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Sample records for facet joint loading

  1. The effects of orientation of lumbar facet joints on the facet joint contact forces: an in vitro biomechanical study.

    PubMed

    Liu, Xiang; Huang, Zhiping; Zhou, Ruozhou; Zhu, Qingan; Ji, Wei; Long, Yaowu; Wang, Jixing

    2017-07-28

    A biomechanical human cadaveric study. The aim of this study was to measure L2-L3 facet joint contact forces in a flexibility test using thin film electroresistive sensors, and facet joint orientation on CT scan images, to examine the effects of orientation of lumbar facet joint on the facet joint contact forces. Biomechanically the bilateral facet joints play a critical role in maintaining stability of the lumbar spine by sharing load. The effect of orientation of lumbar facet joints on the contact forces remains unknown. Eight human cadaveric lumbar spine specimens (L2-L3) were tested by applying a pure moment of ± 7.5 Nm in 3 directions of loading(flexion-extension, lateral bending and axial rotation) with and without a follower preload of 300 N. The orientation of the lumbar facet joints at the L2-L3 was measured on axial CT scans. Bilateral facet contact forces were measured during flexibility tests using thin film electroresistive sensors (Tekscan 6900). The average total peak facet loads was 66 N in axial rotation, 27 N in extension and 20 N in lateral bending under a pure moment. Under a pure moment and with a follower preload of 300N, the average total peak facet loads was 53 N in axial rotation, 43 N in extension and 24 N in lateral bending. The facet joint forces were correlated positively and significantly with the orientation in all directions with and without a compressive follower preload (P < 0.05). In addition, the facet joint contact forces at neutral position with a follower preload were correlated positively with the orientation (rs = 0.759, P = 0.001). This study identified that the greater coronal orientation of lumbar facet joints are, the higher the facet joint contact forces are. 3.

  2. Whiplash-like facet joint loading initiates glutamatergic responses in the DRG and spinal cord associated with behavioral hypersensitivity

    PubMed Central

    Dong, Ling; Quindlen, Julia C.; Lipschutz, Daniel E.; Winkelstein, Beth A.

    2012-01-01

    The cervical facet joint and its capsule are a common source of neck pain from whiplash. Mechanical hyperalgesia elicited by painful facet joint distraction is associated with spinal neuronal hyperexcitability that can be induced by transmitter/receptor systems that potentiate the synaptic activation of neurons. This study investigated the temporal response of a glutamate receptor and transporters in the dorsal root ganglia (DRG) and spinal cord. Bilateral C6/C7 facet joint distractions were imposed in the rat either to produce behavioral sensitivity or without inducing any sensitivity. Neuronal metabotropic glutamate receptor-5 (mGluR5) and protein kinase C-epsilon (PKCε) expression in the DRG and spinal cord were evaluated on days 1 and 7. Spinal expression of a glutamate transporter, excitatory amino acid carrier 1 (EAAC1), was also quantified at both time points. Painful distraction produced immediate behavioral hypersensitivity that was sustained for 7 days. Increased expression of mGluR5 and PKCε in the DRG was not evident until day 7 and only following painful distraction; this increase was observed in small-diameter neurons. Only painful facet joint distraction produced a significant increase (p<0.001) in neuronal mGluR5 over time, and this increase also was significantly elevated (p ≤ 0.05) over responses in the other groups at day 7. However, there were no differences in spinal PKCε expression on either day or between groups. Spinal EAAC1 expression was significantly increased (p<0.03) only in the nonpainful groups on day 7. Results from this study suggest spinal glutamatergic plasticity is selectively modulated in association with facet-mediated pain. PMID:22578356

  3. Pain generation in lumbar and cervical facet joints.

    PubMed

    Cavanaugh, John M; Lu, Ying; Chen, Chaoyang; Kallakuri, Srinivasu

    2006-04-01

    Facet joints are implicated as a major source of neck and low-back pain. Both cervical and lumbar facet syndromes have been described in the medical literature. Biomechanical studies have shown that lumbar and cervical facet-joint capsules can undergo high strains during spine-loading. Neuroanatomic studies have demonstrated free and encapsulated nerve endings in facet joints as well as nerves containing substance P and calcitonin gene-related peptide. Neurophysiologic studies have shown that facet-joint capsules contain low-threshold mechanoreceptors, mechanically sensitive nociceptors, and silent nociceptors. Inflammation leads to decreased thresholds of nerve endings in facet capsules as well as elevated baseline discharge rates. Recent biomechanical studies suggest that rear-end motor-vehicle impacts give rise to excessive deformation of the capsules of lower cervical facet joints. Still unresolved is whether this stretch is sufficient to activate nociceptors in the joint capsule. To answer this question, recent studies indicate that low stretch levels activate proprioceptors in the facet-joint capsule. Excessive capsule stretch activates nociceptors, leads to prolonged neural afterdischarges, and can cause damage to the capsule and to axons in the capsule. In instances in which a whiplash event is severe enough to injure the joint capsule, facet capsule overstretch is a possible cause of persistent neck pain.

  4. Image-guided facet joint injection

    PubMed Central

    Peh, WCG

    2011-01-01

    Chronic spine pain poses a peculiar diagnostic and therapeutic challenge due to multiple pain sources, overlapping clinical features and nonspecific radiological findings. Facet joint injection is an interventional pain management tool for facet-related spinal pain that can be effectively administered by a radiologist. This technique is the gold standard for identifying facet joints as the source of spinal pain. The major indications for facet injections include strong clinical suspicion of the facet syndrome, focal tenderness over the facet joints, low back pain with normal radiological findings, post-laminectomy syndrome with no evidence of arachnoiditis or recurrent disc disease, and persistent low back pain after spinal fusion. The contraindications are more ancillary, with none being absolute. Like any synovial joint degeneration, inflammation and injury can lead to pain on motion, initiating a vicious cycle of physical deconditioning, irritation of facet innervations and muscle spasm. Image-guided injection of local anesthetic and steroid into or around the facet joint aims to break this vicious cycle and thereby provide pain relief. This outpatient procedure has high diagnostic accuracy, safety and reproducibility but the therapeutic outcome is variable. PMID:21655113

  5. Strain and load thresholds for cervical muscle recruitment in response to quasi-static tensile stretch of the caprine C5-C6 facet joint capsule.

