcian blue) and collagen (Picrosirius red) (Fig. 4,Fig. 5). Figure 2 Disc replacement surgery a Operative situs with native disc that has been disassociated from both adjacent vertebrae b Native disc (left) and tissue-engineered implant (right) c Implant in situ before wound closureAF: Annulus fi brosus, nP: nucleus pulposus, eP: endplate, M: Muscle, T: Tendon, s: skin, art: artery, GP: Growth plate, B: BoneFigure 3 Disc replacement surgery. Anatomy of the rat caudal disc space a Pircrosirius red stained axial cut of native disc space b Saffranin-O stained sagittal cut of native disc spaceFigure 4 Histologies of three separate motion segments from three different rats. Animal one = native IVD, Animal two = status after discectomy, Animal three = tissue-engineered implant (1 month) a-c H&E (overall tissue staining for light micrsocopy) d-f Alcian blue (proteoglycans) g-i Picrosirius red (collagen I and II)Figure 5 Histology from one motion segment four months after implantation of a bio-engineered disc construct a Picrosirius red staining (collagen) b Polarized light microscopy showing collagen staining and collagen organization in AF region c Increased Safranin-O staining (proteoglycans) in NP region of the disc implant d Higher magnification of figure 5c: Integration between implanted tissue-engineered total disc replacement and vertebral body boneFigure 6 MRI a Disc space height measurements in flash/T1 sequence (top: implant (714.0 micrometer), bottom: native disc (823.5 micrometer) b T2 sequence, red circle surrounding the implant NPFigure 7 7 Tesla MRI imaging of rat tail IVDs showing axial images (preliminary pilot data) a Diffusion tensor imaging (DTI) on two explanted rat tail discs in Formalin b Higher magnification of a, showing directional alignment of collagen fibers (red and green) when compared to the color ball on top which maps fibers' directional alignment (eg, fibers directing from left to right: red, from top to bottom: blue) c Native IVD in vivo (successful imaging of top and bottom of the IVD (red) d Gradient echo sequence (GE) showing differentiation between NP (light grey) and AF (dark margin) e GE of reimplanted tail IVD at the explantation level f T1Rho sequence demonstrating the NP (grey) within the AF (dark margin), containing the yellow marked region of interest for value acquisition (preliminary data are consistent with values reported in the literature). g T2 image of native IVD in vivo for monitoring of hydration (white: NP) Results:  The model allowed reproducible and complete discectomies as well as disc implantation in the rat tail spine without any surgical or postoperative complications. Discectomy resulted in immediate collapse of the disc space. Preliminary results indicate that disc space height was maintained after disc implantation in groups II, III and IV over time. MRI revealed high resolution images of normal intervertebral discs in vivo. Eight out of twelve animals (groups III and IV) showed a positive signal in T2-weighted images after 1 month (grade 0 = 4, grade 1 = 4, grade 2 = 4). Positive staining was seen for collagen as well as proteoglycans at the site of disc implantation after 1 month in each of the six animals with engineered implants (group III). Analysis of group IV showed positive T2 signal in five out of six animals and disc-height preservation in all animals after 6 months.  This study demonstrates for the first time that tissue-engineered composite IVDs with circumferentially aligned collagen fibrils survive and integrate with surrounding vertebral bodies when placed in the rat spine for up to 6 months. Tissue-engineered composite IVDs restored function to the rat spine as indicated by maintenance of disc height and vertebral alignment. A significant finding was that maintenance of the composite structure in group III was observed, with increased proteoglycan staining in the nucleus pulposus region (Figure 4d-f). Proteoglycan and collagen matrix as well as disc height preservation and positive T2 signals in MRI are promising parameters and indicate functionality of the implants.

Boomerang deformity of cervical spinal cord migrating between split laminae after laminoplasty.

PubMed

Kimura, S; Gomibuchi, F; Shimoda, H; Ikezawa, Y; Segawa, H; Kaneko, F; Uchiyama, S; Homma, T

2000-04-01

Patients with cervical compression myelopathy were studied to elucidate the mechanism underlying boomerang deformity, which results from the migration of the cervical spinal cord between split laminae after laminoplasty with median splitting of the spinous processes (boomerang sign). Thirty-nine cases, comprising 25 patients with cervical spondylotic myelopathy, 8 patients with ossification of the posterior longitudinal ligament, and 6 patients with cervical disc herniation with developmental canal stenosis, were examined. The clinical and radiological findings were retrospectively compared between patients with (B group, 8 cases) and without (C group, 31 cases) boomerang sign. Moderate increase of the grade of this deformity resulted in no clinical recovery, although there was no difference in clinical recovery between the two groups. Most boomerang signs developed at the C4/5 and/or C5/6 level, where maximal posterior movement of the spinal cord was achieved. Widths between lateral hinges and between split laminae in the B group were smaller than in the C group. Flatness of the spinal cord in the B group was more severe than in the C group. In conclusion, the boomerang sign was caused by posterior movement of the spinal cord, narrower enlargement of the spinal canal and flatness of the spinal cord.

The effects of massage therapy after decompression and fusion surgery of the lumbar spine: a case study.

PubMed

Keller, Glenda

2012-01-01

Spinal fusion and decompression surgery of the lumbar spine are common procedures for problems such as disc herniations. Various studies for postoperative interventions have been conducted; however, no massage therapy studies have been completed. The objective of this study is to determine if massage therapy can beneficially treat pain and dysfunction associated with lumbar spinal decompression and fusion surgery. Client is a 47-year-old female who underwent spinal decompression and fusion surgery of L4/L5 due to chronic disc herniation symptoms. The research design was a case study in a private clinic involving the applications of seven, 30-minute treatments conducted over eight weeks. Common Swedish massage and myofascial techniques were applied to the back, shoulders, posterior hips, and posterior legs. Outcomes were assessed using the following measures: VAS pain scale, Hamstring Length Test, Oswestry Disability Index, and the Roland-Morris Disability Questionnaire. Hamstring length improved (in degrees of extension) from pretreatment measurements in the right leg of 40° and left leg 65° to post-treatment measurement at the final visit, when the results were right 50° and left 70°. The Oswestry Disability Index improved 14%, from 50% to 36% disability. Roland-Morris Disability decreased 1 point, from 3/24 to 2/24. The VAS pain score decreased by 2 points after most treatments, and for three of the seven treatments, client had a post-treatment score of 0/10. Massage for pain had short-term effects. Massage therapy seemed to lengthen the hamstrings bilaterally. Massage therapy does appear to have positive effects in the reduction of disability. This study is beneficial for understanding the relationship between massage therapy and clients who have undergone spinal decompression and fusion. Further research is warranted.

Neurologic outcome after thoracolumbar partial lateral corpectomy for intervertebral disc disease in 72 dogs.

PubMed

Salger, Florian; Ziegler, Luisa; Böttcher, Irene Christine; Oechtering, Gerhard; Böttcher, Peter; Flegel, Thomas

2014-07-01

To determine neurologic outcome and factors influencing outcome after thoracolumbar partial lateral corpectomy (PLC) in dogs with intervertebral disc disease (IVDD) causing ventral spinal cord compression. Retrospective case series. Dogs with IVDD (n = 72; 87 PLC). Dogs with IVDD between T9 and L5 were included if treated by at least 1 PLC. Exclusion criteria were: previous spinal surgery, combination of PLC with another surgical procedure. Neurologic outcome was assessed by: (1) modified Frankel score (MFS) based on neurologic examinations at 4 time points (before surgery, immediately after PLC, at discharge and 4 weeks after PLC); and (2) owner questionnaire. The association of the following factors with neurologic outcome was analyzed: age, body weight, duration of current neurologic dysfunction (acute, chronic), IVDD localization, breed (chondrodystrophic, nonchondrodystrophic), number of PLCs, degree of presurgical spinal cord compression and postsurgical decompression, slot depth, presurgical MFS. Presurgical spinal cord compression was determined by CT myelography (71 dogs) or MRI (1 dog), whereas postsurgical decompression and slot depth were determined on CT myelography (69 dogs). MFS was improved in 18.7%, 31.7%, and 64.2% of dogs at the 3 postsurgical assessments, whereas it was unchanged in 62.6%, 52.8%, and 32.0% at corresponding time points. Based on owner questionnaire, 91.4% of dogs were ambulatory 6 months postsurgically with 74.5% having a normal gait. Most improvement in neurologic function developed within 6 months after surgery. Presurgical MFS was the only variable significantly associated with several neurologic outcome measurements (P < .01). PLC is an option for decompression in ventrally compressing thoracolumbar IVDD. Prognosis is associated with presurgical neurologic condition. © Copyright 2014 by The American College of Veterinary Surgeons.

Intralesional hemorrhage and thrombosis without rupture in a pure spinal epidural cavernous angioma: a rare cause of acute lumbal radiculopathy

PubMed Central

Riemenschneider, Markus; Herdmann, Jörg

2010-01-01

Pure spinal epidural cavernous angiomas are extremely rare lesions, and their normal shape is that of a fusiform mass in the dorsal aspects of the spinal canal. We report a case of a lumbo-sacral epidural cavernous vascular malformation presenting with acute onset of right-sided S1 radiculopathy. Clinical aspects, imaging, intraoperative findings, and histology are demonstrated. The patient, a 27-year-old man presented with acute onset of pain, paraesthesia, and numbness within the right leg corresponding to the S1 segment. An acute lumbosacral disc herniation was suspected, but MRI revealed a cystic lesion with the shape of a balloon, a fluid level and a thickened contrast-enhancing wall. Intraoperatively, a purple-blue tumor with fibrous adhesions was located between the right S1 and S2 nerve roots. Macroscopically, no signs of epidural bleedings could be denoted. After coagulation of a reticular venous feeder network and dissection of the adhesions the rubber ball-like lesion was resected in total. Histology revealed a prominent venous vessel with a pathologically thickened, amuscular wall surrounded by smaller, hyalinized, venous vessels arranged in a back-to-back position typical for the diagnosis of a cavernous angioma. Lumina were partially occluded by thrombi. The surrounding fibrotic tissue showed signs of recurrent bleedings. There was no obvious mass hemorrhage into the surrounding tissue. In this unique case, the pathologic mechanism was not the usual rupture of the cavernous angioma with subsequent intraspinal hemorrhage, but acute mass effect by intralesional bleedings and thrombosis with subsequent increase of volume leading to nerve root compression. Thus, even without a sudden intraspinal hemorrhage a spinal cavernous malformation can cause acute symptoms identical to the clinical features of a soft disc herniation. PMID:20213297

Adjacent segment disease after instrumented fusion for adult lumbar spondylolisthesis: Incidence and risk factors.

PubMed

Zhong, Zhao-Ming; Deviren, Vedat; Tay, Bobby; Burch, Shane; Berven, Sigurd H

2017-05-01

A potential long-term complication of lumbar fusion is the development of adjacent segment disease (ASD), which may necessitate second surgery and adversely affect outcomes. The objective of this is to determine the incidence of ASD following instrumented fusion in adult patients with lumbar spondylolisthesis and to identify the risk factors for this complication. We retrospectively assessed adult patients who had undergone decompression and instrumented fusion for lumbar spondylolisthesis between January 2006 and December 2012. The incidence of ASD was analyzed. Potential risk factors included the patient-related factors, surgery-related factors, and radiographic variables such as sagittal alignment, preexisting disc degeneration and spinal stenosis at the adjacent segment. A total of 154 patients (mean age, 58.4 years) were included. Mean duration of follow-up was 28.6 months. Eighteen patients (11.7%) underwent a reoperation for ASD; 15 patients had reoperation at cranial ASD and 3 at caudal ASD. The simultaneous decompression at adjacent segment (p=0.002) and preexisting spinal stenosis at cranial adjacent segment (p=0.01) were identified as risk factors for ASD. The occurrence of ASD was not affected by patient-related factors, the types, grades and levels of spondylolisthesis, surgical approach, fusion procedures, levels of fusion, number of levels fused, types of bone graft, use of bone morphogenetic proteins, sagittal alignment, preexisting adjacent disc degeneration and preexisting spinal stenosis at caudal adjacent segments. Our findings suggest the overall incidence of ASD is 11.7% in adult patients with lumbar spondylolisthesis after decompression and instrumented fusion at a mean follow-up of 28.6 months, the simultaneous decompression at the adjacent segment and preexisting spinal stenosis at cranial adjacent segment are risk factors for ASD. Copyright © 2017. Published by Elsevier B.V.

Clinical and radiological factors related to the presence of motor deficit in lumbar disc prolapse: a prospective analysis of 70 consecutive cases with neurological deficit.

PubMed

Krishnan, Vibhu; Rajasekaran, Shanmuganathan; Aiyer, Siddharth N; Kanna, Rishi; Shetty, Ajoy Prasad

2017-10-01

To analyse the clinic-radiological factors associated with neurological deficit following lumbar disc herniation. A prospective, cross-sectional study was performed in 140 cases of micro-discectomy following lumbar disc herniation. Group 1 included 70 consecutive patients with motor deficit and group 2 (controls) included 70 patients with intact neurology. Motor deficit was defined as the occurrence of motor power ≤3/5 in L2-S1 myotomes. Multiple clinical and radiological parameters were studied between the two groups. Patients with diabetes (p 0.004), acute onset of symptoms (p 0.036), L3-4 discs (p 0.001), sequestrated discs (p 0.004), superiorly migrated discs (p 0.012) and central discs (p 0.004), greater antero-posterior disc dimension (p 0.023), primary canal stenosis (p 0.0001); and greater canal compromise (p 0.002) had a significant correlation with the development of neurological deficit. The presence of four or more of these risk factors showed a higher chance of the presence of motor deficit (sensitivity of 74%, specificity of 77%). Age, sex, previous precipitating events, severity of pain, smoking, and number of herniations levels did not affect the occurrence of deficit (p > 0.05 for all). Patients with or without bladder symptoms were similar with respect to all clinico-radiological parameters. However, the time delay since the occurrence of deficit was significantly shorter in patients with bladder involvement (p 0.001). Patients with diabetes, acute presentation, central, sequestrated and superiorly migrated discs, high lumbar disc prolapse, and greater spinal canal compromise are predisposed to the presence of motor deficit.

Biomechanical Effects of the Geometry of Ball-and-Socket Artificial Disc on Lumbar Spine: A Finite Element Study.

PubMed

Choi, Jisoo; Shin, Dong-Ah; Kim, Sohee

2017-03-15

A three-dimensional finite element model of intact lumbar spine was constructed and four surgical finite element models implanted with ball-and-socket artificial discs with four different radii of curvature were compared. To investigate biomechanical effects of the curvature of ball-and-socket artificial disc using finite element analysis. Total disc replacement (TDR) has been accepted as an alternative treatment because of its advantages over spinal fusion methods in degenerative disc disease. However, the influence of the curvature of artificial ball-and-socket discs has not been fully understood. Four surgical finite element models with different radii of curvature of ball-and-socket artificial discs were constructed. The range of motion (ROM) increased with decreasing radius of curvature in extension, flexion, and lateral bending, whereas it increased with increasing radius of curvature in axial torsion. The facet contact force was minimum with the largest radius of curvature in extension, flexion, and lateral bending, whereas it was maximum with the largest radius in axial torsion. It was also affected by the disc placement, more with posterior placement than anterior placement. The stress in L4 cancellous bone increased when the radius of curvature was too large or small. The geometry of ball-and-socket artificial disc significantly affects the ROM, facet contact force, and stress in the cancellous bone at the surgical level. The implication is that in performing TDR, the ball-and-socket design may not be ideal, as ROM and facet contact force are sensitive to the disc design, which may be exaggerated by the individual difference of anatomical geometry. N/A.

Tracing notochord-derived cells using a Noto-cre mouse: implications for intervertebral disc development.

PubMed

McCann, Matthew R; Tamplin, Owen J; Rossant, Janet; Séguin, Cheryle A

2012-01-01

Back pain related to intervertebral disc degeneration is the most common musculoskeletal problem, with a lifetime prevalence of 82%. The lack of effective treatment for this widespread problem is directly related to our limited understanding of disc development, maintenance and degeneration. The aim of this study was to determine the developmental origins of nucleus pulposus cells within the intervertebral disc using a novel notochord-specific Cre mouse. To trace the fate of notochordal cells within the intervertebral disc, we derived a notochord-specific Cre mouse line by targeting the homeobox gene Noto. Expression of this gene is restricted to the node and the posterior notochord during gastrulation [embryonic day 7.5 (E7.5)-E12.5]. The Noto-cre mice were crossed with a conditional lacZ reporter for visualization of notochord fate in whole-mount embryos. We performed lineage-tracing experiments to examine the contribution of the notochord to spinal development from E12.5 through to skeletally mature mice (9 months). Fate mapping studies demonstrated that, following elongation and formation of the primitive axial skeleton, the notochord gives rise to the nucleus pulposus in fully formed intervertebral discs. Cellular localization of β-galactosidase (encoded by lacZ) and cytokeratin-8 demonstrated that both notochordal cells and chondrocyte-like nucleus pulposus cells are derived from the embryonic notochord. These studies establish conclusively that notochordal cells act as embryonic precursors to all cells found within the nucleus pulposus of the mature intervertebral disc. This suggests that notochordal cells might serve as tissue-specific progenitor cells within the disc and establishes the Noto-cre mouse as a unique tool to interrogate the contribution of notochordal cells to both intervertebral disc development and disc degeneration.

Tracing notochord-derived cells using a Noto-cre mouse: implications for intervertebral disc development

PubMed Central

McCann, Matthew R.; Tamplin, Owen J.; Rossant, Janet; Séguin, Cheryle A.

2012-01-01

SUMMARY Back pain related to intervertebral disc degeneration is the most common musculoskeletal problem, with a lifetime prevalence of 82%. The lack of effective treatment for this widespread problem is directly related to our limited understanding of disc development, maintenance and degeneration. The aim of this study was to determine the developmental origins of nucleus pulposus cells within the intervertebral disc using a novel notochord-specific Cre mouse. To trace the fate of notochordal cells within the intervertebral disc, we derived a notochord-specific Cre mouse line by targeting the homeobox gene Noto. Expression of this gene is restricted to the node and the posterior notochord during gastrulation [embryonic day 7.5 (E7.5)-E12.5]. The Noto-cre mice were crossed with a conditional lacZ reporter for visualization of notochord fate in whole-mount embryos. We performed lineage-tracing experiments to examine the contribution of the notochord to spinal development from E12.5 through to skeletally mature mice (9 months). Fate mapping studies demonstrated that, following elongation and formation of the primitive axial skeleton, the notochord gives rise to the nucleus pulposus in fully formed intervertebral discs. Cellular localization of β-galactosidase (encoded by lacZ) and cytokeratin-8 demonstrated that both notochordal cells and chondrocyte-like nucleus pulposus cells are derived from the embryonic notochord. These studies establish conclusively that notochordal cells act as embryonic precursors to all cells found within the nucleus pulposus of the mature intervertebral disc. This suggests that notochordal cells might serve as tissue-specific progenitor cells within the disc and establishes the Noto-cre mouse as a unique tool to interrogate the contribution of notochordal cells to both intervertebral disc development and disc degeneration. PMID:22028328

In vivo Loads in the Lumbar L3-4 Disc during a Weight Lifting Extension

PubMed Central

Wang, Shaobai; Park, Won Man; Kim, Yoon Hyuk; Cha, Thomas; Wood, Kirkham; Li, Guoan

2014-01-01

Background Knowledge of in vivo human lumbar loading is critical for understanding the lumbar function and for improving surgical treatments of lumbar pathology. Although numerous experimental measurements and computational simulations have been reported, non-invasive determination of in vivo spinal disc loads is still a challenge in biomedical engineering. The object of the study is to investigate the in vivo human lumbar disc loads using a subject-specific and kinematic driven finite element approach. Methods Three dimensional (3D) lumbar spine models of three living subjects were created using MR images. A 3D finite element model of the L3-4 disc, including the annulus fibrosus and nucleus pulposus, was built for each subject. The endplate kinematics of the L3-4 segment of each subject during a dynamic weight lifting extension was determined using a dual fluoroscopic imaging technique. The endplate kinematics was used as displacement boundary conditions of the subject specific finite element model of the L3-4 disc to calculate the in-vivo disc forces and moments during the weight lifting activity. Findings During the weight lifting extension, the L3-4 disc experienced maximum shear load of about 230 N or 0.34 bodyweight at the flexion position and maximum compressive load of 1500 N or 2.28 bodyweight at the upright position. The disc experienced a primary flexion-extension moment during the motion which reached a maximum of 4.2 Nm at upright position with stretched arms holding the weight. Interpretation This study provided quantitative data on in vivo disc loading that could help understand intrinsic biomechanics of the spine and improve surgical treatment of pathological discs using fusion or arthroplasty techniques. PMID:24345591

The Influence of Artificial Cervical Disc Prosthesis Height on the Cervical Biomechanics: A Finite Element Study.

PubMed

Yuan, Wei; Zhang, Haiping; Zhou, Xiaoshu; Wu, Weidong; Zhu, Yue

2018-05-01

Artificial cervical disc replacement is expected to maintain normal cervical biomechanics. At present, the effect of the Prestige LP prosthesis height on cervical biomechanics has not been thoroughly studied. This finite element study of the cervical biomechanics aims to predict how the parameters, like range of motion (ROM), adjacent intradiscal pressure, facet joint force, and bone-implant interface stress, are affected by different heights of Prestige LP prostheses. The finite element model of intact cervical spine (C3-C7) was obtained from our previous study, and the model was altered to implant Prestige LP prostheses at the C5-C6 level. The effects of the height of 5, 6, and 7 mm prosthesis replacement on ROM, adjacent intradiscal pressure, facet joint force, as well as the distribution of bone-implant interface stress were examined. ROM, adjacent intradiscal pressure, and facet joint force increased with the prosthesis height, whereas ROM and facet joint force decreased at C5-C6. The maximal stress on the inferior surface of the prostheses was greater than that on the superior surface, and the stresses increased with the prosthesis height. The biomechanical changes were slightly affected by the height of 5 and 6 mm prostheses, but were strongly affected by the 7-mm prosthesis. An appropriate height of the Prestige LP prosthesis can preserve normal ROM, adjacent intradiscal pressure, and facet joint force. Prostheses with a height of ≥2 mm than normal can lead to marked changes in the cervical biomechanics and bone-implant interface stress. Copyright © 2018 Elsevier Inc. All rights reserved.

Management of a case with misdiagnosed spinal dural arterio-venous fistula.

PubMed

Lien, Chia-Yi; Lui, Chun-Chung; Lu, Cheng-Hsien; Chang, Wen-Neng

2014-03-01

Spinal dural arterio-venous fistula (SDAVF) is an uncommon and easily misdiagnosed vascular malformation. We aimed to report the diagnosis and management of a case with SDAVF. A 62-year-old man suffered from acute paraparesis about 15 months before this study. He underwent a neurosurgical procedure for herniated discs of the cervical spine at that time but there was no relief and the symptoms worsened despite the surgery. Neurologically, he had spastic paraparesis and decreased vibration sensation of the lower limbs. Spinal magnetic resonance imaging (MRI) revealed intra-medullary hyper-intensity lesion at T8 to T10 levels and tubular-like signal void structures in the corresponding posterior sub-arachnoid space. Further trans-arterial angiography through right T6 intercostal artery catheterization revealed engorged veins, thereby confirming the diagnosis of SDAVF. The patient was treated via endovascular embolization (18% Onyx, EV3TM MIT, Bonn, Germany) through spinal angiography and the results showed a marked decrease in engorged veins. After a 4-month follow-up, the patient was symptomatic but stable. Follow-up MRI showed a complete disappearance of the hyper-intensity change of the spinal cord. Spinal MR angiography did not reveal any recurrence of SDAVF. This case study demonstrated the easily misdiagnosed state of SDAVF. Serial neuroimage studies including spinal MRI, endovascular embolization through spinal angiography and MR angiography can be useful tools for its diagnostic confirmation, management and follow-up study.

Spinal Health during Unloading and Reloading Associated with Spaceflight

PubMed Central

Green, David A.; Scott, Jonathan P. R.

2018-01-01

Spinal elongation and back pain are recognized effects of exposure to microgravity, however, spinal health has received relatively little attention. This changed with the report of an increased risk of post-flight intervertebral disc (IVD) herniation and subsequent identification of spinal pathophysiology in some astronauts post-flight. Ground-based analogs, particularly bed rest, suggest that a loss of spinal curvature and IVD swelling may be factors contributing to unloading-induced spinal elongation. In flight, trunk muscle atrophy, in particular multifidus, may precipitate lumbar curvature loss and reduced spinal stability, but in-flight (ultrasound) and pre- and post-flight (MRI) imaging have yet to detect significant IVD changes. Current International Space Station missions involve short periods of moderate-to-high spinal (axial) loading during running and resistance exercise, superimposed upon a background of prolonged unloading (microgravity). Axial loading acting on a dysfunctional spine, weakened by anatomical changes and local muscle atrophy, might increase the risk of damage/injury. Alternatively, regular loading may be beneficial. Spinal pathology has been identified in-flight, but there are few contemporary reports of in-flight back injury and no recent studies of post-flight back injury incidence. Accurate routine in-flight stature measurements, in- and post-flight imaging, and tracking of pain and injury (herniation) for at least 2 years post-flight is thus warranted. These should be complemented by ground-based studies, in particular hyper buoyancy floatation (HBF) a novel analog of spinal unloading, in order to elucidate the mechanisms and risk of spinal injury, and to evaluate countermeasures for exploration where injury could be mission critical. PMID:29403389

Spinal Health during Unloading and Reloading Associated with Spaceflight.

PubMed

Green, David A; Scott, Jonathan P R

2017-01-01

Spinal elongation and back pain are recognized effects of exposure to microgravity, however, spinal health has received relatively little attention. This changed with the report of an increased risk of post-flight intervertebral disc (IVD) herniation and subsequent identification of spinal pathophysiology in some astronauts post-flight. Ground-based analogs, particularly bed rest, suggest that a loss of spinal curvature and IVD swelling may be factors contributing to unloading-induced spinal elongation. In flight, trunk muscle atrophy, in particular multifidus , may precipitate lumbar curvature loss and reduced spinal stability, but in-flight (ultrasound) and pre- and post-flight (MRI) imaging have yet to detect significant IVD changes. Current International Space Station missions involve short periods of moderate-to-high spinal (axial) loading during running and resistance exercise, superimposed upon a background of prolonged unloading (microgravity). Axial loading acting on a dysfunctional spine, weakened by anatomical changes and local muscle atrophy, might increase the risk of damage/injury. Alternatively, regular loading may be beneficial. Spinal pathology has been identified in-flight, but there are few contemporary reports of in-flight back injury and no recent studies of post-flight back injury incidence. Accurate routine in-flight stature measurements, in- and post-flight imaging, and tracking of pain and injury (herniation) for at least 2 years post-flight is thus warranted. These should be complemented by ground-based studies, in particular hyper buoyancy floatation (HBF) a novel analog of spinal unloading, in order to elucidate the mechanisms and risk of spinal injury, and to evaluate countermeasures for exploration where injury could be mission critical.

Comparison of instrumented anterior interbody fusion with instrumented circumferential lumbar fusion.

PubMed

Madan, S S; Boeree, N R

2003-12-01

Posterior lumbar interbody fusion (PLIF) restores disc height, the load bearing ability of anterior ligaments and muscles, root canal dimensions, and spinal balance. It immobilizes the painful degenerate spinal segment and decompresses the nerve roots. Anterior lumbar interbody fusion (ALIF) does the same, but could have complications of graft extrusion, compression and instability contributing to pseudarthrosis in the absence of instrumentation. The purpose of this study was to assess and compare the outcome of instrumented circumferential fusion through a posterior approach [PLIF and posterolateral fusion (PLF)] with instrumented ALIF using the Hartshill horseshoe cage, for comparable degrees of internal disc disruption and clinical disability. It was designed as a prospective study, comparing the outcome of two methods of instrumented interbody fusion for internal disc disruption. Between April 1994 and June 1998, the senior author (N.R.B.) performed 39 instrumented ALIF procedures and 35 instrumented circumferential fusion with PLIF procedures. The second author, an independent assessor (S.M.), performed the entire review. Preoperative radiographic assessment included plain radiographs, magnetic resonance imaging (MRI) and provocative discography in all the patients. The outcome in the two groups was compared in terms of radiological improvement and clinical improvement, measured on the basis of improvement of back pain and work capacity. Preoperatively, patients were asked to fill out a questionnaire giving their demographic details, maximum walking distance and current employment status in order to establish the comparability of the two groups. Patient assessment was with the Oswestry Disability Index, quality of life questionnaire (subjective), pain drawing, visual analogue scale, disability benefit, compensation status, and psychological profile. The results of the study showed a satisfactory outcome (score< or =30) on the subjective (quality of life questionnaire) score of 71.8% (28 patients) in the ALIF group and 74.3% (26 patients) in the PLIF group (P>0.05). On categorising Oswestry Index scores into "excellent", "better", "same", and "worse", we found no difference in outcome between the two groups: 79.5% (n=31) had satisfactory outcome with ALIF and 80% (n=28) had satisfactory outcome with PLIF. The rate of return to work was no different in the two groups. On radiological assessment, we found two nonunions in the circumferential fusion (PLIF) group (94.3% fusion rate) and indirect evidence of no nonunions in the ALIF group. There was no significant difference between the compensation rate and disability benefit rate between the two groups. There were three complications in ALIF group and four in the PLIF (circumferential) group. On the basis of these results, we conclude that it is possible to treat discogenic back pain by anterior interbody fusion with Hartshill horseshoe cage or with circumferential fusion using instrumented PLIF.

The Lumbar Lordosis in Males and Females, Revisited

PubMed Central

Hay, Ori; Dar, Gali; Abbas, Janan; Stein, Dan; May, Hila; Masharawi, Youssef; Peled, Nathan; Hershkovitz, Israel

2015-01-01

Background Whether differences exist in male and female lumbar lordosis has been debated by researchers who are divided as to the nature of variations in the spinal curve, their origin, reasoning, and implications from a morphological, functional and evolutionary perspective. Evaluation of the spinal curvature is constructive in understanding the evolution of the spine, as well as its pathology, planning of surgical procedures, monitoring its progression and treatment of spinal deformities. The aim of the current study was to revisit the nature of lumbar curve in males and females. Methods Our new automated method uses CT imaging of the spine to measure lumbar curvature in males and females. The curves extracted from 158 individuals were based on the spinal canal, thus avoiding traditional pitfalls of using bone features for curve estimation. The model analysis was carried out on the entire curve, whereby both local and global descriptors were examined in a single framework. Six parameters were calculated: segment length, curve length, curvedness, lordosis peak location, lordosis cranial peak height, and lordosis caudal peak height. Principal Findings Compared to males, the female spine manifested a statistically significant greater curvature, a caudally located lordotic peak, and greater cranial peak height. As caudal peak height is similar for males and females, the illusion of deeper lordosis among females is due partially to the fact that the upper part of the female lumbar curve is positioned more dorsally (more backwardly inclined). Conclusions Males and females manifest different lumbar curve shape, yet similar amount of inward curving (lordosis). The morphological characteristics of the female spine were probably developed to reduce stress on the vertebral elements during pregnancy and nursing. PMID:26301782

Failed back surgery syndrome: the role of symptomatic segmental single-level instability after lumbar microdiscectomy.

PubMed

Schaller, B

2004-05-01

Segmental instability represents one of several different factors that may cause or contribute to the failed back surgery syndrome after lumbar microdiscectomy. As segmental lumbar instability poses diagnostic problems by lack of clear radiological and clinical criteria, only little is known about the occurrence of this phenomenon following primary microdiscectomy. Retrospectively, the records of 2,353 patients were reviewed according to postoperative symptomatic segmental single-level instability after lumbar microdiscectomy between 1989 and 1997. Progressive neurological deficits increased (mean of 24 months; SD: 12, range 1-70) after the initial surgical procedure in 12 patients. The mean age of the four men and eight women was 43 years (SD: 6, range 40-77). The main symptoms and signs of secondary neurological deterioration were radicular pain in 9 of 12 patients, increased motor weakness in 6 of 12 patients and sensory deficits in 4 of 12 patients. All 12 symptomatic patients had radiological evidence of segmental changes correlating with the clinical symptoms and signs. All but one patient showed a decrease in the disc height greater than 30% at the time of posterior spondylodesis compared with the preoperative images before lumbar microdiscectomy. All patients underwent secondary laminectomy and posterior lumbar sponylodesis. Postoperatively, pain improved in 8 of 9 patients, motor weakness in 3 of 6 patients, and sensory deficits in 2 of 4 patients. During the follow-up period of 72+/-7 months, one patient required a third operation to alleviate spinal stenosis at the upper end of the laminectomy. Patients with secondary segmental instability following microdiscectomy were mainly in their 40s. Postoperative narrowing of the intervertebral space following lumbar microdiscectomy is correlated to the degree of intervertebral disc resection. It can therefore be concluded that (1) patients in their 40s are prone to postoperative narrowing of the intervertebral disc space and hence subsequent intervertebral instability and (2) that a small extent of intervertebral disc resection and preservation of the "segmental frame" may be beneficial in those patients. The present study demonstrated for the first time that the degree of extensive operative techniques in microdiscectomy increased the risk of subsequent segmental instability. In addition, narrowing of the intervertebral space of more than 30% represents a clear radiological sign of segmental instability.

Dentin abrasivity of various desensitizing toothpastes.

PubMed

Arnold, W H; Gröger, Ch; Bizhang, M; Naumova, E A

2016-04-02

The aim of this study was to compare the abrasivity of various commercially available toothpastes that claim to reduce dentin hypersensitivity. Dentin discs were prepared from 70 human extracted molars. The discs were etched with lemon juice for 5 min, and one half of the discs were covered with aluminum tape. Following this, they were brushed with 6 different toothpastes, simulating a total brushing time of 6 months. As a negative control, discs were brushed with tap water only. The toothpastes contained pro-arginine and calcium carbonate, strontium acetate, stannous fluoride, zinc carbonate and hydroxyapatite, new silica, or tetrapotassium pyrophosphate and hydroxyapatite. After brushing, the height differences between the control halves and the brushed halves were determined with a profilometer and statistically compared using a Mann-Whitney U test for independent variables. A significant difference (p < 0.001) in height difference between the controls and the toothpaste-treated samples was found in all cases, except for the stannous fluoride-containing toothpaste (p = 0.583). The highest abrasion was found in the toothpaste containing zinc carbonate and hydroxyapatite, and the lowest was found in the toothpaste containing pro-arginine and calcium carbonate. Desensitizing toothpastes with different desensitizing ingredients have different levels of abrasivity, which may have a negative effect on their desensitizing abilities over a long period of time.

Large Steel Tank Fails and Rockets to Height of 30 meters - Rupture Disc Installed Incorrectly.

PubMed

Hedlund, Frank H; Selig, Robert S; Kragh, Eva K

2016-06-01

At a brewery, the base plate-to-shell weld seam of a 90-m(3) vertical cylindrical steel tank failed catastrophically. The 4 ton tank "took off" like a rocket leaving its contents behind, and landed on a van, crushing it. The top of the tank reached a height of 30 m. The internal overpressure responsible for the failure was an estimated 60 kPa. A rupture disc rated at < 50 kPa provided overpressure protection and thus prevented the tank from being covered by the European Pressure Equipment Directive. This safeguard failed and it was later discovered that the rupture disc had been installed upside down. The organizational root cause of this incident may be a fundamental lack of appreciation of the hazards of large volumes of low-pressure compressed air or gas. A contributing factor may be that the standard piping and instrumentation diagram (P&ID) symbol for a rupture disc may confuse and lead to incorrect installation. Compressed air systems are ubiquitous. The medium is not toxic or flammable. Such systems however, when operated at "slight overpressure" can store a great deal of energy and thus constitute a hazard that ought to be addressed by safety managers.

Value of repeat CT scans in low back pain and radiculopathy.

PubMed

Schroeder, Josh E; Barzilay, Yair; Kaplan, Leon; Itshayek, Eyal; Hiller, Nurith

2016-02-01

We assessed the clinical value of repeat spine CT scan in 108 patients aged 18-60 years who underwent repeat lumbar spine CT scan for low back pain or radiculopathy from January 2008 to December 2010. Patients with a neoplasm or symptoms suggesting underlying disease were excluded from the study. Clinical data was retrospectively reviewed. Index examinations and repeat CT scan performed at a mean of 24.3 ± 11.3 months later were compared by a senior musculoskeletal radiologist. Disc abnormalities (herniation, sequestration, bulge), spinal stenosis, disc space narrowing, and bony changes (osteophytes, fractures, other changes) were documented. Indications for CT scan were low back pain (60 patients, 55%), radiculopathy (46 patients, 43%), or nonspecific back pain (two patients, 2%). A total of 292 spine pathologies were identified in 98 patients (90.7%); in 10 patients (9.3%) no spine pathology was seen on index or repeat CT scan. At repeat CT scan, 269/292 pathologies were unchanged (92.1%); 10/292 improved (3.4%), 8/292 worsened (2.8%, disc herniation or spinal stenosis), and five new pathologies were identified. No substantial therapeutic change was required in patients with worsened or new pathology. Added diagnostic value from repeat CT scan performed within 2-3 years was rare in patients suffering chronic or recurrent low back pain or radiculopathy, suggesting that repeat CT scan should be considered only in patients with progressive neurologic deficits, new neurologic complaints, or signs implying serious underlying conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

In vitro assessment of biomaterial-induced remodeling of subchondral and cancellous bone for the early intervention of joint degeneration with focus on the spinal disc

NASA Astrophysics Data System (ADS)

McCanless, Jonathan D.

Osteoarthritis-associated pain of the spinal disc, knee, and hip derives from degeneration of cartilagenous tissues in these joints. Traditional therapies have focused on these cartilage (and disc specific nucleus pulposus) changes as a means of treatment through tissue grafting, regenerative synthetic implants, non-regenerative space filling implants, arthroplasty, and arthrodesis. Although such approaches may seem apparent upon initial consideration of joint degeneration, tissue pathology has shown changes in the underlying bone and vascular bed precede the onset of cartilaginous changes. It is hypothesized that these changes precedent joint degeneration and as such may provide a route for early prevention. The current work proposes an injectable biomaterial-based therapy within these subchondral and cancellous bone regions as a means of preventing or reversing osteoarthritis. Two human concentrated platelet releasate-containing alginate hydrogel/beta-tricalcium phosphate composites have been developed for this potential biomaterial application. The undertaking of assessing these materials through bench-, in vitro, and ex vivo work is described herein. These studies showed the capability of the biomaterials to initiate a wound healing response in monocytes, angiogenic and differentiation behavior in immature endothelial cells, and early osteochondral differentiation in mesenchymal stem cells. These cellular activities are associated with fracture healing and endochondral bone formation, demonstrating the potential of the biomaterials to induce osseous and vascular tissue remodeling underlying osteoarthritic joints as a novel therapy for a disease with rapidly growing healthcare costs.

A rare etiology of cauda equina syndrome.

PubMed

Batra, Sumit; Arora, Sumit; Meshram, Hemant; Khanna, Geetika; Grover, Shabnam B; Sharma, Vinod K

2011-02-01

Fungal infections of the spine are very rare and usually seen in immunocompromised patients. Acute cauda equina syndrome presenting in an immunocompetent patient is usually due to a prolapse of the intervertebral disc. Infective pathology caused by Mycobacterium tuberculosis with epidural collection can also have a similar presentation. We present a case of spinal epidural abscess caused by Aspergillus fumigatus, presenting as acute cauda equina syndrome. To the best of our knowledge, spinal aspergillosis presenting as cauda equina syndrome in an immunocompetent patient has not been reported before in the English-language based medical literature. Surgical decompression with antifungal treatment with oral itraconazole yielded a good recovery.

Progression of lumbar disc degeneration over a decade: a heritability study

PubMed Central

Williams, Frances M K; Popham, Maria; Sambrook, Philip N; Jones, Annette F; Spector, Tim D; MacGregor, Alex J

2011-01-01

Objectives Lumbar disc degeneration (LDD) is prevalent, age-related and contributes to low back pain. Cross-sectional LDD as determined by MRI scan is known to be highly heritable. The authors postulated that the rate of progression might also be controlled by genetic factors. Methods A 10-year follow-up of MRI-determined LDD was performed in 234 pairs of twin volunteers in the UK and Australia, comprising 90 monozygotic pairs and 144 dizygotic same-sex twin pairs. Of the total sample, 95% were female. The mean age at baseline was 53.3 years (range 32.3–69.5). The rate of progression was calculated and, because the effect of age was non-linear, the sample was divided into age strata and heritability estimated for each trait's progression. Results All MRI-determined traits worsened significantly over the period of follow-up (p<0.0001 for each). Change in disc height was not heritable at any age while posterior disc bulge was heritable across all age categories (range 28–53%), with higher heritability in those over 60 years. Change in disc signal intensity and anterior osteophytes were found to be heritable only in those aged under 50 years at baseline (heritability estimates 76% (95% CI 44% to 100%) and 74% (42% to 100%), respectively). Conclusions Longitudinal change in LDD traits is heritable for all traits except disc height, but there is a significant influence of age, which varies across traits. Future studies to define the genetic variants influencing LDD progression should examine MRI traits individually and in women should focus on those under 50 years of age. PMID:21402564

Primary limited lumbar discectomy with an annulus closure device: one-year clinical and radiographic results from a prospective, multi-center study.

PubMed

Lequin, Michiel B; Barth, Martin; Thomė, Claudius; Bouma, Gerrit J

2012-12-01

Discectomy as a treatment for herniated lumbar discs results in outcomes after surgery that are not uniformly positive. Surgeons face the dilemma between limited nucleus removal which is associated with a higher risk of recurrence, or more aggressive nucleus removal which may lead to disc height loss and persistent back-pain. annulus closure devices may allow for the benefits of limited nucleus removal without the increased risk of recurrence. This is an interim report of an ongoing 24-month post-marketing study of the Barricaid® annulus closure device, consisting of a flexible polymer mesh that blocks the defect, held in place by a titanium bone anchor. We prospectively enrolled 45 patients at four hospitals, and implanted the Barricaid® after a limited discectomy. annulus defect size and volume of removed nucleus were recorded. Reherniations were reported, pain and function were monitored and imaging was performed at regular intervals during 24 months of follow-up. At 12 months postsurgery, pain and function were significantly improved, comparing favorably to reported results from limited discectomy. Disc height has been well maintained. One reherniation has occurred (2.4%), which was associated with a misplaced device. No device fracture, subsidence or migration has been observed. The use of an annulus closure device may provide a reduction in reherniation rate for lumbar discectomy patients with large annulus defects who are at the greatest risk of recurrence. Using such a device should provide the surgeon increased confidence in minimizing nucleus removal, which, in turn, may preserve disc height and biomechanics, reducing degeneration and associated poor clinical outcomes in the long-term. A randomized multicenter study evaluating limited discectomy with and without the Barricaid® is currently underway, and will provide a higher level of evidence.

In vivo biofunctional evaluation of hydrogels for disc regeneration.

PubMed

Reitmaier, Sandra; Kreja, Ludwika; Gruchenberg, Katharina; Kanter, Britta; Silva-Correia, Joana; Oliveira, Joaquim Miguel; Reis, Rui Luís; Perugini, Valeria; Santin, Matteo; Ignatius, Anita; Wilke, Hans-Joachim

2014-01-01

Regenerative strategies aim to restore the original biofunctionality of the intervertebral disc. Different biomaterials are available, which might support disc regeneration. In the present study, the prospects of success of two hydrogels functionalized with anti-angiogenic peptides and seeded with bone marrow derived mononuclear cells (BMC), respectively, were investigated in an ovine nucleotomy model. In a one-step procedure iliac crest aspirates were harvested and, subsequently, separated BMC were seeded on hydrogels and implanted into the ovine disc. For the cell-seeded approach a hyaluronic acid-based hydrogel was used. The anti-angiogenic potential of newly developed VEGF-blockers was investigated on ionically crosslinked metacrylated gellan gum hydrogels. Untreated discs served as nucleotomy controls. 24 adult merino sheep were used. After 6 weeks histological, after 12 weeks histological and biomechanical analyses were conducted. Biomechanical tests revealed no differences between any of the implanted and nucleotomized discs. All implanted discs significantly degenerated compared to intact discs. In contrast, there was no marked difference between implanted and nucleotomized discs. In tendency, albeit not significant, degeneration score and disc height index deteriorated for all but not for the cell-seeded hydrogels from 6 to 12 weeks. Cell-seeded hydrogels slightly decelerated degeneration. None of the hydrogel configurations was able to regenerate biofunctionality of the intervertebral disc. This might presumably be caused by hydrogel extrusion. Great importance should be given to the development of annulus sealants, which effectively exploit the potential of (cell-seeded) hydrogels for biological disc regeneration and restoration of intervertebral disc functioning.

Comparison of the efficacy of saline, local anesthetics, and steroids in epidural and facet joint injections for the management of spinal pain: A systematic review of randomized controlled trials

PubMed Central

Manchikanti, Laxmaiah; Nampiaparampil, Devi E.; Manchikanti, Kavita N.; Falco, Frank J.E.; Singh, Vijay; Benyamin, Ramsin M.; Kaye, Alan D.; Sehgal, Nalini; Soin, Amol; Simopoulos, Thomas T.; Bakshi, Sanjay; Gharibo, Christopher G.; Gilligan, Christopher J.; Hirsch, Joshua A.