    PubMed

    Azar, Nadia R; Kallakuri, Srinivasu; Chen, Chaoyang; Lu, Ying; Cavanaugh, John M

    2009-12-01

    The aim of this study was to investigate the response of cervical muscles to physiologic tensile stretch of cervical facet joint capsule (FJC) at a quasi-static displacement rate of 0.5mm/s. In vivo caprine left C5-C6 FJC preparations were subjected to an incremental tensile displacement paradigm. EMG activity was recorded during FJC stretch from the right trapezius (TR) and multifidus (MF) muscle groups at the C5 and C6 levels and bilaterally from the sternomastoid (SM) and longus colli (LC) muscle groups at the C5-C6 level. Onset of muscular activity was later analyzed using visual and computer-based methods. Capsule load and strain at the time of onset were recorded and compared between the muscle groups. Results indicated capsule load was a better indicator of the tensile stretch thresholds for muscular recruitment than capsule strain. MF responded at significantly smaller capsule loads than TR and LC, while TR and LC activation loads were not significantly different. SM did not respond to physiologic FJC stretch. Muscle group recruitment order reflected the muscles' fiber type compositions and functional roles in the spine. This study provides the first evidence that the cervical ligamento-muscular reflex pathways are activated via tensile FJC stretch and extend to superficial and deep musculature on the anterior and posterior aspects of the neck, ipsilateral and contralateral to the side of FJC stretch.

  6. Osteoarthritis of the spine: the facet joints.

    PubMed

    Gellhorn, Alfred C; Katz, Jeffrey N; Suri, Pradeep

    2013-04-01

    Osteoarthritis (OA) of the spine involves the facet joints, which are located in the posterior aspect of the vertebral column and, in humans, are the only true synovial joints between adjacent spinal levels. Facet joint osteoarthritis (FJ OA) is widely prevalent in older adults, and is thought to be a common cause of back and neck pain. The prevalence of facet-mediated pain in clinical populations increases with increasing age, suggesting that FJ OA might have a particularly important role in older adults with spinal pain. Nevertheless, to date FJ OA has received far less study than other important OA phenotypes such as knee OA, and other features of spine pathoanatomy such as degenerative disc disease. This Review presents the current state of knowledge of FJ OA, including relevant anatomy, biomechanics, epidemiology, and clinical manifestations. We present the view that the modern concept of FJ OA is consonant with the concept of OA as a failure of the whole joint, and not simply of facet joint cartilage.

  7. Osteoarthritis of the spine: the facet joints

    PubMed Central

    Gellhorn, Alfred C.; Katz, Jeffrey N.; Suri, Pradeep

    2014-01-01

    Osteoarthritis (OA) of the spine involves the facet joints, which are located in the posterior aspect of the vertebral column and, in humans, are the only true synovial joints between adjacent spinal levels. Facet joint osteoarthritis (FJ OA) is widely prevalent in older adults, and is thought to be a common cause of back and neck pain. The prevalence of facet-mediated pain in clinical populations increases with increasing age, suggesting that FJ OA might have a particularly important role in older adults with spinal pain. Nevertheless, to date FJ OA has received far less study than other important OA phenotypes such as knee OA, and other features of spine pathoanatomy such as degenerative disc disease. This Review presents the current state of knowledge of FJ OA, including relevant anatomy, biomechanics, epidemiology, and clinical manifestations. We present the view that the modern concept of FJ OA is consonant with the concept of OA as a failure of the whole joint, and not simply of facet joint cartilage. PMID:23147891

  8. [Interventions on facet joints. Techniques of facet joint injection, medial branch block and radiofrequency ablation].

    PubMed

    Artner, J; Klessinger, S

    2015-10-01

    Fluoroscopy-guided interventions on facet joints have been used for decades for the symptomatic management of pain in spinal disorders. A large number of imaging techniques are used to achieve a precise and safe needle placement in interventional procedures. Pulsed fluoroscopy is one of the most widely used and well-accepted tools for these procedures. This article presents a technical overview of commonly used fluoroscopy-guided interventions on the facet joints of the cervical and lumbar spine, such as facet joint injection, blockade of the medial nerve branches and radiofrequency ablation.

  9. Management of lumbar zygapophysial (facet) joint pain

    PubMed Central

    Manchikanti, Laxmaiah; Hirsch, Joshua A; Falco, Frank JE; Boswell, Mark V

    2016-01-01

    AIM: To investigate the diagnostic validity and therapeutic value of lumbar facet joint interventions in managing chronic low back pain. METHODS: The review process applied systematic evidence-based assessment methodology of controlled trials of diagnostic validity and randomized controlled trials of therapeutic efficacy. Inclusion criteria encompassed all facet joint interventions performed in a controlled fashion. The pain relief of greater than 50% was the outcome measure for diagnostic accuracy assessment of the controlled studies with ability to perform previously painful movements, whereas, for randomized controlled therapeutic efficacy studies, the primary outcome was significant pain relief and the secondary outcome was a positive change in functional status. For the inclusion of the diagnostic controlled studies, all studies must have utilized either placebo controlled facet joint blocks or comparative local anesthetic blocks. In assessing therapeutic interventions, short-term and long-term reliefs were defined as either up to 6 mo or greater than 6 mo of relief. The literature search was extensive utilizing various types of electronic search media including PubMed from 1966 onwards, Cochrane library, National Guideline Clearinghouse, clinicaltrials.gov, along with other sources including previous systematic reviews, non-indexed journals, and abstracts until March 2015. Each manuscript included in the assessment was assessed for methodologic quality or risk of bias assessment utilizing the Quality Appraisal of Reliability Studies checklist for diagnostic interventions, and Cochrane review criteria and the Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment tool for therapeutic interventions. Evidence based on the review of the systematic assessment of controlled studies was graded utilizing a modified schema of qualitative evidence with best evidence synthesis, variable from level I to level V