2015-01-01

Background: The efficacy of epidural and facet joint injections has been assessed utilizing multiple solutions including saline, local anesthetic, steroids, and others. The responses to these various solutions have been variable and have not been systematically assessed with long-term follow-ups. Methods: Randomized trials utilizing a true active control design were included. The primary outcome measure was pain relief and the secondary outcome measure was functional improvement. The quality of each individual article was assessed by Cochrane review criteria, as well as the criteria developed by the American Society of Interventional Pain Physicians (ASIPP) for assessing interventional techniques. An evidence analysis was conducted based on the qualitative level of evidence (Level I to IV). Results: A total of 31 trials met the inclusion criteria. There was Level I evidence that local anesthetic with steroids was effective in managing chronic spinal pain based on multiple high-quality randomized controlled trials. The evidence also showed that local anesthetic with steroids and local anesthetic alone were equally effective except in disc herniation, where the superiority of local anesthetic with steroids was demonstrated over local anesthetic alone. Conclusion: This systematic review showed equal efficacy for local anesthetic with steroids and local anesthetic alone in multiple spinal conditions except for disc herniation where the superiority of local anesthetic with steroids was seen over local anesthetic alone. PMID:26005584

Comparison between cranial thoracic intervertebral disc herniations in German Shepherd dogs and other large breed dogs.

PubMed

Gaitero, Luis; Nykamp, Stephanie; Daniel, Rob; Monteith, Gabrielle

2013-01-01

Cranial thoracic intervertebral disc herniations have been reported to be rare in dogs due to the presence of the intercapital ligament, however some studies have proposed they may not be uncommon in German Shepherd dogs. The purpose of this retrospective study was to compare cranial thoracic intervertebral disc herniations in German Shepherd dogs and other large breed dogs (control group). Medical records at the Ontario Veterinary College were searched for German Shepherd dogs and other large breed dogs that had magnetic resonance imaging studies including the T1-T9 region. For each dog and each disc space from T1-T9, three variables (compression, disc degeneration, and herniation) were recorded and graded based on review of sagittal T2-weighted images. Twenty-three German Shepherd dogs and 47 other large breed dogs met inclusion criteria. The German Shepherd dog group had higher scores than the control group for compression (P = 0.0099) and herniation (P < 0.001), but not disc degeneration (P = 0.97). In the German Shepherd dog group, intervertebral discs T2-T3 and T4-T5 had an increased risk for compression and T3-T4 had an increased risk for compression and herniation. Findings from this study indicated that German Shepherd dogs may be more likely than other large breed dogs to have spinal cord compression due to cranial thoracic disc herniations. Imaging of the cranial thoracic spine, including T2-T3, is recommended for German Shepherd dogs with T3-L3 neurological signs. © 2012 Veterinary Radiology & Ultrasound.

Intervertebral disc regeneration or repair with biomaterials and stem cell therapy--feasible or fiction?

PubMed

Chan, Samantha C W; Gantenbein-Ritter, Benjamin

2012-05-31

The "gold standard" for treatment of intervertebral disc herniations and degenerated discs is still spinal fusion, corresponding to the saying "no disc - no pain". Mechanical prostheses, which are currently implanted, do only have medium outcome success and have relatively high re-operation rates. Here, we discuss some of the biological intervertebral disc replacement approaches, which can be subdivided into at least two classes in accordance to the two different tissue types, the nucleus pulposus (NP) and the annulus fibrosus (AF). On the side of NP replacement hydrogels have been extensively tested in vitro and in vivo. However, these gels are usually a trade-off between cell biocompatibility and load-bearing capacity, hydrogels which fulfill both are still lacking. On the side of AF repair much less is known and the question of the anchoring of implants is still to be addressed. New hope for cell therapy comes from developmental biology investigations on the existence of intervertebral disc progenitor cells, which would be an ideal cell source for cell therapy. Also notochordal cells (remnants of the embryonic notochord) have been recently pushed back into focus since these cells have regenerative potential and can activate disc cells. Growth factor treatment and molecular therapies could be less problematic. The biological solutions for NP and AF replacement are still more fiction than fact. However, tissue engineering just scratched the tip of the iceberg, more satisfying solutions are yet to be added to the biomedical pipeline.

Spinal cord lesions in Bangladesh: an epidemiological study 1994 - 1995.

PubMed

Hoque, M F; Grangeon, C; Reed, K

1999-12-01

Spinal Cord Lesions are a major public health problem in Bangladesh. This epidemiological study was undertaken in order to identify the causes of spinal cord lesions and thus to allow prevention and control programs to be developed. The records of 247 patients with spinal cord lesions admitted to The Centre for the Rehabilitation of the Paralysed (CRP), Savar, Dhaka from January 1994 to June 1995 were reviewed retrospectively. Comparisons were made with the reports of studies from other countries, both developing and developed. The most common cause of traumatic lesions was a fall from a height followed by falling when carrying a heavy weight on the head and road traffic accidents. Most of the patients were between 20 - 40 years old and the overall age group ranged from 10 - 70 years. The male:female ratio was 7.5 : 1.0. Among the traumatic spinal cord lesions, 60% were paraplegics and 40% tetraplegics. Among the non-traumatic spinal cord lesions cases 84% were paraplegics and 16% tetraplegics. The leading cause of death resulted from respiratory complications and these deaths occurred in the very early period of admission. From the results it can be deduced that the high incidence of spinal cord lesion as a result from falls from a height, and from falling when carrying a heavy weight on the head, can be explained by the mainly agricultural based economy of Bangladesh. The most common age group (10 - 40 years) of patients reflects the socio-economic conditions of Bangladesh. The male:female ratio (7.5 : 1.0) of patients with a spinal cord lesion is due to the socio-economic status and to the traditional culture of the society.

Characteristic microwave background distortions from collapsing domain wall bubbles

NASA Technical Reports Server (NTRS)

Goetz, Guenter; Noetzold, Dirk

1990-01-01

The magnitude and angular pattern of distortions of the microwave background are analyzed by collapsing spherical domain walls. A characteristic pattern of redshift distortions of red or blue spikes surrounded by blue discs was found. The width and height of a spike is related to the diameter and magnitude of the disc. A measurement of the relations between these quantities thus can serve as an unambiguous indicator for a collapsing spherical domain wall. From the redshift distortion in the blue discs an upper bound was found on the surface energy density of the walls sigma is less than or approximately 8 MeV cubed.

Acute spinal injury after centrifuge training in asymptomatic fighter pilots.

PubMed

Kang, Kyung-Wook; Shin, Young Ho; Kang, Seungcheol

2015-04-01

Many countries have hypergravity training centers using centrifuges for pilots to cope with a high gravity (G) environment. The high G training carries potential risk for the development of spinal injury. However, no studies evaluated the influence of centrifuge training on the spines of asymptomatic fighter pilots on a large scale. Study subjects were 991 male fighter pilots with high G training at one institution. Subject variables included information about physical characteristics, flight hours of pilots prior to the training, and G force exposure related factors during training. The two dependent variables were whether the pilots developed acute spinal injury after training and the severity of the injury (major/minor). The incidence of acute spinal injury after high G training was 2.3% (23 of 991 subjects). There were 19 subjects who developed minor injury and 4 subjects who developed a herniated intervertebral disc, which is considered a major injury. In multivariate analysis, only the magnitude of G force during training was significantly related to the development of acute spinal injury. However, there was no significant factor related to the severity of the injury. These results suggest that high G training could cause negative effects on fighter pilots' spines. The magnitude of G force during training seemed to be the most significant factor affecting the occurrence of acute spinal injury.

Effect of collagen fibre orientation on intervertebral disc torsion mechanics.

PubMed

Yang, Bo; O'Connell, Grace D

2017-12-01

The intervertebral disc is a complex fibro-cartilaginous material, consisting of a pressurized nucleus pulposus surrounded by the annulus fibrosus, which has an angle-ply structure. Disc injury and degeneration are noted by significant changes in tissue structure and function, which significantly alters stress distribution and disc joint stiffness. Differences in fibre orientation are thought to contribute to changes in disc torsion mechanics. Therefore, the objective of this study was to evaluate the effect of collagen fibre orientation on internal disc mechanics under compression combined with axial rotation. We developed and validated a finite element model (FEM) to delineate changes in disc mechanics due to fibre orientation from differences in material properties. FEM simulations were performed with fibres oriented at [Formula: see text] throughout the disc (uniform by region and fibre layer). The initial model was validated by published experimental results for two load conditions, including [Formula: see text] axial compression and [Formula: see text] axial rotation. Once validated, fibre orientation was rotated by [Formula: see text] or [Formula: see text] towards the horizontal plane, resulting in a decrease in disc joint torsional stiffness. Furthermore, we observed that axial rotation caused a sinusoidal change in disc height and radial bulge, which may be beneficial for nutrient transport. In conclusion, including anatomically relevant fibre angles in disc joint FEMs is important for understanding stress distribution throughout the disc and will be important for understanding potential causes for disc injury. Future models will include regional differences in fibre orientation to better represent the fibre architecture of the native disc.

Monoradiculopathy and secondary segmental instability caused by postoperative pars interarticularis fracture: a case report.

PubMed

Kaner, Tuncay; Tutkan, Ibrahim

2009-04-01

Instability can develop after lumbar spinal surgery. What is also known as secondary segmental instability is one of the important causes of failed back syndrome. In this paper, we described a 45-year-old female patient who was diagnosed with secondary segmental instability caused by left L3 pars interarticularis fracture after a high lumbar disc surgery and was subsequently treated with re-operation. We evaluated the clinical course, diagnosis, and treatment methods for secondary segmental instability caused by postoperative pars interarticularis fracture. Furthermore, we emphasized the importance of preserving the pars interarticularis during upper lumbar disc surgeries in order to avoid a potential stress fracture.

CT and MRI in the evaluation of extraspinal sciatica

PubMed Central

Ergun, T; Lakadamyali, H

2010-01-01

Sciatica is the most frequently encountered symptom in neurosurgical practice and is observed in 40% of adults at some point in their lives. It is described as pain of the hip and the lower extremity secondary to pathologies affecting the sciatic nerve within its intraspinal or extraspinal course. The most frequent cause is a herniating lumbar disc pressing on the neural roots. Extraspinal causes of sciatic pain are usually overlooked because they are extremely rare and due to intraspinal causes (lumbar spinal stenosis, facet joint osteoarthritis, fracture, and tumors of the spinal cord and spinal column) being the main consideration. Early diagnosis of sciatica significantly improves the likelihood of relieving symptoms, as well as avoiding any additional neurologic injury and unnecessary surgery. We evaluate histolopathologically confirmed extraspinal causes of sciatica cases, accompanied by their presented computed tomography and/or magnetic resonance imaging findings. PMID:20647515

[Low back pain vs. leg dominant pain].

PubMed

Kovac, Ida

2011-01-01

There are two patterns of back pain: 1) back-dominant pain and 2) leg pain dominant, greater than back pain. The causes of back pain are very different and numerous, but mostly are due to vertebral, mechanical etiology, and rarely because of non vertebral, visceral etiology. Leg pain greater than back pain is mostly disease of spinal nerve root, generally presented by radicular pain in a dermatomal distribution. Mechanical compression of spinal roots, caused by disc herniation or by spinal stenosis, results in radicular symptoms. Rarely, in about 1% of patients, there are some other reasons except vertebral mechanical cause, like infection, tumor or fracture. There are several causes of pseudoradicular pain like periferal neuropathy, myifascial syndromes, vascular diseases, osteoarthritis. Spondylarthropathies should be taken in cosideration as well. A complete history and physical examination is important to determine further diagnostic evaluation and to provide eficient therapy.

Torus models of the outer disc of the Milky Way using LAMOST survey data

NASA Astrophysics Data System (ADS)

Wang, Qiao; Wang, Yougang; Liu, Chao; Mao, Shude; Long, R. J.

2017-09-01

With a sample of 48 161 K giant stars selected from the LAMOST DR 2 catalogue, we construct torus models in a large volume extending, for the first time, from the solar vicinity to a Galactocentric distance of ∼20 kpc, reaching the outskirts of the Galactic disc. We show that the kinematics of the K giant stars match conventional models, e.g. as created by Binney in 2012, in the Solar vicinity. However such two-disc models fail if they are extended to the outer regions, even if an additional disc component is utilized. If we loosen constraints in Sun's vicinity, we find that an effective thick disc model could explain the anticentre of the MW. The Large Area Multi-Object Spectroscopic Telescope data imply that the sizes of the Galactic discs are much larger, and that the outer disc is much thicker, than previously thought, or alternatively that the outer structure is not a conventional disc at all. However, the velocity dispersion σ0z of the kinematically thick disc in the best-fitting model is about 80 km s-1 and has a scale parameter Rσ for an exponential distribution function of ∼19 kpc. Such a height σ0z is strongly rejected by current measurements in the solar neighbourhood, and thus a model beyond quasi-thermal, two or three thin or thick discs is required.

Classification of High Intensity Zones of the Lumbar Spine and Their Association with Other Spinal MRI Phenotypes: The Wakayama Spine Study.

PubMed

Teraguchi, Masatoshi; Samartzis, Dino; Hashizume, Hiroshi; Yamada, Hiroshi; Muraki, Shigeyuki; Oka, Hiroyuki; Cheung, Jason Pui Yin; Kagotani, Ryohei; Iwahashi, Hiroki; Tanaka, Sakae; Kawaguchi, Hiroshi; Nakamura, Kozo; Akune, Toru; Cheung, Kenneth Man-Chee; Yoshimura, Noriko; Yoshida, Munehito

2016-01-01

High intensity zones (HIZ) of the lumbar spine are a phenotype of the intervertebral disc noted on MRI whose clinical relevance has been debated. Traditionally, T2-weighted (T2W) magnetic resonance imaging (MRI) has been utilized to identify HIZ of lumbar discs. However, controversy exists with regards to HIZ morphology, topography, and association with other MRI spinal phenotypes. Moreover, classification of HIZ has not been thoroughly defined in the past and the use of additional imaging parameters (e.g. T1W MRI) to assist in defining this phenotype has not been addressed. A cross-sectional study of 814 (69.8% females) subjects with mean age of 63.6 years from a homogenous Japanese population was performed. T2W and T1W sagittal 1.5T MRI was obtained on all subjects to assess HIZ from L1-S1. We created a morphological and topographical HIZ classification based on disc level, shape type (round, fissure, vertical, rim, and enlarged), location within the disc (posterior, anterior), and signal type on T1W MRI (low, high and iso intensity) in comparison to the typical high intensity on T2W MRI. HIZ was noted in 38.0% of subjects. Of these, the prevalence of posterior, anterior, and both posterior/anterior HIZ in the overall lumbar spine were 47.3%, 42.4%, and 10.4%, respectively. Posterior HIZ was most common, occurring at L4/5 (32.5%) and L5/S1 (47.0%), whereas anterior HIZ was most common at L3/4 (41.8%). T1W iso-intensity type of HIZ was most prevalent (71.8%), followed by T1W high-intensity (21.4%) and T1W low-intensity (6.8%). Of all discs, round types were most prevalent (anterior: 3.6%, posterior: 3.7%) followed by vertical type (posterior: 1.6%). At all affected levels, there was a significant association between HIZ and disc degeneration, disc bulge/protrusion and Modic type II (p<0.01). Posterior HIZ and T1W high-intensity type of HIZ were significantly associated with disc bulge/protrusion and disc degeneration (p<0.01). In addition, posterior HIZ was significantly associated with Modic type II and III. T1W low-intensity type of HIZ was significantly associated with Modic type II. This is the first large-scale study reporting a novel classification scheme of HIZ of the lumbar spine. This study is the first that has utilized T2W and T1W MRIs in differentiating HIZ sub-phenotypes. Specific HIZ sub-phenotypes were found to be more associated with specific MRI degenerative changes. With a more detailed description of the HIZ phenotype, this scheme can be standardized for future clinical and research initiatives.

The sensitivity and specificity of the Slump and the Straight Leg Raising tests in patients with lumbar disc herniation.

PubMed

Majlesi, Javid; Togay, Halit; Unalan, Halil; Toprak, Sadk

2008-04-01

An accurate and specific diagnosis prevents the recurrences of low back pain and chronic spinal pain. The physical examination is the most useful tool to diagnosis. The examiner must aim to determine the exact tissue that pain arises from to make the specific diagnosis. Lumbar disc herniation is 1 disease that physical examination, symptoms, and findings on imaging technique do not always correlate with each other. The Straight Leg Raising (SLR) test has been used as the primary test to diagnosis lumbar disc herniations and found to have high correlation with findings on operation since its sensitivity is high in only disc herniations leading to root compression that may eventually need operation. More sensitive test, like the Slump, might be used in herniations in which the SLR is negative. The Slump test is really a variant of the SLR and the Lasègue's tests performed in the seated position and is a progressive series of maneuvers designed to place the sciatic nerve roots under increasing tension. At each step in the procedure, the patient informs the examiner what is being felt and whether radicular pain is produced. As a result, the Slump test applies traction to the nerve roots by incorporating spinal and hip joint flexion into the leg raising and would warn the examiner of the presence of nerve root compression when there is a negative SLR test. This study measured the sensitivity and specificity of the Slump test and compare it with the SLR test in patients with and without lumbar disc herniations. A prospective case control study of 75 patients with complaints suggestive of lumbar disc herniation was carried out in the outpatient clinics of the neurosurgery department of a state teaching hospital. Seventy-five referred or self-admitted patients with low back, leg, or low back and leg pain who had results of magnetic resonance imaging (MRI) of the lumbar spine were included in the study. Thirty-eight patients had signs of herniation demonstrated by MRI. Control patients (n = 37) had no disc bulges or herniations on MRI. Both the Slump and SLR tests were performed during the assessment of all the patients by the second author. The MRI results were assessed and recorded by the first author. The Slump test was found to be more sensitive (0.84) than the SLR (0.52) in the patients with lumbar disc herniations. However, the SLR was found to be a slightly more specific test (0.89) than the Slump test (0.83). The Slump test might be used more frequently as a sensitive physical examination tool in patients with symptoms of lumbar disc herniations. In contrast, owing to its higher specificity, the SLR test may especially help identify patients who have herniations with root compression requiring surgery.

Human Disc Nucleus Properties and Vertebral Endplate Permeability

PubMed Central

Rodriguez, Azucena G.; Slichter, Chloe K.; Acosta, Frank L.; Rodriguez-Soto, Ana E.; Burghardt, Andrew J.; Majumdar, Sharmila; Lotz, Jeffrey C.

2010-01-01

Study of human cadaveric discs quantifying endplate permeability and porosity and correlating these with measures of disc quality: cell density, proteoglycan content, and overall degeneration. Permeability and porosity increased with age and were not correlated with cell density or overall degeneration, suggesting that endplate calcification may not accelerate disc degeneration. Study Design Experimental quantification of relationships between vertebral endplate morphology, permeability, disc cell density, glycosaminoglycan content and degeneration in samples harvested from human cadaveric spines. Objective To test the hypothesis that variation in endplate permeability and porosity contribute to changes in intervertebral disc cell density and overall degeneration. Summary of Background Data Cells within the intervertebral disc are dependent on diffusive exchange with capillaries in the adjacent vertebral bone. Previous findings suggest that blocked routes of transport negatively affect disc quality, yet there are no quantitative relationships between human vertebral endplate permeability, porosity, cell density and disc degeneration. Such relationships would be valuable for clarifying degeneration risk factors, and patient features that may impede efforts at disc tissue engineering. Methods Fifty-one motion segments were harvested from 13 frozen cadaveric human lumbar spines (32 to 85 years) and classified for degeneration using the MRI-based Pfirrmann scale. A cylindrical core was harvested from the center of each motion segment that included vertebral bony and cartilage endplates along with adjacent nucleus tissue. The endplate mobility, a type of permeability, was measured directly using a custom-made permeameter before and after the cartilage endplate was removed. Cell density within the nucleus tissue was estimated using the picogreen method while the nuclear GAG content was quantified using the DMMB technique. Specimens were imaged at 8 μm resolution using microCT, bony porosity was calculated. Analysis of variance, linear regression, and multiple comparison tests were used to analyze the data. Results Nucleus cell density increased as the disc height decreased (R2=0.13; p=0.01) but was not related to subchondral bone porosity (p>0.5), total mobility (p>0.4) or age (p>0.2). When controlling for disc height however, a significant, negative effect of age on cell density was observed (p=0.03). In addition to this, GAG content decreased with age non-linearly (R2=0.83, p<0.0001) and a cell function measurement, GAGs/cell decreased with degeneration (R2=0.24; p<0.0001). Total mobility (R2=0.14; p<0.01) and porosity (R2=0.1, p<0.01) had a positive correlation with age. Conclusion Although cell density increased with degeneration, cell function indicated that GAGs/cell decreased. Since permeability and porosity increase with age and degeneration, this implies that cell dysfunction, rather than physical barriers to transport, accelerate disc disease. PMID:21240044

Effect of Interbody Fusion on the Remaining Discs of the Lumbar Spine in Subjects with Disc Degeneration.

PubMed

Ryu, Robert; Techy, Fernando; Varadarajan, Ravikumar; Amirouche, Farid

2016-02-01

To study effects (stress loads) of lumbar fusion on the remaining segments (adjacent or not) of the lumbar spine in the setting of degenerated adjacent discs. A lumbar spine finite element model was built and validated. The full model of the lumbar spine was a parametric finite element model of segments L 1-5 . Numerous hypothetical combinations of one-level lumbar spine fusion and one-level disc degeneration were created. These models were subjected to 10 Nm flexion and extension moments and the stresses on the endplates and consequently on the intervertebral lumbar discs measured. These values were compared to the stresses on healthy lumbar spine discs under the same load and fusion scenarios. Increased stress at endplates was observed only in the settings of L4-5 fusion and L3-4 disc degeneration (8% stress elevation at L2,3 in flexion or extension, and 25% elevation at L3,4 in flexion only). All other combinations showed less endplate stress than did the control model. For fusion at L3-4 and degeneration at L4-5 , the stresses in the endplates at the adjacent level inferior to the fused disc decreased for both loading disc height reductions. Stresses in flexion decreased after fusion by 29.5% and 25.8% for degeneration I and II, respectively. Results for extension were similar. For fusion at L2-3 and degeneration at L4-5 , stresses in the endplates decreased more markedly at the degenerated (30%), than at the fused level (14%) in the presence of 25% disc height reduction and 10 Nm flexion, whereas in extension stresses decreased more at the fused (24.3%) than the degenerated level (5.86%). For fusion at L3-4 and degeneration at L2-3 , there were no increases in endplate stress in any scenario. For fusion at L4-5 and degeneration at L3-4 , progression of degeneration from I to II had a significant effect only in flexion. A dramatic increase in stress was noted in the endplates of the degenerated disc (L3-4 ) in flexion for degeneration II. Stresses are greater in flexion at the endplates of L3-4 and in flexion and extension at L2-3 in the presence of L3-4 disc disease and L4-5 fusion than in the control group. In all other combinations of fusion and disc disease, endplate stress was less for all levels tested than in the control model. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

[Lumbar spondylosis].

PubMed

Seichi, Atsushi

2014-10-01

Lumbar spondylosis is a chronic, noninflammatory disease caused by degeneration of lumbar disc and/or facet joints. The etiology of lumbar spondylosis is multifactorial. Patients with lumbar spondylosis complain of a broad variety of symptoms including discomfort in the low back lesion, whereas some of them have radiating leg pain or neurologenic intermittent claudication (lumbar spinal stenosis). The majority of patients with spondylosis and stenosis of the lumbosacral spine can be treated nonsurgically. Nonsteroidal anti-inflammatory drugs and COX-2 inhibitors are helpful in controlling symptoms. Prostaglandin, epidural injection, and transforaminal injection are also helpful for leg pain and intermittent claudication. Operative therapy for spinal stenosis or spondylolisthesis is reserved for patients who are totally incapacitated by their condition.

Challenges of transcutaneous laser application for the potential of photobiomodulation of the spinal cord at the scale of a large companion animal

NASA Astrophysics Data System (ADS)

Piao, Daqing; Sypniewski, Lara A.; Bartels, Kenneth E.

2017-02-01

Photobiomodulation (PBM) has been used successfully for the treatment of nervous system and has been demonstrated in the rodent model. In contrast, the percutaneous use of PBM to treat spinal cord of companion animals is expected to be challenging due to the significant attenuation of light energy as it travels through the thick and heterogeneous layers of tissue and bone to reach the level of the spinal cord. This pilot study was performed on a cadaverous dog to determine if the recommended bio-stimulatory treatment dose can be delivered to the spinal canal via percutaneous application of a clinically acceptable surface dose. The dose reaching the spinal canal after percutaneous application was measured at 980nm by using a miniature photo-diode sensor with a dose-response sensitivity of 1V per 1mW/cm2 dose and a 2mm spherical isotropic fiber-optical diffusor probe. The two sensors were embedded in different longitudinal positions along the dorsal portion of the spinal canal just below the soft tissues and vertebral processes in a 40lbs cadaverous dog. The spinal cord was then accessed via a hemilaminectomy. Once embedded in the target tissue, 1W-10 W surface irradiation was applied. At the T12/13 and T13/L1 intervertebral disc positions, photo-diode sensors detected the intra-spinal dose above the noise floor at the 10W surface dose. A narrow treatment window for percutaneous PBM in large dog may exist only for the shallowest segment of the spinal cord, which may be important to avoid potential collateral photothermal effects. Works for simultaneous multi-site intra-spinal measurements are on-going.

Height increase, neuromuscular function, and back pain during 6 degrees head-down tilt with traction

NASA Technical Reports Server (NTRS)

Styf, J. R.; Ballard, R. E.; Fechner, K.; Watenpaugh, D. E.; Kahan, N. J.; Hargens, A. R.

1997-01-01

BACKGROUND: Spinal lengthening and back pain are commonly experienced by astronauts exposed to microgravity. METHODS: To develop a ground-based simulation for spinal adaptation to microgravity, we investigated height increase, neuromuscular function and back pain in 6 subjects all of whom underwent two forms of bed rest for 3 d. One form consisted of 6 degrees of head-down tilt (HDT) with balanced traction, while the other was horizontal bed rest (HBR). Subjects had a 2-week recovery period in between the studies. RESULTS: Total body and spinal length increased significantly more and the subjects had significantly more back pain during HDT with balanced traction compared to HBR. The distance between the lower endplate of L4 and upper endplate of S1, as measured by ultrasonography, increased significantly in both treatments to the same degree. Intramuscular pressures in the erector spinae muscles and ankle torque measurements during plantarflexion and dorsiflexion did not change significantly during either treatment. CONCLUSION: Compared to HBR, HDT with balanced traction may be a better method to simulate changes of total body and spinal lengths, as well as back pain seen in microgravity.

Comprehensive review of neurophysiologic basis and diagnostic interventions in managing chronic spinal pain.

PubMed

Manchikanti, Laxmaiah; Boswell, Mark V; Singh, Vijay; Derby, Richard; Fellows, Bert; Falco, Frank J E; Datta, Sukdeb; Smith, Howard S; Hirsch, Joshua A

2009-01-01

Understanding the neurophysiological basis of chronic spinal pain and diagnostic interventional techniques is crucial in the proper diagnosis and management of chronic spinal pain. Central to the understanding of the structural basis of chronic spinal pain is the provision of physical diagnosis and validation of patient symptomatology. It has been shown that history, physical examination, imaging, and nerve conduction studies in non-radicular or discogenic pain are unable to diagnose the precise cause in 85% of the patients. In contrast, controlled diagnostic blocks have been shown to determine the cause of pain in as many as 85% of the patients. To provide evidence-based clinical practice guidelines for diagnostic interventional techniques. Best evidence synthesis. Strength of evidence was assessed by the U.S. Preventive Services Task Force (USPSTF) criteria utilizing 5 levels of evidence ranging from Level I to III with 3 subcategories in Level II. Diagnostic criteria established by systematic reviews were utilized with controlled diagnostic blocks. Diagnostic criteria included at least 80% pain relief with controlled local anesthetic blocks with the ability to perform multiple maneuvers which were painful prior to the diagnostic blocks for facet joint and sacroiliac joint blocks, whereas for provocation discography, the criteria included concordant pain upon stimulation of the target disc with 2 adjacent discs producing no pain at all. The indicated level of evidence for diagnostic lumbar, cervical, and thoracic facet joint nerve blocks is Level I or II-1. The indicated evidence is Level II-2 for lumbar and cervical discography, whereas it is Level II-3 for thoracic provocation discography. The evidence for diagnostic sacroiliac joint nerve blocks is Level II-2. Level of evidence for selective nerve root blocks for diagnostic purposes is Level II-3. Limitations of this guideline preparation include a continued paucity of literature and conflicts in preparation of systematic reviews and guidelines. These guidelines include the evaluation of evidence for diagnostic interventional procedures in managing chronic spinal pain and recommendations. However, these guidelines do not constitute inflexible treatment recommendations. These guidelines also do not represent a "standard of care."

Cervical Lordosis Actually Increases With Aging and Progressive Degeneration in Spinal Deformity Patients.

PubMed

Kim, Han Jo; Lenke, Lawrence G; Oshima, Yasushi; Chuntarapas, Tapanut; Mesfin, Addisu; Hershman, Stuart; Fogelson, Jeremy L; Riew, K Daniel

2014-09-01

Retrospective. The authors hypothesized that cervical lordosis (CL) would decrease with aging and increasing degeneration. It is theorized that with age and degeneration, the cervical spine loses lordosis and becomes progressively more kyphotic; however, no studies support these conclusions in patients with various spinal deformities. The authors performed a radiographic analysis of asymptomatic adults (referring to their cervical spine) of varying ages, with differing forms of spinal deformity to the thoracic/lumbar spine to see how cervical lordosis changes with increasing age. A total of 104 total spine EOS X-rays of adult (aged >18 years) spinal deformity patients without documented neck pain, prior neck surgery, or cervical deformity were reviewed. The researchers only reviewed EOS X-rays because they allow complete visualization from occiput to feet. Cervical lordosis, standard Cobb measurements, sagittal balance parameters, and cervical degeneration were quantified radiographically by the method previously described by Gore et al. Statistical analysis was performed with 1-way analysis of variance to compare significant differences between groups aged <40, 40-60 and >60 years as well as changes in sagittal balance. A p-value < .05 was considered significant. Average CL actually increased with increasing age (10.3 ± 14.7, 15.4 ± 15.1, and 23.3 ± 1.6.7 for age < 40, 40-60, and > 60 years, respectively; p < .05). Average cervical degeneration score increased at all disc space levels from C2 to C7 across age groups (0.7 ± 1.2, 9.9 ± 69, and 16.3 ± 8.9 for age <40, 40-60, and >60 years, respectively; p < .01), with the highest degeneration at the C5-6 and C6-7 disc spaces (3.7 ± 3.3 and 3.2 ± 2.9, respectively; p < .01). This increase did not correlate with the increase in CL seen with aging (r = 0.02; p = .84). Cervical lordosis increased with aging in adult spinal deformity patients. There was no relationship between cervical degeneration and lordosis despite the strong relationship seen between increasing CL in older age groups. Copyright © 2014 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

A simplified method of walking track analysis to assess short-term locomotor recovery after acute spinal cord injury caused by thoracolumbar intervertebral disc extrusion in dogs.

PubMed

Song, R B; Oldach, M S; Basso, D M; da Costa, R C; Fisher, L C; Mo, X; Moore, S A

2016-04-01

The purpose of this study was to evaluate a simplified method of walking track analysis to assess treatment outcome in canine spinal cord injury. Measurements of stride length (SL) and base of support (BS) were made using a 'finger painting' technique for footprint analysis in all limbs of 20 normal dogs and 27 dogs with 28 episodes of acute thoracolumbar spinal cord injury (SCI) caused by spontaneous intervertebral disc extrusion. Measurements were determined at three separate time points in normal dogs and on days 3, 10 and 30 following decompressive surgery in dogs with SCI. Values for SL, BS and coefficient of variance (COV) for each parameter were compared between groups at each time point. Mean SL was significantly shorter in all four limbs of SCI-affected dogs at days 3, 10, and 30 compared to normal dogs. SL gradually increased toward normal in the 30 days following surgery. As measured by this technique, the COV-SL was significantly higher in SCI-affected dogs than normal dogs in both thoracic limbs (TL) and pelvic limbs (PL) only at day 3 after surgery. BS-TL was significantly wider in SCI-affected dogs at days 3, 10 and 30 following surgery compared to normal dogs. These findings support the use of footprint parameters to compare locomotor differences between normal and SCI-affected dogs, and to assess recovery from SCI. Additionally, our results underscore important changes in TL locomotion in thoracolumbar SCI-affected dogs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Interference of Detection Rate of Lumbar Disc Herniation by Socioeconomic Status

PubMed Central

Ji, Gyu Yeul; Jung, Nak-Yong; An, Seong Dae; Choi, Won-Seok; Kim, Jung Hoon

2013-01-01

Study Design Retrospective study. Purpose The objective of the study is to evaluate the relationship between the detection rate of lumbar disc herniation and socioeconomic status. Overview of Literature Income is one important determinant of public health. Yet, there are no reports about the relationship between socioeconomic status and the detective rate of disc herniation. Methods In this study, 443 cases were checked for lumbar computed tomography for lumbar disc herniation, and they reviewed questionnaires about their socioeconomic status, the presence of back pain or radiating pain and the presence of a medical certificate (to check the medical or surgical treatment for the pain) during the Korean conscription. Results Without the consideration for the presence of a medical certificate, there was no difference in spinal physical grade according to socioeconomic status (p=0.290). But, with the consideration of the presence of a medical certificate, the significant statistical differences were observed according to socioeconomic status in 249 cases in the presence of a medical certificate (p=0.028). There was a lower detection rate in low economic status individuals than those in the high economic class. The common reason for not submitting a medical certificate is that it is neither necessary for the people of lower socioeconomic status nor is it financially affordable. Conclusions The prevalence of lumbar disc herniation is not different according to socioeconomic status, but the detective rate was affected by socioeconomic status. Socioeconomic status is an important factor for detecting lumbar disc herniation. PMID:23508288

Comparison of the intervertebral disc spaces between axial and anterior lean cervical traction.

PubMed

Chung, Chin-Teng; Tsai, Sen-Wei; Chen, Chun-Jung; Wu, Ting-Chung; Wang, David; Lan, Haw-Chang H; Wu, Shyi-Kuen

2009-11-01

The insufficient investigations on the changes of spinal structures during traction prevent further exploring the possible therapeutic mechanism of cervical traction. A blind randomized crossover-design study was conducted to quantitatively compare the intervertebral disc spaces between axial and anterior lean cervical traction in sitting position. A total of 96 radiographic images from the baseline measurements, axial and anterior lean tractions in 32 asymptomatic subjects were digitized for further analysis. The intra- and inter-examiner reliabilities for measuring the intervertebral disc spaces were in good ranges (ICCs = 0.928-0.942). With the application of anterior lean traction, the statistical increases were detected both in anterior and in posterior disc spaces compared to the baseline (0.29 mm and 0.24 mm; both P < 0.01) and axial traction (0.16 mm and 0.35 mm; both P < 0.01). The greater intervertebral disc spaces obtained during anterior lean traction might be associated with the more even distribution of traction forces over the anterior and posterior neck structures. The neck extension moment through mandible that generally occurred in the axial traction could be counteracted by the downward force of head weight during anterior lean traction. This study quantitatively demonstrated that anterior lean traction in sitting position provided more intervertebral disc space enlargements in both anterior and posterior aspects than axial traction did. These findings may serve as a therapeutic reference when cervical traction is suggested.

Interference of detection rate of lumbar disc herniation by socioeconomic status.

PubMed

Ji, Gyu Yeul; Oh, Chang Hyun; Jung, Nak-Yong; An, Seong Dae; Choi, Won-Seok; Kim, Jung Hoon

2013-03-01

Retrospective study. The objective of the study is to evaluate the relationship between the detection rate of lumbar disc herniation and socioeconomic status. Income is one important determinant of public health. Yet, there are no reports about the relationship between socioeconomic status and the detective rate of disc herniation. In this study, 443 cases were checked for lumbar computed tomography for lumbar disc herniation, and they reviewed questionnaires about their socioeconomic status, the presence of back pain or radiating pain and the presence of a medical certificate (to check the medical or surgical treatment for the pain) during the Korean conscription. Without the consideration for the presence of a medical certificate, there was no difference in spinal physical grade according to socioeconomic status (p=0.290). But, with the consideration of the presence of a medical certificate, the significant statistical differences were observed according to socioeconomic status in 249 cases in the presence of a medical certificate (p=0.028). There was a lower detection rate in low economic status individuals than those in the high economic class. The common reason for not submitting a medical certificate is that it is neither necessary for the people of lower socioeconomic status nor is it financially affordable. The prevalence of lumbar disc herniation is not different according to socioeconomic status, but the detective rate was affected by socioeconomic status. Socioeconomic status is an important factor for detecting lumbar disc herniation.

The deformation behavior of the cervical spine segment

NASA Astrophysics Data System (ADS)

Kolmakova, T. V.; Rikun, Yu. A.

2017-09-01

The paper describes the model of the cervical spine segment (C3-C4) and the calculation results of its deformation behavior at flexion. The segment model was built based on the experimental literature data taking into account the presence of the cortical and cancellous bone tissue of vertebral bodies. Degenerative changes of the intervertebral disk (IVD) were simulated through a reduction of the disc height and an increase of Young's modulus. The construction of the geometric model of the cervical spine segment and the calculations of the stress-strain state were carried out in the ANSYS software complex. The calculation results show that the biggest protrusion of the IVD in bending direction of segment is observed when IVD height is reduced. The disc protrusion is reduced with an increase of Young's modulus. The largest protrusion in the direction of flexion of the segment is the intervertebral disk with height of 4.3 mm and elastic modulus of 2.5 MPa. The results of the study can be useful to specialists in the field of biomechanics, medical materials science and prosthetics.

Effect of abdominal irradiation on growth in boys treated for a Wilms' tumor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallace, W.H.; Shalet, S.M.; Morris-Jones, P.H.

1990-01-01

To study the effect of abdominal irradiation on spinal growth in childhood we have measured final height, sitting height, and leg length in 30 male survivors of a Wilms' tumor. Twenty-one patients received whole abdominal irradiation by either megavoltage therapy (MV: n = 11) or orthovoltage therapy (OV: n = 10); the remainder received flank irradiation. To examine the effect of the adolescent growth spurt on the irradiated spine we have followed prospectively seven patients who received whole abdominal irradiation and nine patients who received flank irradiation through puberty. Compared to a normal population there is a modest reduction inmore » median final standing height SDS (H.SDS: -1.15) accompanied by a marked reduction in median final sitting height SDS (S.HT SDS: -2.41) with no apparent effect on median subischial leg length SDS (SILL.SDS: 0.04). This reduction in spinal growth is reflected by a strongly positive disproportion score (DPS; (SILL SDS-S.HT SDS) + 2.81). The incidence of scoliosis after abdominal irradiation has been low (10%). During puberty there is a significant fall in median sitting height SDS after both whole abdominal (median fall: -0.9, P = 0.02) and flank irradiation (median fall: -1.85, P = 0.01), and this is reflected in a significant increase in disproportion (DPS: whole abdominal; median rise +1.4, P = 0.02: flank, median rise +1.34, P = 0.01). After MV irradiation there is a significant correlation between the degree of disproportion and the age at treatment (P less than 0.0005). The younger the patient is at treatment the more severe is the restriction on spinal growth and the shorter and more disproportionate they become as an adult. The estimated eventual loss in potential height from abdominal irradiation at the age of one is 10 cm and at five years is 7 cm.« less

The impact of posture and prolonged cyclic compressive loading on vertebral joint mechanics.

PubMed

Gooyers, Chad E; McMillan, Robert D; Howarth, Samuel J; Callaghan, Jack P

2012-08-01

An in vitro biomechanics investigation exposing porcine functional spinal units (FSUs) to submaximal cyclic or static compressive forces while in a flexed, neutral, or extended posture. To investigate the combined effect of cyclically applied compressive force (e.g., vibration) and postural deviation on intervertebral joint mechanics. Independently, prolonged vibration exposure and non-neutral postures are known risk factors for development of low back pain and injury. However, there is limited basic scientific evidence to explain how the risk of low back injury from vibration exposure is modified by other mechanical factors. This work examined the influence of static postural deviation on vertebral joint height loss and compressive stiffness under cyclically applied compressive force. Forty-eight FSUs, consisting of 2 adjacent vertebrae, ligaments, and the intervening intervertebral disc were included in the study. Each specimen was randomized to 1 of 3 experimental posture conditions (neutral, flexed, or extended) and assigned to 1 of 2 loading protocols, consisting of (1) cyclic (1500 ± 1200 N applied at 5 Hz using a sinusoidal waveform, resulting in 0.2 g rms acceleration) or (2) 1500 N of static compressive force. RESULTS.: As expected, FSU height loss followed a typical first-order response in both the static and cyclic loading protocols, with the majority (~50%) of the loss occurring in the first 20 minutes of testing. A significant interaction between posture and loading protocol (P < 0.001) was noted in the magnitude of FSU height loss. Subsequent analysis of simple effects revealed significant differences between cyclic and static loading protocols in both a neutral (P = 0.016) and a flexed posture (P < 0.0001). No significant differences (P = 0.320) were noted between pre/postmeasurements of FSU compressive stiffness. Posture is an important mechanical factor to consider when assessing the risk of injury from cyclic loading to the lumbar spine.

Disruption of biomineralization pathways in spinal tissues of a mouse model of diffuse idiopathic skeletal hyperostosis.

PubMed

Ii, Hisataka; Warraich, Sumeeta; Tenn, Neil; Quinonez, Diana; Holdsworth, David W; Hammond, James R; Dixon, S Jeffrey; Séguin, Cheryle A

2016-09-01

Equilibrative nucleoside transporter 1 (ENT1) mediates passage of adenosine across the plasma membrane. We reported previously that mice lacking ENT1 (ENT1(-/-)) exhibit progressive ectopic mineralization of spinal tissues resembling diffuse idiopathic skeletal hyperostosis (DISH) in humans. Here, we investigated mechanisms underlying aberrant mineralization in ENT1(-/-) mice. Micro-CT revealed ectopic mineralization of spinal tissues in both male and female ENT1(-/-) mice, involving the annulus fibrosus of the intervertebral discs (IVDs) of older mice. IVDs were isolated from wild-type and ENT1(-/-) mice at 2months of age (prior to disc mineralization), 4, and 6months of age (disc mineralization present) and processed for real-time PCR, cell isolation, or histology. Relative to the expression of ENTs in other tissues, ENT1 was the primary nucleoside transporter expressed in wild-type IVDs and mediated the functional uptake of [(3)H]2-chloroadenosine by annulus fibrosus cells. No differences in candidate gene expression were detected in IVDs from ENT1(-/-) and wild-type mice at 2 or 4months of age. However, at 6months of age, expression of genes that inhibit biomineralization Mgp, Enpp1, Ank, and Spp1 were reduced in IVDs from ENT1(-/-) mice. To assess whether changes detected in ENT1(-/-) mice were cell autonomous, annulus fibrosus cell cultures were established. Compared to wild-type cells, cells isolated from ENT1(-/-) IVDs at 2 or 6months of age demonstrated greater activity of alkaline phosphatase, a promoter of biomineralization. Cells from 2-month-old ENT1(-/-) mice also showed greater mineralization than wild-type. Interestingly, altered localization of alkaline phosphatase activity was detected in the inner annulus fibrosus of ENT1(-/-) mice in vivo. Alkaline phosphatase activity, together with the marked reduction in mineralization inhibitors, is consistent with the mineralization of IVDs seen in ENT1(-/-) mice at older ages. These findings establish that both cell-autonomous and systemic mechanisms contribute to ectopic mineralization in ENT1(-/-) mice. Copyright © 2016 Elsevier Inc. All rights reserved.

Thoracic myelopathy with alkaptonuria.

PubMed

Akeda, Koji; Kasai, Yuichi; Kawakita, Eiji; Matsumura, Yoshihiro; Kono, Toshibumi; Murata, Tetsuya; Uchida, Atsumasa

2008-01-15

A case of thoracic myelopathy with alkaptonuria (ochronotic spondyloarthropathy) is presented. To present and review the first reported case of an alkaptonuric patient with concomitant thoracic myelopathy. Alkaptonuria, a rare hereditary metabolic disease, is characterized by accumulation of homogentistic acid, ochronosis, and destruction of connective tissue resulting in degenerative spondylosis and arthritis. Despite the high incidence of intervertebral disc diseases among patients with alkaptonuria, neurologic symptoms caused by spinal disease are rare. Thoracic myelopathy in a patient with alkaptonuria has not been previously reported. The clinical course, radiologic features, pathology, and treatment outcome of an alkaptonuria patient with thoracic myelopathy was documented. Myelopathy of the patient was caused by rupture of a thoracic intervertebral disc. The neurologic symptoms of the patient were markedly improved after surgery. We have reported for the first time, that an alkaptonuria patient showed thoracic myelopathy caused by rupture of a thoracic intervertebral disc. Decompression followed by the instrumented fusion of the thoracic spine was effective for improving the neurologic symptoms.