  10. Relationship between facet tropism and facet joint degeneration in the sub-axial cervical spine.

    PubMed

    Rong, Xin; Liu, Ziyang; Wang, Beiyu; Pan, Xuelin; Liu, Hao

    2017-02-20

    Facet tropism is the angular asymmetry between the left and right facet joint orientation. Although debatable, facet tropism was suggested to be associated with disc degeneration, facet degeneration and degenerative spondylolisthesis in the lumbar spine. The purpose of this study was to explore the relationship between facet tropism and facet degeneration in the sub-axial cervical spine. A total of 200 patients with cervical spondylosis were retrospectively analyzed. Facet degeneration was categorized into 4 grade: grade I, normal; grade II, degenerative changes including joint space narrowing, cyst formation, small osteophytes (<3 mm) without joint hypertrophy; grade III, joint hypertrophy secondary to large osteophytes (>3 mm) without fusion of the joint; grade IV, bony fusion of the facet joints. Facet orientations and facet tropisms with respect to the transverse, sagittal and coronal plane were calculated from the reconstructed cervical spine, which was based on the axial CT scan images. The paired facet joints were then categorized into three types: symmetric, moderated tropism and severe tropism. Univariate and multivariate analysis were performed to evaluate the relationship between any demographic and anatomical factor and facet degeneration. The mean age of enrolled patients was 46.23 years old (ranging from 30 to 64 years old). There were 114 males and 86 females. The degrees of facet degeneration varied according to cervical levels and ages. Degenerated facet joints were most common at C2-C3 level and more common in patients above 50 years old. The facet orientations were also different from level to level. By univariate analysis, genders, ages, cervical levels, facet orientations and facet tropisms were all significantly different between the normal facets and degenerated facets. However, results from multivariate logistic regression suggested only age and facet tropism with respect to the sagittal plane were related to facet degeneration. Facet

  11. [Lumbosacral facet syndrome: functional and organic disorders of lumbosacral facet joints].

    PubMed

    Grgić, Vjekoslav

    2011-01-01

    Disorders of lumbosacral (LS) facet joints are manifested by low back pain with or without referred leg pain and decreased mobility of the LS spine (LS facet syndrome). The most frequent causes of LS facet syndrome are functional disorders (functional blockade or dysfunction of facet joint=reversible restriction of facet joint movements caused by meniscoid entrapment) and degenerative changes of facet joints while the others are less frequent (spondyloarthropathies, infection, tuberculosis, synovial cyst, injury). Although it has been proven that the facet joints are one of the most frequent sources of chronic low back pain (15-45%), the fact is that the facet syndrome has been frequently overlooked in patients with chronic low back pain. Following are the main reasons for explaining why the facet syndrome has been overlooked in patients with chronic low back pain: 1. Facet joints disorders are manifested by non-specific clinical picture, 2.Diagnosis of facet syndrome cannot be established by either the conventional clinical examination or radiological examinations, 3. A very small number of doctors are practicing manual functional examination which can establish the diagnosis of facet joint dysfunction and 4. Diagnostic anesthetic block which can confirm the facet syndrome diagnosis is not a widely accessible method. There is a lack of research in frequency of facet syndrome in patients with acute low back pain. Chronic mechanical low back pain caused by dysfunction of several structurally unchanged facet joints can have the same features as the inflammatory pain which can result in misdiagnosis of spondyloarthropathy. Acute LS facet syndrome caused by dysfunction of facet joints responds very well to manual therapy. The most important therapeutic options in patients with chronic LS facet syndrome caused by degenerative changes and/or dysfunction of facet joints are manual therapy, kinesiotherapy (flexion exercises), therapeutic blocks and radiofrequency

  12. The relationship between lower neck shear force and facet joint kinematics during automotive rear impacts.

    PubMed

    Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A; Maiman, Dennis J

    2011-04-01

    A primary goal of biomechanical safety research is the definition of localized injury thresholds in terms of quantities that are repeatable and easily measureable during experimentation. Recent biomechanical experimentation using human cadavers has highlighted the role of lower cervical facet joints in the injury mechanism resulting from low-speed automotive rear impacts. The present study was conducted to correlate lower neck forces and moments with facet joint motions during simulated rear impacts in an effort to define facet joint injury tolerance thresholds that can be used to assess automobile safety. Four male and four female intact head-neck complexes were obtained from cadaveric specimens and subjected to simulated automotive rear impacts using a pendulum-minisled device. Cervical spine segmental angulations and localized facet joint kinematics were correlated to shear and axial forces, and bending moments at the cervico-thoracic junction using linear regression. R(2) coefficients indicated that spinal kinematics correlated well with lower neck shear force and bending moment. Correlation slope was steeper in female specimens, indicating greater facet joint motions for a given loading magnitude. This study demonstrated that lower neck loads can be used to predict lower cervical facet joint kinematics during automotive rear impacts. Higher correlation slope in female specimens corresponds to higher injury susceptibility in that population. Although lower neck shear force and bending moment demonstrated adequate correlation with lower cervical facet joint motions, shear force is likely the better predictor due to similarity in the timing of peak magnitudes with regard to maximum facet joint motions.