Operative techniques of percutaneous endoscopic mini-hemilaminectomy using a uniportal approach in dogs

PubMed Central

MOON, Hee-Sup; HWANG, Yong-Hyun; LEE, Hee-Chun; LEE, Jae-Hoon

2017-01-01

The present study aimed to investigate the technical feasibility of percutaneous endoscopic mini-hemilaminectomy via a uniportal approach, and to evaluate the possibility of decompression and endoscopic examination of the thoracic and lumbar spinal canals in small dogs during such procedures. Fresh canine cadavers of mixed-breed dogs (n=7) were used in this study. Following injection of a barium and agarose mixture (BA-gel) to stimulate intervertebral disc herniation, percutaneous endoscopic mini-hemilaminectomy was performed using a lateral approach to the thoracic and lumbar vertebrae. BA-gel was removed to decompress the spinal cord using an elevator and rongeurs after mini-hemilaminectomy. Pre and post-operative computed tomography (CT) scans were obtained to evaluate surgical outcomes. Intra-operative complications, incision length, and procedure time were recorded. All procedures were completed with clear visualization of the spinal cord and floor of the spinal canal. The mean total operating time was 58.00 ± 18.06 min. Lengths of incision were under 1 cm in all dogs. Intra-operative complications included iatrogenic nerve root injuries caused by the micro-rongeur in two dogs. CT imaging revealed that removal of BA-gel resulted in sufficient spinal cord decompression. Our findings indicated that percutaneous endoscopic thoracolumbar mini-hemilaminectomy is feasible for spinal cord decompression and allows for adequate observation of the spinal canal. Thus, this technique may be an alternative surgical option for treatment of thoracolumbar disk disease in dogs. PMID:28757523

Feasibility of minimally-invasive fiber-based evaluation of chondrodystrophoid canine intervertebral discs by light absorption and scattering spectroscopy

NASA Astrophysics Data System (ADS)

Jiang, Yuanyuan; McKeirnan, Kelci; Piao, Daqing; Bartels, Kenneth E.

2011-03-01

Extrusion or protrusion of an intervertebral disc is a common, frequently debilitating, painful, and sometimes fatal neurologic disease in the chondrodystrophic dog (dachshund, Pekingese, etc.). A similar condition of intervertebral disc degeneration with extrusion/protrusion is also a relatively common neurologic condition in human patients. Degeneration of the relatively avascular chondrodystrophoid intervertebral disc is associated with loss of water content, increased collagen, and deposits of calcified mineral in the nucleus pulposus. Current diagnostic methods have many limitations for providing accurate information regarding disc composition in situ prior to surgical intervention. Disc composition (i.e., mineralization), can influence the type of treatment regime and potentially prognosis and recurrence rates. The objective of this study is to investigate the feasibility of using a fiber-needle spectroscopy sensor to analyze the changes of tissue compositions involved in the chondrodystrophoid condition of the canine intervertebral disc. The nucleous pulposus, in which the metaplastic process / degeneration develops, is approximately 2mm thick and 5mm in diameter in the dachshund-sized dog. It lies in the center of the disc, surrounded by the annulus fibrosis and is enclosed by cartilaginous vertebral endplates cranially and caudally. This "shallow-and-small-slab" geometry limits the configuration of a fiber probe to sense the disc tissue volume without interference from the vertebrae. A single-fiber sensor is inserted into a 20 gauge myelographic spinal needle for insertion into the disc in situ and connected via a bifurcated fiber to the light source and a spectrometer. A tungsten light source and a 940nm light-emitting-diode are combined for spectral illumination covering VIS/NIR with expected improved sensitivity to water. Analysis of the reflectance spectra is expected to provide information of scattering and absorption compositions of tissue in proximity to the fiber-tip. Preliminary measurements on cadaveric canine intervertebral discs indicated significant reduction of scattering constituents and possible diminishment of water content after percutaneous laser disc ablation (PLDA). This fiber-needle based sensing configuration may be feasible for integrating the evaluation of calcification and water content into the work-flow of holmium:YAG laser disc ablation for pre-operative in-line detection and post-operative evaluation of therapeutic interventions regarding the chondrodystrophic disc.

Development of a Methodology to Gather Seated Anthropometry in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Rajulu, Sudhakar; Young, Karen; Mesloh, Miranda

2009-01-01

The Constellation Program's Crew Exploration Vehicle (CEV) is required to accommodate the full population range of crewmembers according to the anthropometry requirements stated in the Human-Systems Integration Requirement (HSIR) document (CxP70024). Seated height is one of many critical dimensions of importance to the CEV designers in determining the optimum seat configuration in the vehicle. Changes in seated height may have a large impact to the design, accommodation, and safety of the crewmembers. Seated height can change due to elongation of the spine when crewmembers are exposed to microgravity. Spinal elongation is the straightening of the natural curvature of the spine and the expansion of inter-vertebral disks. This straightening occurs due to fluid shifts in the body and the lack of compressive forces on the spinal vertebrae. Previous studies have shown that as the natural curvature of the spine straightens, an increase in overall height of 3% of stature occurs which has been the basis of the current HSIR requirements. However due to variations in the torso/leg ratio and impact of soft tissue, data is nonexistent as to how spinal elongation specifically affects the measurement of seated height. In order to obtain this data, an experiment was designed to collect spinal elongation data while in a seated posture in microgravity. The purpose of this study was to provide quantitative data that represents the amount of change that occurs in seated height due to spinal elongation in microgravity environments. Given the schedule and budget constraints of ISS and Shuttle missions and the uniqueness of the problem, a methodology had to be developed to ensure that the seated height measurements were accurately collected. Therefore, simulated microgravity evaluations were conducted to test the methodology and procedures of the experiment. This evaluation obtained seat pan pressure and seated height data to a) ensure that the lap restraint provided sufficient restraint to eliminate any gap between the subject s gluteal surface and the seat pan and b) to document any necessary design and procedural changes needed due to the microgravity environment. The methodology and setup used during the simulated microgravity evaluations was replicable to the proposed methodology and setup for in-space missions. A flight-like Shuttle seat, pressure sensors, anthropometer, and existing hardware was used to measure seated height and contact area while experiencing microgravity. The outlying buttock and thigh surface contact areas were collected to determine if the subjects were in contact with the seat pan, while a measurer recorded their seated height with an anthropometer. The Anthropometry and Biomechanics Facility (ABF) completed data collection from three microgravity flights to assess the restraint methods and techniques to be used for the in-flight procedures performed by the crewmembers in orbit. The first flight demonstrated that the restraint system on the seat, used in a nominal configuration, did not sufficiently restrain a person in the seat. The results showed the subjects were not in full contact with the seat pan, resulting in inaccurate sitting height data. Thus, a second flight was conducted to test different restraint system options. The results showed that by 1) changing the restraint system from the nominal 3-points of the 5-point harness, which is used for crewmembers when fully suited with emergency equipment, and 2) rerouting the lap straps around the joint of the backrest, where the backrest and seat pan are joined, resulted in the optimal method to restrain a subject. This rerouting method allowed for the anchor location to change and pull the subjects back into the seat instead of being anchored at the side of the subjects thighs. The results from the third flight validated the final restraint system, which resulted in a verified methodology for collecting seated anthropometry to ultimately determine the amount of spil elongation in a microgravity environment.

Effects of Different Angles of the Traction Table on Lumbar Spine Ligaments: A Finite Element Study.

PubMed

Farajpour, Hekmat; Jamshidi, Nima

2017-12-01

The traction bed is a noninvasive device for treating lower back pain caused by herniated intervertebral discs. In this study, we investigated the impact of the traction bed on the lower back as a means of increasing the disc height and creating a gap between facet joints. Computed tomography (CT) images were obtained from a female volunteer and a three-dimensional (3D) model was created using software package MIMICs 17.0. Afterwards, the 3D model was analyzed in an analytical software (Abaqus 6.14). The study was conducted under the following traction loads: 25%, 45%, 55%, and 85% of the whole body weight in different angles. Results indicated that the loading angle in the L3-4 area had 36.8%, 57.4%, 55.32%, 49.8%, and 52.15% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4-5 area were 32.3%, 10.6%, 53.4%, 56.58%, and 57.35%. Also, the body weight had 63.2%, 42.6%, 44.68%, 50.2%, and 47.85% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4-5 area were 67.7%, 89.4%, 46.6%, 43.42% and 42.65%. The authenticity of results was checked by comparing with the experimental data. The results show that traction beds are highly effective for disc movement and lower back pain relief. Also, an optimal angle for traction can be obtained in a 3D model analysis using CT or magnetic resonance imaging images. The optimal angle would be different for different patients and thus should be determined based on the decreased height of the intervertebral disc, weight and height of patients.

Multidirectional testing of one- and two-level ProDisc-L versus simulated fusions.

PubMed

Panjabi, Manohar; Henderson, Gweneth; Abjornson, Celeste; Yue, James

2007-05-20

An in vitro human cadaveric biomechanical study. To evaluate intervertebral rotation changes due to lumbar ProDisc-L compared with simulated fusion, using follower load and multidirectional testing. Artificial discs, as opposed to the fusions, are thought to decrease the long-term accelerated degeneration at adjacent levels. A biomechanical assessment can be helpful, as the long-term clinical evaluation is impractical. Six fresh human cadaveric lumbar specimens (T12-S1) underwent multidirectional testing in flexion-extension, bilateral lateral bending, and bilateral torsion using the Hybrid test method. First, intact specimen total range of rotation (T12-S1) was determined. Second, using pure moments again, this range of rotation was achieved in each of the 5 constructs: A) ProDisc-L at L5-S1; B) fusion at L5-S1; C) ProDisc-L at L4-L5 and fusion at L5-S1; D) ProDisc-L at L4-L5 and L5-S1; and E) 2-level fusion at L4-L5 to L5-S1. Significant changes in the intervertebral rotations due to each construct were determined at the operated and nonoperated levels using repeated measures single factor ANOVA and Bonferroni statistical tests (P < 0.05). Adjacent-level effects (ALEs) were defined as the percentage changes in intervertebral rotations at the nonoperated levels due to the constructs. One- and 2-level ProDisc-L constructs showed only small ALE in any of the 3 rotations. In contrast, 1- and 2-level fusions showed increased ALE in all 3 directions (average, 7.8% and 35.3%, respectively, for 1 and 2 levels). In the disc plus fusion combination (construct C), the ALEs were similar to the 1-level fusion alone. In general, ProDisc-L preserved physiologic motions at all spinal levels, while the fusion simulations resulted in significant ALE.

Hybrid testing of lumbar CHARITE discs versus fusions.

PubMed

Panjabi, Manohar; Malcolmson, George; Teng, Edward; Tominaga, Yasuhiro; Henderson, Gweneth; Serhan, Hassan

2007-04-20

An in vitro human cadaveric biomechanical study. To quantify effects on operated and other levels, including adjacent levels, due to CHARITE disc implantations versus simulated fusions, using follower load and the new hybrid test method in flexion-extension and bilateral torsion. Spinal fusion has been associated with long-term accelerated degeneration at adjacent levels. As opposed to the fusion, artificial discs are designed to preserve motion and diminish the adjacent-level effects. Five fresh human cadaveric lumbar specimens (T12-S1) underwent multidirectional testing in flexion-extension and bilateral torsion with 400 N follower load. Intact specimen total ranges of motion were determined with +/-10 Nm unconstrained pure moments. The intact range of motion was used as input for the hybrid tests of 5 constructs: 1) CHARITE disc at L5-S1; 2) fusion at L5-S1; 3) CHARITE discs at L4-L5 and L5-S1; 4) CHARITE disc at L4-L5 and fusion at L5-S1; and 5) 2-level fusion at L4-L5-S1. Using repeated-measures single factor analysis of variance and Bonferroni statistical tests (P < 0.05), intervertebral motion redistribution of each construct was compared with the intact. In flexion-extension, 1-level CHARITE disc preserved motion at the operated and other levels, while 2-level CHARITE showed some amount of other-level effects. In contrast, 1- and 2-level fusions increased other-level motions (average, 21.0% and 61.9%, respectively). In torsion, both 1- and 2-level discs preserved motions at all levels. The 2-level simulated fusion increased motions at proximal levels (22.9%), while the 1-level fusion produced no significant changes. In general, CHARITE discs preserved operated- and other-level motions. Fusion simulations affected motion redistribution at other levels, including adjacent levels.

Evidence for the concurrent growth of thick discs and central mass concentrations from S4G imaging

NASA Astrophysics Data System (ADS)

Comerón, S.; Elmegreen, B. G.; Salo, H.; Laurikainen, E.; Holwerda, B. W.; Knapen, J. H.

2014-11-01

We have produced 3.6 μm + 4.5 μm vertically integrated radial luminosity profiles of 69 edge-on galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G). We decomposed the luminosity profiles into a disc and a central mass concentration (CMC). These fits, combined with thin/thick disc decompositions from our previous studies, allow us to estimate the masses of the CMCs, the thick discs, and the thin discs (ℳCMC, ℳT, and ℳT). We obtained atomic disc masses (ℳg) from the literature. We then consider the CMC and the thick disc to be dynamically hot components and the thin disc and the gas disc to be dynamically cold components. We find that the ratio between the mass of the hot components and that of the cold components, (ℳCMC + ℳT)/(ℳt + ℳg), does not depend on the total galaxy mass as described by circular velocities (vc). We also find that the higher the vc, the more concentrated the hot component of a galaxy. We suggest that our results are compatible with having CMCs and thick discs built in a short and early high star forming intensity phase. These components were born thick because of the large scale height of the turbulent gas disc in which they originated. Our results indicate that the ratio between the star forming rate in the former phase and that of the formation of the thin disc is of the order of 10, but the value depends on the duration of the high star forming intensity phase. Appendix A is available in electronic form at http://www.aanda.org

A minimally invasive in-fiber Bragg grating sensor for intervertebral disc pressure measurements

NASA Astrophysics Data System (ADS)

Dennison, Christopher R.; Wild, Peter M.; Wilson, David R.; Cripton, Peter A.

2008-08-01

We present an in-fiber Bragg grating (FBG) based intervertebral disc (IVD) pressure sensor that has pressure sensitivity seven times greater than that of a bare fiber, and a major diameter and sensing area of only 400 µm and 0.03 mm2, respectively. This is the only optical, the smallest and the most mechanically compliant disc pressure sensor reported in the literature. This is also an improvement over other FBG pressure sensors that achieve increased sensitivity through mechanical amplification schemes, usually resulting in major diameters and sensing lengths of many millimeters. Sensor sensitivity is predicted using numerical models, and the predicted sensitivity is verified through experimental calibrations. The sensor is validated by conducting IVD pressure measurements in porcine discs and comparing the FBG measurements to those obtained using the current standard sensor for IVD pressure. The predicted sensitivity of the FBG sensor matched with that measured experimentally. IVD pressure measurements showed excellent repeatability and agreement with those obtained from the standard sensor. Unlike the current larger sensors, the FBG sensor could be used in discs with small disc height (i.e. cervical or degenerated discs). Therefore, there is potential to conduct new measurements that could lead to new understanding of the biomechanics.

The Galactic thick disc density profile traced with RR Lyrae stars

NASA Astrophysics Data System (ADS)

Mateu, Cecilia; Vivas, A. Katherina

2018-05-01

We used a combination of public RR Lyrae star catalogs and a Bayesian methodology to derive robust structural parameters of the inner halo (<25 kpc) and thick disc of the Milky Way. RR Lyrae stars are an unequivocal tracer of old metal-poor populations, for which accurate distances and extinctions can be individually estimated and so, are a reliable independent means of tracing the population of the old high-[α/Fe] disc usually associated to the thick disc. In particular, the chosen RR Lyrae sample spans regions at low galactic latitude toward the anti-center direction, allowing to probe the outermost parts of the disc. Our results favour a thick disc with short scale height and short scale length, h_z=0.65_{-0.05}^{+0.09} kpc, h_R=2.1_{-0.25}^{+0.82} kpc, for a model in which the inner halo has a constant flattening of q=0.90_{-0.03}^{+0.05} and a power law index of n=-2.78_{-0.05}^{+0.05}. Similar short scales for the thick disc are also found when considering an inner halo with flattening dependent on radius. We also explored a model in which the thick disc has a flare and, although this is only mildly constrained with our data, a flare onset in the inner ˜11 kpc is highly disfavoured.

Biological intervertebral disc replacement: an in vivo model and comparison of two surgical techniques to approach the rat caudal disc

PubMed Central

Gebhard, Harry; James, Andrew R.; Bowles, Robby D.; Dyke, Jonathan P.; Saleh, Tatianna; Doty, Stephen P.; Bonassar, Lawrence J.; Härtl, Roger

2011-01-01

Study design: Prospective randomized animal study. Objective: To determine a surgical technique for reproducible and functional intervertebral disc replacement in an orthotopic animal model. Methods: The caudal 3/4 intervertebral disc (IVD) of the rat tail was approached by two surgical techniques: blunt dissection, stripping and retracting (Technique 1) or incising and repairing (Technique 2) the dorsal longitudinal tendons. The intervertebral disc was dissected and removed, and then either discarded or reinserted. Outcome measures were perioperative complications, spontaneous tail movement, 7T MRI (T1- and T2-sequences for measurement of disc space height (DSH) and disc hydration). Microcomputed tomographic imaging (micro CT) was additionally performed postmortem. Results: No vascular injuries occurred and no systemic or local infections were observed over the course of 1 month. Tail movements were maintained. With tendon retraction (Technique 1) gross loss of DSH occurred with both discectomy and reinsertion. Tendon division (Technique 2) maintained DSH with IVD reinsertion but not without. The DSH was demonstrated on MRI measurement. A new scoring system to assess IVD appearances was described. Conclusions: The rat tail model, with a tendon dividing surgical technique, can function as an orthotopic animal model for IVD research. Mechanical stimulation is maintained by preserved tail movements. 7T MRI is a feasible modality for longitudinal monitoring for the rat caudal disc. PMID:22956934

Vertebral Augmentation can Induce Early Signs of Degeneration in the Adjacent Intervertebral Disc: Evidence from a Rabbit Model.

PubMed

Feng, Zhiyun; Chen, Lunhao; Hu, Xiaojian; Yang, Ge; Wang, Yue; Chen, Zhong

2018-04-11

An experimental study. The aim of this study was to determine the effect of polymethylmethacrylate (PMMA) augmentation on the adjacent disc. Vertebral augmentation with PMMA reportedly may predispose the adjacent vertebra to fracture. The influence of PMMA augmentation on the adjacent disc, however, remains unclear. Using a retroperitoneal approach, PMMA augmentation was performed for 23 rabbits. For each animal, at least one vertebra was augmented with 0.2 to 0.3 mL PMMA. The disc adjacent to the augmented vertebra and a proximal control disc were studied using magnetic resonance (MR) imaging, histological and molecular level evaluation at 1, 3, and 6 months postoperatively. Marrow contact channels in the endplate were quantified in histological slices and number of invalid channels (those without erythrocytes inside) was rated. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) was performed to determine disc cell apoptosis. On MR images, the signal and height of the adjacent disc did not change 6 months after vertebral augmentation. Histological scores of the adjacent disc increased over time, particularly for the nucleus pulposus. The adjacent disc had greater nucleus degeneration score than the control disc at 3 months (5.7 vs. 4.5, P < 0.01) and 6 months (6.9 vs. 4.4, P < 0.001). There were more invalid marrow contact channels in the endplate of augmented vertebra than the control (43.3% vs. 11.1%, P < 0.01). mRNA of ADAMTS-5, MMP-13, HIF-1α, and caspase-3 were significantly upregulated in the adjacent disc at 3 and 6 months (P < 0.05 for all). In addition, there were more TUNEL-positive cells in the adjacent disc than in the control disc (43.4% vs. 24.0%, P < 0.05) at 6 months postoperatively. Vertebral augmentation can induce early degenerative signs in the adjacent disc, which may be due to impaired nutrient supply to the disc. N/A.

Biomechanical Changes in Disc Pressure and Facet Strain after Lumbar Spinal Arthroplasty with CharitéTM in the Human Cadaveric Spine under Physiologic Compressive Follower Preload.

PubMed

Choi, Jong-Il; Kim, Se-Hoon; Lim, Dong-Jun; Ha, Sung-Kon; Kim, Sang-Dae

2017-01-01

Arthroplasty maintains the biomechanical features of a healthy disc, decreases the adjacent segment disease rate, and decreases the accelerated degeneration rate of the neighboring discs in traditional fusion procedures. However, there are only a few reports on adjacent disc pressure (DP) and facet strain (FS) after lumbar arthroplasty under a physiologic compressive preload. Baseline DP and FS measurements were obtained from five intact cadaveric human lumbosacral spines for different modes of motion. DP was measured by inserting pressure transducer needle tips into the L3-L4 and L5-S1 discs. FS gauges were fixed on both sides of the laminae near the L3-L4, L4-L5, and L5-S1 facet joints. After SB Charité < sup > TM < /sup > III implantation at the L4-L5 level, the measurements were repeated at preload and compared with those of the intact spine. Under the preload condition, the central DP of the upper disc was decreased during extension and bending, and it significantly increased during rotation (p < 0.05). In the lower disc, the central DP insignificantly decreased during bending and increased during extension and flexion. A statistically significant increase in FS was observed during rotation at the operative facet (p < 0.05). Compared to the intact spine, all FS values were insignificantly decreased during lateral bending but increased during axial rotation. In an ex-vivo physiologic preload setting, the SB Charité < sup > TM < /sup > III provided relatively inconsistent and sometimes increased DP or FS at the operative and adjacent levels after arthroplasty.

In vivo performance of an acellular disc-like angle ply structure (DAPS) for total disc replacement in a small animal model.

PubMed

Martin, John T; Kim, Dong Hwa; Milby, Andrew H; Pfeifer, Christian G; Smith, Lachlan J; Elliott, Dawn M; Smith, Harvey E; Mauck, Robert L

2017-01-01

Total intervertebral disc replacement with a biologic engineered disc may be an alternative to spinal fusion for treating end-stage disc disease. In previous work, we developed disc-like angle ply structures (DAPS) that replicate the structure and function of the native disc and a rat tail model to evaluate DAPS in vivo. Here, we evaluated a strategy in which, after in vivo implantation, endogenous cells could colonize the acellular DAPS and form an extracellular matrix organized by the DAPS topographical template. To do so, acellular DAPS were implanted into the caudal spines of rats and evaluated over 12 weeks by mechanical testing, histology, and microcomputed tomography. An external fixation device was used to stabilize the implant site and various control groups were included to evaluate the effect of immobilization. There was robust tissue formation within the DAPS after implantation and compressive mechanical properties of the implant matched that of the native motion segment. Immobilization provided a stable site for fibrous tissue formation after either a discectomy or a DAPS implantation, but bony fusion eventually resulted, with segments showing intervertebral bridging after long-term implantation, a process that was accelerated by the implanted DAPS. Thus, while compressive mechanical properties were replicated after DAPS implantation, methods to actively prevent fusion must be developed. Future work will focus on limiting fusion by remobilizing the motion segment after a period of integration, delivering pro-chondrogenic factors, and pre-seeding DAPS with cells prior to implantation. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:23-31, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Quadrennial Review of Military Compensation (5th). Volume 3. Special and Incentive Pays.

DTIC Science & Technology

1984-01-01

Airlines, Inc. ..- Professional Pilot Magazine President’s Private Sector Survey Cost Control Group REHAB , Inc. "p Taylor Diving and Salvage Co...compensation to per- * 0 , sonnel performing duty involving highly toxic pesticides. Duty requiring the use of pesticides of high acute toxicity...The compounding effects of continual exposure to jumping result . in spinal disc, knee, shoulder, ankle , and general bone problems. Doctors

Comparison of Lumbosacral Alignment in Geriatric and Non-Geriatric patients suffering low back pain.

PubMed

Kocyigit, Burhan Fatih; Berk, Ejder

2018-01-01

Lumbosacral alignment is a crucial factor for an appropriate spinal function. Changes in spinal alignment lead to diminished body biomechanics. Additionally, lumbosacral alignment may affect quality of life, sagittal balance and fall risk in elderly. In this study, we aimed to compare lumbosacral alignment in geriatric and non-geriatric patients suffering from low back pain. A total of 202 (120 male and 82 female) patients who visited to physical medicine and rehabilitation clinic with low back pain between January 2017 and August 2017 were enrolled in this study. Standing lateral lumbar radiographs were obtained from the electronic hospital database. Lumbar lordosis angle, sacral tilt, lumbosacral angle and lumbosacral disc angle were calculated on lateral standing lumbar radiographs. The mean age of the non-geriatric group was 43.02 ± 13.20 years, the geriatric group was 71.61 ± 6.42 years. In geriatric patients, lumbar lordosis angle, sacral tilt and lumbosacral disc angle were significantly smaller (p = 0.042, p = 0.017 and p = 0.017). No significant differences were observed in lumbosacral angle between the groups (p = 0.508). Our study indicates the specific changes in lumbosacral alignment with aging. Identifying these changes in lumbosacral alignment in the geriatric population will enable to create proper rehabilitation strategies.

Retrieval analysis of motion preserving spinal devices and periprosthetic tissues

PubMed Central

Kurtz, Steven M.; Steinbeck, Marla; Ianuzzi, Allyson; van Ooij, André; Punt, Ilona M.; Isaza, Jorge; Ross, E.R.S.

2009-01-01

This article reviews certain practical aspects of retrieval analysis for motion preserving spinal implants and periprosthetic tissues as an essential component of the overall revision strategy for these implants. At our institution, we established an international repository for motion-preserving spine implants in 2004. Our repository is currently open to all spine surgeons, and is intended to be inclusive of all cervical and lumbar implant designs such as artificial discs and posterior dynamic stabilization devices. Although a wide range of alternative materials is being investigated for nonfusion spine implants, many of the examples in this review are drawn from our existing repository of metal-on-polyethylene, metal-on-metal lumbar total disc replacements (TDRs), and polyurethane-based dynamic motion preservation devices. These devices are already approved or nearing approval for use in the United States, and hence are the most clinically relevant at the present time. This article summarizes the current literature on the retrieval analysis of these implants and concludes with recommendations for the development of new test methods that are based on the current state of knowledge of in vivo wear and damage mechanisms. Furthermore, the relevance and need to evaluate the surrounding tissue to obtain a complete understanding of the biological reaction to implant component corrosion and wear is reviewed. PMID:25802641

Novel spinal instrumentation to enhance osteogenesis and fusion: a preliminary study.

PubMed

MacEwan, Matthew R; Talcott, Michael R; Moran, Daniel W; Leuthardt, Eric C

2016-09-01

OBJECTIVE Instrumented spinal fusion continues to exhibit high failure rates in patients undergoing multilevel lumbar fusion or pseudarthrosis revision; with Grade II or higher spondylolisthesis; or in those possessing risk factors such as obesity, tobacco use, or metabolic disorders. Direct current (DC) electrical stimulation of bone growth represents a unique surgical adjunct in vertebral fusion procedures, yet existing spinal fusion stimulators are not optimized to enhance interbody fusion. To develop an advanced method of applying DC electrical stimulation to promote interbody fusion, a novel osteogenic spinal system capable of routing DC through rigid instrumentation and into the vertebral bodies was fabricated. A pilot study was designed to assess the feasibility of osteogenic instrumentation and compare the ability of osteogenic instrumentation to promote successful interbody fusion in vivo to standard spinal instrumentation with autograft. METHODS Instrumented, single-level, posterior lumbar interbody fusion (PLIF) with autologous graft was performed at L4-5 in adult Toggenburg/Alpine goats, using both osteogenic spinal instrumentation (plus electrical stimulation) and standard spinal instrumentation (no electrical stimulation). At terminal time points (3 months, 6 months), animals were killed and lumbar spines were explanted for radiographic analysis using a SOMATOM Dual Source Definition CT Scanner and high-resolution Microcat II CT Scanner. Trabecular continuity, radiodensity within the fusion mass, and regional bone formation were examined to determine successful spinal fusion. RESULTS Quantitative analysis of average bone density in pedicle screw beds confirmed that electroactive pedicle screws used in the osteogenic spinal system focally enhanced bone density in instrumented vertebral bodies. Qualitative and quantitative analysis of high-resolution CT scans of explanted lumbar spines further demonstrated that the osteogenic spinal system induced solid bony fusion across the L4-5 disc space as early as 6 weeks postoperatively. In comparison, inactive spinal instrumentation with autograft was unable to promote successful interbody fusion by 6 months postoperatively. CONCLUSIONS Results of this study demonstrate that novel osteogenic spinal instrumentation supports interbody fusion through the focal delivery of DC electrical stimulation. With further technical development and scientific/clinical validation, osteogenic spinal instrumentation may offer a unique alternative to biological scaffolds and pharmaceutical adjuncts used in spinal fusion procedures.

Demographic and clinical characteristics of persons with spinal cord injury in Turkey: One-year experience of a primary referral rehabilitation center.

PubMed

Taşoğlu, Özlem; Koyuncu, Engin; Daylak, Rabia; Karacif, Derya Yumuşak; İnce, Zerrin; Yenigün, Didem; Özgirgin, Neşe

2018-03-01

To define the demographic and clinical characteristics of persons with spinal cord injury, rehabilitated in a primary referral rehabilitation center in Turkey. Retrospective study. Ankara Physical Medicine and Rehabilitation Training and Research Hospital, Ankara, Turkey. Medical records of all patients with spinal cord injury (acute-subacute-chronic) at a single academic referral center over the course of one year were reviewed. Variables of each patient were recorded, including: age, sex, etiology, length of rehabilitation stay, neurological level of injury, level of neurological impairment and severity of injury. Among 262 persons with spinal cord injury, 69.8% were male (male:female ratio is 2.31 : 1). Mean age was 38.3 ± 17.6 years. Falls were the most common cause of injury. The majority of falls were falls from a height (93.3%). More than 20% of falls from a height were related to occupational injury. The most common neurological level of injury was L1. Of all persons 46.2% had thoracic, 27.5% had lumbar and 26.3% had cervical lesions. The mean length of rehabilitation stay was 52.1 ± 25.5 days. Persons with motor complete injury and with a shorter (<12 months) time since injury had longer length of rehabilitation stay. The mean age of SCI population is increasing. Falls constitute the majority of etiologic factors and are more common in persons >60 years old. More than 20% of falls from a height are related to occupational injury. Male-female ratio is decreasing. Thoraco-lumbar injures are more common than cervical injuries.

Comparison of Morphological Characteristics of the Subaxial Cervical Spine between Athetoid Cerebral Palsy and Normal Control.

PubMed

Kim, Jun Young; Kwon, Jae Yeol; Kim, Moon Seok; Lee, Jeong Jae; Kim, Il Sup; Hong, Jae Taek

2018-03-01

To compare the morphometry of subaxial cervical spine between cerebral palsy (CP) and normal control. We retrospectively analyzed 72 patients with CP, as well as 72 patients from normal population. The two groups were matched for age, sex, and body mass index. Pedicle, lateral mass (LM), and vertebral foramen were evaluated using computed tomography (CT) imaging. Pedicle diameter, LM height, thickness, width and vertebral foramen asymmetry (VFA) were measured and compared between the two groups. Cervical dynamic motion, disc and facet joint degeneration were investigated. Additionally, we compared the morphology of LM between convex side and concave side with cervical scoliotic CP patients. LM height was smaller in CP group. LM thickness and width were larger in CP group at mid-cervical level. In 40 CP patients with cervical scoliosis, there were no height and width differences between convex and concave side. Pedicle outer diameter was not statistically different between two groups. Pedicle inner diameter was significantly smaller in CP group. Pedicle sclerosis was more frequent in CP patients. VFA was larger in CP group at C3, C4, and C5. Disc/facet degeneration grade was higher in the CP group. Cervical motion of CP group was smaller than those of the control group. LM morphology of CP patients was different from normal population. Sclerotic pedicles and vertebral foramen asymmetry were more commonly identified in CP patients. CP patients were more likely to demonstrate progressive disc/facet degeneration. This data may provide useful information on cervical posterior instrumentation in CP patients.

Comparison of temporomandibular joint and ramus morphology between class II and class III cases before and after bi-maxillary osteotomy.

PubMed

Iguchi, Ran; Yoshizawa, Kunio; Moroi, Akinori; Tsutsui, Takamitsu; Hotta, Asami; Hiraide, Ryota; Takayama, Akihiro; Tsunoda, Tatsuya; Saito, Yuki; Sato, Momoko; Baba, Nana; Ueki, Koichiro

2017-12-01

The purpose of this study was to compare changes in temporomandibular joint (TMJ) and ramus morphology between class II and III cases before and after sagittal split ramus osteotomy (SSRO) and Le Fort I osteotomy. The subjects were 39 patients (78 sides) who underwent bi-maxillary surgery. They consisted of 2 groups (18 class II cases and 21 class III cases), and were selected randomly from among patients who underwent surgery between 2012 and 2016. The TMJ disc tissue and joint effusion were assessed by magnetic resonance imaging (MRI) and the TMJ space, condylar height, ramus height, ramus inclination and condylar square were assessed by computed tomography (CT), pre- and post-operatively. The number of joints with anterior disc displacement in class II was significantly higher than that in class III (p < 0.0001). However, there were no significant differences between the two classes regarding ratio of joint symptoms and ratio of joint effusion pre- and post-operatively. Class II was significantly better than class III regarding reduction ratio of condylar height (p < 0.0001) and square (p = 0.0005). The study findings suggest that condylar morphology could change in both class II and III after bi-maxillary surgery. The findings of the numerical analysis also demonstrated that reduction of condylar volume occurred frequently in class II, although TMJ disc position classification did not change significantly, as previously reported. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Osteoporosis

MedlinePlus

... to restore the height of the vertebrae) Spinal fusion (bones of your spine are joined together so ... osteoporosis Patient Instructions Hip fracture - discharge Preventing falls Images Compression fracture Bone density scan Osteoporosis Osteoporosis Hip ...

Morphological Features and Important Parameters of Large Optic Discs for Diagnosing Glaucoma

PubMed Central

Okimoto, Satoshi; Yamashita, Keiko; Shibata, Tetsuo; Kiuchi, Yoshiaki

2015-01-01

Purpose To compare the optic disc parameters of glaucomatous eyes to those of non-glaucomatous eyes with large discs. Methods We studied 225 consecutive eyes with large optic discs (>2.82 mm2): 91 eyes with glaucoma and 134 eyes without glaucoma. An eye was diagnosed with glaucoma when visual field defects were detected by the Humphrey Field Analyzer. All of the Heidelberg Retina Tomograph II (HRT II) parameters were compared between the non-glaucomatous and glaucomatous eyes. A logistic regression analysis of the HRT II parameters was used to establish a new formula for diagnosing glaucoma, and the sensitivity and specificity of the Moorfields Regression Analysis (MRA) was compared to the findings made by our analyses. Results The mean disc area was 3.44±0.50 mm2 in the non-glaucomatous group and 3.40±0.52 mm2 in the glaucoma group. The cup area, cup volume, cup-to-disc area ratio, linear cup/disc ratio, mean cup depth, and the maximum cup depth were significantly larger in glaucomatous eyes than in the non-glaucomatous eyes. The rim area, rim volume, cup shape measurement, mean retinal nerve fiber layer (RNFL) thickness, and RFNL cross-sectional area were significantly smaller in glaucomatous eyes than in non-glaucomatous eyes. The cup-to-disc area ratio, the height variation contour (HVC), and the RNFL cross-sectional area were important parameters for diagnosing the early stage glaucoma, and the cup-to-disc area ratio and cup volume were useful for diagnosing advanced stage glaucoma in eyes with a large optic disc. The new formula had higher sensitivity and specificity for diagnosing glaucoma than MRA. Conclusions The cup-to-disc area ratio, HVC, RNFL cross-sectional area, and cup volume were important parameters for diagnosing glaucoma in eyes with a large optic disc. The important disc parameters to diagnose glaucoma depend on the stage of glaucoma in patients with large discs. PMID:25798580

[In situ analysis of pathomechanisms of human intervertebral disc degeneration].

PubMed

Weiler, C

2013-11-01

Low back pain is one of the major causes of pain and disability in the western world, with a constantly rising life-time prevalence of approximately 60-85 %. Degeneration of the intervertebral disc is believed to be a major cause of low back pain. Semiquantitative macroscopic and microscopic changes of the intervertebral disc were assessed and classified. Furthermore additional methods, such as immunohistochemistry, in situ hybridization and in situ zymography were used to analyze phenotypic cellular and matrix changes. We have developed and tested a practicable, valid and reliable histological classification system for lumbar discs which can serve as a morphological reference framework to allow more sophisticated molecular biological studies on the pathogenesis of ageing and degeneration of discs. Secondly, we were able to demonstrate that intrinsic (genetic) and extrinsic (e.g. overweight) factors have a profound effect on the process of disc degeneration. Cells with a notochord-like phenotype are present in a considerable fraction of adult lumbar intervertebral discs. The presence of these cells is associated with distinct features of (early) age-related disc degeneration. During the process of disc degeneration, the intervertebral disc shows a progressive and significant reduction in height due to tissue resorption. This matrix loss is related to an imbalance between matrix synthesis and degradation. During this process an inflammatory reaction takes place and resident disc cells are causatively involved. In summary, disc degeneration is a multifactorial disease with a strong intrinsic (hereditary) and extrinsic (e.g. mechanical factors) background. The process starts as early as in the second decade of life and shows high interindividual differences. The loss of regenerative capacity in the intervertebral disc is probably related to the loss of stem cells, e.g. notochord-like cells. Resident disc cells are involved in the inflammatory reaction with increased matrix degradation, resorption and reduced matrix synthesis.

Association of low back pain with muscle stiffness and muscle mass of the lumbar back muscles, and sagittal spinal alignment in young and middle-aged medical workers.

PubMed

Masaki, Mitsuhiro; Aoyama, Tomoki; Murakami, Takashi; Yanase, Ko; Ji, Xiang; Tateuchi, Hiroshige; Ichihashi, Noriaki

2017-11-01

Muscle stiffness of the lumbar back muscles in low back pain (LBP) patients has not been clearly elucidated because quantitative assessment of the stiffness of individual muscles was conventionally difficult. This study aimed to examine the association of LBP with muscle stiffness assessed using ultrasonic shear wave elastography (SWE) and muscle mass of the lumbar back muscle, and spinal alignment in young and middle-aged medical workers. The study comprised 23 asymptomatic medical workers [control (CTR) group] and 9 medical workers with LBP (LBP group). Muscle stiffness and mass of the lumbar back muscles (lumbar erector spinae, multifidus, and quadratus lumborum) in the prone position were measured using ultrasonic SWE. Sagittal spinal alignment in the standing and prone positions was measured using a Spinal Mouse. The association with LBP was investigated by multiple logistic regression analysis with a forward selection method. The analysis was conducted using the shear elastic modulus and muscle thickness of the lumbar back muscles, and spinal alignment, age, body height, body weight, and sex as independent variables. Multiple logistic regression analysis showed that muscle stiffness of the lumbar multifidus muscle and body height were significant and independent determinants of LBP, but that muscle mass and spinal alignment were not. Muscle stiffness of the lumbar multifidus muscle in the LBP group was significantly higher than that in the CTR group. The results of this study suggest that LBP is associated with muscle stiffness of the lumbar multifidus muscle in young and middle-aged medical workers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ten Important Tips in Treating a Patient with Lumbar Disc Herniation

PubMed Central

Hejrati, Hamid; Ariamanesh, Shahrara

2016-01-01

Lumbar disc herniation is a common spinal disorder that usually responds favorably to conservative treatment. In a small percentage of the patients, surgical decompression is necessary. Even though lumbar discectomy constitutes the most common and easiest spine surgery globally, adverse or even catastrophic events can occur. Appropriate patient selection and effective neural decompression constitute the most important points for better surgical outcomes and avoidance of unpleasant complications. Other important tips include timely performance of magnetic resonance imaging, correct interpretation of scan data, preoperative detection of underlying instability, exclusion of non-discogenic sciatica, determination of the main cause of clinical pathology, avoidance of the wrong side or level, and being sure that the more detailed procedure does not necessarily mean the more effective procedure. PMID:27790328

In vitro measurement of nucleus pulposus swelling pressure: A new technique for studies of spinal adaptation to gravity

NASA Technical Reports Server (NTRS)

Hargens, A. R.; Glover, M. G.; Mahmood, M. M.; Gott, S.; Garfin, S. R.; Ballard, R.; Murthy, G.; Brown, M. D.

1992-01-01

Swelling of the intervertebral disc nucleus pulposus is altered by posture and gravity. We have designed and tested a new osmometer for in vitro determination of nucleus pulposus swelling pressure. The functional principle of the osmometer involves compressing a sample of nucleus pulposus with nitrogen gas until saline pressure gradients across a 0.45 microns Millipore filter are eliminated. Swelling pressure of both pooled dog and pooled pig lumbar disc nucleus pulposus were measured on the new osmometer and compared to swelling pressures determined using the equilibrium dialysis technique. The osmometer measured swelling pressures comparable to those obtained by the dialysis technique. This osmometer provides a rapid, direct, and accurate measurement of swelling pressure of the nucleus pulposus.

The "tract" of history in the treatment of lumbar degenerative disc disease.

PubMed

Chedid, Khalil J; Chedid, Mokbel K

2004-01-15

In this paper past, present, and future treatments of degenerative disc disease (DDD) of the lumbar spine are outlined in a straight forward manner. This is done to review previous knowledge of the disease, define current treatment procedures, and discuss future perspectives. An analysis of a subject of this magnitude dictates that one describes as accurate a history as possible: an anatomical/historical "tract" with emphasis on all possible deviations. Although spinal disorders have been recognized for a long time, the view of DDD as a particular disease entity is a more recent development. In this paper, the authors attempt to outline the history of DDD of the lumbar spine in an unbiased and scientific fashion. Physiological, diagnostic, and therapeutic implications will all be addressed in this study.

What the Milky Way bulge reveals about the initial metallicity gradients in the disc

NASA Astrophysics Data System (ADS)

Fragkoudi, F.; Di Matteo, P.; Haywood, M.; Khoperskov, S.; Gomez, A.; Schultheis, M.; Combes, F.; Semelin, B.

2017-11-01

We use APOGEE DR13 data to examine the metallicity trends in the Milky Way (MW) bulge and we explore their origin by comparing two N-body models of isolated galaxies that develop a bar and a boxy/peanut (b/p) bulge. Both models have been proposed as scenarios for reconciling a disc origin of the MW bulge with a negative vertical metallicity gradient. The first model is a superposition of co-spatial, I.e. overlapping, disc populations with different scale heights, kinematics, and metallicities. In this model the thick, metal-poor, and centrally concentrated disc populations contribute significantly to the stellar mass budget in the inner galaxy. The second model is a single disc with an initial steep radial metallicity gradient; this disc is mapped by the bar into the b/p bulge in such a way that the vertical metallicity gradient of the MW bulge is reproduced, as has been shown already in previous works in the literature. However, as we show here, the latter model does not reproduce the positive longitudinal metallicity gradient of the inner disc, nor the metal-poor innermost regions seen in the data. On the other hand, the model with co-spatial thin and thick disc populations reproduces all the aforementioned trends. We therefore see that it is possible to reconcile a (primarily) disc origin for the MW bulge with the observed trends in metallicity by mapping the inner thin and thick discs of the MW into a b/p. For this scenario to reproduce the observations, the α-enhanced, metal-poor, thick disc populations must have a significant mass contribution in the inner regions, as has been suggested for the Milky Way.

Advanced Multi-Axis Spine Testing: Clinical Relevance and Research Recommendations

PubMed Central

Holsgrove, Timothy P.; Nayak, Nikhil R.; Welch, William C.

2015-01-01

Back pain and spinal degeneration affect a large proportion of the general population. The economic burden of spinal degeneration is significant, and the treatment of spinal degeneration represents a large proportion of healthcare costs. However, spinal surgery does not always provide improved clinical outcomes compared to non-surgical alternatives, and modern interventions, such as total disc replacement, may not offer clinically relevant improvements over more established procedures. Although psychological and socioeconomic factors play an important role in the development and response to back pain, the variation in clinical success is also related to the complexity of the spine, and the multi-faceted manner by which spinal degeneration often occurs. The successful surgical treatment of degenerative spinal conditions requires collaboration between surgeons, engineers, and scientists in order to provide a multi-disciplinary approach to managing the complete condition. In this review, we provide relevant background from both the clinical and the basic research perspectives, which is synthesized into several examples and recommendations for consideration in increasing translational research between communities with the goal of providing improved knowledge and care. Current clinical imaging, and multi-axis testing machines, offer great promise for future research by combining invivo kinematics and loading with in-vitro testing in six degrees of freedom to offer more accurate predictions of the performance of new spinal instrumentation. Upon synthesis of the literature, it is recommended that in-vitro tests strive to recreate as many aspects of the in-vivo environment as possible, and that a physiological preload is a critical factor in assessing spinal biomechanics in the laboratory. A greater link between surgical procedures, and the outcomes in all three anatomical planes should be considered in both the in-vivo and in-vitro settings, to provide data relevant to quality of motion, and stability. PMID:26273552

Impact of McKenzie Method Therapy Enriched by Muscular Energy Techniques on Subjective and Objective Parameters Related to Spine Function in Patients with Chronic Low Back Pain

PubMed Central

Szulc, Paweł; Wendt, Michał; Waszak, Małgorzata; Tomczak, Maciej; Cieślik, Krystyna; Trzaska, Tadeusz

2015-01-01

Background The high incidence and inconsistencies in diagnostic and therapeutic process of low back pain (LBP) stimulate the continuing search for more efficient treatment modalities. Integration of the information obtained with various therapeutic methods and a holistic approach to the patient seem to be associated with positive outcomes. The aim of this study was to analyze the efficacy of combined treatment with McKenzie method and Muscle Energy Technique (MET), and to compare it with the outcomes of treatment with McKenzie method or standard physiotherapy in specific chronic lumbar pain. Material/Methods The study included 60 men and women with LBP (mean age 44 years). The patients were randomly assigned to 1 of 3 therapeutic groups, which were further treated with: 1) McKenzie method and MET, 2) McKenzie method alone, or 3) standard physiotherapy for 10 days. The extent of spinal movements (electrogoniometry), level of experienced pain (Visual Analogue Scale and Revised Oswestry Pain Questionnaire), and structure of the spinal discs (MRI) were examined prior to the intervention, immediately thereafter, and 3 months after the intervention. Results McKenzie method enriched with MET had the best therapeutic outcomes. The mobility of cervical, thoracic, and lumbar spine normalized at levels corresponding to 87.1%, 66.7%, and 95% of respective average normative values. Implementation of McKenzie method, both alone and combined with MET, was associated with a significant decrease in Oswestry Disability Index, significant alleviation of pain (VAS), and significantly reduced size of spinal disc herniation. Conclusions The combined method can be effectively used in the treatment of chronic LBP. PMID:26418868

Herpes zoster sciatica mimicking lumbar canal stenosis: a case report.