  13. The biomechanical impact of facet tropism on the intervertebral disc and facet joints in the cervical spine.

    PubMed

    Rong, Xin; Wang, Beiyu; Ding, Chen; Deng, Yuxiao; Chen, Hua; Meng, Yang; Yan, Weijie; Liu, Hao

    2017-07-13

    Facet tropism is defined as the angular difference between the left and the right facet orientation. Facet tropism was suggested to be associated with the disc degeneration and facet degeneration in the lumbar spine. However, little is known about the relationship between facet tropism and pathologic changes in the cervical spine and the mechanism behind. This study was conducted to investigate the biomechanical impact of facet tropism on the intervertebral disc and facet joints. A finite element analysis study. The computed tomography (CT) scans of a 28-year-old male volunteer was used to construct the finite element model. First, a symmetrical cervical model from C2 to C7 was constructed. The facet orientations at each level were simulated using the data from our previously published study. Second, the facet orientations at the C5-C6 level were altered to simulate facet tropism with respect to the sagittal plane. The angular difference of the moderate facet tropism model was set to be 7 degrees, whereas the severe facet tropism model was set to be 14 degrees. The inferior of the C7 vertebra was fixed. A 75 N follower loading was applied to simulate the weight of the head. A 1.0 N⋅m moments was applied on the odontoid process of the C2 to simulate flexion, extension, lateral bending, and axial rotation. The intradiscal pressure (IDP) at the C5-C6 level of the severe facet tropism model increased by 49.02%, 57.14%, 39.06%, and 30.67%, under flexion, extension, lateral bending, and axial rotation moments, in comparison with the symmetrical model. The contact force of the severe facet tropism model increased by 35.64%, 31.74%, 79.26%, and 59.47% from the symmetrical model under flexion, extension, lateral bending, and axial rotation, respectively. Facet tropism with respect to the sagittal plane at the C5-C6 level increased the IDP and facet contact force under flexion, extension, lateral bending, and axial rotation. The results suggested that facet tropism might

  14. Facet joint disturbance induced by miniscrews in plated cervical laminoplasty

    PubMed Central

    Chen, Hua; Li, Huibo; Wang, Beiyu; Li, Tao; Gong, Quan; Song, Yueming; Liu, Hao

    2016-01-01

    Abstract A retrospective cohort study. Plated cervical laminoplasty is an increasingly common technique. A unique facet joint disturbance induced by lateral mass miniscrews penetrating articular surface was noticed. Facet joints are important to maintain cervical spine stability and kinetic balance. Whether this facet joint disturbance could affect clinical and radiologic results is still unknown. The objective of this study is to investigate the clinical and radiologic outcomes of patients with facet joints disturbance induced by miniscrews in plated cervical laminoplasty. A total of 105 patients who underwent cervical laminoplasty with miniplate fixation between May 2010 and February 2014 were comprised. Postoperative CT images were used to identify whether facet joints destroyed by miniscrews. According to facet joints destroyed number, all the patients were divided into: group A (none facet joint destroyed), group B (1–2 facet joints destroyed), and group C (≥3 facet joints destroyed). Clinical data (JOA, VAS, and NDI scores), radiologic data (anteroposterior diameter and Palov ratio), and complications (axial symptoms and C5 palsy) were evaluated and compared among the groups. There were 38, 40, and 27 patients in group A, B, and C, respectively. The overall facet joints destroyed rate was 30.7%. All groups gained significant JOA and NDI scores improvement postoperatively. The preoperative JOA, VAS, NDI scores, and postoperative JOA scores did not differ significantly among the groups. The group C recorded significant higher postoperative VAS scores than group A (P = 0.002) and B (P = 0.014) and had significant higher postoperative NDI scores than group A (P = 0.002). The pre- and postoperative radiologic data were not significant different among the groups. The group C had a significant higher axial symptoms incidence than group A (12/27 vs 8/38, P = 0.041). Facet joints disturbance caused by miniscrews in plated cervical laminoplasty may not influence

  15. Characterization of degenerative human facet joints and facet joint capsular tissues

    PubMed Central

    Kim, Jae-Sung; Ali, Mir H.; Wydra, Frank; Li, Xin; Hamilton, John L.; An, Howard S.; Cs-Szabo, Gabriella; Andrews, Steven; Moric, Mario; Xiao, Guozhi; Wang, James H-C; Chen, Di; Cavanaugh, John M.; Im, Hee-Jeong

    2015-01-01

    SUMMARY Objective Lumbar facet joint degeneration (FJD) may be an important cause of low back pain (LBP) and sciatica. The goal of this study was to characterize cellular alterations of inflammatory factor expression and neovascularization in human degenerative facet joint capsular (FJC) tissue, defined as the fibrous connective tissue lined with synovium that surrounds the joint. The role of these alterations in FJC tissues in pain stimulation was also assessed. Design Lumbar facet joints (FJs) were obtained from consented patients undergoing spinal reconstruction surgery and cadaveric donors with no medical history of back pain. Histological analyses of the FJ were performed to assess general structure, cellular morphology, and proteoglycan content; immunohistochemistry was used to reveal inflammatory factors and neovascularization. Cytokine antibody array and quantitative real- time polymerase chain reaction (qPCR) were used to determine the production of multiple pro- and anti- inflammatory cytokines, and western blotting (WB) was used to assay for cartilage-degrading enzymes and pain mediators. Studies using ex vivo rat dorsal root ganglion (DRG) co-culture with human FJC tissues were also performed. Results Increased neovascularization, infiltration of inflammatory cells, and pain-related axonal-promoting factors were observed in degenerative FJC tissues surgically obtained from symptomatic subjects; this was not seen in normal donor tissues. Increased angiogenic factor, VEGF, axonal promoting factor (NGF/TrkA) and sensory neuronal distribution were also detected in degenerative FJC tissues from subjects with LBP. qPCR and WB results demonstrated highly upregulated inflammatory cytokines, pain mediators, and cartilage-degrading enzymes in degenerative FJCs compared to normal. The DRG and FJC tissue ex vivo co-culture results demonstrated that degenerative FJCs from subjects reporting severe LBP altered the functional properties of DRG sensory neurons, as

  16. Accuracy and repeatability of a new method for measuring facet loads in the lumbar spine.

    PubMed

    Wilson, Derek C; Niosi, Christina A; Zhu, Qingan A; Oxland, Thomas R; Wilson, David R

    2006-01-01

    We assessed the repeatability and accuracy of a relatively new, resistance-based sensor (Tekscan 6900) for measuring lumbar spine facet loads, pressures, and contact areas in cadaver specimens. Repeatability of measurements in the natural facet joint was determined for five trials of four specimens loaded in pure moment (+/- 7.5 N m) flexibility tests in axial rotation and flexion-extension. Accuracy of load measurements in four joints was assessed by applying known compressive loads of 25, 50, and 100 N to the natural facet joint in a materials testing machine and comparing the known applied load to the measured load. Measurements of load were obtained using two different calibration approaches: linear and two-point calibrations. Repeatability for force, pressure, and area (average of standard deviation as a percentage of the mean for all trials over all specimens) was 4-6% for axial rotation and 7-10% for extension. Peak resultant force in axial rotation was 30% smaller when calculated using the linear calibration method. The Tekscan sensor overestimated the applied force by 18 +/- 9% (mean+/-standard deviation), 35 +/- 7% and 50 +/- 9% for compressive loads of 100, 50, and 25 N, respectively. The two-point method overestimated the loads by 35 +/- 16%, 45 +/- 7%, and 56 +/- 10% for the same three loads. Our results show that the Tekscan sensor is repeatable. However, the sensor measurement range is not optimal for the small loads transmitted by the facets and measurement accuracy is highly dependent on calibration protocol.

  17. The Interface of Mechanics and Nociception in Joint Pathophysiology: Insights From the Facet and Temporomandibular Joints.

    PubMed

    Sperry, Megan M; Ita, Meagan E; Kartha, Sonia; Zhang, Sijia; Yu, Ya-Hsin; Winkelstein, Beth

    2017-02-01

    Chronic joint pain is a widespread problem that frequently occurs with aging and trauma. Pain occurs most often in synovial joints, the body's load bearing joints. The mechanical and molecular mechanisms contributing to synovial joint pain are reviewed using two examples, the cervical spinal facet joints and the temporomandibular joint (TMJ). Although much work has focused on the macroscale mechanics of joints in health and disease, the combined influence of tissue mechanics, molecular processes, and nociception in joint pain has only recently become a focus. Trauma and repeated loading can induce structural and biochemical changes in joints, altering their microenvironment and modifying the biomechanics of their constitutive tissues, which themselves are innervated. Peripheral pain sensors can become activated in response to changes in the joint microenvironment and relay pain signals to the spinal cord and brain where pain is processed and perceived. In some cases, pain circuitry is permanently changed, which may be a potential mechanism for sustained joint pain. However, it is most likely that alterations in both the joint microenvironment and the central nervous system (CNS) contribute to chronic pain. As such, the challenge of treating joint pain and degeneration is temporally and spatially complicated. This review summarizes anatomy, physiology, and pathophysiology of these joints and the sensory pain relays. Pain pathways are postulated to be sensitized by many factors, including degeneration and biochemical priming, with effects on thresholds for mechanical injury and/or dysfunction. Initiators of joint pain are discussed in the context of clinical challenges including the diagnosis and treatment of pain.

  18. The Hip-Spine Effect: A Biomechanical Study of Ischiofemoral Impingement Effect on Lumbar Facet Joints.

    PubMed

    Gómez-Hoyos, Juan; Khoury, Anthony; Schröder, Ricardo; Johnson, Eric; Palmer, Ian J; Martin, Hal D

    2017-01-01

    To assess the relation between ischiofemoral impingement (IFI) and lumbar facet joint load during hip extension in cadavers. Twelve hips in 6 fresh T1-to-toes cadaveric specimens were tested. A complete pretesting imaging evaluation was performed using computed tomography scan. Cadavers were positioned in lateral decubitus and fixed to a dissection table. Both legs were placed on a frame in a simulated walking position. Through a posterior lumbar spine approach L3-4 and L4-5 facet joints were dissected bilaterally. In addition, through a posterolateral approach to the hip, the space between the ischium and the lesser trochanter was dissected and measured. Ultrasensitive, and previously validated, piezoresistive force sensors were placed in lumbar facet joints of L3-4 and L4-5. Lumbar facet loads during hip extension were measured in native hip conditions and after simulating IFI by performing lesser trochanter osteotomy and lengthening. Four paired t-tests were performed comparing normal and simulated IFI on the L3-L4 and L4-L5 facet joint loads. After simulating IFI, mean absolute differences of facet joint load were 10.8 N (standard error of the mean [SEM] ±4.53, P = .036) for L3-4 at 10° of hip extension, 13.71 N (SEM ±4.53, P = .012) for L3-4 at 20° of hip extension, 11.49 N (SEM ±4.33, P = .024) for L4-5 at 10° of hip extension, and 6.67 N (SEM ±5.43, P = .245) for L4-5 at 20° of hip extension. A statistically significant increase in L3-4 and L4-5 lumbar facet joint loads of 30.81% was found in the IFI state as compared with the native state during terminal hip extension. Limited terminal hip extension due to simulated IFI significantly increases L3-4 and L4-5 lumbar facet joint load when compared with non-IFI native hips. This biomechanical study directly links IFI to increased lumbar facet loads and supports the clinical findings of IFI causing lumbar pathology. Assessing and treating (open or endoscopic) hip disorders that limit extension