PubMed

Koda, Masao; Mannoji, Chikato; Oikawa, Makiko; Murakami, Masazumi; Okamoto, Yuzuru; Kon, Tamiyo; Okawa, Akihiko; Ikeda, Osamu; Yamazaki, Masashi; Furuya, Takeo

2015-07-29

Symptom of herpes zoster is sometimes difficult to distinguish from sciatica induced by spinal diseases, including lumbar disc herniation and spinal canal stenosis. Here we report a case of sciatica mimicking lumbar canal stenosis. A 74-year-old Chinese male patient visited our hospital for left-sided sciatic pain upon standing or walking for 5 min of approximately 1 month's duration. At the first visit to our hospital, there were no skin lesions. A magnetic resonance imaging showed spinal canal stenosis between the 4th and 5th lumbar spine. Thus, we diagnosed the patient with sciatica induced by spinal canal stenosis. We considered decompression surgery for the stenosis of 4th and 5th lumbar spine because conservative therapy failed to relieve the patient's symptom. At that time, the patient complained of a skin rash involving his left foot for several days. A vesicular rash and erythema were observed on the dorsal and plantar surfaces of the great toe and lateral malleolus. The patient was diagnosed with herpes zoster in the left 5th lumbar spinal nerve area based on clinical findings, including the characteristics of the pain and vesicular rash and erythema in the 5th lumbar spinal dermatome. The patient was treated with famciclovir (1,500 mg/day) and non-steroidal anti-inflammatory drugs. After 1 week of medication, the skin rash resolved and pain relief was obtained. In conclusion, spinal surgeons should keep in mind herpes zoster infection as one of the possible differential diagnoses of sciatica, even if there is no typical skin rash.

Retrospective analysis of spinal trauma in patients with ankylosing spondylitis: a descriptive study in Indian population.

PubMed

Mahajan, R; Chhabra, H S; Srivastava, A; Venkatesh, R; Kanagaraju, V; Kaul, R; Tandon, V; Nanda, A; Sangondimath, G; Patel, N

2015-05-01

This study aims to understand the demographics, mode of trauma, hospital stay, complications, neurological improvement, mortality and expenditure incurred by Indian patients with spinal trauma and ankylosing spondylitis (AS). Retrospective analysis of the patient data admitted to a tertiary referral hospital from 2008 to 2013 with the diagnosis of AS and spinal trauma was carried out. The variables studied were demographics, mode of trauma, neurological status, neurological improvement, involved vertebral level, duration of hospital stay, comorbid factors, expenditure and complications during the stay. Forty-six patients with diagnosis of AS with spine trauma were admitted over the last 5 years with a total of 52 fractures. All were male patients; 58.6% had injury because of trivial trauma and 78.2% patients presented with neurological injury. C5 C6, C6 C7, C7 D1 and D12 were the most common injured level. Fractures through intervertebral disc were most common in cervical spine. Of the patients, 52.7% had shown neurological improvement of at least grade 1(AIS). Mean expenditure of patient admitted with spinal cord injury (SCI) with AS is 7957 USD (United States dollar), which is around five times the per capita income in India (as per year 2013). Males with AS are much more prone to spinal fractures than females and its incidence may be higher than previously reported. Domestic falls are the most common mechanism of spinal trauma in this population. High velocity injuries are associated with complete SCI. The study reinforces the need for development of subsidized spinal care services for SCI management.

Identification of spinal tissues loaded by manual therapy: a robot-based serial dissection technique applied in porcine motion segments.

PubMed

Kawchuk, Gregory N; Carrasco, Alejandro; Beecher, Grayson; Goertzen, Darrell; Prasad, Narasimha

2010-10-15

Serial dissection of porcine motion segments during robotic control of vertebral kinematics. To identify which spinal tissues are loaded in response to manual therapy (manipulation and mobilization) and to what magnitude. Various theoretical constructs attempt to explain how manual therapies load specific spinal tissues. By using a parallel robot to control vertebral kinematics during serial dissection, it is possible to quantify the loads experienced by discrete spinal tissues undergoing common therapeutic procedures such as manual therapy. In 9 porcine cadavers, manual therapy was provided to L3 and the kinematic response of L3-L4 recorded. The exact kinematic trajectory experienced by L3-L4 in response to manual therapy was then replayed to the isolated segment by a parallel robot equipped with a 6-axis load cell. Discrete spinal tissues were then removed and the kinematic pathway replayed. The change in forces and moments following tissue removal were considered to be those applied to that specific tissue by manual therapy. In this study, both manual therapies affected spinal tissues. The intervertebral disc experienced the greatest forces and moments arising from both manipulation and mobilization. This study is the first to identify which tissues are loaded in response to manual therapy. The observation that manual therapy loads some tissues to a much greater magnitude than others offers a possible explanation for its modest treatment effect; only conditions involving these tissues may be influenced by manual therapy. Future studies are planned to determine if manual therapy can be altered to target (or avoid) specific spinal tissues.

[Recalibration via a postero-lateral approach in recent traumatic stenosis of the dorsal and lumbar spine. Modalities and results apropos of 31 cases].

PubMed

Richaud, J; Bousquet, P; Ealet, G; Clamens, J; Beltchika, K; Lazorthes, Y

1990-01-01

The authors present 31 cases of spinal trauma affecting thoraco lumbar level with severe spinal canal stenosis secondary to compressive trauma of the anterior disco-corpereal region. Associated neurological disorders were of varying severity. 23 cases were investigated by computed tomography. In all cases, the surgical procedure involved rectification of spinal deformities, with initially a unilateral postero-lateral approach permitting anterior spinal canal recalibration, either by impaction of protrusive fragments or ablation of free disc fragments. The stabilization was usually achieved by complementary bilateral plates using Roy-Camille or Privat material in 22 cases, associated with postero-lateral arthrodesis by grafting with reconstruction of the articulo-pedicular structure in 19 cases. Emergency operation was done in 14 cases; in 5 cases operation was done on the 2nd or 3rd day and in 11 cases after the 3rd day. The functional spinal result was excellent, and recalibration was verified by tomography in all cases. In those cases showing neurological deficiency, good and early recovery was attributable to the suppression of spinal canal stenosis, and a consequently neurological improvement was always obtained, even for the most serious of lesions except those at the thoracis level superior to T10. The application of this postero-lateral approach for severe spinal trauma seems to represent, in all cases of recent lesions, an alternative to the anterior or combined methods. We do not share the opinion that delay in decompression does not influence the neurological prognosis and emergency operation is advisable.

Proteomic analysis of ligamentum flavum from patients with lumbar spinal stenosis.

PubMed

Kamita, Masahiro; Mori, Taiki; Sakai, Yoshihito; Ito, Sadayuki; Gomi, Masahiro; Miyamoto, Yuko; Harada, Atsushi; Niida, Shumpei; Yamada, Tesshi; Watanabe, Ken; Ono, Masaya

2015-05-01

Lumbar spinal stenosis (LSS) is a syndromic degenerative spinal disease and is characterized by spinal canal narrowing with subsequent neural compression causing gait disturbances. Although LSS is a major age-related musculoskeletal disease that causes large decreases in the daily living activities of the elderly, its molecular pathology has not been investigated using proteomics. Thus, we used several proteomic technologies to analyze the ligamentum flavum (LF) of individuals with LSS. Using comprehensive proteomics with strong cation exchange fractionation, we detected 1288 proteins in these LF samples. A GO analysis of the comprehensive proteome revealed that more than 30% of the identified proteins were extracellular. Next, we used 2D image converted analysis of LC/MS to compare LF obtained from individuals with LSS to that obtained from individuals with disc herniation (nondegenerative control). We detected 64 781 MS peaks and identified 1675 differentially expressed peptides derived from 286 proteins. We verified four differentially expressed proteins (fibronectin, serine protease HTRA1, tenascin, and asporin) by quantitative proteomics using SRM/MRM. The present proteomic study is the first to identify proteins from degenerated and hypertrophied LF in LSS, which will help in studying LSS. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clinical Evidence for Spinal Cord Stimulation for Failed Back Surgery Syndrome (FBSS): Systematic Review.

PubMed

Kapural, Leonardo; Peterson, Erika; Provenzano, David A; Staats, Peter

2017-07-15

A systematic review. A systematic literature review of the clinical data from prospective studies was undertaken to assess the efficacy of spinal cord stimulation (SCS) in the treatment of failed back surgery syndrome (FBSS) in adults. For patients with unrelenting back pain due to mechanical instability of the spine, degenerative disc disease, spinal injury, or deformity, spinal surgery is a well-accepted treatment option; however, even after surgical intervention, many patients continue to experience chronic back pain that can be notoriously difficult to treat. Clinical evidence suggests that for patients with FBSS, repeated surgery will not likely offer relief. Additionally, evidence suggests long-term use of opioid pain medications is not effective in this population, likely presents additional complications, and requires strict management. A systematic literature review was performed using several bibliographic databases, prospective studies in adults using SCS for FBSS were included. SCS has been shown to be a safe and efficacious treatment for this patient population. Recent technological developments in SCS offer even greater pain relief to patients' refractory to other treatment options, allowing patients to regain functionality and improve their quality of life with significant reductions in pain. N/A.

Cervical Stand-Alone Polyetheretherketone Cage versus Zero-Profile Anchored Spacer in Single-Level Anterior Cervical Discectomy and Fusion : Minimum 2-Year Assessment of Radiographic and Clinical Outcome.

PubMed

Cho, Hyun-Jun; Hur, Junseok W; Lee, Jang-Bo; Han, Jin-Sol; Cho, Tai-Hyoung; Park, Jung-Yul

2015-08-01

We compared the clinical and radiographic outcomes of stand-alone polyetheretherketone (PEEK) cage and Zero-Profile anchored spacer (Zero-P) for single level anterior cervical discectomy and fusion (ACDF). We retrospectively reviewed 121 patients who underwent single level ACDF within 2 years (Jan 2011-Jan 2013) in a single institute. Total 50 patients were included for the analysis who were evaluated more than 2-year follow-up. Twenty-nine patients were allocated to the cage group (m : f=19 : 10) and 21 for Zero-P group (m : f=12 : 9). Clinical (neck disability index, visual analogue scale arm and neck) and radiographic (Cobb angle-segmental and global cervical, disc height, vertebral height) assessments were followed at pre-operative, immediate post-operative, post-3, 6, 12, and 24 month periods. Demographic features and the clinical outcome showed no difference between two groups. The change between final follow-up (24 months) and immediate post-op of Cobb-segmental angle (p=0.027), disc height (p=0.002), vertebral body height (p=0.033) showed statistically better outcome for the Zero-P group than the cage group, respectively. The Zero-Profile anchored spacer has some advantage after cage for maintaining segmental lordosis and lowering subsidence rate after single level anterior cervical discectomy and fusion.

Biomechanical Analysis of Cervical Disc Replacement and Fusion Using Single Level, Two Level, and Hybrid Constructs.

PubMed

Gandhi, Anup A; Kode, Swathi; DeVries, Nicole A; Grosland, Nicole M; Smucker, Joseph D; Fredericks, Douglas C

2015-10-15

A biomechanical study comparing arthroplasty with fusion using human cadaveric C2-T1 spines. To compare the kinematics of the cervical spine after arthroplasty and fusion using single level, 2 level and hybrid constructs. Previous studies have shown that spinal levels adjacent to a fusion experience increased motion and higher stress which may lead to adjacent segment disc degeneration. Cervical arthroplasty achieves similar decompression but preserves the motion at the operated level, potentially decreasing the occurrence of adjacent segment disc degeneration. 11 specimens (C2-T1) were divided into 2 groups (BRYAN and PRESTIGE LP). The specimens were tested in the following order; intact, single level total disc replacement (TDR) at C5-C6, 2-level TDR at C5-C6-C7, fusion at C5-C6 and TDR at C6-C7 (Hybrid construct), and lastly a 2-level fusion. The intact specimens were tested up to a moment of 2.0 Nm. After each surgical intervention, the specimens were loaded until the primary motion (C2-T1) matched the motion of the respective intact state (hybrid control). An arthroplasty preserved motion at the implanted level and maintained normal motion at the nonoperative levels. Arthrodesis resulted in a significant decrease in motion at the fused level and an increase in motion at the unfused levels. In the hybrid construct, the TDR adjacent to fusion preserved motion at the arthroplasty level, thereby reducing the demand on the other levels. Cervical disc arthroplasty with both the BRYAN and PRESTIGE LP discs not only preserved the motion at the operated level, but also maintained the normal motion at the adjacent levels. Under simulated physiologic loading, the motion patterns of the spine with the BRYAN or PRESTIGE LP disc were very similar and were closer than fusion to the intact motion pattern. An adjacent segment disc replacement is biomechanically favorable to a fusion in the presence of a pre-existing fusion.

Aggravation and subsequent disappearance of cervical disc herniation after cervical open-door laminoplasty: A case report.

PubMed

Meng, Yang; Wang, Xiaofei; Wang, Beiyu; Wu, Tingkui; Liu, Hao

2018-03-01

Cervical open-door laminoplasty can enlarge the volume of the cervical vertebral canal and thus has become an effective and safe treatment for multilevel cervical disc herniation and cervical stenosis. Some post-surgery complications exist, such as reduction of cervical alignment and local kyphosis. However, aggravation of cervical disc herniation at the surgical level during short-term follow-up has not been discussed. Additionally, spontaneous disappearance of herniated disc pulposus is a common phenomenon in the lumbar region but is relatively rare in the cervical region. A 42-year-old female presented with a 7-year history of neck pain and a 2-year history of paresthesia and weakness in the upper and lower limbs. The sensations and muscle strength of both upper and lower limbs were decreased. The radiological findings showed that the Pavlov ratios from C3-7 were decreased obviously. Osteophytes as well as spinal cord compression were observed at C4/5, C5/6, and C6/7. Considering the symptoms and clinical examinations, the patient was diagnosed with cervical stenosis. We performed cervical open-door laminoplasty at C3-7 to enlarge the space of the cervical vertebral canal. At the 6-month post-surgery follow-up, the patient showed obvious improvement in paresthesia and weakness in the upper limbs. The cervical disc herniation at C3/4 was aggravated. However, at the 18-month follow-up, the symptoms were relieved, and the herniated cervical disc at C3/4 spontaneously disappeared without any special treatment. We suggest that the attachment points of deep muscles in the neck region should be carefully protected during this surgery. Patients who undergo cervical open-door laminoplasty should pay attention to their cervical position and perform neck exercises to train their neck muscles. MRI is an important imaging method to observe dynamic changes in herniated discs for patients with cervical disc herniation.

Percutaneous treatment of intervertebral disc herniation.

PubMed

Buy, Xavier; Gangi, Afshin

2010-06-01

Interventional radiology plays a major role in the management of symptomatic intervertebral disc herniations. In the absence of significant pain relief with conservative treatment including oral pain killers and anti-inflammatory drugs, selective image-guided periradicular infiltrations are generally indicated. The precise control of needle positioning allows optimal distribution of steroids along the painful nerve root. After 6 weeks of failure of conservative treatment including periradicular infiltration, treatment aiming to decompress or remove the herniation is considered. Conventional open surgery offers suboptimal results and is associated with significant morbidity. To achieve minimally invasive discal decompression, different percutaneous techniques have been developed. Their principle is to remove a small volume of nucleus, which results in an important reduction of intradiscal pressure and subsequently reduction of pressure inside the disc herniation. However, only contained disc herniations determined by computed tomography or magnetic resonance are indicated for these techniques. Thermal techniques such as radiofrequency or laser nucleotomy seem to be more effective than purely mechanical nucleotomy; indeed, they achieve discal decompression but also thermal destruction of intradiscal nociceptors, which may play a major role in the physiopathology of discal pain. The techniques of image-guided spinal periradicular infiltration and percutaneous nucleotomy with laser and radiofrequency are presented with emphasis on their best indications.

Biomechanics of Thoracolumbar Burst and Chance-Type Fractures during Fall from Height

PubMed Central

Ivancic, Paul C.

2014-01-01

Study Design In vitro biomechanical study. Objective To investigate the biomechanics of thoracolumbar burst and Chance-type fractures during fall from height. Methods Our model consisted of a three-vertebra human thoracolumbar specimen (n = 4) stabilized with muscle force replication and mounted within an impact dummy. Each specimen was subjected to a single fall from an average height of 2.1 m with average velocity at impact of 6.4 m/s. Biomechanical responses were determined using impact load data combined with high-speed movie analyses. Injuries to the middle vertebra of each spinal segment were evaluated using imaging and dissection. Results Average peak compressive forces occurred within 10 milliseconds of impact and reached 40.3 kN at the ground, 7.1 kN at the lower vertebra, and 3.6 kN at the upper vertebra. Subsequently, average peak flexion (55.0 degrees) and tensile forces (0.7 kN upper vertebra, 0.3 kN lower vertebra) occurred between 43.0 and 60.0 milliseconds. The middle vertebra of all specimens sustained pedicle and endplate fractures with comminution, bursting, and reduced height of its vertebral body. Chance-type fractures were observed consisting of a horizontal split fracture through the laminae and pedicles extending anteriorly through the vertebral body. Conclusions We hypothesize that the compression fractures of the pedicles and vertebral body together with burst fracture occurred at the time of peak spinal compression, 10 milliseconds. Subsequently, the onset of Chance-type fracture occurred at 20 milliseconds through the already fractured and weakened pedicles and vertebral body due to flexion-distraction and a forward shifting spinal axis of rotation. PMID:25083357

U.S. Navy Aeromedical Reference and Waiver Guide

DTIC Science & Technology

2010-05-05

Disc Disease 13.5 Knees: Ligament/Meniscal Tears 13.6 Orthopedic Hardware Retained 13.7 Recurrent Shoulder Dislocation 13.8 Spinal Fractures 13.9...therapy or facial fracture . See MMD paragraph 15-95 or Physical Exam section of ARWG for text. U.S. Navy Aeromedical Reference and Waiver Guide... fracture . See MMD paragraph 15-95 or Physical Exam section of ARWG for text. U.S. Navy Aeromedical Reference and Waiver Guide Physical

Medical Surveillance Monthly Report (MSMR). Volume 18, Number 05, May 2011

DTIC Science & Technology

2011-05-01

most ED visits – injuries and poisonings, signs and symptoms of ill-defi ned conditions, and respiratory diseases – were similar among military...176,066) were the most frequent specifi c diagnoses reported during injury/poisoning-related visits (data not shown). “Signs, symptoms , and ill...diagnosis overall (Table 2). “Other signs, symptoms and ill-defi ned conditions” and “spinal disorders” (which includes intervertebral disc Figure 1

Efficiency of thin magnetically arrested discs around black holes

NASA Astrophysics Data System (ADS)

Avara, Mark J.; McKinney, Jonathan C.; Reynolds, Christopher S.

2016-10-01

The radiative and jet efficiencies of thin magnetized accretion discs around black holes (BHs) are affected by BH spin and the presence of a magnetic field that, when strong, could lead to large deviations from Novikov-Thorne (NT) thin disc theory. To seek the maximum deviations, we perform general relativistic magnetohydrodynamic simulations of radiatively efficient thin (half-height H to radius R of H/R ≈ 0.10) discs around moderately rotating BHs with a/M = 0.5. First, our simulations, each evolved for more than 70 000 rg/c (gravitational radius rg and speed of light c), show that large-scale magnetic field readily accretes inward even through our thin disc and builds-up to the magnetically arrested disc (MAD) state. Secondly, our simulations of thin MADs show the disc achieves a radiative efficiency of ηr ≈ 15 per cent (after estimating photon capture), which is about twice the NT value of ηr ˜ 8 per cent for a/M = 0.5 and gives the same luminosity as an NT disc with a/M ≈ 0.9. Compared to prior simulations with ≲10 per cent deviations, our result of an ≈80 per cent deviation sets a new benchmark. Building on prior work, we are now able to complete an important scaling law which suggests that observed jet quenching in the high-soft state in BH X-ray binaries is consistent with an ever-present MAD state with a weak yet sustained jet.

In vitro biomechanical comparison after fixed- and mobile-core artificial cervical disc replacement versus fusion

PubMed Central

Lou, Jigang; Li, Yuanchao; Wang, Beiyu; Meng, Yang; Wu, Tingkui; Liu, Hao

2017-01-01

Abstract In vitro biomechanical analysis after cervical disc replacement (CDR) with a novel artificial disc prosthesis (mobile core) was conducted and compared with the intact model, simulated fusion, and CDR with a fixed-core prosthesis. The purpose of this experimental study was to analyze the biomechanical changes after CDR with a novel prosthesis and the differences between fixed- and mobile-core prostheses. Six human cadaveric C2–C7 specimens were biomechanically tested sequentially in 4 different spinal models: intact specimens, simulated fusion, CDR with a fixed-core prosthesis (Discover, DePuy), and CDR with a mobile-core prosthesis (Pretic-I, Trauson). Moments up to 2 Nm with a 75 N follower load were applied in flexion–extension, left and right lateral bending, and left and right axial rotation. The total range of motion (ROM), segmental ROM, and adjacent intradiscal pressure (IDP) were calculated and analyzed in 4 different spinal models, as well as the differences between 2 disc prostheses. Compared with the intact specimens, the total ROM, segmental ROM, and IDP at the adjacent segments showed no significant difference after arthroplasty. Moreover, CDR with a mobile-core prosthesis presented a little higher values of target segment (C5/6) and total ROM than CDR with a fixed-core prosthesis (P > .05). Besides, the difference in IDP at C4/5 after CDR with 2 prostheses was without statistical significance in all the directions of motion. However, the IDP at C6/7 after CDR with a mobile-core prosthesis was lower than CDR with a fixed-core prosthesis in flexion, extension, and lateral bending, with significant difference (P < .05), but not under axial rotation. CDR with a novel prosthesis was effective to maintain the ROM at the target segment and did not affect the ROM and IDP at the adjacent segments. Moreover, CDR with a mobile-core prosthesis presented a little higher values of target segment and total ROM, but lower IDP at the inferior adjacent segment than CDR with a fixed-core prosthesis. PMID:29019902

Stem cell-mediated osteogenesis: therapeutic potential for bone tissue engineering

PubMed Central

Neman, Josh; Hambrecht, Amanda; Cadry, Cherie; Jandial, Rahul

2012-01-01

Intervertebral disc degeneration often requires bony spinal fusion for long-term relief. Current arthrodesis procedures use bone grafts from autogenous bone, allogenic backed bone, or synthetic materials. Autogenous bone grafts can result in donor site morbidity and pain at the donor site, while allogenic backed bone and synthetic materials have variable effectiveness. Given these limitations, researchers have focused on new treatments that will allow for safe and successful bone repair and regeneration. Mesenchymal stem cells have received attention for their ability to differentiate into osteoblasts, cells that synthesize new bone. With the recent advances in scaffold and biomaterial technology as well as stem cell manipulation and transplantation, stem cells and their scaffolds are uniquely positioned to bring about significant improvements in the treatment and outcomes of spinal fusion and other injuries. PMID:22500114

Stem cell-mediated osteogenesis: therapeutic potential for bone tissue engineering.

PubMed

Neman, Josh; Hambrecht, Amanda; Cadry, Cherie; Jandial, Rahul

2012-01-01

Intervertebral disc degeneration often requires bony spinal fusion for long-term relief. Current arthrodesis procedures use bone grafts from autogenous bone, allogenic backed bone, or synthetic materials. Autogenous bone grafts can result in donor site morbidity and pain at the donor site, while allogenic backed bone and synthetic materials have variable effectiveness. Given these limitations, researchers have focused on new treatments that will allow for safe and successful bone repair and regeneration. Mesenchymal stem cells have received attention for their ability to differentiate into osteoblasts, cells that synthesize new bone. With the recent advances in scaffold and biomaterial technology as well as stem cell manipulation and transplantation, stem cells and their scaffolds are uniquely positioned to bring about significant improvements in the treatment and outcomes of spinal fusion and other injuries.

The mechanical consequence of failure of ossified union in attempted posterior spinal fusion. A canine model.

PubMed

Stonecipher, T K; Vanderby, R; Sciammarella, C A; Lei, S S; Fisk, J R

1983-01-01

The mechanical behavior of pseudarthrosis in posterior spinal fusion was investigated. A canine model was developed in which an incompletely ossified posterior fusion mass was consistently produced. The spines were excised, and the motion segments were mechanically tested using a specially developed loading apparatus. Tests were performed to evaluate stiffness of the segments to loading with compression, torsion, and anterioposterior and lateral bending shear stiffness. Changes in other modes of loading were less consistent. The motion characteristics of the pseudarthrosis could not be predicted from the extent of the osseous defect noted on roentgenograms. These findings correlate clinically with the progression of curvature seen with pseudarthrosis in scoliosis surgery and the unpredictable results of pseudarthrosis in posterior fusion performed in treatment of degenerative disc disease.

Three-dimensional disc-satellite interaction: torques, migration, and observational signatures

NASA Astrophysics Data System (ADS)

Arzamasskiy, Lev; Zhu, Zhaohuan; Stone, James M.

2018-04-01

The interaction of a satellite with a gaseous disc results in the excitation of spiral density waves, which remove angular momentum from the orbit. In addition, if the orbit is not coplanar with the disc, three-dimensional effects will excite bending and eccentricity waves. We perform three-dimensional hydrodynamic simulations to study nonlinear disc-satellite interaction in inviscid protoplanetary discs for a variety of orbital inclinations from 0° to 180°. It is well known that three-dimensional effects are important even for zero inclination. In this work, we (1) show that for planets with small inclinations (as in the Solar system), effects such as the total torque and migration rate strongly depend on the inclination and are significantly different (about 2.5 times smaller) from the two-dimensional case, (2) give formulae for the migration rate, inclination damping, and precession rate of planets with different inclination angles in disc with different scale heights, and (3) present the observational signatures of a planet on an inclined orbit with respect to the protoplanetary disc. For misaligned planets, we find good agreement with linear theory in the limit of small inclinations, and with dynamical friction estimates for intermediate inclinations. We find that in the latter case, the dynamical friction force is not parallel to the relative planetary velocity. Overall, the derived formulae will be important for studying exoplanets with obliquity.

The Use of Arm Span as a Substitute for Height in Calculating Body Mass Index (BMI) for Spine Deformity Patients.

PubMed

Opoku, Harriet; Yirerong, Theresa; Osei-Onwona, Belinda; Boachie-Adjei, Oheneba

To compare arm span and height in body mass index (BMI) calculation in patients with spinal curvature and investigate their impact on interpretation of BMI. Prospective case-control cohorts. The BMI value is based on weight to height ratio. Spine deformity patients experience height loss and its use in calculating BMI is likely to produce errors. A surrogate for height should therefore be sought in BMI determination. Ninety-three spine deformity patients were matched with 64 normal children. Anthropometric values (height, arm span, and weight) and spinal curve were obtained. BMIs using arm span and height were calculated, and statistical analysis performed to assess the relationship between BMI/height and BMI/arm span in both groups as well as the relationship between these values and Arm Span to Height difference (Delta AH). There were 46 males and 47 females, the average age was 15.5 years in Group 1 versus 33 males and 31 females, average age 14.8 years in Group 2. Major scoliosis in Group 1 averaged 125.7° (21° to 252°). The extreme curves show vertebral transposition, with overlapping segments making it more than 180°. A logistic regression showed that there was linearity in BMI scores (R 2 = 0.97) for both arm span and height (R 2 = 0.94) in group 2 patients. For group 1 patients there was a significant difference in the BMI values when comparing BMI/arm span versus BMI/height (p < .0001). Mean BMI values using height was overstated by 2.8 (18.6%). The threshold at which BMI score must be calculated using arm span as opposed to the height (Delta AH) was determined to be 3 cm. Spine deformity patients experience height loss, which can impact their true BMI values thereby giving an erroneous impression of their nutritional status. The arm span should be used in patients with Delta AH >3 cm to properly assess nutritional status. Copyright © 2017 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

A Systematic Review of the Safety and Efficacy of Mesenchymal Stem Cells for Disc Degeneration: Insights and Future Directions for Regenerative Therapeutics

PubMed Central

Yim, Rita Lok-Hay; Lee, Juliana Tsz-Yan; Bow, Cora H.; Meij, Björn; Leung, Victor; Cheung, Kenneth M.C.; Vavken, Patrick

2014-01-01

Intervertebral disc degeneration is associated with low-back pain. Mesenchymal stem cells (MSCs) have been used to “regenerate” the disc. The aim of this study was to perform a systematic review of comparative controlled studies that have assessed the safety and efficacy of using MSCs for disc regeneration. Literature databases were extensively searched. Trial design, subject-type, MSC sources, injection method, disc assessment, outcome intervals, and complication events were assessed. Validity of each study was performed. Twenty-four animal studies were included with 20.8% of the studies reporting randomization of groups. Trials in humans fulfilling inclusion criteria were not noted. The studies represented 862 discs that were injected with MSCs and 1,603 discs as controls. All three types of MSCs (ie, bone marrow, synovial, and adipose tissues) showed successful inhibition of disc degeneration. Bone-marrow-derived MSCs demonstrated superior quality of repair compared with other non-MSC treatments. A 2.7% overall complication rate was noted, whereby complications were noted only in rabbits. Overall, evidence suggested that MSCs increased disc space height in the majority of animal models. This is the first systematic review to assess the safety and efficacy of MSCs for the treatment of disc degeneration. Short-term MSC transplantation is safe and effective; however, additional, larger, and higher-quality studies are needed to assess the long-term safety and efficacy. Inconsistencies in methodological design and outcome parameters prevent any robust conclusions. Human-based clinical trials are needed. Recommendations are further made to improve efficacy, reduce potential complications, and standardize techniques for future studies. PMID:25050446

ACR Appropriateness Criteria Myelopathy.

PubMed

Roth, Christopher J; Angevine, Peter D; Aulino, Joseph M; Berger, Kevin L; Choudhri, Asim F; Fries, Ian Blair; Holly, Langston T; Kendi, Ayse Tuba Karaqulle; Kessler, Marcus M; Kirsch, Claudia F; Luttrull, Michael D; Mechtler, Laszlo L; O'Toole, John E; Sharma, Aseem; Shetty, Vilaas S; West, O Clark; Cornelius, Rebecca S; Bykowski, Julie

2016-01-01

Patients presenting with myelopathic symptoms may have a number of causative intradural and extradural etiologies, including disc degenerative diseases, spinal masses, infectious or inflammatory processes, vascular compromise, and vertebral fracture. Patients may present acutely or insidiously and may progress toward long-term paralysis if not treated promptly and effectively. Noncontrast CT is the most appropriate first examination in acute trauma cases to diagnose vertebral fracture as the cause of acute myelopathy. In most nontraumatic cases, MRI is the modality of choice to evaluate the location, severity, and causative etiology of spinal cord myelopathy, and predicts which patients may benefit from surgery. Myelopathy from spinal stenosis and spinal osteoarthritis is best confirmed without MRI intravenous contrast. Many other myelopathic conditions are more easily visualized after contrast administration. Imaging performed should be limited to the appropriate spinal levels, based on history, physical examination, and clinical judgment. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals, and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Radiculopathy in the setting of lumbar nerve root compression due to an extradural intraforaminal lipoma: a report of 3 cases.

PubMed

Loriaux, Daniel B; Adogwa, Owoicho; Gottfried, Oren N

2015-07-01

A true adult spinal lipoma is an exceedingly rare cause of lumbar compression neuropathy. Only 5 cases of true extradural intraforaminal lipomas have been documented in the medical literature. The diagnostic criteria and treatment guidelines for this specific lipoma have yet to be established. This report features 3 histologically confirmed cases of extradural intraforaminal spinal lipomas that recently presented to the authors' practice. In addition, the literature was surveyed to include the 5 previously reported cases of true adult extradural intraforaminal spinal lipomas. The consistency in presentation, response to surgical intervention, and postoperative recovery in these 8 cases supports surgical intervention at the time of diagnosis. The authors' findings support elevated clinical suspicion, efficient diagnosis based on MRI, and early surgical intervention for this rare pathological entity. All cases presented in this report were symptomatic and occurred in the absence of other significant pathologies such as general spinal epidural lipomatosis, intradural lesions, tethering, or severe degenerative stenosis or herniated discs. The clinical, neuroradiological, and histological findings characteristic of a true adult extradural intraforaminal lipoma are emphasized to differentiate this lesion from the more common etiologies for lumbar compression neuropathy. Heightened awareness and clinical suspicion for the focal, foraminal spinal lipoma as a cause of radiculopathy symptoms will enable more efficient diagnosis and treatment.

Effective robotic assistive pattern of treadmill training for spinal cord injury in a rat model

PubMed Central

Zhao, Bo-Lun; Li, Wen-Tao; Zhou, Xiao-Hua; Wu, Su-Qian; Cao, Hong-Shi; Bao, Zhu-Ren; An, Li-Bin

2018-01-01

The purpose of the present study was to establish an effective robotic assistive stepping pattern of body-weight-supported treadmill training based on a rat spinal cord injury (SCI) model and assess the effect by comparing this with another frequently used assistive stepping pattern. The recorded stepping patterns of both hind limbs of trained intact rats were edited to establish a 30-sec playback normal rat stepping pattern (NRSP). Step features (step length, step height, step number and swing duration), BBB scores, latencies, and amplitudes of the transcranial electrical motor-evoked potentials (tceMEPs) and neurofilament 200 (NF200) expression in the spinal cord lesion area during and after 3 weeks of body-weight-supported treadmill training (BWSTT) were compared in rats with spinal contusion receiving NRSP assistance (NRSPA) and those that received manual assistance (MA). Hind limb stepping performance among rats receiving NRSPA during BWSTT was greater than that among rats receiving MA in terms of longer step length, taller step height, and longer swing duration. Furthermore a higher BBB score was also indicated. The rats in the NRSPA group achieved superior results in the tceMEPs assessment and greater NF200 expression in the spinal cord lesion area compared with the rats in the MA group. These findings suggest NRSPA was an effective assistive pattern of treadmill training compared with MA based on the rat SCI model and this approach could be used as a new platform for animal experiments for better understanding the mechanisms of SCI rehabilitation. PMID:29545846

In vitro wear assessment of the Charité Artificial Disc according to ASTM recommendations.

PubMed

Serhan, Hassan A; Dooris, Andrew P; Parsons, Matthew L; Ares, Paul J; Gabriel, Stefan M

2006-08-01

Biomechanical laboratory research. To evaluate the potential for Ultra High Molecular Weight Polyethylene (UHMWPE) wear debris from the Charité Artificial Disc. Cases of osteolysis from artificial discs are extremely rare, but hip and knee studies demonstrate the osteolytic potential and clinical concern of UHMWPE wear debris. Standards for testing artificial discs continue to evolve, and there are few detailed reports of artificial disc wear characterizations. Implant assemblies were tested to 10 million cycles of +/- 7.5 degrees flexion-extension or +/- 7.5 degrees left/right lateral bending, both with +/- 2 degrees axial rotation and 900 N to 1,850 N cyclic compression. Cores were weighed, measured, and photographed. Soak and loaded soak controls were used. Wear debris was analyzed via scanning electron microscopy and particle counters. The average total wear of the implants was 0.11 and 0.13 mg per million cycles, before and after accounting for serum absorption, respectively. Total height loss was approximately 0.2 mm. Wear debris ranged from submicron to > 10 microm in size. Under these test conditions, the Charité Artificial Disc produced minimal wear debris. Debris size and morphology tended to be similar to other CoCr-UHMWPE joints. More testing is necessary to evaluate the implants under a spectrum of loading conditions.

Diagnosis of unstable cervical spine injuries: laboratory support for the use of axial traction to diagnose cervical spine instability.

PubMed

Kalantar, Babak S; Hipp, John A; Reitman, Charles A; Dreiangel, Niv; Ben-Galim, Peleg

2010-10-01

The ability to detect damage to the intervertebral structures is critical in the management of patients after blunt trauma. A practical and inexpensive method to identify severe structural damage not clearly seen on computed tomography would be of benefit. The objective of this study was to assess whether ligamentous injury in the subaxial cervical spine can be reliably detected by analysis of lateral radiographs taken with and without axial traction. Twelve fresh, whole, postrigor-mortis cadavers were used for this study. Lateral cervical spine radiographs were obtained during the application of 0 N, 89 N, and 178 N of axial traction applied to the head. Progressive incremental sectioning of posterior structures was then performed at C4-C5 with traction imaging repeated after each intervention. Intervertebral distraction was analyzed using computer-assisted software. Almost imperceptible intervertebral separation was found when traction was applied to intact spines. In the subaxial cervical spine, the average posterior disc height consistently increased under traction in severely injured spines. The average disc height increase was 14% of the C4 upper endplate width, compared with an average of 2% in the noninjured spines. A change of more than 5% in posterior disc height under traction was above the 95% confidence interval for intact spines, with sensitivity of 83% and specificity of 80%. Applied force of 89 N (20 lb) was sufficient to demonstrate injury. The combination of assessing alignment and distraction under traction increased both the sensitivity and specificity to nearly 100%. This study supports further clinical investigations to determine whether low-level axial traction may be a useful adjunct for detecting unstable subaxial cervical spine injuries in an acute setting.

Clinical Characterization of Patients With Autosomal Dominant Short Stature due to Aggrecan Mutations

PubMed Central

Gkourogianni, Alexandra; Andrew, Melissa; Tyzinski, Leah; Crocker, Melissa; Douglas, Jessica; Dunbar, Nancy; Fairchild, Jan; Funari, Mariana F. A.; Heath, Karen E.; Jorge, Alexander A. L.; Kurtzman, Tracey; LaFranchi, Stephen; Lalani, Seema; Lebl, Jan; Lin, Yuezhen; Los, Evan; Newbern, Dorothee; Nowak, Catherine; Olson, Micah; Popovic, Jadranka; Průhová, Štěpánka; Elblova, Lenka; Quintos, Jose Bernardo; Segerlund, Emma; Sentchordi, Lucia; Shinawi, Marwan; Stattin, Eva-Lena; Swartz, Jonathan; del Angel, Ariadna González; Cuéllar, Sinhué Diaz; Hosono, Hidekazu; Sanchez-Lara, Pedro A.; Hwa, Vivian; Baron, Jeffrey; Dauber, Andrew

2017-01-01

Context: Heterozygous mutations in the aggrecan gene (ACAN) cause autosomal dominant short stature with accelerated skeletal maturation. Objective: We sought to characterize the phenotypic spectrum and response to growth-promoting therapies. Patients and Methods: One hundred three individuals (57 females, 46 males) from 20 families with autosomal dominant short stature and heterozygous ACAN mutations were identified and confirmed using whole-exome sequencing, targeted next-generation sequencing, and/or Sanger sequencing. Clinical information was collected from the medical records. Results: Identified ACAN variants showed perfect cosegregation with phenotype. Adult individuals had mildly disproportionate short stature [median height, −2.8 standard deviation score (SDS); range, −5.9 to −0.9] and a history of early growth cessation. The condition was frequently associated with early-onset osteoarthritis (12 families) and intervertebral disc disease (9 families). No apparent genotype–phenotype correlation was found between the type of ACAN mutation and the presence of joint complaints. Childhood height was less affected (median height, −2.0 SDS; range, −4.2 to −0.6). Most children with ACAN mutations had advanced bone age (bone age − chronologic age; median, +1.3 years; range, +0.0 to +3.7 years). Nineteen individuals had received growth hormone therapy with some evidence of increased growth velocity. Conclusions: Heterozygous ACAN mutations result in a phenotypic spectrum ranging from mild and proportionate short stature to a mild skeletal dysplasia with disproportionate short stature and brachydactyly. Many affected individuals developed early-onset osteoarthritis and degenerative disc disease, suggesting dysfunction of the articular cartilage and intervertebral disc cartilage. Additional studies are needed to determine the optimal treatment strategy for these patients. PMID:27870580

Variations in Practice Patterns among Neurosurgeons and Orthopaedic Surgeons in the Management of Spinal Disorders.

PubMed

Hussain, Manzar; Nasir, Sadaf; Moed, Amber; Murtaza, Ghulam

2011-12-01

This is a case series. We wanted to identify variations in the practice patterns among neurosurgeons and orthopedic surgeons for the management of spinal disorders. Spinal disorders are common in the clinical practice of both neurosurgeons and orthopedic surgeons. It has been observed that despite the availability of various guidelines, there is lack of consensus among surgeons about the management of various disorders. A questionnaire was distributed, either directly or via e-mail, to the both the neurosurgeons and orthopedic surgeons who worked at 5 tertiary care centers within a single region of Korea. The surgeons were working either in private practice or in academic institutions. The details of the questionnaire included demographic details and the specialty (orthopedic/neurosurgeon). The surgeons were classified according to the level of experience as up to 5 years, 6-10 years and > 10 years. Questions were asked about the approach to lumbar discectomy (fragmentectomy or aggressive disc removal), using steroids for treating discitis, the fusion preference for spondylolisthesis, the role of an orthosis after fusion, the preferred surgical approach for spinal stenosis, the operative approach for spinal trauma (early within 72 hours or late > 72 hours) and the role of surgery in complete spinal cord injury. The data was analyzed using SPSS ver 16. p-values < 0.05 were considered to be significant. Of the 30 surgeons who completed the questionnaire, 20 were neurosurgeons and 10 were orthopedic surgeons. Statistically significant differences were observed for the management of spinal stenosis, spondylolisthesis, using an orthosis after fusion, the type of lumbar discectomy and the value of surgical intervention after complete spinal cord injury. Our results suggest that there continues to exist a statistically significant lack of consensus among neurosurgeons and orthopedic spine surgeons when considering using an orthosis after fusion, the type of discectomy and the value of intervention after complete spinal injury.

Variations in Practice Patterns among Neurosurgeons and Orthopaedic Surgeons in the Management of Spinal Disorders

PubMed Central

Nasir, Sadaf; Moed, Amber; Murtaza, Ghulam

2011-01-01

Study Design This is a case series. Purpose We wanted to identify variations in the practice patterns among neurosurgeons and orthopedic surgeons for the management of spinal disorders. Overview of Literature Spinal disorders are common in the clinical practice of both neurosurgeons and orthopedic surgeons. It has been observed that despite the availability of various guidelines, there is lack of consensus among surgeons about the management of various disorders. Methods A questionnaire was distributed, either directly or via e-mail, to the both the neurosurgeons and orthopedic surgeons who worked at 5 tertiary care centers within a single region of Korea. The surgeons were working either in private practice or in academic institutions. The details of the questionnaire included demographic details and the specialty (orthopedic/neurosurgeon). The surgeons were classified according to the level of experience as up to 5 years, 6-10 years and > 10 years. Questions were asked about the approach to lumbar discectomy (fragmentectomy or aggressive disc removal), using steroids for treating discitis, the fusion preference for spondylolisthesis, the role of an orthosis after fusion, the preferred surgical approach for spinal stenosis, the operative approach for spinal trauma (early within 72 hours or late > 72 hours) and the role of surgery in complete spinal cord injury. The data was analyzed using SPSS ver 16. p-values < 0.05 were considered to be significant. Results Of the 30 surgeons who completed the questionnaire, 20 were neurosurgeons and 10 were orthopedic surgeons. Statistically significant differences were observed for the management of spinal stenosis, spondylolisthesis, using an orthosis after fusion, the type of lumbar discectomy and the value of surgical intervention after complete spinal cord injury. Conclusions Our results suggest that there continues to exist a statistically significant lack of consensus among neurosurgeons and orthopedic spine surgeons when considering using an orthosis after fusion, the type of discectomy and the value of intervention after complete spinal injury. PMID:22164314

Quantification of Propionic Acid in the Bovine Spinal Disk After Infection of the Tissue With Propionibacteria acnes Bacteria.

PubMed

Magnitsky, Sergey; Dudli, Stefan; Tang, Xinyan; Kaur, Jaskanwaljeet; Diaz, Joycelyn; Miller, Steve; Lotz, Jeffrey C

2018-06-01

Research. The goal of this study was to investigate whether Propionibacteria acnes infection of the intervertebral disc can be detected noninvasively by nuclear magnetic resonance (NMR) spectroscopy. Microbiological studies of surgical samples suggest that a significant subpopulation of back pain patients may have occult disc infection with P. acnes bacteria. This hypothesis is further supported by a double-blind clinical trial showing that back pain patients with Modic type 1 changes may respond to antibiotic treatment. Because significant side effects are associated with antibiotic treatment, there is a need for a noninvasive method to detect whether specific discs in back pain patients are infected with P acnes bacteria. P. acnes bacteria were obtained from human patients. NMR detection of a propionic acid (PA) in the bacteria extracts was conducted on 500 MHz high-resolution spectrometer, whereas in vivo NMR spectroscopy of an isolated bovine disk tissue infected with P. acnes was conducted on 7 T magnetic resonance imaging scanner. NMR spectra of P. acnes metabolites revealed a distinct NMR signal with identical chemical shits (1.05 and 2.18 ppm) as PA (a primary P. acne metabolite). The 1.05 ppm signal does not overlap with other bacteria metabolites, and its intensity increases linearly with P. acnes concentration. Bovine disks injected with P. acnes bacteria revealed a very distinct NMR signal at 1.05 ppm, which linearly increased with P. acnes concentration. The 1.05 ppm NMR signal from PA can be used as a marker of P. acnes infection of discs. This signal does not overlap with other disc metabolites and linearly depends on P. acnes concentration. Consequently, NMR spectroscopy may provide a noninvasive method to detect disc infection in the clinical setting. N/A.

Surgical treatment of thoracic disc disease via minimally invasive lateral transthoracic trans/retropleural approach: analysis of 33 patients.

PubMed

Nacar, Osman Arikan; Ulu, Mustafa Onur; Pekmezci, Murat; Deviren, Vedat

2013-07-01

Thoracic disc herniations are associated with serious neurological consequences if not treated appropriately. Although a number of techniques have been described, there is no consensus about the best surgical approach. In this study, the authors report their experience in the operative management of patients with thoracic disc herniations using minimally invasive lateral transthoracic trans/retropleural approach. A series of 33 consecutive patients with thoracic disc herniations who underwent anterior spinal cord decompression followed by instrumented fusion through lateral approach is being reported. Demographic and radiographic data, perioperative complications, and clinical outcomes were reviewed. Forty disc levels in 33 patients (18F/15M; mean age, 52.9) were treated. Twenty-three patients presented with myelopathy (69 %), 31 had radiculopathy (94 %), and 31 had axial pain (94 %). Among patients with myelopathy, 14 (42.4 %) had bladder and/or bowel dysfunction. In the last eight cases (24 %), the approach was retropleural instead of transpleural. Patients were followed up for 18.2 months on average. The mean length of hospital stay was 5 days. None of the patients developed neurological deterioration postoperatively. Among 23 patients who had myelopathy signs, 21 (91 %) had improved postoperatively. The mean preoperative visual analog scale pain score, Oswestry Disability Index score, SF-36 PCS, and mental component summary scores were 7.5, 42.4, 29.6, and 37.5 which improved to 3.5, 33.2, 35.5, and 52.6, respectively. Perioperative complications occurred in six patients (18.1 %), all of which resolved uneventfully. Minimally invasive lateral transthoracic trans/retropleural approach is a safe and efficacious technique for achieving adequate decompression in thoracic disc herniations in a less invasive manner than conventional approaches.

Evaluation of T2-weighted versus short-tau inversion recovery sagittal sequences in the identification and localization of canine intervertebral disc extrusion with low-field magnetic resonance imaging.

PubMed

Housley, Daniel; Caine, Abby; Cherubini, Giunio; Taeymans, Olivier

2017-07-01

Sagittal T2-weighted sequences (T2-SAG) are the foundation of spinal protocols when screening for the presence of intervertebral disc extrusion. We often utilize sagittal short-tau inversion recovery sequences (STIR-SAG) as an adjunctive screening series, and experience suggests that this combined approach provides superior detection rates. We hypothesized that STIR-SAG would provide higher sensitivity than T2-SAG in the identification and localization of intervertebral disc extrusion. We further hypothesized that the parallel evaluation of paired T2-SAG and STIR-SAG series would provide a higher sensitivity than could be achieved with either independent sagittal series when viewed in isolation. This retrospective diagnostic accuracy study blindly reviewed T2-SAG and STIR-SAG sequences from dogs (n = 110) with surgically confirmed intervertebral disc extrusion. A consensus between two radiologists found no significant difference in sensitivity between T2-SAG and STIR-SAG during the identification of intervertebral disc extrusion (T2-SAG: 92.7%, STIR-SAG: 94.5%, P = 0.752). Nevertheless, STIR-SAG accurately identified intervertebral disc extrusion in 66.7% of cases where the evaluation of T2-SAG in isolation had provided a false negative diagnosis. Additionally, one radiologist found that the parallel evaluation of paired T2-SAG and STIR-SAG series provided a significantly higher sensitivity than T2-SAG in isolation, during the identification of intervertebral disc extrusion (T2-SAG: 78.2%, paired T2-SAG, and STIR-SAG: 90.9%, P = 0.017). A similar nonsignificant trend was observed when the consensus of both radiologists was taken into consideration (T2-SAG: 92.7%, paired T2-SAG, and STIR-SAG = 97.3%, P = 0.392). We therefore conclude that STIR-SAG is capable of identifying intervertebral disc extrusion that is inconspicuous in T2-SAG, and that STIR-SAG should be considered a useful adjunctive sequence during preliminary sagittal screening for intervertebral disc extrusion in low-field magnetic resonance. © 2017 American College of Veterinary Radiology.

Rationale, principles and experimental evaluation of the concept of soft stabilization.

PubMed

Mulholland, Robert C; Sengupta, Dilip K

2002-10-01

The apparent clinical success of spinal stabilization methods that restrict rather than abolish movement in relieving mechanical back pain indicates that the concept of the aetiology of back pain should be reviewed. Further understanding of how degeneration affects disc biomechanics, and an understanding of how current soft stabilization systems alters them, may allow us to define more precisely what are the essential requirements of an ideal soft stabilization system. It appears that abnormal patterns of loading rather than abnormal movement are the reason that disc degeneration causes back pain in some patients. Abnormal load transmission is the principal cause of pain in osteoarthritic joints, and both osteotomy and, indeed, joint replacement succeed because they alter the load transmission across the joint. This concept is supported by the fact that abnormal patterns of stress distribution measured across the disc correlate with painful discs on discography. Clinically, it is often noted that back pain is primarily related to position or posture, rather than movement of the lumbar spine. Clinical success after solid fusion is unpredictable because it does not necessarily prevent painful loading across the disc, and also it may interfere with maintenance of sagittal balance in varying postures. The Graf ligament restricted flexion, and was modestly successful. It unfortunately increased the load over the posterior annulus. The Dynesys system reduces movement both in flexion and extension, and appears to be more successful. However, often it also unloads the disc to a degree that is unpredictable. The authors believe that this unloading of the disc is an important feature of a flexible stabilization system. A new a design of a flexible stabilization system has recently been described in an in vitro study, which unloads the disc by introduction of a load-sharing fulcrum near the axis of movement together with an elastic posterior ligament. This design produces maximal unloading of the disc, whilst allowing a restricted range of movement, which serves the important purpose of allowing the patient to maintain sagittal balance in varying postures.

Health Care Burden of Spinal Diseases in the Republic of Korea: Analysis of a Nationwide Database From 2012 Through 2016

PubMed Central

Lee, Chang-Hyun; Kim, Chi Heon; Kwon, Ji-Woong

2018-01-01

Objective This study aimed to determine the incidence and analyze trends related to spinal diseases based on a national database in the Republic of Korea (ROK) and to elucidate the healthcare burden that will serve as a useful resource for researchers, clinicians, and patients. Methods This study was a retrospective analysis of data obtained from Healthcare Bigdata Hub, the Korean Statistical Information Service, and Open Data Portal from 2012 through 2016. The main disease codes for spinal diseases (M40–M54) were used for identification of these conditions. Results The overall annual incidence rates for spinal disease in the ROK was median 15,877 (men, 13,181; women, 18,588) per 100,000 population, and sex ratio was 1:1.41 (p<0.01). The incidence rate and annual costs per patient increased by 7.6% and 14.7% over 5 years continuously, respectively. The age-adjusted incidence rate increased with age; the highest rates were 42.6% in the 75–79 years group. Patients older than 65 years old accounted for median 31.0% of number of patients and 40.1% of medical expenses over 5 years. Lumbar disc herniation (M51) and spinal stenosis (M48) might accounted for both the highest incidence and medical expenses in patients under the age of 60 and over 60 years, respectively. Conclusion The incidence and medical expenditures of spinal disease increased continuously. As the population of ROK in aging, the incidence and medical expenditures due to spondylosis and stenosis (M48) for the old are also increasing. The social burden of spinal diseases in elder patients needs to be prudently considered in health policy makers. PMID:29656624

Health Care Burden of Spinal Diseases in the Republic of Korea: Analysis of a Nationwide Database From 2012 Through 2016.

PubMed

Lee, Chang-Hyun; Chung, Chun Kee; Kim, Chi Heon; Kwon, Ji-Woong

2018-03-01

This study aimed to determine the incidence and analyze trends related to spinal diseases based on a national database in the Republic of Korea (ROK) and to elucidate the healthcare burden that will serve as a useful resource for researchers, clinicians, and patients. This study was a retrospective analysis of data obtained from Healthcare Bigdata Hub, the Korean Statistical Information Service, and Open Data Portal from 2012 through 2016. The main disease codes for spinal diseases (M40-M54) were used for identification of these conditions. The overall annual incidence rates for spinal disease in the ROK was median 15,877 (men, 13,181; women, 18,588) per 100,000 population, and sex ratio was 1:1.41 (p<0.01). The incidence rate and annual costs per patient increased by 7.6% and 14.7% over 5 years continuously, respectively. The age-adjusted incidence rate increased with age; the highest rates were 42.6% in the 75-79 years group. Patients older than 65 years old accounted for median 31.0% of number of patients and 40.1% of medical expenses over 5 years. Lumbar disc herniation (M51) and spinal stenosis (M48) might accounted for both the highest incidence and medical expenses in patients under the age of 60 and over 60 years, respectively. The incidence and medical expenditures of spinal disease increased continuously. As the population of ROK in aging, the incidence and medical expenditures due to spondylosis and stenosis (M48) for the old are also increasing. The social burden of spinal diseases in elder patients needs to be prudently considered in health policy makers.

Temporary short-segment pedicle screw fixation for thoracolumbar burst fractures: comparative study with or without vertebroplasty.

PubMed

Aono, Hiroyuki; Ishii, Keisuke; Tobimatsu, Hidekazu; Nagamoto, Yukitaka; Takenaka, Shota; Furuya, Masayuki; Chiaki, Horii; Iwasaki, Motoki

2017-08-01

Short-segment posterior spinal instrumentation for thoracolumbar burst fracture provides superior correction of kyphosis by an indirect reduction technique, but it has a high failure rate. The purpose of the study we report here was to compare outcomes for temporary short-segment pedicle screw fixation with vertebroplasty and for such fixation without vertebroplasty. This is a prospective multicenter comparative study. We studied 62 consecutive patients with thoracolumbar burst fracture who underwent short-segment posterior instrumentation using ligamentotaxis with Schanz screws with or without vertebroplasty. Radiological parameters (Cobb angle on standing lateral radiographs) were used. Implants were removed approximately 1 year after surgery. Neurologic function, kyphotic deformity, canal compromise, and fracture severity were evaluated prospectively. After surgery, all patients with neurologic deficit had improvement equivalent to at least one grade on the American Spinal Injury Association impairment scale and had fracture union. Kyphotic deformity was reduced significantly, and reduction of the vertebrae was maintained with and without vertebroplasty, regardless of load-sharing classification. Although no patient required additional anterior reconstruction, kyphotic change was observed at disc level mainly after implant removal with or without vertebroplasty. Temporary short-segment fixation yielded satisfactory results in the reduction and maintenance of fractured vertebrae with or without vertebroplasty. Kyphosis recurrence may be inevitable because adjacent discs can be injured during the original trauma. Copyright © 2017 Elsevier Inc. All rights reserved.

Pawsey, Joseph Lade (1908-62)

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

Radiophysicist and astronomer, born Ararat, Victoria, Australia, pioneered the use of a Lloyd's mirror arrangement for radio interferometry at Dover Heights in Australia, and located the source of solar radio noise within the disc of the Sun. As John Hey had suggested, the radio noise came from sunspots....

The Effect of Single-Level Disc Degeneration on Dynamic Response of the Whole Lumbar Spine to Vertical Vibration.

PubMed

Guo, Li-Xin; Fan, Wei

2017-09-01

The objective of this study was to investigate the effect of single-level disc degeneration on dynamic response of the whole lumbar spine to vertical whole body vibration that is typically present when driving vehicles. Ligamentous finite element models of the lumbar L1-S1 motion segment in different grades of degeneration (healthy, mild, and moderate) at the L4-L5 level were developed with consideration of changing disc height and material properties of the nucleus pulpous. All models were loaded with a compressive follower preload of 400 N and a sinusoidal vertical vibration load of ±40 N. After transient dynamic analyses, computational results for the 3 models in terms of disc bulge, von-Mises stress in annulus ground substance, and nucleus pressure were plotted as a function of time and compared. All the predicted results showed a cyclic response with time. At the degenerated L4-L5 disc level, as degeneration progressed, maximum value of the predicted response showed a decrease in disc bulge and von-Mises stress in annulus ground substance but a slight increase in nucleus pressure, and their vibration amplitudes were all decreased. At the adjacent levels of the degenerated disc, there was a slight decrease in maximum value and vibration amplitude of these predicted responses with the degeneration. The results indicated that single-level disc degeneration can alter vibration characteristics of the whole lumbar spine especially for the degenerated disc level, and increasing the degeneration did not deteriorate the effect of vertical vibration on the spine. Copyright © 2017 Elsevier Inc. All rights reserved.

Pathogenesis and Treatment of Spine Disease in the Mucopolysaccharidoses

PubMed Central

Peck, Sun H.; Casal, Margret L.; Malhotra, Neil R.; Ficicioglu, Can; Smith, Lachlan J.

2016-01-01

The mucopolysaccharidoses (MPS) are a family of lysosomal storage disorders characterized by deficient activity of enzymes that degrade glycosaminoglycans (GAGs). Skeletal disease is common in MPS patients, with the severity varying both within and between subtypes. Within the spectrum of skeletal disease, spinal manifestations are particularly prevalent. Developmental and degenerative abnormalities affecting the substructures of the spine can result in compression of the spinal cord and associated neural elements. Resulting neurological complications, including pain and paralysis, significantly reduce patient quality of life and life expectancy. Systemic therapies for MPS such as hematopoietic stem cell transplantation and enzyme replacement therapy have shown limited efficacy for improving spinal manifestations in patients and animal models, and there is therefore a pressing need for new therapeutic approaches that specifically target this debilitating aspect of the disease. In this review, we examine how pathological abnormalities affecting the key substructures of the spine – the discs, vertebrae, odontoid process and dura – contribute to the progression of spinal deformity and symptomatic compression of neural elements. Specifically, we review current understanding of the underlying pathophysiology of spine disease in MPS, how the tissues of the spine respond to current clinical and experimental treatments, and discuss future strategies for improving the efficacy of these treatments. PMID:27296532

METABOLIC EFFECTS OF ANGULATION, COMPRESSION AND REDUCED MOBILITY ON ANNULUS FIBROSIS IN A MODEL OF ALTERED MECHANICAL ENVIRONMENT IN SCOLIOSIS

PubMed Central

Stokes, Ian A.F.; McBride, Carole; Aronsson, David D.; Roughley, Peter J.

2013-01-01

Study Design Comparison of disc tissue from rat tails in six groups having different mechanical conditions imposed. Objectives To identify disc annulus changes associated with the supposed altered biomechanical environment in a spine with scoliosis deformity using an immature rat model that produces disc narrowing and wedging. Background Intervertebral discs become wedged and narrowed in a scoliosis curve, probably due in part to altered biomechanical environment. Methods Tail discs of 5-week-old immature Sprague-Dawley rats were subjected to an altered mechanical environment using an external apparatus applying permutations of loading and deformity for 5 weeks. Four groups of rats (A) 15 degrees Angulation, (B) Angulation with 0.1 MPa Compression, (C) 0.1 MPa Compression, and (R) Reduced mobility, together with a sham and a control group were studied. Disc height changes and matrix composition (water, DNA, GAG and HA content) were measured after 5 weeks, and proline and sulphate incorporation and mRNA expression were measured at 5 days and 5 weeks. Results After 5 weeks, disc space was significantly narrowed relative to internal controls in all four intervention groups. Water content and cellularity (DNA content) were not different at interventional levels relative to internal controls and not different between the concave and convex sides of the angulated discs. There was increased GAG content in compressed tissue (in Groups B and C), as expected, and compression resulted in a decrease in hyaluronic acid size. Slightly increased incorporation of tritiated-proline into the concave side of angulated discs and compressed discs was observed. Asymmetries of gene expression in Groups A and B, and some group-wise differences, did not identify consistent patterns associating the discs’ responses to mechanical alterations. Conclusions Intervertebral discs in this model underwent substantial narrowing after 5 weeks, with minimal alteration in tissue composition and minimal evidence of metabolic changes. PMID:27927288

[Surgical treatment of thoracic disc herniation].

PubMed

Hrabálek, L; Kalita, O; Langová, K

2010-08-01

The aim of this study was to compare the efficiency of different surgical approaches to thoracic disc herniation, and to show the role of segmental fusion and selection of an appropriate microsurgical decompression technique for the successful outcome of surgery. A group of 27 patients, 10 men and 17 women, between 31 and 70 years (average age, 49.33 years) were included in this prospective study. They underwent surgery for thoracic degeneration disc disease in the period from June 1994 to August 2008. In all patients, the severity of myelopathy was assessed using the grading Frankel system and JOA score, axial and radicular pain intensity was evaluated with VAS and ODI rating systems. The diagnosis was established on the basis of thoracic spine radiography, thoracic spine MRI and a CT scan of the segment. A total of 30 thoracic segments, in the range of Th4/Th5 to Th12/L1, were indicated for surgery. Localisation of the hernia was medial at 19 segments, mediolateral at three and lateral at eight segments. Soft disc herniation was found in 17 cases and hard disc protrusion at the remaining 13 segments. Surgery for significant myelopathy was carried out in 23 patients and for pain in four patients. According to the surgical procedure used, the patients were allocated to two groups: group A comprised 10 patients treated without disc replacement through a laminectomy or a costotransversectomy exposure, and group B consisted of 17 patients undergo- ing intersomatic fusion via a thoracotomy. Clinical and radiographic examinations were made at regular intervals for at least 1 year of follow-up. The results of clinical assessment, including JOA scores, JOA Recovery Rate, VAS scores at rest and after exercise and ODI, were statistically analysed for each group and compared. There was a statistically significant difference in JOA evaluation of myelopathy between the groups in group A, the mean JOA score declined from 7.9 to 7.0, i.e., -0.9 point, while in group B it increased from 6.71 to 9.12, i.e., +2.41 points. The mean JOA Recovery Rate did not reach a plus value in group A, while in group B it improved by 55 %. JOA Recovery Rate: Of the seven patients in group A evaluated for myelopathy, a fair result was in one, unchanged in two and worse in four patients. Of the 16 patients evaluated for myelopathy in group B, the results were excellent in four, good in six, fair in four and unchanged in two patients. Frankel grade function: In group A, one patient improved by one grade, two remained unchanged, two deteriorated by one grade and two by two grades. In group B, five patients improved by one grade, two patients by two grades and two patients by three grades. Eight patients remained unchanged and no patient deteriorated. The post-operative pain intensity, as assessed by the mean VAS score, was lower at rest and after exercise in both groups; the score was better in group B, but the difference was not statistically significant. The ODI was evaluated only in group B its mean value improved from 41.4% to 26.1%, i.e., by 15.3%. Between 7 to 15 % of the patients have asymptomatic thoracic disc herniation, while symptomatic herniation is very rare and accounts for only 0.25 % to 0.57 % of herniated discs in the whole spine. Severe or progressive myelopathy is a clear indication for surgical intervention in thoracic disc herniation, but the role of surgery in pain control is controversial. There are five approaches for thoracic disc herniation. Transpleural anterolateral thoracotomy has an advantage over the other methods because it permits the treatment of all types of herniation, whether localised centrally, laterally or contralaterally, i.e., soft, calcified or sequestered intradural disc herniation. The results of treatment will depend on the outcome of surgical spinal cord decompression and the degree of spinal stabilisation achieved. The surgical procedure via thoracotomy with intersomatic fusion resulted in a statistically more significant improvement of myelopathy than the posterior approach without disc replacement, and it provided greater pain relief. The authors recommend to treat thoracic disc herniation by discectomy via a thoracotomy and by intersomatic fusion.

Does location of rotation center in artificial disc affect cervical biomechanics?

PubMed

Mo, Zhongjun; Zhao, Yanbin; Du, Chengfei; Sun, Yu; Zhang, Ming; Fan, Yubo

2015-04-15

A 3-dimensional finite element investigation. To compare the biomechanical performances of different rotation centers (RCs) in the prevalent artificial cervical discs. Various configurations are applied in artificial discs. Design parameters may influence the biomechanics of implanted spine. The RC is a primary variation in the popular artificial discs. Implantation of 5 prostheses was simulated at C5-C6 on the basis of a validated finite element cervical model (C3-C7). The prostheses included ball-in-socket design with a fixed RC located on the inferior endplate (BS-FI) and on the superior endplate (BS-FS), with a mobile RC at the inferior endplate (BS-MI), dual articulation with a mobile RC between the endplates (DA-M), and sliding articulation with various RCs (SA-V). The spinal motions in flexion and extension served as a displacement loading at the C3 vertebrae. Total disc replacements reduced extension moment. The ball-in-socket designs required less flexion moment, whereas the flexion stiffness of the spines with DA-M and SA-V was similar to that of the healthy model. The contributions of the implanted level to the global motions increased in the total disc replacements, except in the SA-V and DA-M models (in flexion). Ball-in-socket designs produced severe stress distributions in facet cartilage, whereas DA-M and SA-V produced more severe stress distribution on the bone-implant interface. Cervical stability was extremely affected in extension and partially affected in flexion by total disc replacement. With the prostheses with mobile RC, cervical curvature was readjusted under a low follower load. The SA-V and BS-FS designs exhibited better performances in the entire segmental stiffness and in the stability of the operative level than the BS-MI and BS-FI designs in flexion. The 5 designs demonstrated varying advantages relative to the stress distribution in the facet cartilages and on the bone-implant interface. 5.

Morphology of the 13CO(3–2) millimetre emission across the gas disc surrounding the triple protostar GG Tau A using ALMA observations

NASA Astrophysics Data System (ADS)

Phuong, Nguyen Thi; Diep, Pham Ngoc; Dutrey, Anne; Chapillon, Edwige; Darriulat, Pierre; Guilloteau, Stéphane; Hoai, Do Thi; Tuyet Nhung, Pham; Tang, Ya-Wen; Thao, Nguyen Thi; Tuan-Anh, Pham

2018-03-01

Observations by the Atacama Large Millimetre/sub-millimetre Array of the dust continuum and 13CO(3–2) millimetre emissions of the triple stellar system GG Tau A are analysed, giving evidence for a rotating gas disc and a concentric and coplanar dust ring. The present work complements an earlier analysis (Tang et al.) by exploring detailed properties of the gas disc. A 95% confidence level upper limit of 0.24″ (34 au) is placed on the disc scale height at a distance of 1″ (140 au) from the central stars. Evidence for Keplerian rotation of the gas disc is presented, with the rotation velocity reaching ∼3.1 km s‑1 at 1″ from the central stars, and a 99% confidence level upper limit of 9% is placed on relative contribution from a possible in-fall velocity. Variations of the intensity across the disc area are studied in detail and confirm the presence of a hot spot in the south-eastern quadrant. However several other significant intensity variations, in particular a depression in the northern direction, are also revealed. Variations of the intensity are found to be positively correlated to variations of the line width. Possible contributions to the measured line width are reviewed, suggesting an increase of the disc temperature and opacity with decreasing distance from the stars.

Application of Piezosurgery in Anterior Cervical Corpectomy and Fusion.

PubMed

Pan, Sheng-Fa; Sun, Yu

2016-05-01

Anterior cervical corpectomy and fusion (ACCF) is frequently used to decompress the cervical spine; however, this procedure is risky when dealing with a hard disc or ossification of the posterior longitudinal ligament (OPLL). Piezosurgery offers a useful tool for performing this procedure. In this article, we present a 50 years old man who had cervical spondylotic myelopathy with OPLL at the C 6 level and segmental stenosis of the cervical spinal canal. When removing the posterior wall of his C 6 vertebral body and OPLL, piezosurgery was used to selectively cut hard structures piece by piece without injuring delicate soft tissues like the nerve roots and spinal cord. Because there is no bleeding from the bone surface with piezosurgery, it provides a clean operative field. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

A comparison between porcine, ovine, and bovine intervertebral disc anatomy and single lamella annulus fibrosus tensile properties.

PubMed

Monaco, Lauren A; DeWitte-Orr, Stephanie J; Gregory, Diane E

2016-02-01

This project aimed to compare gross anatomical measures and biomechanical properties of single lamellae from the annulus fibrosus of ovine and porcine lumbar vertebrae, and bovine tail vertebrae. The morphology of the vertebrae of these species differ significantly both from each other and from human, yet how these differences alter biomechanical properties is unknown. Geometric parameters measured in this study included: 1) absolute and relative intervertebral (IVD) and vertebral body height and 2) absolute and relative intervertebral disc (IVD) anterior-posterior (AP) and medial-lateral (ML) widths. Single lamella tensile properties included toe-region stress and stretch ratio, stiffness, and tensile strength. As expected, the bovine tail IVD revealed a more circular shape compared with both the ovine and porcine lumbar IVD. The bovine tail also had the largest IVD to vertebral body height ratio (due to having the highest absolute IVD height). Bovine tail lamellae were also found to be strongest and stiffest (in tension) while ovine lumbar lamellae were weakest and most compliant. Histological analysis revealed the greatest proportion of collagen in the bovine corroborating findings of increased strength and stiffness. The observed differences in anatomical shape, connective tissue composition, and tensile properties need to be considered when choosing an appropriate model for IVD research. © 2015 Wiley Periodicals, Inc.

Radio haloes in nearby galaxies modelled with 1D cosmic ray transport using SPINNAKER

NASA Astrophysics Data System (ADS)

Heesen, V.; Krause, M.; Beck, R.; Adebahr, B.; Bomans, D. J.; Carretti, E.; Dumke, M.; Heald, G.; Irwin, J.; Koribalski, B. S.; Mulcahy, D. D.; Westmeier, T.; Dettmar, R.-J.

2018-05-01

We present radio continuum maps of 12 nearby (D ≤ 27 Mpc), edge-on (i ≥ 76°), late-type spiral galaxies mostly at 1.4 and 5 GHz, observed with the Australia Telescope Compact Array, Very Large Array, Westerbork Synthesis Radio Telescope, Effelsberg 100-m, and Parkes 64-m telescopes. All galaxies show clear evidence of radio haloes, including the first detection in the Magellanic-type galaxy NGC 55. In 11 galaxies, we find a thin and a thick disc that can be better fitted by exponential rather than Gaussian functions. We fit our SPINNAKER (SPectral INdex Numerical Analysis of K(c)osmic-ray Electron Radio-emission) 1D cosmic ray transport models to the vertical model profiles of the non-thermal intensity and to the non-thermal radio spectral index in the halo. We simultaneously fit for the advection speed (or diffusion coefficient) and magnetic field scale height. In the thick disc, the magnetic field scale heights range from 2 to 8 kpc with an average across the sample of 3.0 ± 1.7 kpc; they show no correlation with either star formation rate (SFR), SFR surface density (ΣSFR), or rotation speed (Vrot). The advection speeds range from 100 to 700 km s - 1 and display correlations of V∝SFR0.36 ± 0.06 and V∝ Σ _SFR^{0.39± 0.09}; they agree remarkably well with the escape velocities (0.5 ≤ V/Vesc ≤ 2), which can be explained by cosmic ray-driven winds. Radio haloes show the presence of disc winds in galaxies with ΣSFR > 10 - 3 M⊙ yr - 1 kpc - 2 that extend over several kpc and are driven by processes related to the distributed star formation in the disc.

Evaluation of lumbar segmental instability in degenerative diseases by using a new intraoperative measurement system.

PubMed

Hasegawa, Kazuhiro; Kitahara, Ko; Hara, Toshiaki; Takano, Ko; Shimoda, Haruka; Homma, Takao

2008-03-01

In vivo quantitative measurement of lumbar segmental stability has not been established. The authors developed a new measurement system to determine intraoperative lumbar stability. The objective of this study was to clarify the biomechanical properties of degenerative lumbar segments by using the new method. Twenty-two patients with a degenerative symptomatic segment were studied and their measurements compared with those obtained in normal or asymptomatic degenerative segments (Normal group). The measurement system produces cyclic flexion-extension through spinous process holders by using a computer-controlled motion generator with all ligamentous structures intact. The following biomechanical parameters were determined: stiffness, absorption energy (AE), and neutral zone (NZ). Discs with degeneration were divided into 2 groups based on magnetic resonance imaging grading: degeneration without collapse (Collapse[-]) and degeneration with collapse (Collapse[+]). Biomechanical parameters were compared among the groups. Relationships among the biomechanical parameters and age, diagnosis, or radiographic parameters were analyzed. The mean stiffness value in the Normal group was significantly greater than that in Collapse(-) or Collapse(+) group. There was no significant difference in the average AE value among the Normal, Collapse(-), and Collapse(+) groups. The NZ in the Collapse(-) was significantly higher than in the Normal or Collapse(+) groups. Stiffness was negatively and NZ was positively correlated with age. Stiffness demonstrated a significant negative and NZ a significant positive relationship with disc height, however. There were no significant differences in stiffness between spines in the Collapse(-) and Collapse(+) groups. The values of a more sensitive parameter, NZ, were higher in Collapse(-) than in Collapse(+) groups, demonstrating that degenerative segments with preserved disc height have a latent instability compared to segments with collapsed discs.

Screw Placement Accuracy for Minimally Invasive Transforaminal Lumbar Interbody Fusion Surgery: A Study on 3-D Neuronavigation-Guided Surgery

PubMed Central

Torres, Jorge; James, Andrew R.; Alimi, Marjan; Tsiouris, Apostolos John; Geannette, Christian; Härtl, Roger

2012-01-01

Purpose The aim of this study was to assess the impact of 3-D navigation for pedicle screw placement accuracy in minimally invasive transverse lumbar interbody fusion (MIS-TLIF). Methods A retrospective review of 52 patients who had MIS-TLIF assisted with 3D navigation is presented. Clinical outcomes were assessed with the Oswestry Disability Index (ODI), Visual Analog Scales (VAS), and MacNab scores. Radiographic outcomes were assessed using X-rays and thin-slice computed tomography. Result The mean age was 56.5 years, and 172 screws were implanted with 16 pedicle breaches (91.0% accuracy rate). Radiographic fusion rate at a mean follow-up of 15.6 months was 87.23%. No revision surgeries were required. The mean improvement in the VAS back pain, VAS leg pain, and ODI at 11.3 months follow-up was 4.3, 4.5, and 26.8 points, respectively. At last follow-up the mean postoperative disc height gain was 4.92 mm and the mean postoperative disc angle gain was 2.79 degrees. At L5–S1 level, there was a significant correlation between a greater disc space height gain and a lower VAS leg score. Conclusion Our data support that application of 3-D navigation in MIS-TLIF is associated with a high level of accuracy in the pedicle screw placement. PMID:24353961

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitera, Gunita, E-mail: Gunita.Mitera@Sunnybrook.ca; Probyn, Linda; Ford, Michael

Purpose: To correlate computed tomography (CT) imaging features of spinal metastases with pain relief after radiotherapy (RT). Methods and Materials: Thirty-three patients receiving computed tomography (CT)-simulated RT for spinal metastases in an outpatient palliative RT clinic from January 2007 to October 2008 were retrospectively reviewed. Forty spinal metastases were evaluated. Pain response was rated using the International Bone Metastases Consensus Working Party endpoints. Three musculoskeletal radiologists and two orthopaedic surgeons evaluated CT features, including osseous and soft tissue tumor extent, presence of a pathologic fracture, severity of vertebral height loss, and presence of kyphosis. Results: The mean patient age wasmore » 69 years; 24 were men and 9 were women. The mean worst pain score was 7/10, and the mean total daily oral morphine equivalent was 77.3 mg. Treatment doses included 8 Gy in one fraction (22/33), 20 Gy in five fractions (10/33), and 20 Gy in eight fractions (1/33). The CT imaging appearance of spinal metastases included vertebral body involvement (40/40), pedicle involvement (23/40), and lamina involvement (18/40). Soft tissue component (10/40) and nerve root compression (9/40) were less common. Pathologic fractures existed in 11/40 lesions, with resultant vertebral body height loss in 10/40 and kyphosis in 2/40 lesions. At months 1, 2, and 3 after RT, 18%, 69%, and 70% of patients experienced pain relief. Pain response was observed with various CT imaging features. Conclusions: Pain response after RT did not differ in patients with and without pathologic fracture, kyphosis, or any other CT features related to extent of tumor involvement. All patients with painful spinal metastases may benefit from palliative RT.« less

Pathophysiology, diagnosis, and treatment of discogenic low back pain

PubMed Central

Peng, Bao-Gan

2013-01-01

Discogenic low back pain is a serious medical and social problem, and accounts for 26%-42% of the patients with chronic low back pain. Recent studies found that the pathologic features of discs obtained from the patients with discogenic low back pain were the formation of the zones of vascularized granulation tissue, with extensive innervation in fissures extending from the outer part of the annulus into the nucleus pulposus. Studies suggested that the degeneration of the painful disc might originate from the injury and subsequent repair of annulus fibrosus. Growth factors such as basic fibroblast growth factor, transforming growth factor β1, and connective tissue growth factor, macrophages and mast cells might play a key role in the repair of the injured annulus fibrosus and subsequent disc degeneration. Although there exist controversies about the role of discography as a diagnostic test, provocation discography still is the only available means by which to identify a painful disc. A recent study has classified discogenic low back pain into two types that were annular disruption-induced low back pain and internal endplate disruption-induced low back pain, which have been fully supported by clinical and theoretical bases. Current treatment options for discogenic back pain range from medicinal anti-inflammation strategy to invasive procedures including spine fusion and recently spinal arthroplasty. However, these treatments are limited to relieving symptoms, with no attempt to restore the disc’s structure. Recently, there has been a growing interest in developing strategies that aim to repair or regenerate the degenerated disc biologically. PMID:23610750

[Subcutaneous stimulation as additional therapy to spinal cord stimulation in a post-laminectomy syndrome patient].

PubMed

Akbaş, Mert; Yeğin, Mehmet Arif; Özdemir, İrem; Göksu, Ethem; Akyüz, Mahmut

2016-01-01

Spinal cord stimulation as treatment of chronic low back pain via neuromodulation has been frequently performed in recent years. The dorsal column is stimulated by an electrode placed at the epidural region. In the case presently described, subcutaneous lead was implanted in a patient with failed back syndrome after spinal cord stimulation was inadequate to treat back and gluteal pain. A 65-year-old male had undergone surgery to treat lumbar disc herniation, after which he received physical therapy and multiple steroid injections due to unrelieved pain. He was admitted to the pain clinic with pain radiating to right gluteal muscle and leg. Spinal cord stimulation was performed and, as pain was not relieved, subcutaneous lead was applied to the right cluneal nerve distribution. Following treatment, the patient scored 1-2 on visual analog scale. Pain had been reduced by over 80%. Octad electrode was placed between T8 and T10 vertebrae after Tuohy needle was introduced to intervertebral area between L1 and L2. Paresthesia occurred in the right extremity. Boundaries were determined by area of right gluteal region in which paresthesia did not occur. Octad electrode was placed subcutaneously after vertical line was drawn from center point. Paresthesia occurred throughout the region. Pulse wave was 390-450 msec; frequency was 10-30 Hz. Subcutaneous electrode replacement is effective additional therapy when pain is not relieved by spinal cord stimulation.

Video-assisted removal of metal pellet fragments from the vertebral canal following gunshot injury and long-term outcome in a cat.

PubMed

Matres-Lorenzo, Luis; Bernardé, Antoine; Bernard, Fabrice

2016-09-20

 To describe the surgical management and long-term outcome of a spinal gunshot injury in a cat. A two-year-old, 4.2 kg castrated European Shorthair male cat was referred for evaluation of bilateral acute hindlimb paralysis with loss of deep pain perception in the right hindlimb associated with a perforating gunshot wound in the left side of the flank. Based on the clinical findings, the injury was localized to the fourth lumbar-first sacral spinal cord segment. The orthogonal spinal radiographs and computed tomography examination showed several metal pellet fragments within the vertebral canal of the sixth lumbar vertebra. A left mini-hemilaminectomy of the sixth lumbar vertebra pedicle combined with a mini dorsal laminectomy over the sixth to seventh lumbar vertebrae disc space were performed. A 2.4 mm 30° arthroscope was then introduced within the spinal canal to improve visibility and help with the fragment extraction. The cat was discharged from the hospital five days after surgery and the owners were encouraged to continue passive and active physiotherapy movements. The cat was ambulatory with a plantigrade stance eight weeks following surgery. At the last follow-up examination (24 months postoperatively), the cat was able to jump on chairs, although intermittent urinary and faecal incontinence, proprioceptive deficits, and plantigrade stance were still present.  Decompressive surgery may promote neurological status improvement following spinal gunshot injury.

Injectible bodily prosthetics employing methacrylic copolymer gels

DOEpatents

Mallapragada, Surya K.; Anderson, Brian C.

2007-02-27

The present invention provides novel block copolymers as structural supplements for injectible bodily prosthetics employed in medical or cosmetic procedures. The invention also includes the use of such block copolymers as nucleus pulposus replacement materials for the treatment of degenerative disc disorders and spinal injuries. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol) methyl ether polymer.

Cauda equina syndrome: a comprehensive review.

PubMed

Gitelman, Alex; Hishmeh, Shuriz; Morelli, Brian N; Joseph, Samuel A; Casden, Andrew; Kuflik, Paul; Neuwirth, Michael; Stephen, Mark

2008-11-01

Cauda equina syndrome (CES) is a rare syndrome that has been described as a complex of symptoms and signs--low back pain, unilateral or bilateral sciatica, motor weakness of lower extremities, sensory disturbance in saddle area, and loss of visceral function--resulting from compression of the cauda equina. CES occurs in approximately 2% of cases of herniated lumbar discs and is one of the few spinal surgical emergencies. In this article, we review information that is critical in understanding, diagnosing, and treating CES.

Anthropometry, spinal canal width, and flexibility of the spine and hamstring muscles in 45-55-year-old men with and without low back pain.

PubMed

Hultman, G; Saraste, H; Ohlsen, H

1992-09-01

One hundred fifty 45-55-year-old men were divided into three groups: those with healthy backs, recurrent low back pain (LBP), and chronic LBP. These groups were studied with respect to anthropometry, spinal canal width, spinal sagittal configuration and flexibility, and the flexibility of the hamstrings musculature with straight leg raising (SLR). There were no differences between the groups with respect to anthropometry. The group with healthy backs had significantly greater lordosis and sagittal flexibility than the other groups. The width of the spinal canal was correlated to body height. The SLR test showed significantly higher values in the group with healthy backs and in the recurrent pain group than in the chronic pain group. The possible role of restoring normal range of motion to minimize the risk of LBP recurrence is discussed.

Medulloblastoma: Long-term follow-up of patients treated with electron irradiation of the spinal field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaspar, L.E.; Dawson, D.J.; Tilley-Gulliford, S.A.

1991-09-01

Thirty-two patients with posterior fossa medulloblastoma underwent treatment with electron irradiation to the spinal field. The 5- and 10-year actuarial survival rates were 57% and 50%, respectively. Late complications observed in the 15 patients followed up for more than 5 years were short stature (six patients), decreased sitting-standing height ratio (four patients), scoliosis (two patients), poor school performance (seven patients), xerostomia (one patient), esophageal stricture (one patient), pituitary dysfunction (four patients), primary hypothyroidism (one patient), bilateral eighth-nerve deafness (one patient), and carcinoma of the thyroid (one patient). Complications following treatment with electrons to a spinal field are compared with reportedmore » complications following treatment with photons to the spinal field. Although short-term reactions were minimal, the authors found no difference in late complications. More sophisticated treatment planning may show such a long-term benefit in the future.« less

Transforaminal Percutaneous Endoscopic Discectomy and Foraminoplasty after Lumbar Spinal Fusion Surgery.

PubMed

Wu, Jian-Jun; Chen, Hui-Zhen; Zheng, Changkun

2017-07-01

The most common causes of pain following lumbar spinal fusions are residual herniation, or foraminal fibrosis and foraminal stenosis that is ignored, untreated, or undertreated. The original surgeon may advise his patient that nothing more can be done in his opinion that the nerve was visually decompressed by the original surgery. Post-operative imaging or electrophysiological assessment may be inadequate to explain all the reasons for residual or recurrent symptoms. Treatment of failed lumbar spinal fusions by repeat traditional open revision surgery usually incorporates more extensive decompression causing increased instability and back pain. The authors, having limited their practice to endoscopic surgery over the last 10 years, report on their experience gained during that period to relieve pain by transforaminal percutaneous endoscopic revision of lumbar spinal fusions. To assess the effectiveness of transforaminal percutaneous endoscopic discectomy and foraminoplasty in patients with pain after lumbar spinal fusion. Retrospective study. Inpatient surgery center. Sixteen consecutive patients with pain after lumbar spinal fusions presenting with back and leg pain that had supporting imaging diagnosis of foraminal stenosis and/or residual/recurrent disc herniation, or whose pain complaint was supported by relief from diagnostic and therapeutic injections, were offered percutaneous transforaminal endoscopic discectomy and foraminoplasty over a repeat open procedure. Each patient sought consultation following a transient successful, partially successful or unsuccessful open lumbar spinal fusions treatment for disc herniation or spinal stenosis. Endoscopic foraminoplasty was also performed to either decompress the bony foramen in the case of foraminal stenosis, or to allow for endoscopic visual examination of the affected traversing and exiting nerve roots in the axilla. The average follow-up time was 30.3 months, minimum 12 months. Outcome data at each visit included MacNab criteria, visual analog scale (VAS), and Oswestry Disability Index (ODI). The average leg VAS improved from 9.1 ± 2.0 to 2.0 ± 0.8 (P < 0.005). Ten patients had excellent outcomes, 5 had good outcomes, one had a fair outcome, and none had poor outcomes, according to the MacNab criteria. Fifteen of 16 patients had excellent or good outcomes, for an overall success rate of 93.7%. No patients required reoperation. There were no incidental durotomies, infections, vascular, or visceral injuries. There was one complication, a case of leg numbness caused by dorsal root ganglion injury. The numbness improved after 2 weeks. After 3 months, physical exam showed that the total area of numbness in the legs had decreased. At last follow-up, the patient had no pain, and only a few areas with numbness remained that did not affect the patient's activities of daily living. The patient was relieved to be able to avoid open decompression. This is a retrospective study. The transforaminal endoscopic approach is effective for patients with back or leg pain after lumbar spinal fusions due to residual/recurrent nucleus pulposus and foraminal stenosis. Failed initial index surgery may involve failure to recognize patho-anatomy in the axilla of the foramen housing the traversing and the exiting nerve. The transforaminal endoscopic approach effectively decompresses the foramen and does not further destabilize the spine needing stabilization. It also avoids going through the previous surgical site. Full-endoscopic, foraminal stenosis, recurrent herniation, surgical treatment, fusion.

Review of early clinical results and complications associated with oblique lumbar interbody fusion (OLIF).

PubMed

Phan, Kevin; Maharaj, Monish; Assem, Yusuf; Mobbs, Ralph J

2016-09-01

Lumbar interbody fusion represents an effective surgical intervention for patients with lumbar degenerative diseases, spondylolisthesis, disc herniation, pseudoarthrosis and spinal deformities. Traditionally, conventional open anterior lumbar interbody fusion and posterior/transforaminal lumbar interbody fusion techniques have been employed with excellent results, but each with their own advantages and caveats. Most recently, the antero-oblique trajectory has been introduced, providing yet another corridor to access the lumbar spine. Termed the oblique lumbar interbody fusion, this approach accesses the spine between the anterior vessels and psoas muscles, avoiding both sets of structures to allow efficient clearance of the disc space and application of a large interbody device to afford distraction for foraminal decompression and endplate preparation for rapid and thorough fusion. This review aims to summarize the early clinical results and complications of this new technique and discusses potential future directions of research. Copyright © 2016 Elsevier Ltd. All rights reserved.

KYNREFREV - the XSPEC model for X-ray reverberation in the lamp-post geometry

NASA Astrophysics Data System (ADS)

Dovciak, M.; Caballero-Garcia, M.; Epitropakis, A.; Papadakis, I.; Alston, W.; Miniutti, G.; Kara, E.; De Marco, B.; Karas, V.; Matt, G.