  19. The relation between the instantaneous center of rotation and facet joint forces - A finite element analysis.

    PubMed

    Schmidt, Hendrik; Heuer, Frank; Claes, Lutz; Wilke, Hans-Joachim

    2008-03-01

    The instantaneous center of rotation in a functional spinal unit is an indicator for mechanical disorders and is relevant for the development of motion preserving techniques. In addition to the intervertebral disc, the facet joints also play a major role for load transmission through the spine, providing stability to it. The relationship between the rotation center and facet joint forces is not fully understood, since previous studies have separated both; spinal motion and facet forces. A finite element model of a L4-5 lumbar spinal segment was exposed to an axial compression preload of 500 N. Pure unconstrained moments of 7.5 Nm were additionally applied in the three anatomical main planes. The instantaneous center of rotation and the facet joint forces were investigated. For small moments, the center of rotation was found to be almost in the center of the disc, no matter what motion direction. With an increasing flexion moment, the center of rotation moved anteriorly. The facet joints remained unloaded in flexion. With proceeding extension movement, the center of rotation moved posteriorly. The facet forces increased up to 50 N. In lateral bending, with increasing moment the center of rotation migrated posteriorly in the ipsilateral side of the disc. The forces in the facet joints rose to 36 N. In axial rotation, the center of rotation migrated towards the compressed facet joint with increasing moment. Axial rotation yielded the maximum facet forces with 105 N. The determination of the rotation center is highly sensible against measurement resolution obtained during in vivo and in vitro studies. This finite element method can be used to complement the knowledge of the rotation center location from former experimental findings.

  20. Characterization of degenerative human facet joints and facet joint capsular tissues.

    PubMed

    Kim, J-S; Ali, M H; Wydra, F; Li, X; Hamilton, J L; An, H S; Cs-Szabo, G; Andrews, S; Moric, M; Xiao, G; Wang, J H-C; Chen, Di; Cavanaugh, J M; Im, H-J

    2015-12-01

    Lumbar facet joint degeneration (FJD) may be an important cause of low back pain (LBP) and sciatica. The goal of this study was to characterize cellular alterations of inflammatory factor expression and neovascularization in human degenerative facet joint capsular (FJC) tissue. These alterations in FJC tissues in pain stimulation were also assessed. FJs were obtained from consented patients undergoing spinal reconstruction surgery and cadaveric donors with no history of back pain. Histological analyses of the FJs were performed. Cytokine antibody array and quantitative real-time polymerase chain reaction (qPCR) were used to determine the production of inflammatory cytokines, and western blotting analyses (WB) were used to assay for cartilage-degrading enzymes and pain mediators. Ex vivo rat dorsal root ganglion (DRG) co-culture with human FJC tissues was also performed. Increased neovascularization, inflammatory cell infiltration, and pain-related axonal-promoting factors were observed in degenerative FJCs surgically obtained from symptomatic subjects. Increased VEGF, (NGF/TrkA), and sensory neuronal distribution were also detected in degenerative FJC tissues from subjects with LBP. qPCR and WB results demonstrated highly upregulated inflammatory cytokines, pain mediators, and cartilage-degrading enzymes in degenerative FJCs. Results from ex vivo co-culture of the DRG and FJC tissue demonstrated that degenerative FJCs increased the expression of inflammatory pain molecules in the sensory neurons. Degenerative FJCs possess greatly increased inflammatory and angiogenic features, suggesting that these factors play an important role in the progression of FJD and serve as a link between joint degeneration and neurological stimulation of afferent pain fibers. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  1. Lumbar Facet Joint Motion in Patients with Degenerative Spondylolisthesis

    PubMed Central

    Yao, Qi; Wang, Shaobai; Shin, Jae-Hyuk; Li, Guoan; Wood, Kirkham B.

    2012-01-01

    Study Design Controlled laboratory study. Objective To investigate the in vivo biomechanical effect of degenerative lumbar spondylolisthesis (DLS) on the motion of the facet joint during various functional weight-bearing activities. Summary of Background Data Although the morphological changes of the facet joints in patients with DLS have been reported in a few studies, no data has been reported on the kinematics of these facet joints. Methods Ten patients with DLS at L4–L5 were studied. Each patient underwent a magnetic resonance imaging (MRI) scan to obtain three-dimensional (3D) models of the lumbar vertebrae from L2–L5 as well as a dual fluoroscopic imaging scan in different postures: flexion-extension, left-right bending and left-right torsion. The positions of the vertebrae were reproduced by matching the MRI-based vertebral models to the fluoroscopic images. The kinematics of the facet joint and the ranges of motion (ROMs) were compared with those of healthy subjects and those of patients with degenerative disc diseases (DDD) previously published. Results In DLS patients, the range of rotation of the facet joints was significantly less at the DLS level (L4–L5) than that at the adjacent levels (L2–L3 and L3–L4), while the range of translation was similar at all levels. The range of rotation at the facet joints of the DLS level decreased compared to those of both the DDD patients and healthy subjects at the corresponding vertebral level (L4–L5), while no significant difference was found in the range of translation. The ROM of facet joints in DLS and in DDD patients was similar at the adjacent levels (L2–L3 and L3–L4). Conclusion The range of rotation decreased at the facet joints at the DLS level (L4–L5) in patients compared to those in healthy subjects and DDD patients. This decrease in range of rotation implies that the DLS disease may cause restabilization of the joint. The data may help the selection of conservative treatment or different

  2. Three-dimensional evaluation of the facet joints

    NASA Astrophysics Data System (ADS)

    Folio, Les R.

    1990-04-01

    Computerized tomography and magnetic resonance imaging nave revolurionalized analysis of vertebral anatomy and pathology. Further advances with 3-dimensional imaging have recently become an important adjunct for diagnosis and treatment in structural abnormalities. Facets are intimately related to their surrounding musculature and malalignment may cause pain directly or indirectly. High resolution 3-dimensional reformations of CT Scans give us new insight on structure and function of facet joints, since their motion and architecture are ever complex. It is well documented in the literature that facet joint biomecnanics is a partial contributor to the myriad at causes of low back The term "facet Joint syndrome" was coined in 1933 by GhorMley.3 The osteopathic lesion complex is well defined by LeRoy and McCole and comparison of roentgenographic findings before and after manipulation has teen described by Long and Lioyd.4,5 since alterations in facet biamechanics are an important aspect of osteopathic manipulative therapy (OT), 3-dimensional hign resolution imaging will prove to be a great asset in osteopathic research. Rotating the spine allows for different viewing perspectives to provide optimal and consistent measurements of the facet joint. Rotations are performed on the X, Y and 7, axis and measurements pre and post-manipulation are performed and compared on matching axis and perspectives. Rotation about the X, Y and Z axis help appreciate the 3-dimensionality of the vertebral column to project to the viewer a feeling that the spine is floating in space before them. This does give the viewer a 3-D understanding of the object however, only at a perspective at a Lime.

  3. Augmented reality needle guidance improves facet joint injection training

    NASA Astrophysics Data System (ADS)

    Ungi, Tamas; Yeo, Caitlin T.; U-Thainual, Paweena; McGraw, Robert C.; Fichtinger, Gabor

    2011-03-01

    PURPOSE: The purpose of this study was to determine if medical trainees would benefit from augmented reality image overlay and laser guidance in learning how to set the correct orientation of a needle for percutaneous facet joint injection. METHODS: A total of 28 medical students were randomized into two groups: (1) The Overlay group received a training session of four insertions with image and laser guidance followed by two insertions with laser overlay only; (2) The Control group was trained by carrying out six freehand insertions. After the training session, needle trajectories of two facet joint injections without any guidance were recorded by an electromagnetic tracker and were analyzed. Number of successful needle placements, distance covered by needle tip inside the phantom and procedural time were measured to evaluate performance. RESULTS: Number of successful placements was significantly higher in the Overlay group compared to the Control group (85.7% vs. 57.1%, p = 0.038). Procedure time and distance covered inside phantom have both been found to be less in the Overlay group, although not significantly. CONCLUSION: Training with augmented reality image overlay and laser guidance improves the accuracy of facet joint injections in medical students learning image-guided facet joint needle placement.

  4. MR findings of exaggerated fluid in facet joints predicts instability.

    PubMed

    Schinnerer, Kimberly A; Katz, Lee D; Grauer, Jonathan N

    2008-10-01

    Retrospective radiographic review. To determine the incidence of exaggerated fluid signal in lumbar facet joints on magnetic resonance imaging (MRI) and evaluate the correlation of this finding with radiographic evidence of instability. Lumbar spine MRI is routinely used to evaluate low back pain. The presence of exaggerated fluid in the facets joints on MRI has been correlated with dynamic instability. To our knowledge, this correlation has never been evaluated in an objective fashion. One hundred thirty-four consecutive lumbar MRIs obtained by a single surgeon were selected for review. Studies were evaluated for exaggerated fluid in the facets on axial views. Standing plain films of all patients were then evaluated to determine the incidence of spondylolisthesis for patients with and without exaggerated fluid in the facets on MRI. Of 134 consecutive MRIs, 118 were available for review. Sixteen had exaggerated fluid in the facets on axial images (13.6%). Only 2 of these 16 (12.5%) had spondylolisthesis appreciable on the MRI at that level. In contrast, 8 of the 16 (50.0%) had spondylolisthesis at the level of exaggerated fluid when the corresponding radiographs were reviewed. Thus, spondylolisthesis was suggested in 6 of 14 cases (42.9%) when the exaggerated fluid sign was present but spondylolisthesis was not evident on the supine MRI. In comparison, in the population without exaggerated fluid, only 1 in 102 (0.9%) showed a slip on plain film that was not observed on MRI. This difference was statistically significant (P<0.001). Exaggerated fluid in the facets seen on axial MRI is significantly suggestive of spondylolisthesis on standing films, even if this is not appreciated on the supine sagittal MRI sequences. This is the first time that the relative incidence of subtle instability with and without this finding has been evaluated to our knowledge.

  5. Facet joint pain--advances in patient selection and treatment.

    PubMed

    Cohen, Steven P; Huang, Julie H Y; Brummett, Chad

    2013-02-01

    Facetogenic pain, also known as zygapophysial joint pain, is a frequent cause of mechanical spine pain. Diagnostic blocks (for example, medial branch blocks [MBBs]) are the only reliable approach to identify facet joints as the source of neck or back pain. In the absence of a reference standard, MBBs actually serve more of a prognostic than diagnostic role, enabling the selection of patients who might respond to radiofrequency denervation treatment--the standard treatment for facet joint pain. Using double blocks reduces the false-positive rate of MBBs, but will invariably reduce the overall treatment success rate. No studies have evaluated non-interventional treatments for confirmed facetogenic pain, but data from studies in non-specific back pain suggest a modest, short-term beneficial effect for pharmacotherapy and some non-traditional treatments. Trials of intra-articular steroid injections for lumbar and cervical facet joint pain have yielded disappointing results, but evidence suggests that a subpopulation of patients with acute inflammation derive intermediate-term benefit from this therapy. Radiofrequency denervation provides some benefit for up to a year in approximately 60% of individuals. Increasing this success rate might involve enhancing diagnostic specificity and phenotyping, as well as techniques that increase the likelihood of successful nerve ablation, such as maximizing lesion size.

  6. Mechanoreceptor endings in human thoracic and lumbar facet joints.

    PubMed

    McLain, R F; Pickar, J G

    1998-01-15

    Histologic analysis of normal human facet capsules to determine the density and distribution of encapsulated nerve endings in the thoracic and lumbar spine. To quantify the extent of mechanoreceptor innervation in normal facet tissues and determine the relative distribution of three specific receptor types with respect to thoracic and lumbar segments. Ongoing studies of spinal innervation have shown that human facet tissues contain mechanoreceptive endings capable of detecting motion and tissue distortion. The hypothesis has been advanced that spinal proprioception may play a role in modulating protective muscular reflexes that prevent injury or facilitate healing. Whole facet capsules harvested from seven healthy adult patients were processed using a gold chloride staining method and cut into 35-micron sections for histologic analysis. No sampling was performed; all sections were analyzed. Receptor endings were classified by the method of Freeman and Wyke if they met the following three criteria: 1) encapsulation, 2) identifiable morphometry, and 3) consistent morphometry on serial sections. One Type 1 and four Type 2 endings were identified among 10 thoracic facet capsules. Five Type 1, six Type 2, and one Type 3 ending were identified among 13 lumbar facet capsules. Occasional atypical receptive endings were noted that did not fit the established classification. Unencapsulated free nerve endings were seen in every specimen, but were not quantified. Encapsulated nerve endings are believed to be primarily mechanosensitive and may provide proprioceptive and protective information to the central nervous system regarding joint function and position. A consistent, but small population of receptors has been found previously in cervical facets, but innervation of the thoracic and lumbar levels is less consistent. This suggests that proprioceptive function in the thoracic and lumbar spine is less refined and, perhaps, less critical than in the cervical spine.