2017-10-01

In the last decade the X-ray reverberation echos produced by reflection of the coronal emission from the inner parts of the accretion disc was observed in several AGN. To estimate the properties of the system showing these features fast and modular XSPEC model is needed. In this contribution we want to introduce such a model that is ready to be used for both the frequency and energy dependencies of lags in the lamp-post geometry and is fast enough for fitting the data effectively. The parameters of the model, like the black hole spin, height of the corona, density of the disc affecting the disc ionisation profile, reflecting disc region (inner and outer edge and azimuthal segment), circular obscuring cloud and others will be described. The black-body reverberation due to the thermalised part of the illuminating radiation, that is important mainly for low mass AGN and for soft X-ray energy band, is included as well. The power-law hard lag for frequency dependence is also available directly in the model.

Evaluation of Water Content in Lumbar Intervertebral Discs and Facet Joints Before and After Physiological Loading Using T2 Mapping MRI.

PubMed

Yamabe, Daisuke; Murakami, Hideki; Chokan, Kou; Endo, Hirooki; Oikawa, Ryosuke; Sawamura, Shoitsu; Doita, Minoru

2017-12-15

T2 mapping was used to quantify the water content of lumbar spine intervertebral discs (IVDs) and facet joints before and after physiological loading. The aim of this study was to clarify the interaction between lumbar spine IVD and facet joints as load-bearing structures by measuring the water content of their matrix after physiological loading using T2 mapping magnetic resonance imaging (MRI). To date, few reports have functionally evaluated lumbar spine IVD and facet joints, and their interaction in vivo. T2 mapping may help detect changes in the water content of IVD and articular cartilage of facet joints before and after physiological loading, thereby enabling the evaluation of changes in interacted water retention between IVD and facet joints. Twenty asymptomatic volunteers (10 female and 10 male volunteers; mean age, 19.3 years; age range, 19-20 years) underwent MRI before and after physiological loading such as lumbar flexion, extension, and rotation. Each IVD from L1/2 to L5/S1 was sliced at center of the disc space, and the T2 value was measured at the nucleus pulposus (NP), anterior annulus fibrosus (AF), posterior AF, and bilateral facet joints. In the NP, T2 values significantly decreased after exercise at every lumbar spinal level. In the anterior AF, there were no significant differences in T2 values at any level. In the posterior AF, T2 values significantly increased only at L4/5. In the bilateral facet joints, T2 values significantly decreased after exercise at every level. There was a significant decrease in the water content of facet joints and the NP at every lumbar spinal level after dynamic loading by physical lumbar exercise. These changes appear to play an important and interactional role in the maintenance of the interstitial matrix in the IVD NP and cartilage in the facet joint. 3.

Electric field numerical simulation of disc type electrostatic spinning spinneret

NASA Astrophysics Data System (ADS)

Wei, L.; Deng, ZL; Qin, XH; Liang, ZY

2018-01-01

Electrospinning is a new type of free-end spinning built on electric field. Different from traditional single needle spinneret, in this study, a new disc type free surface spinneret is used to produce multiple jets, this will greatly improve production efficiency of nanofiber. The electric-field distribution of spinneret is the crux of the formation and trajectory of jets. In order to probe the electric field intensity of the disc type spinneret, computational software of Ansoft Maxwell 12 is adopted for a precise and intuitive analysis. The results showed that the whole round cambered surface of the spinning solution at edge of each layer of the spinneret with the maximum curvature has the highest electric field intensity, and through the simulation of the electric field distribution of different spinneret parameters such as layer, the height and radius of the spinneret. Influences of various parameters on the electrostatic spinning are obtained.

Parametric modeling of the intervertebral disc space in 3D: application to CT images of the lumbar spine.

PubMed

Korez, Robert; Likar, Boštjan; Pernuš, Franjo; Vrtovec, Tomaž

2014-10-01

Gradual degeneration of intervertebral discs of the lumbar spine is one of the most common causes of low back pain. Although conservative treatment for low back pain may provide relief to most individuals, surgical intervention may be required for individuals with significant continuing symptoms, which is usually performed by replacing the degenerated intervertebral disc with an artificial implant. For designing implants with good bone contact and continuous force distribution, the morphology of the intervertebral disc space and vertebral body endplates is of considerable importance. In this study, we propose a method for parametric modeling of the intervertebral disc space in three dimensions (3D) and show its application to computed tomography (CT) images of the lumbar spine. The initial 3D model of the intervertebral disc space is generated according to the superquadric approach and therefore represented by a truncated elliptical cone, which is initialized by parameters obtained from 3D models of adjacent vertebral bodies. In an optimization procedure, the 3D model of the intervertebral disc space is incrementally deformed by adding parameters that provide a more detailed morphometric description of the observed shape, and aligned to the observed intervertebral disc space in the 3D image. By applying the proposed method to CT images of 20 lumbar spines, the shape and pose of each of the 100 intervertebral disc spaces were represented by a 3D parametric model. The resulting mean (±standard deviation) accuracy of modeling was 1.06±0.98mm in terms of radial Euclidean distance against manually defined ground truth points, with the corresponding success rate of 93% (i.e. 93 out of 100 intervertebral disc spaces were modeled successfully). As the resulting 3D models provide a description of the shape of intervertebral disc spaces in a complete parametric form, morphometric analysis was straightforwardly enabled and allowed the computation of the corresponding heights, widths and volumes, as well as of other geometric features that in detail describe the shape of intervertebral disc spaces. Copyright © 2014 Elsevier Ltd. All rights reserved.

Direct mapping of the temperature and velocity gradients in discs. Imaging the vertical CO snow line around IM Lupi

NASA Astrophysics Data System (ADS)

Pinte, C.; Ménard, F.; Duchêne, G.; Hill, T.; Dent, W. R. F.; Woitke, P.; Maret, S.; van der Plas, G.; Hales, A.; Kamp, I.; Thi, W. F.; de Gregorio-Monsalvo, I.; Rab, C.; Quanz, S. P.; Avenhaus, H.; Carmona, A.; Casassus, S.

2018-01-01

Accurate measurements of the physical structure of protoplanetary discs are critical inputs for planet formation models. These constraints are traditionally established via complex modelling of continuum and line observations. Instead, we present an empirical framework to locate the CO isotopologue emitting surfaces from high spectral and spatial resolution ALMA observations. We apply this framework to the disc surrounding IM Lupi, where we report the first direct, i.e. model independent, measurements of the radial and vertical gradients of temperature and velocity in a protoplanetary disc. The measured disc structure is consistent with an irradiated self-similar disc structure, where the temperature increases and the velocity decreases towards the disc surface. We also directly map the vertical CO snow line, which is located at about one gas scale height at radii between 150 and 300 au, with a CO freeze-out temperature of 21 ± 2 K. In the outer disc (>300 au), where the gas surface density transitions from a power law to an exponential taper, the velocity rotation field becomes significantly sub-Keplerian, in agreement with the expected steeper pressure gradient. The sub-Keplerian velocities should result in a very efficient inward migration of large dust grains, explaining the lack of millimetre continuum emission outside of 300 au. The sub-Keplerian motions may also be the signature of the base of an externally irradiated photo-evaporative wind. In the same outer region, the measured CO temperature above the snow line decreases to ≈15 K because of the reduced gas density, which can result in a lower CO freeze-out temperature, photo-desorption, or deviations from local thermodynamic equilibrium.

Decision making in surgical treatment of chronic low back pain: the performance of prognostic tests to select patients for lumbar spinal fusion.

PubMed

Willems, Paul

2013-02-01

Chronic low back pain (CLBP) is one of the main causes of disability in the western world with a huge economic burden to society. As yet, no specific underlying anatomic cause has been identified for CLBP. Imaging often reveals degenerative findings of the disc or facet joints of one or more lumbar motion segments. These findings, however, can also be observed in asymptomatic people. It has been suggested that pain in degenerated discs may be caused by the ingrowth of nerve fibers into tears or clefts of the annulus fibrosus or nucleus pulposus, and by reported high levels of pro-inflammatory mediators. As this so-called discogenic pain is often exacerbated by mechanical loading, the concept of relieving pain by spinal fusion to stabilise a painful spinal segment, has been developed. For some patients lumbar spinal fusion indeed is beneficial, but its results are highly variable and hard to predict for the individual patient. To identify those CLBP patients who will benefit from fusion, many surgeons rely on tests that are assumed to predict the outcome of spinal fusion. The three most commonly used prognostic tests in daily practice are immobilization in a lumbosacral orthosis, provocative discography and trial immobilization by temporary external transpedicular fixation. Aiming for consensus on the indications for lumbar fusion and in order to improve its results by better patient selection, it is essential to know the role and value of these prognostic tests for CLBP patients in clinical practice. The overall aims of the present thesis were: 1) to evaluate whether there is consensus among spine surgeons regarding the use and appreciation of prognostic tests for lumbar spinal fusion; 2) to verify whether a thoracolumbosacral orthosisis (TLSO) truly minimises lumbosacral motion; 3) to verify whether a TLSO can predict the clinical outcome of fusion for CLBP; 4) to assess whether provocative discography of adjacent segments actually predicts the long-term clinical outcome fusion; 5) to determine the incidence of postdiscography discitis, and whether there is a need for routine antibiotic prophylaxis; 6) to assess whether temporary external transpedicular fixation (TETF) can help to predict the outcome of spinal fusion; 7) to determine the prognostic accuracy of the most commonly used tests in clinical practice to predict the outcome of fusion for CLBP. The results of a national survey among spine surgeons in the Netherlands were presented in Study I. The surgeons were questioned about their opinion on prognostic factors and about the use of predictive tests for lumbar fusion in CLBP patients. The comments were compared with findings from the prevailing literature. The survey revealed a considerable lack of uniformity in the use and appreciation of predictive tests. Prognostic factors known from the literature were not consistently incorporated in the surgeons' decision making process either. This heterogeneity in strategy is most probably caused by the lack of sound scientific evidence for current predictive tests and it was concluded that currently there is not enough consensus among spine surgeons in the Netherlands to create national guidelines for surgical decision making in CLBP. In Study II, the hypothesized working mechanism of a pantaloon cast (i.e., minimisation of lumbosacral joint mobility) was studied. In patients who were admitted for a temporary external transpedicular fixation test (TETF), infrared light markers were rigidly attached to the protruding ends of Steinman pins that were fixed in two spinal levels. In this way three-dimensional motion between these levels could be analysed opto-electronically. During dynamic test conditions such as walking, a plaster cast, either with or without unilateral hip fixation, did not significantly decrease lumbosacral joint motion. Although not substantiated by sound scientific support, lumbosacral orthoses or pantaloon casts are often used in everyday practice as a predictor for the outcome of fusion. A systematic review of the literature supplemented with a prospective cohort study was performed (Study III) in order to assess the value of a pantaloon cast in surgical decision-making. It appeared that only in CLBP patients with no prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative treatment. In patients with prior spine surgery the test is of no value. It is believed by many spine surgeons that provocative discography, unlike plain radiographs or magnetic resonance imaging, is a physiologic test that can truly determine whether a disc is painful and relevant in a patient's pain syndrome, irrespective of the morphology of the disc. It has been suggested that in order to achieve a successful clinical outcome of lumbar fusion, suspect discs should be painful and adjacent control discs should elicit no pain on provocative discography. For this reason, a cohort of patients in whom the decision to perform lumbar fusion was based on an external fixation (TETF) trial, was analysed retrospectively in Study IV. The results of preoperative discography of solely the levels adjacent to the fusion were compared with the clinical results after spinal fusion. It appeared that in this select group of patients the discographic status of discs adjacent to a lumbar fusion did not have any effect on the clinical outcome. The most feared complication of lumbar discography is discitis. Although low in incidence, this is a serious complication for a diagnostic procedure and prevention by the use of prophylactic antibiotics has been advocated. In search for clinical guidelines, the risk of postdiscography discitis was assessed in Study V by means of a systematic literature review and a cohort of 200 consecutive patients. Without the use of prophylactic antibiotics, an overall incidence of postdiscography discitis of 0.25% was found. To prove that antibiotics would actually prevent discitis, a randomised trial of 9,000 patients would be needed to reach significance. Given the possible adverse effects of antibiotics, it was concluded that the routine use of prophylactic antibiotics in lumbar discography is not indicated. In Study VI, the middle- and long-term results of external fixation (TETF) as a test to predict the clinical outcome of lumbar fusion were studied in a group of back pain patients for whom there was doubt about the indication for surgery. The test included a placebo trial, in which the patients were unaware whether the lumbar segmental levels were fixed or dynamised. Using strict and objective criteria of pain reduction on a visual analogue scale, the TETF test failed to predict clinical outcome of fusion in this select group of patients. Pin track infection and nerve root irritation were registered as complications of this invasive test. It was concluded that in chronic low back pain patients with a doubtful indication for fusion, TETF is not recommended as a supplemental tool for surgical decision-making. In Study VII, a systematic literature review was performed regarding the prognostic accuracy of tests that are currently used in clinical practice and that are presumed to predict the outcome of lumbar spinal fusion for CLBP. The tests of interest were magnetic resonance imaging (MRI), TLSO immobilisation, TETF, provocative discography and facet joint infiltration. Only 10 studies reporting on three different index tests (discography, TLSO immobilisation and TETF) that truly reported on test qualifiers, such as sensitivity, specificity and likelihood ratios, could be selected. It appeared that the accuracy of all prognostic tests was low, which confirmed that in many clinical practices patients are scheduled for fusion on the basis of tests, of which the accuracy is insufficient or at best unknown. As the overall methodological quality of included studies was poor, higher quality trials that include negatively tested as well as positively tested patients for fusion, will be needed. It was concluded that at present, best evidence does not support the use of any prognostic test in clinical practice. No subset of patients with low back pain could be identified, for whom spinal fusion is a reliable and effective treatment. In literature, several studies have reported that cognitive behavioural therapy or intensive exercise programs have treatment results similar to those of spinal fusion, but with considerably less complications, morbidity and costs. As the findings of the present thesis show that the currently used tests do not improve the results of fusion by better patient selection, these tests should not be recommended for surgical decision making in standard care. Moreover, spinal fusion should not be proposed as a standard treatment for chronic low back pain. Causality of nonspecific spinal pain is complex and CLBP should not be regarded as a diagnosis, but rather as a symptom in patients with different stages of impairment and disability. Patients should be evaluated in a multidisciplinary setting or Spine Centre according to the so-called biopsychosocial model, which aims to identify underlying psychosocial factors as well as biological factors. Treatment should occur in a stepwise fashion starting with the least invasive treatment. The current approach of CLBP, in which emphasis is laid on self-management and empowerment of patients to take an active course of treatment in order to prevent long-term disability and chronicity, is recommended.

Comparison of Spinal Curvatures in the Sagittal Plane, as Well as Body Height and Mass in Polish Children and Adolescents Examined in the Late 1950s and in the Early 2000s.

PubMed

Mrozkowiak, Mirosław; Walicka-Cupryś, Katarzyna; Magoń, Grzegorz

2018-06-30

BACKGROUND Humans are exposed to various stimuli which lead to somatic modifications and changes in body posture, negatively affecting many of its characteristics. The purpose of this study was to assess significant alterations which occurred in selected morphological features and spinal curvatures in children and adolescents over a period of 40 years. MATERIAL AND METHODS The total of 7041 subjects, aged 4-18 years (mean age 11.3 years) were included in the study, which was designed to compare measurements performed in year 1959 (Group 1, n=3235 individuals) and in year 2003 (Group 2, n=3806 individuals). The children were examined for body height, body mass, as well as thoracic and lumbar curvatures. In 1959, the measurements were carried out using a spherodorsimeter, while in 2003, the CQ System photogrammetry was used, producing corresponding results. The Mann-Whitney U test and the Student's t-test were used for statistical analysis. RESULTS The findings showed a significant decrease in the angle of lumbar lordosis and in sacral inclination as well as an increase in body height and mass, particularly in prepubertal children. On the other hand, the angle of thoracic kyphosis and the partial angles of physiological spinal curvatures changed only to a small degree over the 40-year period. CONCLUSIONS This study provides evidence related to changes which occurred during the relevant period of over 40 years, namely a decrease in both the angle of lumbar lordosis and the sacral inclination angle, as well as an increase in body height and mass. These changes should be taken into consideration in selecting norms and standards applied in healthcare services, and the findings suggest it is necessary to regularly update such standards.

Creation of an injectable in situ gelling native extracellular matrix for nucleus pulposus tissue engineering.

PubMed

Wachs, Rebecca A; Hoogenboezem, Ella N; Huda, Hammad I; Xin, Shangjing; Porvasnik, Stacy L; Schmidt, Christine E

2017-03-01

Disc degeneration is the leading cause of low back pain and is often characterized by a loss of disc height, resulting from cleavage of chondroitin sulfate proteoglycans (CSPGs) present in the nucleus pulposus. Intact CSPGs are critical to water retention and maintenance of the nucleus osmotic pressure. Decellularization of healthy nucleus pulposus tissue has the potential to serve as an ideal matrix for tissue engineering of the disc because of the presence of native disc proteins and CSPGs. Injectable in situ gelling matrices are the most viable therapeutic option to prevent damage to the anulus fibrosus and future disc degeneration. The purpose of this research was to create a gentle decellularization method for use on healthy nucleus pulposus tissue explants and to develop an injectable formulation of this matrix to enable therapeutic use without substantial tissue disruption. Porcine nuclei pulposi were isolated, decellularized, and solubilized. Samples were assessed to determine the degree of cell removal, matrix maintenance, gelation ability, cytotoxic residuals, and native cell viability. Nuclei pulposi were decellularized using serial detergent, buffer, and enzyme treatments. Decellularized nuclei pulposi were solubilized, neutralized, and buffered. The efficacy of decellularization was assessed by quantifying DNA removal and matrix preservation. An elution study was performed to confirm removal of cytotoxic residuals. Gelation kinetics and injectability were quantified. Long-term in vitro experiments were performed with nucleus pulposus cells to ensure cell viability and native matrix production within the injectable decellularized nucleus pulposus matrices. This work resulted in the creation of a robust acellular matrix (>96% DNA removal) with highly preserved sulfated glycosaminoglycans (>47%), and collagen content and microstructure similar to native nucleus pulposus, indicating preservation of disc components. Furthermore, it was possible to create an injectable formulation that gelled in situ within 45 minutes and formed fibrillar collagen with similar diameters to native nucleus pulposus. The processing did not result in any remaining cytotoxic residuals. Solubilized decellularized nucleus pulposus samples seeded with nucleus pulposus cells maintained robust viability (>89%) up to 21 days of culture in vitro, with morphology similar to native nucleus pulposus cells, and exhibited significantly enhanced sulfated glycosaminoglycans production over 21 days. A gentle decellularization of porcine nucleus pulposus followed by solubilization enabled the creation of an injectable tissue-specific matrix that is well tolerated in vitro by nucleus pulposus cells. These matrices have the potential to be used as a minimally invasive nucleus pulposus therapeutic to restore disc height. Copyright © 2016 Elsevier Inc. All rights reserved.

Surgical treatment of adolescent internal condylar resorption (AICR) with articular disc repositioning and orthognathic surgery in the growing patient--a pilot study.

PubMed

Bodine, Trevor P; Wolford, Larry M; Araujo, Eustaquio; Oliver, Donald R; Buschang, Peter H

2016-01-01

The aim of this study was to better understand how surgical repositioning and stabilization of anteriorly displaced articular discs using the Mitek mini-anchor technique affects condylar growth in growing patients with adolescent internal condylar resorption (AICR). Twenty-two adolescent patients diagnosed with AICR and anterior temporomandibular disc displacement were compared to untreated control subjects without AICR matched for age, sex, and Angle classification. Pre-surgical (T1 and T2) and post-surgical (T3 and T4) mandibular tracings were superimposed on natural stable structures to evaluate the horizontal, vertical, and total changes in the position of condylion. The treated group showed an overall decrease in condylar height pre-surgically and statistically significant changes in condylar growth direction between the pre- and post-surgical observation periods. Pre-surgically, the treated group showed significantly more posterior condylar growth than the control group; they also showed inferior condylar growth, while the controls showed superior growth. Controls and patients in the treated group showed no significant differences in condylar growth post-surgically. Adolescent patients diagnosed with AICR and anterior disc displacement treated with mandibular ramus and maxillary osteotomies, along with Mitek anchors to reposition internally deranged discs, showed post-surgical normalization of condylar growth.

Mechanical Restoration and Failure Analyses of a Hydrogel and Scaffold Composite Strategy for Annulus Fibrosus Repair

PubMed Central

Long, Rose G; Bürki, Alexander; Zysset, Philippe; Eglin, David; Grijpma, Dirk W.; Blanquer, Sebastien BG; Hecht, Andrew C; Iatridis, James C

2015-01-01

Unrepaired defects in the annulus fibrosus of intervertebral discs are associated with degeneration and persistent back pain. A clinical need exists for a disc repair strategy that can seal annular defects, be easily delivered during surgical procedures, and restore biomechanics with low risk of herniation. Multiple annulus repair strategies were developed using poly(trimethylene carbonate) scaffolds optimized for cell delivery, polyurethane membranes designed to prevent herniation, and fibrin-genipin adhesive tuned to annulus fibrosus shear properties. This three-part study evaluated repair strategies for biomechanical restoration, herniation risk and failure mode in torsion, bending and compression at physiological and hyper-physiological loads using a bovine injury model. Fibrin-genipin hydrogel restored some torsional stiffness, bending ROM and disc height loss, with negligible herniation risk and failure was observed histologically at the fibrin-genipin mid-substance following rigorous loading. Scaffold-based repairs partially restored biomechanics, but had high herniation risk even when stabilized with sutured membranes and failure was observed histologically at the interface between scaffold and fibrin-genipin adhesive. Fibrin-genipin was the simplest annulus fibrosus repair solution evaluated that involved an easily deliverable adhesive that filled irregularly-shaped annular defects and partially restored disc biomechanics with low herniation risk, suggesting further evaluation for disc repair may be warranted. PMID:26577987

A selective inhibition of c-Fos/activator protein-1 as a potential therapeutic target for intervertebral disc degeneration and associated pain.

PubMed

Makino, Hiroto; Seki, Shoji; Yahara, Yasuhito; Shiozawa, Shunichi; Aikawa, Yukihiko; Motomura, Hiraku; Nogami, Makiko; Watanabe, Kenta; Sainoh, Takeshi; Ito, Hisakatsu; Tsumaki, Noriyuki; Kawaguchi, Yoshiharu; Yamazaki, Mitsuaki; Kimura, Tomoatsu

2017-12-05

Intervertebral disc (IVD) degeneration is a major cause of low back pain. The transcription factor c-Fos/Activator Protein-1 (AP-1) controls the expression of inflammatory cytokines and matrix metalloproteinases (MMPs) that contribute to the pathogenesis IVD degeneration. We investigated the effects of inhibition of c-Fos/AP-1 on IVD degeneration and associated pain. A selective inhibitor, T-5224, significantly suppressed the interleukin-1β-induced up-regulation of Mmp-3, Mmp-13 and Adamts-5 transcription in human nucleus pulposus cells and in a mouse explant culture model of IVD degeneration. We used a tail disc percutaneous needle puncture method to further assess the effects of oral administration of T-5224 on IVD degeneration. Analysis of disc height, T2-magnetic resonance imaging (MRI) findings, and histology revealed that IVD degeneration was significantly mitigated by T-5224. Further, oral administration of T-5224 ameliorated pain as indicated by the extended tail-flick latency in response to heat stimulation of rats with needle-puncture-induced IVD degeneration. These findings suggest that the inhibition of c-Fos/AP-1 prevents disc degeneration and its associated pain and that T-5224 may serve as a drug for the prevention of IVD degeneration.

Impact of post-manipulation corrective core exercises on the spinal deformation and lumbar strength in golfers: a case study

PubMed Central

Shin, Chul-ho; Kim, Minjeong; Park, Gi Duck

2015-01-01

[Purpose] This study examined spinal shape in professional golfers with chronic back pain, and analyzed the effects of a 4-week regimen of semi-weekly manipulation and corrective core exercises on spinal shape. [Subjects] Two golfers with chronic back pain. [Methods] The pelvis and spinal vertebrae were corrected using the Thompson “drop” technique. Angle and force were adjusted to place the pelvis, lumbar spine, and thoracic vertebrae in neutral position. The technique was applied twice weekly after muscle massage in the back and pelvic areas. The golfers performed corrective, warmup stretching exercises, followed by squats on an unstable surface using the Togu ball. They then used a gym ball for repetitions of hip rotation, upper trunk extension, sit-ups, and pelvic anterior-posterior, pelvic left-right, and trunk flexion-extension exercises. The session ended with cycling as a cool-down exercise. Each session lasted 60 minutes. [Results] The difference in height was measured on the left and right sides of the pelvic bone. The pelvic tilt changed significantly in both participants after the 4-week program. [Conclusion] In golfers, core muscles are critical and are closely related to spinal deformation. Core strengthening and spinal correction play a pivotal role in the correction of spinal deformation. PMID:26504350

Histopathologic correlation of magnetic resonance imaging signal patterns in a spinal cord injury model.

PubMed

Weirich, S D; Cotler, H B; Narayana, P A; Hazle, J D; Jackson, E F; Coupe, K J; McDonald, C L; Langford, L A; Harris, J H

1990-07-01

Magnetic resonance imaging (MRI) provides a noninvasive method of monitoring the pathologic response to spinal cord injury. Specific MR signal intensity patterns appear to correlate with degrees of improvement in the neurologic status in spinal cord injury patients. Histologic correlation of two types of MR signal intensity patterns are confirmed in the current study using a rat animal model. Adult male Sprague-Dawley rats underwent spinal cord trauma at the midthoracic level using a weight-dropping technique. After laminectomy, 5- and 10-gm brass weights were dropped from designated heights onto a 0.1-gm impounder placed on the exposed dura. Animals allowed to regain consciousness demonstrated variable recovery of hind limb paraplegia. Magnetic resonance images were obtained from 2 hours to 1 week after injury using a 2-tesla MRI/spectrometer. Sacrifice under anesthesia was performed by perfusive fixation; spinal columns were excised en bloc, embedded, sectioned, and observed with the compound light microscope. Magnetic resonance axial images obtained during the time sequence after injury demonstrate a distinct correlation between MR signal intensity patterns and the histologic appearance of the spinal cord. Magnetic resonance imaging delineates the pathologic processes resulting from acute spinal cord injury and can be used to differentiate the type of injury and prognosis.

2D phase sensitive inversion recovery imaging to measure in-vivo spinal cord gray and white matter areas in clinically feasible acquisition times

PubMed Central

Papinutto, N.; Schlaeger, R.; Panara, V.; Caverzasi, E.; Ahn, S.; Johnson, K.J.; Zhu, A.H.; Stern, W.A.; Laub, G.; Hauser, S.L.; Henry, R.G.

2018-01-01

PURPOSE In-vivo assessment of spinal cord gray matter (GM) and white matter (WM) could become pivotal to study various neurological diseases, but it is challenging because of insufficient GM/WM contrast provided by conventional MRI. Here we present and assess a procedure for measurement of spinal cord total cross-sectional area (TCA) and GM areas based on phase sensitive inversion recovery imaging (PSIR). MATERIALS AND METHODS We acquired 2D PSIR images at 3T at each disc level of the spinal axis on 10 healthy subjects and measured TCA, cord diameters, WM and GM area, and GM area/TCA ratio. We secondly investigated 32 healthy subjects at 4 selected levels (C2–C3, C3–C4, T8–T9, T9–T10, total acquisition time <8 minutes) and generated normative reference values of TCA and GM areas. We assessed test-retest, intra- and inter-operator reliability of the acquisition strategy and measurement steps. RESULTS The measurement procedure based on 2D PSIR imaging allowed TCA and GM area assessments along the entire spinal cord axis. The tests we performed revealed high test-retest/intra-operator reliability (mean coefficient of variation (COV) at C2–C3: TCA=0.41%, GM area=2.75%) and inter-operator reliability of the measurements (mean COV on the 4 levels: TCA=0.44%, GM area= 4.20%; mean intra-class correlation coefficient: TCA=0.998, GM area=0.906). CONCLUSION 2D PSIR allows reliable in-vivo assessment of spinal cord TCA, GM and WM areas in clinically feasible acquisition times. The area measurements presented here are in agreement with previous MRI and post-mortem studies. PMID:25483607

Development and validation of a subject-specific finite element model of the functional spinal unit to predict vertebral strength.

PubMed

Lee, Chu-Hee; Landham, Priyan R; Eastell, Richard; Adams, Michael A; Dolan, Patricia; Yang, Lang

2017-09-01

Finite element models of an isolated vertebral body cannot accurately predict compressive strength of the spinal column because, in life, compressive load is variably distributed across the vertebral body and neural arch. The purpose of this study was to develop and validate a patient-specific finite element model of a functional spinal unit, and then use the model to predict vertebral strength from medical images. A total of 16 cadaveric functional spinal units were scanned and then tested mechanically in bending and compression to generate a vertebral wedge fracture. Before testing, an image processing and finite element analysis framework (SpineVox-Pro), developed previously in MATLAB using ANSYS APDL, was used to generate a subject-specific finite element model with eight-node hexahedral elements. Transversely isotropic linear-elastic material properties were assigned to vertebrae, and simple homogeneous linear-elastic properties were assigned to the intervertebral disc. Forward bending loading conditions were applied to simulate manual handling. Results showed that vertebral strengths measured by experiment were positively correlated with strengths predicted by the functional spinal unit finite element model with von Mises or Drucker-Prager failure criteria ( R 2  = 0.80-0.87), with areal bone mineral density measured by dual-energy X-ray absorptiometry ( R 2  = 0.54) and with volumetric bone mineral density from quantitative computed tomography ( R 2  = 0.79). Large-displacement non-linear analyses on all specimens did not improve predictions. We conclude that subject-specific finite element models of a functional spinal unit have potential to estimate the vertebral strength better than bone mineral density alone.

Mesenchymal Stem Cell Levels of Human Spinal Tissues.

PubMed

Harris, Liam; Vangsness, C Thomas

2018-05-01

Systematic review. The aim of this study was to investigate, quantify, compare, and compile the various mesenchymal stem cell (MSC) tissue sources within human spinal tissues to act as a compendium for clinical and research application. Recent years have seen a dramatic increase in academic and clinical understanding of human MSCs. Previously limited to cells isolated from bone marrow, the past decade has illicited the characterization and isolation of human MSCs from adipose, bone marrow, synovium, muscle, periosteum, peripheral blood, umbilical cord, placenta, and numerous other tissues. As researchers explore practical applications of cells in these tissues, the absolute levels of MSCs in specific spinal tissue will be critical to guide future research. The PubMED, MEDLINE, EMBASE, and Cochrane databases were searched for articles relating to the harvest, characterization, isolation, and quantification of human MSCs from spinal tissues. Selected articles were examined for relevant data, categorized according to type of spinal tissue, and when possible, standardized to facilitate comparisons between sites. Human MSC levels varied widely between spinal tissues. Yields for intervertebral disc demonstrated roughly 5% of viable cells to be positive for MSC surface markers. Cartilage endplate cells yielded 18,500 to 61,875 cells/0.8 mm thick sample of cartilage end plate. Ligamentum flavum yielded 250,000 to 500,000 cells/g of tissue. Annulus fibrosus fluorescence activated cell sorting treatment found 29% of cells positive for MSC marker Stro-1. Nucleus pulposus yielded mean tissue samples of 40,584 to 234,137 MSCs per gram of tissue. Numerous tissues within and surrounding the spine represent a consistent and reliable source for the harvest and isolation of human MSCs. Among the tissues of the spine, the annulus fibrosus and ligamentum flavum each offer considerable levels of MSCs, and may prove comparable to that of bone marrow. 5.

Association of decision-making in spinal surgery with specialty and emotional involvement-the Indications in Spinal Surgery (INDIANA) survey.

PubMed

Sollmann, Nico; Morandell, Carmen; Albers, Lucia; Behr, Michael; Preuss, Alexander; Dinkel, Andreas; Meyer, Bernhard; Krieg, Sandro M

2018-03-01

Although recent trials provided level I evidence for the most common degenerative lumbar spinal disorders, treatment still varies widely. Thus, the Indications in Spinal Surgery (INDIANA) survey explores whether decision-making is influenced by specialty or personal emotional involvement of the treating specialist. Nationwide, neurosurgeons and orthopedic surgeons specialized in spine surgery were asked to answer an Internet-based questionnaire with typical clinical patient cases of lumbar disc herniation (DH), lumbar spinal stenosis (SS), and lumbar degenerative spondylolisthesis (SL). The surgeons were assigned to counsel a patient or a close relative, thus creating emotional involvement. This was achieved by randomly allocating the surgeons to a patient group (PG) and relative group (RG). We then compared neurosurgeons to orthopedic surgeons and the PG to the RG regarding treatment decision-making. One hundred twenty-two spine surgeons completed the questionnaire (response rate 78.7%). Regarding DH and SS, more conservative treatment among orthopedic surgeons was shown (DH: odds ratio [OR] 4.1, 95% confidence interval [CI] 1.7-9.7, p = 0.001; SS: OR 3.9, CI 1.8-8.2, p < 0.001). However, emotional involvement (PG vs. RG) did not affect these results for any of the three cases (DH: p = 0.213; SS: p = 0.097; SL: p = 0.924). The high response rate indicates how important the issues raised by this study actually are for dedicated spine surgeons. Moreover, there are considerable variations in decision-making for the most common degenerative lumbar spinal disorders, although there is high-quality data from large multicenter trials available. Emotional involvement, though, did not influence treatment recommendations.

A comprehensive review of pulsed radiofrequency in the treatment of pain associated with different spinal conditions

PubMed Central

Facchini, Giancarlo; Spinnato, Paolo; Guglielmi, Giuseppe; Bazzocchi, Alberto

2017-01-01

Objective: The objective of this review was to evaluate the efficacy of pulsed radiofrequency (PRF) treatment of pain associated with different spinal conditions. The mechanisms of action and biological effects are shortly discussed to provide the scientific basis for this radiofrequency modality. Methods: We systematically searched for clinical studies on spinal clinical conditions using PRF. We searched the MEDLINE (PubMed) database. We classified the information in one table focusing on randomized controlled trials (RCTs) and other types of studies. Date of last electronic search was October 2016. Results: We found four RCTs that evaluated the efficacy of PRF on cervical radicular pain and five observational studies. Two trials and three observational studies were conducted in patients with facet pain. For disc-related pathology, we found one RCT with PRF applied intradiscally and three RCTs for dorsal root ganglia PRF modulation lumbosacral radicular pain. For sacroiliac joint pain, spondylolisthesis, malignancies and other minor spinal pathology, limited studies were conducted. Conclusion: From the available evidence, the use of PRF to the dorsal root ganglion in cervical radicular pain is compelling. With regard to its lumbosacral counterpart, the use of PRF cannot be similarly advocated in view of the absence of standardization of PRF parameters, enrolment criteria and different methods in reporting results; but, the evidence is interesting. The use of PRF in lumbar facet pain was found to be less effective than conventional RF techniques. For the other different spinal conditions, we need further studies to assess the effectiveness of PRF. Advances in knowledge: The use of PRF in lumbar facet pain was found to be less effective than conventional RF techniques. For the other different spinal conditions, we need further studies to assess the effectiveness of PRF. PMID:28186832

Interventional spinal procedures guided and controlled by a 3D rotational angiographic unit.

PubMed

Pedicelli, Alessandro; Verdolotti, Tommaso; Pompucci, Angelo; Desiderio, Flora; D'Argento, Francesco; Colosimo, Cesare; Bonomo, Lorenzo

2011-12-01

The aim of this paper is to demonstrate the usefulness of 2D multiplanar reformatting images (MPR) obtained from rotational acquisitions with cone-beam computed tomography technology during percutaneous extra-vascular spinal procedures performed in the angiography suite. We used a 3D rotational angiographic unit with a flat panel detector. MPR images were obtained from a rotational acquisition of 8 s (240 images at 30 fps), tube rotation of 180° and after post-processing of 5 s by a local work-station. Multislice CT (MSCT) is the best guidance system for spinal approaches permitting direct tomographic visualization of each spinal structure. Many operators, however, are trained with fluoroscopy, it is less expensive, allows real-time guidance, and in many centers the angiography suite is more frequently available for percutaneous procedures. We present our 6-year experience in fluoroscopy-guided spinal procedures, which were performed under different conditions using MPR images. We illustrate cases of vertebroplasty, epidural injections, selective foraminal nerve root block, facet block, percutaneous treatment of disc herniation and spine biopsy, all performed with the help of MPR images for guidance and control in the event of difficult or anatomically complex access. The integrated use of "CT-like" MPR images allows the execution of spinal procedures under fluoroscopy guidance alone in all cases of dorso-lumbar access, with evident limitation of risks and complications, and without need for recourse to MSCT guidance, thus eliminating CT-room time (often bearing high diagnostic charges), and avoiding organizational problems for procedures that need, for example, combined use of a C-arm in the CT room.

Differentiation of idiopathic spinal cord herniation from dorsal arachnoid webs on MRI and CT myelography.

PubMed

Schultz, Randall; Steven, Andrew; Wessell, Aaron; Fischbein, Nancy; Sansur, Charles A; Gandhi, Dheeraj; Ibrahimi, David; Raghavan, Prashant

2017-06-01

OBJECTIVE Dorsal arachnoid webs (DAWs) and spinal cord herniation (SCH) are uncommon abnormalities affecting the thoracic spinal cord that can result in syringomyelia and significant neurological morbidity if left untreated. Differentiating these 2 entities on the basis of clinical presentation and radiological findings remains challenging but is of vital importance in planning a surgical approach. The authors examined the differences between DAWs and idiopathic SCH on MRI and CT myelography to improve diagnostic confidence prior to surgery. METHODS Review of the picture archiving and communication system (PACS) database between 2005 and 2015 identified 6 patients with DAW and 5 with SCH. Clinical data including demographic information, presenting symptoms and neurological signs, and surgical reports were collected from the electronic medical records. Ten of the 11 patients underwent MRI. CT myelography was performed in 3 patients with DAW and in 1 patient with SCH. Imaging studies were analyzed by 2 board-certified neuroradiologists for the following features: 1) location of the deformity; 2) presence or absence of cord signal abnormality or syringomyelia; 3) visible arachnoid web; 4) presence of a dural defect; 5) nature of dorsal cord indentation (abrupt "scalpel sign" vs "C"-shaped); 6) focal ventral cord kink; 7) presence of the nuclear trail sign (endplate irregularity, sclerosis, and/or disc-space calcification that could suggest a migratory path of a herniated disc); and 8) visualization of a complete plane of CSF ventral to the deformity. RESULTS The scalpel sign was positive in all patients with DAW. The dorsal indentation was C-shaped in 5 of 6 patients with SCH. The ventral subarachnoid space was preserved in all patients with DAW and interrupted in cases of SCH. In no patient was a web or a dural defect identified. CONCLUSIONS DAW and SCH can be reliably distinguished on imaging by scrutinizing the nature of the dorsal indentation and the integrity of the ventral subarachnoid space at the level of the cord deformity.

Evolution over time of the Milky Way's disc shape

NASA Astrophysics Data System (ADS)

Amôres, E. B.; Robin, A. C.; Reylé, C.

2017-06-01

Context. Galactic structure studies can be used as a path to constrain the scenario of formation and evolution of our Galaxy. The dependence with the age of stellar population parameters would be linked with the history of star formation and dynamical evolution. Aims: We aim to investigate the structures of the outer Galaxy, such as the scale length, disc truncation, warp and flare of the thin disc and study their dependence with age by using 2MASS data and a population synthesis model (the so-called Besançon Galaxy Model). Methods: We have used a genetic algorithm to adjust the parameters on the observed colour-magnitude diagrams at longitudes 80° ≤ ℓ ≤ 280° for | b | ≤ 5.5°. We explored parameter degeneracies and uncertainties. Results: We identify a clear dependence of the thin disc scale length, warp and flare shapes with age. The scale length is found to vary between 3.8 kpc for the youngest to about 2 kpc for the oldest. The warp shows a complex structure, clearly asymmetrical with a node angle changing with age from approximately 165° for old stars to 195° for young stars. The outer disc is also flaring with a scale height that varies by a factor of two between the solar neighbourhood and a Galactocentric distance of 12 kpc. Conclusions: We conclude that the thin disc scale length is in good agreement with the inside-out formation scenario and that the outer disc is not in dynamical equilibrium. The warp deformation with time may provide some clues to its origin.

Truncated disc surface brightness profiles produced by flares

NASA Astrophysics Data System (ADS)

Borlaff, Alejandro; Eliche-Moral, M. Carmen; Beckman, John; Font, Joan

2017-03-01

Previous studies have discarded that flares in galactic discs may explain the truncation that are frequently observed in highly-inclined galaxies (Kregel et al. 2002). However, no study has systematically analysed this hypothesis using realistic models for the disc, the flare and the bulge. We derive edge-on and face-on surface brightness profiles for a series of realistic galaxy models with flared discs that sample a wide range of structural and photometric parameters across the Hubble Sequence, accordingly to observations. The surface brightness profile for each galaxy model has been simulated for edge-on and face-on views to find out whether the flared disc produces a significant truncation in the disc in the edge-on view compared to the face-on view or not. In order to simulate realistic images of disc galaxies, we have considered the observational distribution of the photometric parameters as a function of the morphological type for three mass bins (10 < log10(M/M ⊙) < 10.7, 10.7 < log10(M/M ⊙) < 11 and log10(M/M ⊙) > 11), and four morphological type bins (S0-Sa, Sb-Sbc, Sc-Scd and Sd-Sdm). For each mass bin, we have restricted the photometric and structural parameters of each modelled galaxy to their characteristic observational ranges (μ0, disc, μeff, bulge, B/T, M abs, r eff, n bulge, h R, disc) and the flare in the disc (h z, disc/h R, disc, ∂h z, disc/∂R, see de Grijs & Peletier 1997, Graham 2001, López-Corredoira et al. 2002, Yoachim & Dalcanton 2006, Bizyaev et al. 2014, Mosenkov et al. 2015). Contrary to previous claims, the simulations show that realistic flared disks can be responsible for the truncations observed in many edge-on systems, preserving the profile of the non-flared analogous model in face-on view. These breaks reproduce the properties of the weak-to-intermediate breaks observed in many real Type-II galaxies in the diagram relating the radial location of the break (R brkII) in units of the inner disk scale-length with the break strength S (Laine et al. 2014). Radial variation of the scale-height of the disc (flaring) can explain the existence of many breaks in edge-on galaxies, especially of those with low break strengths 10\\frac{ho}{hi} \\sim \\ [-0.3,-0.1]$ .

Quality of life in preoperative patients with sacroiliac joint dysfunction is at least as depressed as in other lumbar spinal conditions.

PubMed

Cher, Daniel Joseph; Reckling, W Carlton

2015-01-01

Pain from the sacroiliac joint (SIJ) is an under-recognized cause of low back pain. The degree to which SIJ pain decreases quality of life has not been directly compared to other more familiar conditions of the lumbar spine. Multivariate regression analysis of individual patient data from two prospective multicenter clinical trials of SIJ fusion and three prospective multicenter clinical trials of surgical treatments for degenerative lumbar spine conditions. Controlling for baseline demographic parameters as well as a validated disability score, quality of life scores (EuroQOL 5-D and SF-36) were, in most cases, lower in the SIJ cohorts compared to the three other spine surgery cohorts. Patients with SIJ dysfunction considering surgery have decrements in quality of life as or more severe compared to patients with degenerative spondylolisthesis, spinal stenosis, and intervertebral disc herniation.

MR imaging of peripheral nervous system involvement: Parsonage-Turner syndrome.

PubMed

Zara, Gabriella; Gasparotti, Roberto; Manara, Renzo

2012-04-15

A 55-year-old woman complained of right scapular pain, like burning, radiating down his right arm and numbness in the first three fingers of the hand. Neurologic examination showed a slight deficit of the right brachial triceps muscle. Neurophysiological assessment showed a mild involvement of the seventh right spinal root (C7). Conventional MR imaging of the cervical spine showed mild disc protrusion at level C5-C6 without spinal root compression. High resolution MR neurography with multiplanar reconstruction along the course of the right brachial plexus showed a mild increase in signal intensity and thickening of the C7 root, middle trunk and posterior cord, consistent with Parsonage-Turner Syndrome. STIR images showed increased signal intensity in the right infraspinatus muscle innervated by the suprascapular nerve. In our case, sensitivity and specificity of the new MR sequences are higher than the clinical and neurophysiological evaluations. Copyright © 2011 Elsevier B.V. All rights reserved.

Capillary Hemangioma of the Thoracic Spinal Cord

PubMed Central

Chung, Sung-Kyun; Nam, Taek-Kyun; Park, Seung-Won

2010-01-01

Capillary hemangiomas are common soft tissue tumors on the skin or mucosa of the head and neck in the early childhood, but very rare in the neuraxis. A 47-year-old man presented with one month history of back pain on the lower thoracic area, radiating pain to both legs, and hypesthesia below T7 dermatome. Thoracic spine MRI showed 1×1.3×1.5 cm, well-defined intradural mass at T6-7 disc space level, which showed isointensity to spinal cord on T1, heterogeneous isointensity on T2-weighted images, and homogeneous strong enhancement. The patient underwent T6-7 total laminotomy, complete tumor removal and laminoplasty. Histologically, the mass showed a capsulated nodular lesion composed of capillary-sized vascular channels, which were tightly packed into nodules separated by fibrous septa. These features were consistent with capillary hemangioma. PMID:21082058

Postoperative computed tomography and low-field magnetic resonance imaging findings in dogs with degenerative lumbosacral stenosis treated by dorsal laminectomy.

PubMed

Rapp, Martin; Ley, Charles J; Hansson, Kerstin; Sjöström, Lennart

2017-03-20

To describe postoperative computed tomography (CT) and magnetic resonance imaging (MRI) findings in dogs with degenerative lumbosacral stenosis (DLSS) treated by dorsal laminectomy and partial discectomy. Prospective clinical case study of dogs diagnosed with and treated for DLSS. Surgical and clinical findings were described. Computed tomography and low field MRI findings pre- and postoperatively were described and graded. Clinical, CT and MRI examinations were performed four to 18 months after surgery. Eleven of 13 dogs were clinically improved and two dogs had unchanged clinical status postoperatively despite imaging signs of neural compression. Vacuum phenomenon, spondylosis, sclerosis of the seventh lumbar (L7) and first sacral (S1) vertebrae endplates and lumbosacral intervertebral joint osteoarthritis became more frequent in postoperative CT images. Postoperative MRI showed mild disc extrusions in five cases, and in all cases contrast enhancing non-discal tissue was present. All cases showed contrast enhancement of the L7 spinal nerves both pre- and postoperatively and seven had contrast enhancement of the lumbosacral intervertebral joints and paraspinal tissue postoperatively. Articular process fractures or fissures were noted in four dogs. The study indicates that imaging signs of neural compression are common after DLSS surgery, even in dogs that have clinical improvement. Contrast enhancement of spinal nerves and soft tissues around the region of disc herniation is common both pre- and postoperatively and thus are unreliable criteria for identifying complications of the DLSS surgery.

Are magnetic resonance imaging or radiographic findings correlated with clinical prognosis in spinal cord neuropathy?

PubMed Central

Neshat Halati, Fatemeh; Vajhi, Alireza; Molazem, Mohammad; Dehghan, Mohammad Mehdi; Ansari, Fereshteh

2016-01-01

Dogs presented to the Small Animal Hospital of Veterinary Medicine, University of Tehran were included in the present study if spinal or intervertebral disc involvement was suspected. Clinical signs were recorded as well as general information of the patient such as age, breed and sex. Sixty dogs were examined radiographically and two standard orthogonal lateral and ventrodorsal projections were taken from the suspected region. Then magnetic resonance imaging (MRI) was performed for all patients. Agreement between MRI and radiographic findings, comparison of sex and breed with diagnostic imaging grades, comparison between diagnostic imaging grades and mean age, recovery rate after surgery or medical treatment, effects of diagnostic imaging severity grades on surgical or medical referrals were evaluated statistically. There were no significant association between age, sex and breed and frequency of the intervertebral disk disease. Intervertebral disc involvements between L2-L3 and T13-L1 were estimated as the most frequent sites of involvements. Sensitivity and specificity of radiography were evaluated 90.0% and 46.0%, respectively, by considering the MRI as a gold standard modality. There was a significant association between severity of disease in the MRI with referral to surgery and medical treatment. The recovery rate after surgery was significantly higher than medical treatment. These results can be used as a foundation for other studies with more focuses on details of injury and larger group of patients. PMID:27872724

[CSE vs. augmented epidural anesthesia for cesarean section. Spinal and epidural anesthesia with bupivacaine 0.5% "isobar" require augmentation].

PubMed

Halter, F; Niesel, H C; Gladrow, W; Kaiser, H

1998-09-01

Incomplete anaesthesia is a major clinical problem both in single spinal and in single epidural anaesthesia. The clinical efficacy of epidural anaesthesia with augmentation (aEA) and combined epidural and spinal anesthesia (CSE) for cesarean section was investigated in a prospective randomized study on 45 patients. Anaesthesia extending up to Th5 was aimed for. Depending on the patient's height, epidural anaesthesia was administered with a dose of 18-22 ml 0.5% bupivacaine and spinal anaesthesia with a dose of 11-15 mg 0.5% bupivacaine. Augmentation was carried out in all cases in epidural anaesthesia, initially with 7.5 ml 1% Lidocaine with epinephrine 1:400,000, raised by 1.5 ml per missing segment. The epidural reinjection in CSE was carried out as necessary with 9.5-15 ml 1% lidocaine with epinephrine, depending on the height and difference from the segment Th5. The extension of anaesthesia achieved in epidural anaesthesia after an initial dose of 101.8 mg bupivacaine and augmenting dose of 99 mg lidocaine reached the segment Th5. The primary spinal anaesthesia dose up to 15 mg corresponding to height led to a segmental extension to a maximum of Th3 under CSE. Augmentation was necessary in 13 patients; in 5 cases because of inadequate extent of anaesthesia and 8 cases because of pain resulting from premature reversion. The augmenting dose required was 13.9 ml. Readiness for operation was attained after 19.8 min (aEA) and after 10.5 min (CSE). No patient required analgesics before delivery. The additional analgesic requirement during operation was 63.6% (aEA) and 39.1% (CSE). Taking into account pain in the area of surgery, the requirement of analgesics was 50% (aEA) vs. 17.4% (CSE). Antiemetics were required in 18.2 (aEA) and in 65.2% (CSE). The systolic blood pressure fell by 17.7% (aEA) and in 30.3% (CSE). The minimum systolic pressure was observed after 13.4 min in aEA, and after 9.5 min in CSE. The APGAR score and the umbilical pH did not show any differences. General anaesthesia was not required in any case.

Inflammatory cascades mediate synapse elimination in spinal cord compression

PubMed Central

2014-01-01

Background Cervical compressive myelopathy (CCM) is caused by chronic spinal cord compression due to spondylosis, a degenerative disc disease, and ossification of the ligaments. Tip-toe walking Yoshimura (twy) mice are reported to be an ideal animal model for CCM-related neuronal dysfunction, because they develop spontaneous spinal cord compression without any artificial manipulation. Previous histological studies showed that neurons are lost due to apoptosis in CCM, but the mechanism underlying this neurodegeneration was not fully elucidated. The purpose of this study was to investigate the pathophysiology of CCM by evaluating the global gene expression of the compressed spinal cord and comparing the transcriptome analysis with the physical and histological findings in twy mice. Methods Twenty-week-old twy mice were divided into two groups according to the magnetic resonance imaging (MRI) findings: a severe compression (S) group and a mild compression (M) group. The transcriptome was analyzed by microarray and RT-PCR. The cellular pathophysiology was examined by immunohistological analysis and immuno-electron microscopy. Motor function was assessed by Rotarod treadmill latency and stride-length tests. Results Severe cervical calcification caused spinal canal stenosis and low functional capacity in twy mice. The microarray analysis revealed 215 genes that showed significantly different expression levels between the S and the M groups. Pathway analysis revealed that genes expressed at higher levels in the S group were enriched for terms related to the regulation of inflammation in the compressed spinal cord. M1 macrophage-dominant inflammation was present in the S group, and cysteine-rich protein 61 (Cyr61), an inducer of M1 macrophages, was markedly upregulated in these spinal cords. Furthermore, C1q, which initiates the classical complement cascade, was more upregulated in the S group than in the M group. The confocal and electron microscopy observations indicated that classically activated microglia/macrophages had migrated to the compressed spinal cord and eliminated synaptic terminals. Conclusions We revealed the detailed pathophysiology of the inflammatory response in an animal model of chronic spinal cord compression. Our findings suggest that complement-mediated synapse elimination is a central mechanism underlying the neurodegeneration in CCM. PMID:24589419

78 FR 66942 - Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-07

...., polyetheretherketone) materials. They are intended to be inserted between the vertebral bodies into the disc space from... mobility in confined spaces, at an elevated height, climb curbs, ascend/descend stairs, traverse obstacles, travel over a wider variety of terrain, and negotiate uneven/inclined surfaces. Stair-climbing...

Closed-loop neuromodulation of spinal sensorimotor circuits controls refined locomotion after complete spinal cord injury.

PubMed

Wenger, Nikolaus; Moraud, Eduardo Martin; Raspopovic, Stanisa; Bonizzato, Marco; DiGiovanna, Jack; Musienko, Pavel; Morari, Manfred; Micera, Silvestro; Courtine, Grégoire

2014-09-24

Neuromodulation of spinal sensorimotor circuits improves motor control in animal models and humans with spinal cord injury. With common neuromodulation devices, electrical stimulation parameters are tuned manually and remain constant during movement. We developed a mechanistic framework to optimize neuromodulation in real time to achieve high-fidelity control of leg kinematics during locomotion in rats. We first uncovered relationships between neuromodulation parameters and recruitment of distinct sensorimotor circuits, resulting in predictive adjustments of leg kinematics. Second, we established a technological platform with embedded control policies that integrated robust movement feedback and feed-forward control loops in real time. These developments allowed us to conceive a neuroprosthetic system that controlled a broad range of foot trajectories during continuous locomotion in paralyzed rats. Animals with complete spinal cord injury performed more than 1000 successive steps without failure, and were able to climb staircases of various heights and lengths with precision and fluidity. Beyond therapeutic potential, these findings provide a conceptual and technical framework to personalize neuromodulation treatments for other neurological disorders. Copyright © 2014, American Association for the Advancement of Science.

Bilateral chorioretinal coloboma discovered with ultra-wide field retinal imaging

PubMed Central

Barnard, Simon; Shneor, Einat; Brauner, Joel; Millodot, Michel; Gordon-Shaag, Ariela

2012-01-01

Uveal coloboma results from incomplete closure of the optic cup fissure. While conducting an evaluation of a new ultra-wide field retinal imaging camera (Optomap), which provides a view of the fundus up to 200° at one time without mydriasis, we discovered a case of bilateral chorioretinal coloboma in a 21-year-old student. The lesion was located in the midperiphery of each eye less than 2 disc diameters (DD) below the optic disc in the inferonasal quadrants. The size of the coloboma in the right eye was 1.8 DD in height and 1.3 DD in width, while the left lesion was 2.4 DD in height and 2.6 DD in width. The subject was totally asymptomatic and without any complication such as retinal detachment or choroidal neovascularization, which often accompany this type of lesion. The visual field of each eye displayed an absolute scotoma corresponding to the size and location of the coloboma. No management was necessary but the subject was advised to report for visual examination at regular intervals because complications can occur at any age.

Descriptive epidemiology and prior healthcare utilization of patients in the Spine Patient Outcomes Research Trial's (SPORT) three observational cohorts: disc herniation, spinal stenosis, and degenerative spondylolisthesis.

PubMed

Cummins, Justin; Lurie, Jon D; Tosteson, Tor D; Hanscom, Brett; Abdu, William A; Birkmeyer, Nancy J O; Herkowitz, Harry; Weinstein, James

2006-04-01

Prospective observational cohorts. To describe sociodemographic and clinical features, and nonoperative (medical) resource utilization before enrollment, in patients who are candidates for surgical intervention for intervertebral disc herniation (IDH), spinal stenosis (SpS), and degenerative spondylolisthesis (DS) according to SPORT criteria. Intervertebral disc herniation, spinal stenosis, and degenerative spondylolisthesis with stenosis are the three most common diagnoses of low back and leg symptoms for which surgery is performed. There is a paucity of descriptive literature examining large patient cohorts for the relationships among baseline characteristics and medical resource utilization with these three diagnoses. The Spine Patient Outcomes Research Trial (SPORT) conducts three randomized and three observational cohort studies of surgical and nonsurgical treatments for patients with IDH, SpS, and DS. Baseline data include demographic information, prior treatments received, and functional status measured by SF-36 and the Oswestry Disability Index (ODI-AAOS/Modems version). The data presented represent all 1,411 patients (743 IDH, 365 SpS, 303 DS) enrolled in the SPORT observational cohorts. Multiple logistic regression was used to generate independent predictors of utilization adjusted for sociodemographic variables, diagnosis, and duration of symptoms. The average age was 41 years for the IDH group, 64 years for the SpS group, and 66 years for the DS group. At enrollment, IDH patients presented with the most pain as reported on the SF-36 (BP 26.3 vs. 33.2 SpS and 33.8 DS) and were the most impaired (ODI 51 vs. 42.3 SpS and 41.5 DS). IDH patients used more chiropractic treatment (42% vs. 33% SpS and 26% DS), had more Emergency Department (ED) visits (21% vs. 7% SpS and 4% DS), and used more opiate analgesics (49% vs. 29% SpS and 27% DS). After adjusting for age, gender, diagnosis, education, race, duration of symptoms, and compensation, Medicaid patients used significantly more opiate analgesics (58% Medicaid vs. 41% no insurance, 42% employer, 33% Medicare, and 32% private) and had more ED visits compared with other insurance types (31% Medicaid vs. 22% no insurance, 16% employer, 3% Medicare, and 11% private). IDH patients appear to have differences in sociodemographics, resource utilization, and functional impairment when compared with the SpS/DS patients. In addition, the differences in resource utilization for Medicaid patients may reflect differences in access to care. The data provided from these observational cohorts will serve as an important comparison to the SPORT randomized cohorts in the future.

Facetal distraction as treatment for single- and multilevel cervical spondylotic radiculopathy and myelopathy: a preliminary report.

PubMed

Goel, Atul; Shah, Abhidha

2011-06-01

The authors discuss their successful preliminary experience with 36 cases of cervical spondylotic disease by performing facetal distraction using specially designed Goel cervical facet spacers. The clinical and radiological results of treatment are analyzed. The mechanism of action of the proposed spacers and the rationale for their use are evaluated. Between 2006 and February 2010, 36 patients were treated using the proposed technique. Of these patients, 18 had multilevel and 18 had single-level cervical spondylotic radiculopathy and/or myelopathy. The average follow-up period was 17 months with a minimum of 6 months. The Japanese Orthopaedic Association classification system, visual analog scale (neck pain and radiculopathy), and Odom criteria were used to monitor the clinical status of the patient. The patients were prospectively analyzed. The technique of surgery involved wide opening of the facet joints, denuding of articular cartilage, distraction of facets, and forced impaction of Goel cervical facet spacers into the articular cavity. Additionally, the interspinous process ligaments were resected, and corticocancellous bone graft from the iliac crest was placed and was stabilized over the adjoining laminae and facets after adequately preparing the host bone. Eighteen patients underwent single-level, 6 patients underwent 2-level, and 12 patients underwent 3-level treatment. The alterations in the physical architecture of spine and canal dimensions were evaluated before and after the placement of intrafacet joint spacers and after at least 6 months of follow-up. All patients had varying degrees of relief from symptoms of pain, radiculopathy, and myelopathy. Analysis of radiological features suggested that the distraction of facets with the spacers resulted in an increase in the intervertebral foraminal dimension (mean 2.2 mm), an increase in the height of the intervertebral disc space (range 0.4-1.2 mm), and an increase in the interspinous distance (mean 2.2 mm). The circumferential distraction resulted in reduction in the buckling of the posterior longitudinal ligament and ligamentum flavum. The procedure ultimately resulted in segmental bone fusion. No patient worsened after treatment. There was no noticeable implant malfunction. During the follow-up period, all patients had evidence of segmental bone fusion. No patient underwent reexploration or further surgery of the neck. Distraction of the facets of the cervical vertebra can lead to remarkable and immediate stabilization-fixation of the spinal segment and increase in space for the spinal cord and roots. The procedure results in reversal of several pathological events related to spondylotic disease. The safe, firm, and secure stabilization at the fulcrum of cervical spinal movements provided a ground for segmental spinal arthrodesis. The immediate postoperative improvement and lasting recovery from symptoms suggest the validity of the procedure.

Global Body Posture Evaluation in Patients with Temporomandibular Joint Disorder

PubMed Central

Saito, Eliza Tiemi; Akashi, Paula Marie Hanai; de Camargo Neves Sacco, Isabel

2009-01-01

AIM: To identify the relationship between anterior disc displacement and global posture (plantar arches, lower limbs, shoulder and pelvic girdle, vertebral spine, head and mandibles). Common signs and symptoms of anterior disc displacement were also identified. INTRODUCTION: Global posture deviations cause body adaptation and realignment, which may interfere with the organization and function of the temporomandibular joint. METHODS : Global posture evaluation was performed in a group of 10 female patients (20 to 30 years of age) with temporomandibular joint disc displacement and in a control group of 16 healthy female volunteers matched for age, weight and height. Anterior disc displacement signs, symptoms and the presence of parafunctional habits were also identified through interview. RESULTS: Patients with disc displacement showed a higher incidence of pain in the temporomandibular joint area, but there were no differences in parafunctional habits between the groups. In the disc displacement group, postural deviations were found in the pelvis (posterior rotation), lumbar spine (hyperlordosis), thoracic spine (rectification), head (deviation to the right) and mandibles (deviation to the left with open mouth). There were no differences in the longitudinal plantar arches between the groups. CONCLUSION: Our results suggest a close relationship between body posture and temporomandibular disorder, though it is not possible to determine whether postural deviations are the cause or the result of the disorder. Hence, postural evaluation could be an important component in the overall approach to providing accurate prevention and treatment in the management of patients with temporomandibular disorder. PMID:19142549

Expression of receptors for putative anabolic growth factors in human intervertebral disc: implications for repair and regeneration of the disc.

PubMed

Le Maitre, Christine L; Richardson, Stephen M A; Baird, Pauline; Freemont, Anthony J; Hoyland, Judith A

2005-12-01

Low back pain (LBP) is a common, debilitating and economically important disorder. Current evidence implicates loss of intervertebral disc (IVD) matrix consequent upon 'degeneration' as a major cause of LBP. Degeneration of the IVD involves increases in degradative enzymes and decreases in the extracellular matrix (ECM) component in a process that is controlled by a range of cytokines and growth factors. Studies have suggested using anabolic growth factors to regenerate the normal matrix of the IVD, hence restoring disc height and reversing degenerative disc disease. However, for such therapies to be successful it is vital that the target cells (i.e. the disc cells) express the appropriate receptors. This immunohistochemical study has for the first time investigated the expression and localization of four potentially beneficial growth factor receptors (i.e. TGFbetaRII, BMPRII, FGFR3 and IGFRI) in non-degenerate and degenerate human IVDs. Receptor expression was quantified across regions of the normal and degenerate disc and showed that cells of the nucleus pulposus (NP) and inner annulus fibrosus (IAF) expressed significantly higher levels of the four growth factor receptors investigated. There were no significant differences between the four growth factor expression in non-degenerate and degenerate biopsies. However, expression of TGFbetaRII, FGFR3 and IGFRI, but not BMP RII, were observed in the ingrowing blood vessels that characterize part of the disease aetiology. In conclusion, this study has demonstrated the expression of the four growth factor receptors at similar levels in the chondrocyte-like cells of the NP and IAF in both non-degenerate and degenerate discs, implicating a role in normal disc homeostasis and suggesting that the application of these growth factors to the degenerate human IVD would stimulate matrix production. However, the expression of some of the growth factor receptors on ingrowing blood vessels might be problematic in a therapeutic approach. Copyright 2005 Pathological Society of Great Britain and Ireland.

Spinal injury in sport: epidemiologic considerations.

PubMed

Tall, R L; DeVault, W

1993-07-01

Review of previous epidemiologic studies, involving both contact and noncontact sports at all levels of competition ranging from the high school level to the professional level, reveals that the overwhelming majority of sports injuries related to the spine are soft-tissue injuries and self-limiting. The spectrum of injury is related to the mechanism, the force involved, and the point of application of the force. The immediate consequence of a soft-tissue injury is decreased immobilization with result in deconditioning. Most athletes have a strong desire to compete both at the amateur and professional levels. The inability to compete can have both psychologic and emotional consequences. The professional athlete is potentially burdened with financial consequences as well. The mainstay of prevention and treatment is maintaining good strength and flexibility through conditioning. Injuries can occur at the level of the disc, resulting in disc herniation, disc degeneration, and ultimately developmental stenosis. The biochemistry and biomechanics of the disc are age related, and thus, the adolescent and older athlete may have different concerns with regards to the diagnosis, treatment, and prognosis after injury to the spine. Remember, not only injuries cause back pain in the athlete. Athletes, too, can have tumors, infection, rheumatologic disorders, and other nontraumatic etiologies of back pain. Rarely athletic injuries to the spine do result in significant neurologic compromise. These injuries have been brought to national attention with the tragic recent injuries of well-known professional football and hockey athletes.(ABSTRACT TRUNCATED AT 250 WORDS)

What Is the Most Representative Parameter for Describing the Size of the Atlas? CT Morphometric Analysis of the Atlas with Special Reference to Atlas Hypoplasia.

PubMed

Yamahata, Hitoshi; Hirano, Hirofumi; Yamaguchi, Satoshi; Mori, Masanao; Niiro, Tadaaki; Tokimura, Hiroshi; Arita, Kazunori

2017-09-15

The spinal canal diameter (SCD) is one of the most studied factors for the assessment of cervical spinal canal stenosis. The inner anteroposterior diameter (IAP), the SCD, and the cross-sectional area (CSA) of the atlas have been used for the evaluation of the size of the atlas in patients with atlas hypoplasia, a rare form of developmental spinal canal stenosis, however, there is little information on their relationship. The aim of this study was to identify the most useful parameter for depicting the size of the atlas. The CSA, the IAP, and the SCD were measured on computed tomography (CT) images at the C1 level of 213 patients and compared in this retrospective study. These three parameters increased with increasing patient height and weight. There was a strong correlation between IAP and SCD (r = 0.853) or CSA (r = 0.822), while correlation between SCD and CSA (r = 0.695) was weaker than between IAP and CSA. Partial correlation analysis showed that IAP was positively correlated with SCD (r = 0.687) and CSA (r = 0.612) when CSA or SCD were controlled. SCD was negatively correlated with CSA when IAP was controlled (r = -0.21). The IAP can serve as the CSA for the evaluation of the size of the atlas ring, while the SCD does not correlate with the CSA. As the patient height and weight affect the size of the atlas, analysis of the spinal canal at the C1 level should take into account physiologic patient data.

Spinal Cord Herniation After Cervical Corpectomy with Cerebrospinal Fluid Leak: Case Report and Review of the Literature.

PubMed

Guppy, Kern H; Silverthorn, James W

2017-04-01

Spinal cord herniation (SCH) is rare, is mostly idiopathic, and occurs predominantly in the thoracic spine. SCH is less common in the cervical spine and has been reported after posterior cervical spine surgery associated with the development of pseudomeningoceles. Two cases of SCH have been reported after anterior cervical corpectomies for ossified posterior longitudinal ligament with cerebrospinal fluid (CSF) leaks. We report the third such case, but the first in a patient without ossified posterior longitudinal ligament (degenerative disc disease and pseudarthrosis). A 56-year-old woman presented with bilateral arm pain and weakness. She had undergone 3 previous anterior cervical spine surgeries at an outside medical center with the most recent 7 years ago with C5 and C6 corpectomies and fusion with a persistent CSF leak. Magnetic resonance imaging and computed tomography myelography showed spinal cord herniation through the mesh cage at C6. The patient underwent a redo C5 and C6 corpectomy with untethering of the spinal cord. The patient was asymptomatic 2 years later. This is the first reported case of anterior cervical SCH in a patient without ossified posterior longitudinal ligament after multiple anterior cervical fusions including a cervical corpectomy for pseudarthrosis with a CSF leak. We hypothesize that persistent CSF leak causes a pressure gradient across the dura mater through the cage to the lower pressure in the retropharyngeal space, which led to herniation of the spinal cord into the anterior cage. We review the literature and discuss the treatment choices for anterior cervical SCH. Copyright © 2017 Elsevier Inc. All rights reserved.

Electrically evoked compound action potentials recorded from the sheep spinal cord.

PubMed

Parker, John L; Karantonis, Dean M; Single, Peter S; Obradovic, Milan; Laird, James; Gorman, Robert B; Ladd, Leigh A; Cousins, Michael J

2013-01-01

The study aims to characterize the electrical response of dorsal column axons to depolarizing stimuli to help understand the mechanisms of spinal cord stimulation (SCS) for the relief of chronic pain. We recorded electrically evoked compound action potentials (ECAPs) during SCS in 10 anesthetized sheep using stimulating and recording electrodes on the same epidural SCS leads. A novel stimulating and recording system allowed artifact contamination of the ECAP to be minimized. The ECAP in the sheep spinal cord demonstrates a triphasic morphology, with P1, N1, and P2 peaks. The amplitude of the ECAP varies along the length of the spinal cord, with minimum amplitudes recorded from electrodes positioned over each intervertebral disc, and maximum amplitudes recorded in the midvertebral positions. This anatomically correlated depression of ECAP also correlates with the areas of the spinal cord with the highest thresholds for stimulation; thus regions of weakest response invariably had least sensitivity to stimulation by as much as a factor of two. The choice of stimulating electrode location can therefore have a profound effect on the power consumption for an implanted stimulator for SCS. There may be optimal positions for stimulation in the sheep, and this observation may translate to humans. Almost no change in conduction velocity (∼100 ms) was observed with increasing currents from threshold to twice threshold, despite increased Aβ fiber recruitment. Amplitude of sheep Aβ fiber potentials during SCS exhibit dependence on electrode location, highlighting potential optimization of Aβ recruitment and power consumption in SCS devices. © 2013 International Neuromodulation Society.

Lumbar scoliosis associated with spinal stenosis in idiopathic and degenerative cases.

PubMed

Le Huec, J C; Cogniet, A; Mazas, S; Faundez, A

2016-10-01

Degenerative de novo scoliosis is commonly present in older adult patients. The degenerative process including disc bulging, facet arthritis, and ligamentum flavum hypertrophy contributes to the appearance of symptoms of spinal stenosis. Idiopathic scoliosis has also degenerative changes that can lead to spinal stenosis. The aetiology, prevalence, biomechanics, classification, symptomatology, and treatment of idiopathic and degenerative lumbar scoliosis in association with spinal stenosis are reviewed. Review study is based on a review of pertinent but non-exhaustive literature of the last 20 years in PubMed in English language. Retrospective analysis of studies focused on all parameters concerning scoliosis associated with stenosis. Very few publications have focused specifically on idiopathic scoliosis and stenosis, and this was before the advent of modern segmental instrumentation. On the other hand, many papers were found for degenerative scoliosis and stenosis with treatment methods based on aetiology of spinal canal stenosis and analysis of global sagittal and frontal parameters. Satisfactory clinical results after operative treatment range from 83 to 96 % but with increased percentage of complications. Recent literature analysed the importance of stabilizing or not the spine after decompression in such situation knowing the increasing risk of instability after facet resection. No prospective randomized studies were found to support short instrumentation. Long instrumentation and fusion to prevent distabilization after decompression were always associated with higher complication rates. Imbalance patients with unsatisfactory compensation capacities were at risk of complications. Operative treatment using newly proposed classification system of lumbar scoliosis with associated canal stenosis is useful. Sagittal balance and rotatory dislocation are the main parameters to analyse to determine the length of fusion.

[Anterior lumbar interbody fusion. Indications, technique, advantages and disadvantages].

PubMed

Richter, M; Weidenfeld, M; Uckmann, F P

2015-02-01

Anterior lumbar interbody fusion (ALIF) for lumbar interbody fusion from L2 to the sacrum has been an established technique for decades. The advantages and disadvantages of ALIF compared to posterior interbody fusion techniques are discussed. The operative technique is described in detail. Complications and avoidance strategies are discussed. This article is based on a selective literature search using PubMed and the experience of the authors in this medical field. The advantages of ALIF compared to posterior fusion techniques are the free approach to the anterior disc space without opening of the spinal canal or the neural foramina. This gives the possibility of an extensive anterior release and placement of the largest possible cages without the risk of neural structure damage. The disadvantages of ALIF are the additional anterior approach and the related complications. The most frequent complication is due to damage of vessels. The rate of complications is significantly increased in revision surgery. The ALIF technique meaningfully expands the repertoire of the spinal surgeon especially for the treatment of non-union after interbody fusion, in patients with epidural scar tissue at the index level and spinal infections. Advantages and disadvantages should be considered when evaluating the indications for ALIF.

A comparison of 25 gauge Quincke spinal needle with 26 gauge Eldor spinal needle for the elective Caesarian sections: insertion characteristics and complications.

PubMed

Tabedar, S; Maharjan, S K; Shrestha, B R; Shrestha, B M

2003-01-01

The study was designed to compare the insertion characteristics and incidence of PDPH between 25 gauge Quincke needle and 26 gauge Eldor needle for spinal anaesthesia in elective c/s. 60 pregnant women (aged 19-35 yrs and weighing 58 -67 kg) undergoing elective caesarean section were randomized into group A (Quincke spinal needle group) or group B (Eldor spinal needle group). Spinal anaesthesia was performed with 2.9 ml 0.5% heavy bupivacaine using 25 gauge Quincke spinal needle in group A and 26 Gauge Eldor spinal needle in group B. Onset, time of first identification of backflow of CSF, number of attempts, level of sensory and motor blockade, failure of anaesthesia, inadequate anaesthesia and incidence of PDPH were recorded. Quincke spinal needle was found easy at insertion, first attempt was successful in 90% of cases, whereas Eldor spinal needle was successful at first attempt in only 60% of cases. Early identification of CSF was seen in Eldor spinal needle group in 3.5 seconds vs. 5.2 seconds in Quincke spinal needle group. Blood mixed CSF was seen in 8 Quincke spinal needle group vs. none in Eldor spinal needle group. Onset was similar between both groups i.e. in 6 minutes. Failure of anaesthesia was none in Eldor spinal needle group vs. 2 in quincke spinal needle group. Height of sensory block achieved was T4 level in 26 parturients,T6 in 1 ,T8 in 1 and no anaesthesia at all in another 2 parturient as compared to T4 level in 29 and T3 in 1 parturient in Eldor spinal needle group. The degree of motor block with the use of Bromage criteria showed a motor score of 1 or 2 in 26 parturients in Quincke spinal needle group vs. same in all cases in Eldor spinal needle group. The total incidence of PDPH was 8.3 % (5 out of 60 parturient) which occurred all in Quincke spinal needle group. 2 parturient who developed severe PDPH required epidural blood patch. 26 gauge Eldor spinal needle was found to be better than 25 gauge Quincke spinal needle for caesarian sections to decrease the incidence of PDPH, though not all insertion characteristics were in favour of the Eldor needle.

ISSLS PRIZE IN BASIC SCIENCE 2018: Growth differentiation factor-6 attenuated pro-inflammatory molecular changes in the rabbit anular-puncture model and degenerated disc-induced pain generation in the rat xenograft radiculopathy model.

PubMed

Miyazaki, Shingo; Diwan, Ashish D; Kato, Kenji; Cheng, Kevin; Bae, Won C; Sun, Yang; Yamada, Junichi; Muehleman, Carol; Lenz, Mary E; Inoue, Nozomu; Sah, Robert L; Kawakami, Mamoru; Masuda, Koichi

2018-04-01

To elucidate the effects of growth differentiation factor-6 (GDF6) on: (i) gene expression of inflammatory/pain-related molecules and structural integrity in the rabbit intervertebral disc (IVD) degeneration model, and (ii) sensory dysfunction and changes in pain-marker expression in dorsal nerve ganglia (DRGs) in the rat xenograft radiculopathy model. Forty-six adolescent rabbits received anular-puncture in two non-consecutive lumbar IVDs. Four weeks later, phosphate-buffered saline (PBS) or GDF6 (1, 10 or 100 µg) was injected into the nucleus pulposus (NP) of punctured discs and followed for 4 weeks for gene expression analysis and 12 weeks for structural analyses. For pain assessment, eight rabbits were sacrificed at 4 weeks post-injection and NP tissues of injected discs were transplanted onto L5 DRGs of 16 nude rats to examine mechanical allodynia. The rat DRGs were analyzed immunohistochemically. In GDF6-treated rabbit NPs, gene expressions of interleukin-6, tumor necrosis factor-α, vascular endothelial growth factor, prostaglandin-endoperoxide synthase 2, and nerve growth factor were significantly lower than those in the PBS group. GDF6 injections resulted in partial restoration of disc height and improvement of MRI disc degeneration grades with statistical significance in rabbit structural analyses. Allodynia induced by xenograft transplantation of rabbit degenerated NPs onto rat DRGs was significantly reduced by GDF6 injection. Staining intensities for ionized calcium-binding adaptor molecule-1 and calcitonin gene-related peptide in rat DRGs of the GDF6 group were significantly lower than those of the PBS group. GDF6 injection may change the pathological status of degenerative discs and attenuate degenerated IVD-induced pain.

Effect of tillage system and cumulative rainfall on multifractal parameters of soil surface microrelief

NASA Astrophysics Data System (ADS)

Vidal Vázquez, E.; Miranda, J. G. V.; Mirás-Avalos, J. M.; Díaz, M. C.; Paz-Ferreiro, J.

2009-04-01

Mathematical description of the spatial characteristics of soil surface microrelief still remains a challenge. Soil surface roughness parameters are required for modelling overland flow and erosion. The objective of this work was to evaluate the potential of multifractal for analyzing the decay of initial surface roughness induced by natural rainfall under different soil tillage systems. Field experiments were performed on an Oxisol at Campinas, São Paulo State (Brazil). Six tillage treatments, namely, disc harrow, disc plow, chisel plow, disc harrow + disc level, disc plow + disc level and chisel plow + disc level were tested. In each plot soil surface microrelief was measured for times, with increasing amounts of natural rainfall using a pinmeter. The sampling scheme was a square grid with 25 x 25 mm point spacing and the plot size was 1350 x 1350 mm, so that each data set consisted of 3025 individual elevation points. Duplicated measurements were taken per treatment and date, yielding a total of 48 experimental data sets. All the investigated microrelief data sets exhibited, in general, scale properties, and the degree of multifractality showed wide differences between them. Multifractal analysis distinguishes two different patterns of soil surface microrelief, the first one has features close to monofractal spectra and the second clearly indicates multifractal behavior. Both, singularity spectra and generalized dimension spectra allow differentiating between soil tillage systems. In general, changes in values of multifractal parameters under simulated rainfall showed no or little correspondence with the evolution of the vertical microrelief component described by indices such as the standard deviation of the point height measurements. Multifractal parameters provided valuable information for chararacterizing the spatial features of soil surface microrelief as they were able to discriminate data sets with similar values for the vertical component of roughness.

The impact of computer display height and desk design on 3D posture during information technology work by young adults.

PubMed

Straker, L; Burgess-Limerick, R; Pollock, C; Murray, K; Netto, K; Coleman, J; Skoss, R

2008-04-01

Computer display height and desk design to allow forearm support are two critical design features of workstations for information technology tasks. However there is currently no 3D description of head and neck posture with different computer display heights and no direct comparison to paper based information technology tasks. There is also inconsistent evidence on the effect of forearm support on posture and no evidence on whether these features interact. This study compared the 3D head, neck and upper limb postures of 18 male and 18 female young adults whilst working with different display and desk design conditions. There was no substantial interaction between display height and desk design. Lower display heights increased head and neck flexion with more spinal asymmetry when working with paper. The curved desk, designed to provide forearm support, increased scapula elevation/protraction and shoulder flexion/abduction.

Lumbar discography. Position statement from the North American Spine Society Diagnostic and Therapeutic Committee.

PubMed

Guyer, R D; Ohnmeiss, D D

1995-09-15

A comprehensive review of the literature dealing with lumbar discography was conducted. The purpose of the review was to generate a position statement addressing criticisms of lumbar discography, identify indications for its use, and describe a technique for its performance. Lumbar discography remains a controversial diagnostic procedure. There are concerns about its safety and clinical value, although others support its use in specific applications. Articles dealing with lumbar discography were reviewed and summarized in this report. Most of the recent literature supports the use of discography in select patients. Although not to be taken lightly, many of the serious and high complication rates were reported before 1970 and have decreased since because of improvement in injection technique, imaging, and contrast materials. Most of the current literature supports the use of discography in select situations. Particular applications include patients with persistent pain in whom disc abnormality is suspect, but noninvasive tests have not provided sufficient diagnostic information or the images need to be correlated with clinical symptoms. Another application is assessment of discs in patients in whom fusion is being considered. Discography's role in such cases is to determine if discs within the proposed fusion segment are symptomatic and if the adjacent discs are normal. Discography appears to be helpful in patients who have previously undergone surgery but continue to experience significant pain. In such cases, it can be used to differentiate between postoperative scar and recurrent disc herniation and to investigate the condition of a disc within, or adjacent to, a fused spinal segment to better delineate the source of symptoms. When minimally invasive discectomy is being considered, discography can be used to confirm a contained disc herniation, which is generally an indication for such surgical procedures. Lumbar discography should be performed by those well experienced with the procedure and in sterile conditions with a double needle technique and fluoroscopic imaging for proper needle placement. Information assessed and recorded should include the volume of contrast injected, pain response with particular emphasis on its location and similarity to clinical symptoms, and the pattern of dye distribution. Frequently, discography is followed by axial computed tomography scanning to obtain more information about the condition of the disc.

Is it possible to preserve lumbar lordosis after hybrid stabilization? Preliminary results of a novel rigid-dynamic stabilization system in degenerative lumbar pathologies.

PubMed

Formica, Matteo; Cavagnaro, Luca; Basso, Marco; Zanirato, Andrea; Felli, Lamberto; Formica, Carlo

2015-11-01

To evaluate the results of a novel rigid-dynamic stabilization technique in lumbar degenerative segment diseases (DSD), expressly pointing out the preservation of postoperative lumbar lordosis (LL). Forty-one patients with one level lumbar DSD and initial disc degeneration at the adjacent level were treated. Circumferential lumbar arthrodesis and posterior hybrid instrumentation were performed to preserve an initial disc degeneration above the segment that has to be fused. Clinical and spino-pelvic parameters were evaluated pre- and postoperatively. At 2-year follow-up, a significant improvement of clinical outcomes was reported. No statistically significant difference was noted between postoperative and 2-year follow-up in LL and in disc/vertebral body height ratio at the upper adjacent fusion level. When properly selected, this technique leads to good results. A proper LL should be achieved after any hybrid stabilization to preserve the segment above the fusion.

Pedicle screw fixation for isthmic spondylolisthesis: does posterior lumbar interbody fusion improve outcome over posterolateral fusion?

PubMed

La Rosa, Giovanni; Conti, Alfredo; Cacciola, Fabio; Cardali, Salvatore; La Torre, Domenico; Gambadauro, Nicola Maria; Tomasello, Francesco

2003-09-01

Posterolateral fusion involving instrumentation-assisted segmental fixation represents a valid procedure in the treatment of lumbar instability. In cases of anterior column failure, such as in isthmic spondylolisthesis, supplemental posterior lumbar interbody fusion (PLIF) may improve the fusion rate and endurance of the construct. Posterior lumbar interbody fusion is, however, a more demanding procedure and increases costs and risks of the intervention. The advantages of this technique must, therefore, be weighed against those of a simple posterior lumbar fusion. Thirty-five consecutive patients underwent pedicle screw fixation for isthmic spondylolisthesis. In 18 patients posterior lumbar fusion was performed, and in 17 patients PLIF was added. Clinical, economic, functional, and radiographic data were assessed to determine differences in clinical and functional results and biomechanical properties. At 2-year follow-up examination, the correction of subluxation, disc height, and foraminal area were maintained in the group in which a PLIF procedure was performed, but not in the posterolateral fusion-only group (p < 0.05). Nevertheless, no statistical intergroup differences were demonstrated in terms of neurological improvement (p = 1), economic (p = 0.43), or functional (p = 0.95) outcome, nor in terms of fusion rate (p = 0.49). The authors' findings support the view that an interbody fusion confers superior mechanical strength to the spinal construct; when posterolateral fusion is the sole intervention, progressive loss of the extreme correction can be expected. Such mechanical insufficiency, however, did not influence clinical outcome.

Trumpet Laminectomy Microdecompression for Lumbal Canal Stenosis

PubMed Central

Yasuda, Muneyoshi; Arifin, Muhammad Zafrullah; Takayasu, Masakazu; Faried, Ahmad

2014-01-01

Microsurgery techniques are useful innovations towards minimizing the insult of canal stenosis. Here, we describe the trumpet laminectomy microdecompression (TLM) technique, advantages and disadvantages. Sixty-two TLM patients with lumbar disc herniation, facet hypertrophy or yellow ligament or intracanal granulation tissue. The symptoms are low back pain, dysesthesia and severe pain on both legs. Spine levels operated Th11-S1; the patients who had trumpet-type fenestration, 62.9% had hypertrophy of the facet joint, 11.3% had intracanal granulation tissue, 79.1% had hypertrophy of the yellow ligament and 64.5% had disc herniation. The average of procedure duration was 68.9 min and intraoperative blood loss was 47.4 mL. Intraoperative complications were found in 3.2% of patients, with dural damage but without cerebrospinal fluid leakage. The TLM can be performed for all ages and all levels of spinal canal stenosis, without the complication of spondilolistesis. The TLM has a shorter duration, with minimal intraoperative blood loss. PMID:25346821

Ultrasonographic assessment of the atlanto-occipital space in healthy Thoroughbred foals and Thoroughbred foals with neonatal maladjustment syndrome.

PubMed

Mackenzie, C J; Haggett, E F; Pinchbeck, G L; Marr, C M

2017-05-01

Ultrasonography of the atlanto-occipital (AO) space may be useful as a non-invasive diagnostic tool in neonatal foals. The aims of the study were establish a range of values for ultrasonographic measurements of the AO space in healthy Thoroughbred foals and to compare these variables in healthy foals with foals diagnosed with neonatal maladjustment syndrome (NMS). Ultrasonography of the AO space was performed on 38 healthy Thoroughbred foals and 28 Thoroughbred foals with NMS≤4days of age. Transverse image spinal cord height (P=0.001), width (P<0.001) and spinal cord cross sectional area (P<0.001), and longitudinal image dorsoventral diameter of the ventral spinal artery, were significantly smaller in foals with NMS than in healthy foals. Ratios of spinal canal to cord width and cross sectional area were significantly smaller in healthy foals than in foals with NMS (P<0.001). Spinal canal variables were not significantly different between groups. Several ultrasonographic measurements of the AO space were significantly different between healthy foals and foals with NMS. Further investigation is warranted to investigate the clinical application of this technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

The significance of calcified fibrocartilage on the cortical endplate of the translational sheep spine model.

PubMed

Sinclair, Sarina K; Bell, Spencer; Epperson, Richard Tyler; Bloebaum, Roy D

2013-05-01

To gain an understanding of the vertebral cortical endplate and factors that may affect the ability to achieve skeletal attachment to intervertebral implants and fusion, this study aimed to characterize the hypermineralized tissue on the cortical endplate of the vertebral body on a commonly used animal model. Skeletally mature sheep were injected with tetracycline prior to euthanasia and the C2-C3, T5-T6, and L2-L3 spinal motion segments were excised and prepared. Vertebral tissues were imaged using backscatter electron (BSE) imaging, histology, and tetracycline labeling was used to assess bone remodeling within different tissue layers. It was determined that the hypermineralized tissue layer was calcified fibrocartilage (CFC). No tetracycline labels were identified in the CFC layer, in contrast to single and double labels that were present in the underlying bone, indicating the CFC present on the cortical endplate was not being actively remodeled. The average thickness of the CFC layer was 146.3 ± 70.53 µm in the cervical region, 98.2 ± 40.29 µm in the thoracic region, and 150.89 ± 69.25 µm in the lumbar region. This difference in thickness may be attributed to the regional biomechanical properties of the spine. Results from this investigation indicate the presence of a nonremodeling tissue on the cortical endplate of the vertebral body in sheep spines, which attaches the intervertebral disc to the vertebrae. This tissue, if not removed, would likely prevent successful bony attachment to an intervertebral device in spinal fusion studies and total disc replacement surgeries. Copyright © 2013 Wiley Periodicals, Inc.

Implant detectibility of intervertebral disc spacers in post fusion MRI: evaluation of the MRI scan quality by using a scoring system--an in vitro study.

PubMed

Ernstberger, Thorsten; Heidrich, Gabert; Schultz, Wolfgang; Grabbe, Eckhardt

2007-02-01

Intervertebral spacers for anterior spine fusion are made of different materials, such as titanium and cobalt chromium alloys and carbon fiber-reinforced polymers. Implant-related susceptibility artifacts can decrease the quality of MRI scans. The aim of this cadaveric study was to demonstrate the extent that implant-related MRI artifacting affects the postfusion differentiation of determined regions of interest (ROIs). In six cadaveric porcine spines, we evaluated the postimplantation MRI scans of a titanium, cobalt-chromium and carbon spacer that differed in shape and surface qualities. A spacer made of human cortical bone was used as a control. A defined evaluation unit was divided into ROIs to characterize the spinal canal as well as the intervertebral disc space. Considering 15 different MRI sequences read independently by an interobserver-validated team of specialists the artifact-affected image quality of the median MRI slice was rated on a score of 0-3. A maximum score of 18 points (100%) for the determined ROIs was possible. Turbo spin echo sequences produced the best scores for all spacers and the control. Only the control achieved a score of 100%. For the determined ROI maximum scores for the cobalt-chromium, titanium and carbon spacers were 24%, 32% and 84%, respectively. By using favored T1 TSE sequences the carbon spacer showed a clear advantage in postfusion spinal imaging. Independent of artifact dimensions, the scoring system used allowed us to create an implant-related ranking of MRI scan quality in reference to the bone control.

[Diagnostic capability of PULSAR, FDT y HRT-II in glaucoma suspects].

PubMed

González-de-la-Rosa, M; González-Hernández, M; Aguilar-Estévez, J; Díaz-Alemán, T; Armas-Plasencia, R

2007-07-01

To determine the diagnostic capability of PULSAR-T30W, FDT-Threshold-N30 and HRT-II in glaucoma suspects. Forty-seven eyes from 47 referred glaucoma suspects (GS) were examined twice with each technique. Cases with TOP-WW-MD>6dB were excluded. Results were compared with those of 70 eyes from 70 normal controls (C). Mean MD value using TOP-WW in the GS group (0.96dB. sd=1.7) was not significantly different from C (0.8dB. sd=1.77) (p>0.05). Disc area in GS group (2.12 mm(2). sd=0.34) was significantly greater than in C (1.97 mm2. sd=0.45) (p<0.01). For 95.7% specificity, PULSAR-sLV showed the highest sensitivity of 30.9% in individual examinations. The highest reproducible sensitivity in the two examinations was obtained using HRT-II maximum contour elevation (23.4%) and reference height (23.4%), and was 14.9% for various indices after correcting for the influence of disc area (cup area, cup/disc area ratio, maximum contour depression and mean RNFL thickness). Reproducible sensitivity of the perimetric indices was: PULSAR-MD=8.5%, PULSAR-sLV=17%, FDT-MD=6.4%, FDT-PSD=4.3%. The association of perimetric and HRT-II indices achieved high sensitivity but low diagnostic reproducibility. The most effective indices were maximum contour elevation, reference height and PULSAR-sLV, although the inclusion of the optic nerve head assessment in the selection of the GS sample may have favored the HRT-II results.

[Transpedicular dynamics stabilization in the treatment of lumbar stenosis. Fourth years follow-up].

PubMed

Reyes-Sánchez, Alejandro; Sánchez-Bringas, Guadalupe; Zarate-Kalfopulos, Barón; Alpizar-Aguirre, Armando; Lara-Padilla, Eleazar; Rosales-Olivares, Luis Miguel

2013-01-01

We need to evaluate the efficacy and safety of the use of dynamic fixation in patients with narrow lumbar through comparing the assessment of two years with 4 years of follow-up. Prospective, longitudinal, autocontrol deliberately and sequential intervention, in lumbar stenosis patients who made treatment with dynamic stabilization posterior type Acuflex. An evaluation of four of final follow-up. 18 patients who completed follow-up two years results as a basis for comparison: 18 patients, 14 female and 4 male, average age 44.05 years. Pain evaluated with numerical visual scale was found in the lower back at 24 months in an average of 2.84 and 48 months in 3.26. We measured the functional level of Oswestry at two years to be 24% and at four years 22.44%, with a p = 0.373. In the magnetic resonance for classification of patients 15 Pfirrmann without changes and three with increase of a degree. According to patients 2 Modic changes one of type 0 to type III and another to type I. We have observed that five patients have required second surgery for removal of material findings. There is no change between 2 and 4 years in the scale of Oswestry and pain with visual numerical scale functionality. The average height in discs had change with statistical significance, in the comparative period. The intervertebral discs had changes in 3 patients with direct relationship between scale of Pfirrmann and Modic. The rest of patients keep rehydration and normal disc height.

Osthole, a Coumadin Analog from Cnidium monnieri (L.) Cusson, Ameliorates Nucleus Pulposus-Induced Radicular Inflammatory Pain by Inhibiting the Activation of Extracellular Signal-Regulated Kinase in Rats.

PubMed

Wu, Hai-Xuan; Wang, Yi-Min; Xu, Hui; Wei, Ming; He, Qiu-Lan; Li, Mei-Na; Sun, Lai-Bao; Cao, Ming-Hui

2017-01-01

This study was aimed at assessing the role of extracellular signal regulated kinase (ERK) in mechanical allodynia resulting from lumbar disc herniation (LDH) and exploring the osthole's anti-nociceptive effect on ERK activation. Radicular pain was generated by applying nucleus pulposus (NP) to the L5 dorsal root ganglion (DRG). Allodynia was measured using Von Frey filaments to calculate the mechanical pain threshold. Phosphorylated ERK and total ERK protein in the lumbar spinal dorsal horn was detected by using the Western blot technique. Cyclooxygenase 2 (COX-2) mRNA was assessed by real-time reverse-transcription polymerase chain reaction. The application of NP to L5 DRG induced mechanical hypersensitivity which lasted for at least 28 days, and a significant increase of ERK phosphorylation in the ipsilateral spinal dorsal horn from postoperative day (POD) 1 to POD 21. ERK inhibitor attenuated NP-induced hyperalgesia compared to the dimethyl sulfoxide-(vehicle control) administered group (p < 0.05). Epidural treatment with osthole could ameliorate NP-evoked hyperalgesia by suppressing the activation of ERK rather than decreasing the expression of ERK protein. Osthole could also inhibit the increased expression of COX-2 mRNA in spinal dorsal horn, which was a known downstream effect of ERK signaling pathway. Our results suggest that ERK activation in the spinal dorsal horn plays a vital role in NP-evoked hyperalgesia. Osthole exerts analgesic effect on radicular inflammatory pain in LDH rat model, by down-regulating the mRNA expression of the target gene of COX-2 via inhibiting ERK activation in the spinal dorsal horn. © 2017 S. Karger AG, Basel.

Double Crush of L5 Spinal Nerve Root due to L4/5 Lateral Recess Stenosis and Bony Spur Formation of Lumbosacral Transitional Vertebra Pseudoarticulation: A Case Report and Review

PubMed Central

Iwasaki, Motoyuki; Akiyama, Masahiko; Koyanagi, Izumi; Niiya, Yoshimasa; Ihara, Tatsuo; Houkin, Kiyohiro

2017-01-01

We present a case of double-crushed L5 nerve root symptoms caused by inside and outside of the spinal canal with spur formation of the lumbosacral transitional vertebra (LSTV). A 78-year-old man presented with 7-year history of moderate paresis of his toe and left leg pain when walking. Magnetic resonance imaging (MRI) revealed spinal stenosis at the L3/4 and 4/5 spinal levels and he underwent wide fenestration of both levels. Leg pain disappeared and 6-min walk distance (6MWD) improved after surgery, however, the numbness in his toes increased and 6MWD decreased 9 months after surgery. Repeated MR and 3D multiplanar reconstructed computed tomography (CT) images showed extraforaminal impingement of the L5 root by bony spur of the left LSTV. He underwent second decompression surgery of the L5/S via the left sided Wiltse approach, resulting in the improvement of his symptoms. The impingement of L5 spinal nerve root between the transverse process of the fifth lumbar vertebra and the sacral ala is a rare entity of the pathology called “far-out syndrome (FOS)”. Especially, the bony spur formation secondary to the anomalous articulation of the LSTV (LSPA) has not been reported. These articulations could be due to severe disc degeneration, following closer distance and contact between the transverse process and the sacral ala. To our knowledge, this is the first report describing a case with this pathology and may be considered in cases of failed back surgery syndromes (FBSS) of the L5 root symptoms. PMID:29018654

Biomechanical effects of fusion levels on the risk of proximal junctional failure and kyphosis in lumbar spinal fusion surgery.

PubMed

Park, Won Man; Choi, Dae Kyung; Kim, Kyungsoo; Kim, Yongjung J; Kim, Yoon Hyuk

2015-12-01

Spinal fusion surgery is a widely used surgical procedure for sagittal realignment. Clinical studies have reported that spinal fusion may cause proximal junctional kyphosis and failure with disc failure, vertebral fracture, and/or failure at the implant-bone interface. However, the biomechanical injury mechanisms of proximal junctional kyphosis and failure remain unclear. A finite element model of the thoracolumbar spine was used. Nine fusion models with pedicle screw systems implanted at the L2-L3, L3-L4, L4-L5, L5-S1, L2-L4, L3-L5, L4-S1, L2-L5, and L3-S1 levels were developed based on the respective surgical protocols. The developed models simulated flexion-extension using hybrid testing protocol. When spinal fusion was performed at more distal levels, particularly at the L5-S1 level, the following biomechanical properties increased during flexion-extension: range of motion, stress on the annulus fibrosus fibers and vertebra at the adjacent motion segment, and the magnitude of axial forces on the pedicle screw at the uppermost instrumented vertebra. The results of this study demonstrate that more distal fusion levels, particularly in spinal fusion including the L5-S1 level, lead to greater increases in the risk of proximal junctional kyphosis and failure, as evidenced by larger ranges of motion, higher stresses on fibers of the annulus fibrosus and vertebra at the adjacent segment, and higher axial forces on the screw at the uppermost instrumented vertebra in flexion-extension. Therefore, fusion levels should be carefully selected to avoid proximal junctional kyphosis and failure. Copyright © 2015 Elsevier Ltd. All rights reserved.

A systematic review of definitions and classification systems of adjacent segment pathology.

PubMed

Kraemer, Paul; Fehlings, Michael G; Hashimoto, Robin; Lee, Michael J; Anderson, Paul A; Chapman, Jens R; Raich, Annie; Norvell, Daniel C

2012-10-15

Systematic review. To undertake a systematic review to determine how "adjacent segment degeneration," "adjacent segment disease," or clinical pathological processes that serve as surrogates for adjacent segment pathology are classified and defined in the peer-reviewed literature. Adjacent segment degeneration and adjacent segment disease are terms referring to degenerative changes known to occur after reconstructive spine surgery, most commonly at an immediately adjacent functional spinal unit. These can include disc degeneration, instability, spinal stenosis, facet degeneration, and deformity. The true incidence and clinical impact of degenerative changes at the adjacent segment is unclear because there is lack of a universally accepted classification system that rigorously addresses clinical and radiological issues. A systematic review of the English language literature was undertaken and articles were classified using the Grades of Recommendation Assessment, Development, and Evaluation criteria. RESULTS.: Seven classification systems of spinal degeneration, including degeneration at the adjacent segment, were identified. None have been evaluated for reliability or validity specific to patients with degeneration at the adjacent segment. The ways in which terms related to adjacent segment "degeneration" or "disease" are defined in the peer-reviewed literature are highly variable. On the basis of the systematic review presented in this article, no formal classification system for either cervical or thoracolumbar adjacent segment disorders currently exists. No recommendations regarding the use of current classification of degeneration at any segments can be made based on the available literature. A new comprehensive definition for adjacent segment pathology (ASP, the now preferred terminology) has been proposed in this Focus Issue, which reflects the diverse pathology observed at functional spinal units adjacent to previous spinal reconstruction and balances detailed stratification with clinical utility. A comprehensive classification system is being developed through expert opinion and will require validation as well as peer review. Strength of Statement: Strong.

Etiology of lumbar lordosis and its pathophysiology: a review of the evolution of lumbar lordosis, and the mechanics and biology of lumbar degeneration.

PubMed

Sparrey, Carolyn J; Bailey, Jeannie F; Safaee, Michael; Clark, Aaron J; Lafage, Virginie; Schwab, Frank; Smith, Justin S; Ames, Christopher P

2014-05-01

The goal of this review is to discuss the mechanisms of postural degeneration, particularly the loss of lumbar lordosis commonly observed in the elderly in the context of evolution, mechanical, and biological studies of the human spine and to synthesize recent research findings to clinical management of postural malalignment. Lumbar lordosis is unique to the human spine and is necessary to facilitate our upright posture. However, decreased lumbar lordosis and increased thoracic kyphosis are hallmarks of an aging human spinal column. The unique upright posture and lordotic lumbar curvature of the human spine suggest that an understanding of the evolution of the human spinal column, and the unique anatomical features that support lumbar lordosis may provide insight into spine health and degeneration. Considering evolution of the skeleton in isolation from other scientific studies provides a limited picture for clinicians. The evolution and development of human lumbar lordosis highlight the interdependence of pelvic structure and lumbar lordosis. Studies of fossils of human lineage demonstrate a convergence on the degree of lumbar lordosis and the number of lumbar vertebrae in modern Homo sapiens. Evolution and spine mechanics research show that lumbar lordosis is dictated by pelvic incidence, spinal musculature, vertebral wedging, and disc health. The evolution, mechanics, and biology research all point to the importance of spinal posture and flexibility in supporting optimal health. However, surgical management of postural deformity has focused on restoring posture at the expense of flexibility. It is possible that the need for complex and costly spinal fixation can be eliminated by developing tools for early identification of patients at risk for postural deformities through patient history (genetics, mechanics, and environmental exposure) and tracking postural changes over time.

Quality of data regarding diagnoses of spinal disorders in administrative databases. A multicenter study.

PubMed

Faciszewski, T; Broste, S K; Fardon, D

1997-10-01

The purpose of the present study was to evaluate the accuracy of data regarding diagnoses of spinal disorders in administrative databases at eight different institutions. The records of 189 patients who had been managed for a disorder of the lumbar spine were independently reviewed by a physician who assigned the appropriate diagnostic codes according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). The age range of the 189 patients was seventeen to eighty-four years. The six major diagnostic categories studied were herniation of a lumbar disc, a previous operation on the lumbar spine, spinal stenosis, cauda equina syndrome, acquired spondylolisthesis, and congenital spondylolisthesis. The diagnostic codes assigned by the physician were compared with the codes that had been assigned during the ordinary course of events by personnel in the medical records department of each of the eight hospitals. The accuracy of coding was also compared among the eight hospitals, and it was found to vary depending on the diagnosis. Although there were both false-negative and false-positive codes at each institution, most errors were related to the low sensitivity of coding for previous spinal operations: only seventeen (28 per cent) of sixty-one such diagnoses were coded correctly. Other errors in coding were less frequent, but their implications for conclusions drawn from the information in administrative databases depend on the frequency of a diagnosis and its importance in an analysis. This study demonstrated that the accuracy of a diagnosis of a spinal disorder recorded in an administrative database varies according to the specific condition being evaluated. It is necessary to document the relative accuracy of specific ICD-9-CM diagnostic codes in order to improve the ability to validate the conclusions derived from investigations based on administrative databases.

[Volume Growth of Inpatient Treatments for Spinal Disease - Analysis of German Nationwide Hospital Discharge Data from 2005 to 2014].

PubMed

Nimptsch, Ulrike; Bolczek, Claire; Spoden, Melissa; Schuler, Ekkehard; Zacher, Josef; Mansky, Thomas

2018-04-01

Marked volume growth of inpatient treatments for spinal disease has been observed since diagnosis related groups (DRG) were introduced as payment for inpatient services in Germany. This study aims to analyse this increase by population and stratified by types of treatment. Using German nationwide hospital discharge data (DRG statistics), inpatient treatments for spinal disease with or without surgery were identified. Trends in case numbers were analysed from 2005 to 2014 with consideration of demographic changes, in order to explore which age groups and which types of treatment are affected by volume growth. In 2014 (2005), 289 000 (177 000) inpatient treatments with surgery and 463 000 (287 000) treatments without surgery were identified. After adjusting for demographic factors, treatments with and without surgery exhibited a relative volume growth of + 50%. This increase affected higher age groups and women, in particular. Depending on the type of treatment, very different degrees of volume growth were observed. For example, disc surgeries adjusted for demographic change increased by about + 5%, whereas spinal fusion and vertebral replacement surgeries, kypho-/vertebroplasties and decompression of the spine more than doubled. Within the non-surgically treated cases, local pain therapies of the spine increased after adjustment for demographic changes by about + 142%. The conservatively treated cases showed a demographically adjusted increase of + 22%. Apart from demographic changes, this analysis cannot resolve the underlying causes of volume growth in treatments for spinal disease. However, the stratified analysis of various subgroups may help to classify these developments in a more differentiated manner. The results may support a more targeted debate about potential over- or misallocation of inpatient services in this area. Georg Thieme Verlag KG Stuttgart · New York.

Clues on the Milky Way disc formation from population synthesis simulations

NASA Astrophysics Data System (ADS)

Robin, A. C.; Reylé, C.; Bienaymé, O.; Fernandez-Trincado, J. G.; Amôres, E. B.

2016-09-01

In recent years the stellar populations of the Milky Way have been investigated from large scale surveys in different ways, from pure star count analysis to detailed studies based on spectroscopic surveys. While in the former case the data can constrain the scale height and scale length thanks to completeness, they suffer from high correlation between these two values. On the other hand, spectroscopic surveys suffer from complex selection functions which hardly allow to derive accurate density distributions. The scale length in particular has been difficult to be constrained, resulting in discrepant values in the literature. Here, we investigate the thick disc characteristics by comparing model simulations with large scale data sets. The simulations are done from the population synthesis model of Besançon. We explore the parameters of the thick disc (shape, local density, age, metallicity) using a Monte Carlo Markov Chain method to constrain the model free parameters (Robin et al. 2014). Correlations between parameters are limited due to the vast spatial coverage of the used surveys (SDSS + 2MASS). We show that the thick disc was created during a long phase of formation, starting about 12 Gyr ago and finishing about 10 Gyr ago, during which gravitational contraction occurred, both vertically and radially. Moreover, in its early phase the thick disc was flaring in the outskirts. We conclude that the thick disc has been created prior to the thin disc during a gravitational collapse phase, slowed down by turbulence related to a high star formation rate, as explained for example in Bournaud et al. (2009) or Lehnert et al. (2009). Our result does not favor a formation from an initial thin disc thickened later by merger events or by secular evolution of the thin disc. We then study the in-plane distribution of stars in the thin disc from 2MASS and show that the thin disc scale length varies as a function of age, indicating an inside out formation. Moreover, we investigate the warp and flare and demonstrate that the warp amplitude is changing with time and the node angle is slightly precessing. Finally, we show comparisons between the new model and spectroscopic surveys. The new model allows to correctly simulate the kinematics, the metallicity, and α-abundance distributions in the solar neighbourhood as well as in the bulge region.

Spine kinematics exhibited during the stop-jump by physically active individuals with adolescent idiopathic scoliosis and spinal fusion.

PubMed

Kakar, Rumit Singh; Li, Yumeng; Brown, Cathleen N; Kim, Seock-Ho; Oswald, Timothy S; Simpson, Kathy J

2018-01-01

Individuals with adolescent idiopathic scoliosis post spinal fusion often return to exercise and sport. However, the movements that individuals with spinal fusion for adolescent idiopathic scoliosis (SF-AIS) use to compensate for the loss of spinal flexibility during high-effort tasks are not known. The objective of this study was to compare the spinal kinematics of the trunk segments displayed during the stop-jump, a maximal effort task, between SF-AIS and healthy control groups. The study used a case-controlled design. Ten SF-AIS (physically active, posterior-approach spinal fusion: 11.2±1.9 fused segments, postop time: 2±.6 years) and nine control individuals, pair matched for gender, age (17.4±1.3 years and 20.6±1.5 years, respectively), mass (63.50±12.2 kg and 66. 40±10.9 kg), height (1.69±.09 m and 1.72±.08 m), and level of physical activity, participated in the study. Individuals with spinal fusion for adolescent idiopathic scoliosis and controls (CON) performed five acceptable trials of the stop-jump task. Spatial locations of 21 retroreflective trunk and pelvis markers were recorded via high-speed motion capture methodology. Mean differences and analysis of covariance (jump height=covariate, p<.05) were used to compare the groups' relative angle (RelAng) and segmental angle (SegAng) of the three trunk segments (trunk segments=upper trunk [C7-T8], middle trunk [MT: T9-T12], lower trunk [LT: L1-L5]) for each rotation plane in the three phases of interest (flight, stance, and the vertical flight phases). No significant group differences for jump height and RelAng were detected in the three phases of stop-jump. Individuals with spinal fusion for adolescent idiopathic scoliosis displayed 3.2° greater transverse plane RelAng of LT compared with CON (p=.059) in the stance phase. Group differences for RelAng ranged from 0° to 15.3°. For SegAng in the stance phase, LT demonstrated greater SegAng in the sagittal and frontal planes (mean difference: 3.2°-6.2°), whereas SegAng for MT was 5.1° greater in the sagittal plane and had a tendency of 2° greater displacement in the frontal plane (p=.070). In the vertical flight phase, greater LT displacement in the frontal plane was observed for SF-AIS than CON. In the flight phase, LT had a tendency for greater SegAng for SF-AIS than for CON in the transverse plane (p=.089). Overall, SF-AIS who participate in physical activity on a regular basis are able to demonstrate similar trunk kinematics during a high-intensity stop-jump task as their matched healthy peers. Fewer group differences for relative angular displacements of the spine were observed than anticipated. This finding suggests that the fused MT appeared to be moving synchronously with the LT, thereby suggesting a compensatory adaptation of SF-AIS to achieve sufficient trunk movements during this high-effort movement. Copyright © 2017 Elsevier Inc. All rights reserved.

Postero-Lateral Disc Prosthesis Combined With a Unilateral Facet Replacement Device Maintains Quantity and Quality of Motion at a Single Lumbar Level

PubMed Central

Nayak, Aniruddh N.; Doarn, Michael C.; Gaskins, Roger B.; James, Chris R.; Cabezas, Andres F.; Castellvi, Antonio E.

2014-01-01

Background Mechanically replacing one or more pain generating articulations in the functional spinal unit (FSU) may be a motion preservation alternative to arthrodesis at the affected level. Baseline biomechanical data elucidating the quantity and quality of motion in such arthroplasty constructs is non-existent. Purpose The purpose of the study was to quantify the motion-preserving effect of a posterior total disc replacement (PDR) combined with a unilateral facet replacement (FR) system at a single lumbar level (L4-L5). We hypothesized that reinforcement of the FSU with unilateral FR to replace the resected, native facet joint following PDR implantation would restore quality and quantity of motion and additionally not change biomechanics at the adjacent levels. Study Design In-vitro study using human cadaveric lumbar spines. Methods Six (n = 6) cadaveric lumbar spines (L1-S1) were evaluated using a pure-moment stability testing protocol (±7.5 Nm) in flexion-extension (F/E), lateral bending (LB) and axial rotation (AR). Each specimen was tested in: (1) intact; (2) unilateral FR; and (3) unilateral FR + PDR conditions. Index and adjacent level ROM (using hybrid protocol) were determined opto-electronically. Interpedicular travel (IPT) and instantaneous center of rotation (ICR) at the index level were radiographically determined for each condition. ROM, ICR, and IPT measurements were compared (repeated measures ANOVA) between the three conditions. Results Compared to the intact spine, no significant changes in F/E, LB or AR ROM were identified as a result of unilateral FR or unilateral FR + PDR. No significant changes in adjacent L3-L4 or L5-S1 ROM were identified in any loading mode. No significant differences in IPT were identified between the three test conditions in F/E, LB or AR at the L4-L5 level. The ICRs qualitatively were similar for the intact and unilateral FR conditions and appeared to follow placement (along the anterior-posterior (AP) direction) of the PDR in the disc space Conclusion Biomechanically, quantity and quality of motion are maintained with combined unilateral FR + PDR at a single lumbar spinal level. PMID:25694929

The Incidence of Adjacent Segment Degeneration after the Use of a Versatile Dynamic Hybrid Stabilization Device in Lumbar Stenosis: Results of a 5–8-Year Follow-up

PubMed Central

Dobran, Mauro; Esposito, Domenico Paolo; Gladi, Maurizio; Scerrati, Massimo; Iacoangeli, Maurizio

2018-01-01

Study Design Retrospective study with long-term follow-up. Purpose To evaluate the long-term incidence of adjacent segment degeneration (ASD) and clinical outcomes in a consecutive series of patients who underwent spinal decompression associated with dynamic or hybrid stabilization with a Flex+TM stabilization system (SpineVision, Antony, France) for lumbar spinal stenosis. Overview of Literature The incidence of ASD and clinical outcomes following dynamic or hybrid stabilization with the Flex+TM system used for lumbar spinal stenosis have not been well investigated. Methods Twenty-one patients with lumbar stenosis and probable post-decompressive spinal instability underwent decompressive laminectomy followed by spinal stabilization using the Flex+TM stabilization system. The indication for a mono-level dynamic stabilization was a preoperative magnetic resonance imaging (MRI) demonstrating evidence of severe disc disease associated with severe spinal stenosis. The hybrid stabilization (rigid-dynamic) system was used for multilevel laminectomies with associated initial degenerative scoliosis, first-grade spondylolisthesis, or rostral pathology. Results The improvement in Visual Analog Scale and Oswestry Disability Index scores at follow-up were statistically significant (p<0.0001 and p<0.0001, respectively). At the 5–8-year follow-up, clinical examination, MRI, and X-ray findings showed an ASD complication with pain and disability in one of 21 patients. The clinical outcomes were similar in patients treated with dynamic or hybrid fixation. Conclusions Patients treated with laminectomy and Flex+TM stabilization presented a satisfactory clinical outcome after 5–8 years of follow-up, and ASD incidence in our series was 4.76% (one patient out of 21). We are aware that this is a small series, but our long-term follow-up may be sufficient to contribute to the expanding body of literature on the development of symptomatic ASD associated with dynamic or hybrid fixation. PMID:29713407

Spinal injuries in professional rugby union: a prospective cohort study.

PubMed

Fuller, Colin W; Brooks, John H M; Kemp, Simon P T

2007-01-01

To determine the incidence, severity, nature, and causes of cervical, thoracic, and lumbar spine injuries sustained during competition and training in professional rugby union. A 2 season prospective cohort design. Twelve English Premiership rugby union clubs. Five hundred and forty-six male rugby union players of whom 296 were involved in both seasons. Location, diagnosis, severity (number of days unavailable for training and matches), and cause of injury: incidence of match and training injuries (injuries/1000 player-hours). Player age, body mass, stature, playing position, use of headgear, and activity and period of season. The incidences of spinal injuries were 10.90 (9.43 to 12.60) per 1000 player match-hours and 0.37 (0.29 to 0.47) per 1000 player training-hours. No player sustained a catastrophic spinal injury, but 3 players sustained career-ending injuries. Overall, players were more likely to sustain a cervical injury during matches and a lumbar injury during training. Forwards were significantly more likely to sustain a spinal injury than backs during both matches (P < 0.01) and training (P = 0.02). During matches, injuries to the cervical (average: 13 days; P < 0.01) and lumbar (13 days; P < 0.01) spine were more severe than injuries to the thoracic (5 days) spine; during training, injuries to the lumbar spine (26 days) were more severe than injuries to the cervical (13 days; P = 0.10) or thoracic (12 days; P = 0.06) spine. A total of 4037 days were lost to competition and training through spinal injuries with lumbar disc injuries sustained during training accounting for 926 days (23%) and cervical nerve root injuries sustained during matches for 621 days (15%). During matches, more injuries were caused by tackles (37%), and during training more injuries were caused by weight-training (33%). The results showed that rugby union players were exposed to a high risk of noncatastrophic spinal injury during tackling, scrummaging, and weight-training activities; injury prevention strategies, therefore, should be focused on these activities.

Evaluation of intervertebral disc regeneration with implantation of bone marrow mesenchymal stem cells (BMSCs) using quantitative T2 mapping: a study in rabbits.

PubMed

Cai, Feng; Wu, Xiao-Tao; Xie, Xin-Hui; Wang, Feng; Hong, Xin; Zhuang, Su-Yang; Zhu, Lei; Rui, Yun-Feng; Shi, Rui

2015-01-01

The aim of the study was to investigate the curative effects of transplantation of bone marrow mesenchymal stem cells (BMSCs) on intervertebral disc regeneration and to investigate the feasibility of the quantitative T2 mapping method for evaluating repair of the nucleus pulposus after implantation of BMSCs. Forty-eight New Zealand white rabbits were used to establish the lumber disc degenerative model by stabbing the annulus fibrosus and then randomly divided into four groups, i.e. two weeks afterwards, BMSCs or phosphate-buffered saline (PBS) were transplanted into degenerative discs (BMSCs group and PBS group), while the operated rabbits without implantation of BMSCs or PBS served as the sham group and the rabbits without operation were used as the control group. At weeks two, six and ten after operation, the T2 values and disc height indices (DHI) were calculated by magnetic resonance imaging (MRI 3.0 T), and the gene expressions of type II collagen (COL2) and aggrecan (ACAN) in degenerative discs were evaluated by real-time reverse transcription polymerase chain reaction (RT-PCR). T2 values for the nucleus pulposus were correlated with ACAN or COL2 expression by regression analysis. Cell clusters, disorganised fibres, interlamellar glycosaminoglycan (GAG) matrix and vascularisation were observed in lumber degenerative discs. BMSCs could be found to survive in intervertebral discs and differentiate into nucleus pulposus-like cells expressing COL2 and ACAN. The gene expression of COL2 and ACAN increased during ten weeks after transplantation as well as the T2 signal intensity and T2 value. The DHI in the BMSCs group decreased more slowly than that in PBS and sham groups. The T2 value correlated significantly with the gene expression of ACAN and COL2 in the nucleus pulposus. Transplantation of BMSCs was able to promote the regeneration of degenerative discs. Quantitative and non-invasive T2 mapping could be used to evaluate the regeneration of the nucleus pulposus with good sensitivity.

Low Back Pain in Athletes

PubMed Central

Mortazavi, Javad; Zebardast, Jayran; Mirzashahi, Babak

2015-01-01

Context: Low Back Pain (LBP) in athletes is common and has a broad spectrum of differential diagnoses that must be taken in to account when a clinician approaches the patient with LBP. The physicians should take into account spinal and extra spinal causes of low back pain in athletes. Evidence Acquistion: A literature review was performed for the years 1951 through 2013. Keywords used were Low Back Pain and Athletes. We searched MEDLINE, EMBASE, OVID, PUBMED, the Cochrane Library, ELSEVIER, and the references of reviewed articles, for English-language of Low Back Pain in Athletes. Results: The two most common causes of LBP arising from spine in athletes are degenerative disc disease and spondylolysis with or without listhesis. Although most athletes, respond well to conservative treatment, surgical treatment is indicated when conservative treatment failes. Conclusions: The major concern in athletes with LBP is return to play and previous level of their activity after treatment. There is insufficient evidence regarding this issue in literature to define the optimal time of return to play following treatment. PMID:26448841

The afferent pathways of discogenic low-back pain. Evaluation of L2 spinal nerve infiltration.

PubMed

Nakamura, S I; Takahashi, K; Takahashi, Y; Yamagata, M; Moriya, H

1996-07-01

The afferent pathways of discogenic low-back pain have not been fully investigated. We hypothesised that this pain was transmitted mainly by sympathetic afferent fibres in the L2 nerve root, and in 33 patients we used selective local anaesthesia of this nerve. Low-back pain disappeared or significantly decreased in all patients after the injection. Needle insertion provoked pain which radiated to the low back in 23 patients and the area of skin hypoalgesia produced included the area of pre-existing pain in all but one. None of the nine patients with related sciatica had relief of that component of their symptoms. Our findings show that the main afferent pathways of pain from the lower intervertebral discs are through the L2 spinal nerve root, presumably via sympathetic afferents from the sinuvertebral nerves. Discogenic low-back pain should be regarded as a visceral pain in respect of its neural pathways. Infiltration of the L2 nerve is a useful diagnostic test and also has some therapeutic value.

Human spaceflight and space adaptations: Computational simulation of gravitational unloading on the spine

NASA Astrophysics Data System (ADS)

Townsend, Molly T.; Sarigul-Klijn, Nesrin

2018-04-01

Living in reduced gravitational environments for a prolonged duration such, as a fly by mission to Mars or an extended stay at the international space station, affects the human body - in particular, the spine. As the spine adapts to spaceflight, morphological and physiological changes cause the mechanical integrity of the spinal column to be compromised, potentially endangering internal organs, nervous health, and human body mechanical function. Therefore, a high fidelity computational model and simulation of the whole human spine was created and validated for the purpose of investigating the mechanical integrity of the spine in crew members during exploratory space missions. A spaceflight exposed spine has been developed through the adaptation of a three-dimensional nonlinear finite element model with the updated Lagrangian formulation of a healthy ground-based human spine in vivo. Simulation of the porohyperelastic response of the intervertebral disc to mechanical unloading resulted in a model capable of accurately predicting spinal swelling/lengthening, spinal motion, and internal stress distribution. The curvature of this space adaptation exposed spine model was compared to a control terrestrial-based finite element model, indicating how the shape changed. Finally, the potential of injury sites to crew members are predicted for a typical 9 day mission.

Risk factors for dysphagia after anterior cervical spine surgery

PubMed Central

Liu, Feng-Yu; Yang, Da-Long; Huang, Wen-Zheng; Huo, Li-Shuang; Ma, Lei; Wang, Hui; Yang, Si-Dong; Ding, Wen-Yuan

2017-01-01

Abstract Background: Dysphagia is a well-known complication following anterior cervical spine surgery. Although risk factors for dysphagia have been reported in the literature, they still remain controversial. This study aims to investigate the risk factors associated with dysphagia following anterior cervical spinal surgery. Methods: PubMed, EMBASE, and The Cochrane Library were searched up to June 2016 for studies examining dysphagia following anterior cervical spinal surgery. Risk factors associated with dysphagia were extracted. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for outcomes. Data analysis was conducted with RevMan 5.3 and STATA 12.0. Results: The final analysis includes a total of 18 distinct studies. The pooled analysis reveals that there are significant differences in female gender (OR = 2.30, 95% CI: 1.76–2.99, P < 0.001), the use of anterior cervical plate (OR = 1.66, 95% CI: 1.05–2.62, P = 0.03), more than 1 surgical level (OR = 2.07, 95% CI: 1.62–2.66, P < 0.001), the upper surgical level at C3/4 (OR = 3.08, 95% CI: 1.44–6.55, P = 0.004), and the use of bone morphogenetic protein-2 (rhBMP-2) (OR = 5.52, 95% CI: 2.16–14.10, P < 0.001). However, no significant difference is found in revision surgery (OR = 1.67, 95% CI: 0.60–4.68, P = 0.33), the type of fusion (OR = 1.02, 95% CI: 0.62–1.67, P = 0.95), and cervical disc arthroplasty (OR = 1.37, 95% CI: 0.75–2.51, P = 0.30). Conclusion: Female gender, the use of anterior cervical plate, more than 1 surgical level, the upper surgical level at C3/4, and the use of rhBMP-2 are the risk factors for dysphagia following anterior cervical spinal surgery. However, revision surgery, the type of fusion, and cervical disc arthroplasty are unassociated with dysphagia. Considering the limited number of studies, this conclusion should be interpreted cautiously, and larger scale studies are required. PMID:28272237

Current and future perspectives on lumbar degenerative disc disease: a UK survey exploring specialist multidisciplinary clinical opinion.

PubMed

Deane, Janet A; McGregor, Alison H

2016-09-15

Despite lumbar degenerative disc disease (LDDD) being significantly associated with non-specific low back pain and effective treatment remaining elusive, specialist multidisciplinary clinical stakeholder opinion remains unexplored. The present study examines the views of such experts. A reliable and valid electronic survey was designed to establish trends using theoretical constructs relating to current assessment and management practices. Clinicians from the Society of Back Pain Research (SBPR) UK were invited to take part. Quantitative data were collated and coded using Bristol Online Surveys (BOS) software, and content analysis was used to systematically code and categorise qualitative data. Specialist multidisciplinary spinal interest group in the UK. 38/141 clinically active, multidisciplinary SBPR members with specialist spinal interest participated. Among them, 84% had >9 years postgraduate clinical experience. None. Frequency distributions were used to establish general trends in quantitative data. Qualitative responses were coded and categorised in relation to each theme and percentage responses were calculated. LDDD symptom recurrence, in the absence of psychosocial influence, was associated with physical signs of joint stiffness (26%), weakness (17%) and joint hypermobility (6%), while physical factors (21%) and the ability to adapt (11%) were postulated as reasons why some experience pain and others do not. No one management strategy was supported exclusively or with consensus. Regarding effective modalities, there was no significant difference between allied health professional and medic responses (p=0.1-0.8). The future of LDDD care was expressed in terms of improvements in patient communication (35%), patient education (38%) and treatment stratification (24%). Results suggest that multidisciplinary expert spinal clinicians appear to follow UK-based assessment guidelines with regard to recurrent LDDD; there are, however, inconsistencies in the management approaches supported. This reflects the current literature and the lack of specific, formalised guidance. LDDD treatment stratification and further research are explicitly supported. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

African Descent and Glaucoma Evaluation Study (ADAGES)

PubMed Central

Girkin, Christopher A.; Sample, Pamela A.; Liebmann, Jeffrey M.; Jain, Sonia; Bowd, Christopher; Becerra, Lida M.; Medeiros, Felipe A.; Racette, Lyne; Dirkes, Keri A.; Weinreb, Robert N.; Zangwill, Linda M.

2010-01-01

Objective To define differences in optic disc, retinal nerve fiber layer, and macular structure between healthy participants of African (AD) and European descent (ED) using quantitative imaging techniques in the African Descent and Glaucoma Evaluation Study (ADAGES). Methods Reliable images were obtained using stereoscopic photography, confocal scanning laser ophthalmoscopy (Heidelberg retina tomography [HRT]), and optical coherence tomography (OCT) for 648 healthy subjects in ADAGES. Findings were compared and adjusted for age, optic disc area, and reference plane height where appropriate. Results The AD participants had significantly greater optic disc area on HRT (2.06 mm2; P<.001) and OCT (2.47 mm2; P<.001) and a deeper HRT cup depth than the ED group (P<.001). Retinal nerve fiber layer thickness was greater in the AD group except within the temporal region, where it was significantly thinner. Central macular thickness and volume were less in the AD group. Conclusions Most of the variations in optic nerve morphologic characteristics between the AD and ED groups are due to differences in disc area. However, differences remain in HRT cup depth, OCT macular thickness and volume, and OCT retinal nerve fiber layer thickness independent of these variables. These differences should be considered in the determination of disease status. PMID:20457974

[Effects of sports and media consumption on the trunk muscle strength, posture and flexibility of the spine in 12- to 14- year-old adolescents].

PubMed

Küster, M

2004-06-01

Back pain and posture deficits get more common in childhood and adolescents. Lack of movement, insufficient physical education and high amounts of TV and PC are known as risk factors for chronic low back pain in later life. In a cross-sectional study, trunk muscle strength, posture and spinal flexibility were assessed in 200 untrained schoolchildren (117 girls, 83 boys). Independent variables, collected by a standardized questionnaire: age, height, weight, gender, weekly scope of TV, PC and sports (conditional, conditional-coordinative, coordinative). spinal parameter, tested by the Zebris CMS-System and IPN Back Check. PC and TV-consumption had negative effects on the spinal parameter, whereas esp. conditional-coordinative sports correlated positively. For general health and preventive reasons, children need a daily minimum of 30 minutes of movement. Conditional-coordinative sports are suited best because of their multifactorial load.

Reduction of discomfort in pushing an industrial trolley using ergonomics

NASA Astrophysics Data System (ADS)

Kumar, M. Wilson; Vijay, S. J.; Vasudev, K. L.; Darius Gnanaraj, S.

2017-11-01

Poor design of industrial trolleys lead to more compressive stress on the low back of industrial workers. The research work reported in this paper recommends a handle height of an industrial trolley for use by the local population, which reduces the compressive stress on the low back. Experiments were conducted in a laboratory on five subjects of varying stature 165, 173, 174, 175 and 182 cm, with five different handle heights 90, 95, 100, 105 and 110 cm. A four wheeled trolley has been used to conduct the experiments. Caster wheels diameters of 100, 125 and 150 mm made of polyurethane were used. It is found that a handle height of 110 cm allows the users to exert minimum force during the initial pushing. A biomechanical model was employed to calculate the compressive force experienced by L5/S1 disc and it is found that the compressive load will be the least when the handle height is 110 cm. Optimization of handle height using Genetic Algorithm approach, Heart rate analysis and EMG analysis confirm that a handle height of 110 cm and a wheel diameter of 150 mm will reduce the discomfort of industry workers pushing trolleys.

Response of the Milky Way's disc to the Large Magellanic Cloud in a first infall scenario

NASA Astrophysics Data System (ADS)

Laporte, Chervin F. P.; Gómez, Facundo A.; Besla, Gurtina; Johnston, Kathryn V.; Garavito-Camargo, Nicolas

2018-01-01

We present N-body and hydrodynamical simulations of the response of the Milky Way's baryonic disc to the presence of the Large Magellanic Cloud during a first infall scenario. For a fiducial Galactic model reproducing the gross properties of the Galaxy, we explore a set of six initial conditions for the Large Magellanic Cloud (LMC) of varying mass which all evolve to fit the measured constraints on its current position and velocity with respect to the Galactic Centre. We find that the LMC can produce strong disturbances - warping of the stellar and gaseous discs - in the Galaxy, without violating constraints from the phase-space distribution of stars in the Solar Neighbourhood. All models correctly reproduce the phases of the warp and its antisymmetrical shape about the disc's mid-plane. If the warp is due to the LMC alone, then the largest mass model is favoured (2.5 × 1011 M⊙). Still, some quantitative discrepancies remain, including deficits in height of ΔZ = 0.7 kpc at R = 22 kpc and ΔZ = 0.7 kpc at R = 16 kpc. This suggests that even higher infall masses for the LMC's halo are allowed by the data. A comparison with the vertical perturbations induced by a heavy Sagittarius dSph model (1011 M⊙) suggest that positive interference with the LMC warp is expected at R = 16 kpc. We conclude that the vertical structure of the Galactic disc beyond the Solar Neighbourhood may jointly be shaped by its most massive satellites. As such, the current structure of the Milky Way suggests we are seeing the process of disc heating by satellite interactions in action.

Function after spinal treatment, exercise and rehabilitation (FASTER): improving the functional outcome of spinal surgery

PubMed Central

2010-01-01

Background The life-time incidence of low back pain is high and diagnoses of spinal stenosis and disc prolapse are increasing. Consequently, there is a steady rise in surgical interventions for these conditions. Current evidence suggests that while the success of surgery is incomplete, it is superior to conservative interventions. A recent survey indicates that there are large differences in the type and intensity of rehabilitation, if any, provided after spinal surgery as well as in the restrictions and advice given to patients in the post-operative period. This trial will test the hypothesis that functional outcome following two common spinal operations can be improved by a programme of post-operative rehabilitation that combines professional support and advice with graded active exercise and/or an educational booklet based on evidence-based messages and advice. Methods/Design The study design is a multi-centre, factorial, randomised controlled trial with patients stratified by surgeon and operative procedure. The trial will compare the effectiveness and cost-effectiveness of a rehabilitation programme and an education booklet for the postoperative management of patients undergoing discectomy or lateral nerve root decompression, each compared with "usual care"using a 2 × 2 factorial design. The trial will create 4 sub-groups; rehabilitation-only, booklet-only, rehabilitation-plus-booklet, and usual care only. The trial aims to recruit 344 patients, which equates to 86 patients in each of the four sub-groups. All patients will be assessed for functional ability (through the Oswestry Disability Index - a disease specific functional questionnaire), pain (using visual analogue scales), and satisfaction pre-operatively and then at 6 weeks, 3, 6 and 9 months and 1 year post-operatively. This will be complemented by a formal analysis of cost-effectiveness. Discussion This trial will determine whether the outcome of spinal surgery can be enhanced by either a post-operative rehabilitation programme or an evidence-based advice booklet or a combination of the two and as such will contribute to our knowledge on how to manage spinal surgery patients in the post-operative period. Trial Registration Current controlled trials ISRCTN46782945 UK CRN ID: 2670 PMID:20102625

Function after spinal treatment, exercise and rehabilitation (FASTER): improving the functional outcome of spinal surgery.

PubMed

McGregor, A H; Doré, C J; Morris, T P; Morris, S; Jamrozik, K

2010-01-26

The life-time incidence of low back pain is high and diagnoses of spinal stenosis and disc prolapse are increasing. Consequently, there is a steady rise in surgical interventions for these conditions. Current evidence suggests that while the success of surgery is incomplete, it is superior to conservative interventions. A recent survey indicates that there are large differences in the type and intensity of rehabilitation, if any, provided after spinal surgery as well as in the restrictions and advice given to patients in the post-operative period. This trial will test the hypothesis that functional outcome following two common spinal operations can be improved by a programme of post-operative rehabilitation that combines professional support and advice with graded active exercise and/or an educational booklet based on evidence-based messages and advice. The study design is a multi-centre, factorial, randomised controlled trial with patients stratified by surgeon and operative procedure. The trial will compare the effectiveness and cost-effectiveness of a rehabilitation programme and an education booklet for the postoperative management of patients undergoing discectomy or lateral nerve root decompression, each compared with "usual care"using a 2 x 2 factorial design. The trial will create 4 sub-groups; rehabilitation-only, booklet-only, rehabilitation-plus-booklet, and usual care only. The trial aims to recruit 344 patients, which equates to 86 patients in each of the four sub-groups. All patients will be assessed for functional ability (through the Oswestry Disability Index - a disease specific functional questionnaire), pain (using visual analogue scales), and satisfaction pre-operatively and then at 6 weeks, 3, 6 and 9 months and 1 year post-operatively. This will be complemented by a formal analysis of cost-effectiveness. This trial will determine whether the outcome of spinal surgery can be enhanced by either a post-operative rehabilitation programme or an evidence-based advice booklet or a combination of the two and as such will contribute to our knowledge on how to manage spinal surgery patients in the post-operative period.

Long-term growth trends of red spruce and fraser fir at Mt. Rogers, Virginia and Mt. Mitchell, North Carolina

Treesearch

J.C.G. Goelz; Thomas E. Burk; Shepard M. Zedaker

1999-01-01

Cross-sectional area growth and height growth of Fraser fir and red spruce trees growing in Virginia and North Carolina were analyzed to identify possible long-term growth trends. Cross-sectional area growth provided no evidence of growth decline. The individual discs were classified according to parameter estimates of the growth trend equation. The predominant pattern...