  7. Neuronal hyperexcitability in the dorsal horn after painful facet joint injury.

    PubMed

    Quinn, Kyle P; Dong, Ling; Golder, Francis J; Winkelstein, Beth A

    2010-11-01

    Excessive cervical facet capsular ligament stretch has been implicated as a cause of whiplash-associated disorders following rear-end impacts, but the pathophysiological mechanisms that produce chronic pain in these cases remain unclear. Using a rat model of C6-C7 cervical facet joint capsule stretch that produces sustained mechanical hyperalgesia, the presence of neuronal hyperexcitability was characterized 7 days after joint loading. Extracellular recordings of spinal dorsal horn neuronal activity between C6 and C8 (117 neurons) were obtained from anesthetized rats, with both painful and non-painful behavioral outcomes established by the magnitude of capsule stretch. The frequency of neuronal firing during noxious pinch (p<0.0182) and von Frey filaments applications (4-26g) to the forepaw was increased (p<0.0156) in the painful group compared to the non-painful and sham groups. In addition, the incidence and frequency of spontaneous and after discharge firing were greater in the painful group (p<0.0307) relative to sham. The proportion of cells in the deep laminae that responded as wide dynamic range neurons also was increased in the painful group relative to non-painful or sham groups (p<0.0348). These findings suggest that excessive facet capsule stretch, while not producing visible tearing, can produce functional plasticity of dorsal horn neuronal activity. The increase in neuronal firing across a range of stimulus magnitudes observed at day 7 post-injury provides the first direct evidence of neuronal modulation in the spinal cord following facet joint loading, and suggests that facet-mediated chronic pain following whiplash injury is driven, at least in part, by central sensitization. Copyright © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  8. Facet joint laser radiation: tissue effects of a new clinical laser application

    NASA Astrophysics Data System (ADS)

    Werkmann, Klaus; Thal, Dietmar R.

    1996-01-01

    Chronic unilateral and bilateral back pain with pseudoradicular symptoms, is a common clinical syndrome, which in many cases can be related to the facet joint syndrome. The pain is caused by mechanical affection of synovial and capsular nerve terminals. Therefore, current therapeutical attempts including physical therapy, intra-articular injection of local anesthetics and steroids and thermocoagulation of the facet joint with a thermocoagulator, are performed. We confirmed laser coagulation of the facet joint. Porcine cadaveric spines were treated immediately after death by intra-articular facet joint laser radiation. With the pulsed Nd:YAG laser (1064 nm) altogether 600 J were applied in three different places 4 mm apart at the top of the facet joint. The results showed that facet joint laser radiation leads to a small (about 1 - 2 mm diameter) lesion restricted to the facet joint cavity and its synovia. Histologically, we found a central carbonization zone and necrosis, including almost the whole cartilage and approximately 0.2 mm of the adjacent bone. These changes are similar to Nd:Yag-laser applications in other skeletal regions. It is suggested that these changes may lead to facet joint denervation by coagulation of the synovial nerve terminals. Cicatration of the laser lesion might cause ankylosis of this joint. In sum, facet joint laser radiation could be an alternative therapeutical tool for lower back pain of the facet joint syndrome type. Therefore, future clinical application of this technique seems to be very promising.

  9. Utilization of Facet Joint and Sacroiliac Joint Interventions in Medicare Population from 2000 to 2014: Explosive Growth Continues!

    PubMed

    Manchikanti, Laxmaiah; Hirsch, Joshua A; Pampati, Vidyasagar; Boswell, Mark V

    2016-10-01

    Increasing utilization of interventional techniques in managing chronic spinal pain, specifically facet joint interventions and sacroiliac joint injections, is a major concern of healthcare policy makers. We analyzed the patterns of utilization of facet and sacroiliac joint interventions in managing chronic spinal pain. The results showed significant increase of facet joint interventions and sacroiliac joint injections from 2000 to 2014 in Medicare FFS service beneficiaries. Overall, the Medicare population increased 35 %, whereas facet joint and sacroiliac joint interventions increased 313.3 % per 100,000 Medicare population with an annual increase of 10.7 %. While the increases were uniform from 2000 to 2014, there were some decreases noted for facet joint interventions in 2007, 2010, and 2013, whereas for sacroiliac joint injections, the decreases were noted in 2007 and 2013. The increases were for cervical and thoracic facet neurolysis at 911.5 % compared to lumbosacral facet neurolysis of 567.8 %, 362.9 % of cervical and thoracic facet joint blocks, 316.9 % of sacroiliac joints injections, and finally 227.3 % of lumbosacral facet joint blocks.

  10. Percutaneous Facet Screw Fixation in the Treatment of Symptomatic Recurrent Lumbar Facet Joint Cyst: A New Technique

    SciTech Connect

    Amoretti, Nicolas Gallo, Giacomo Bertrand, Anne-Sophie; Bard, Robert L.; Kelekis, Alexis

    2016-01-15

    We present a case of percutaneous treatment of symptomatic recurrent lumbar facet joint cyst resistant to all medical treatments including facet joint steroid injection. Percutaneous transfacet fixation was then performed at L4–L5 level with a cannulated screw using CT and fluoroscopy guidance. The procedure time was 30 min. Using the visual analog scale (VAS), pain decreased from 9.5, preoperatively, to 0 after the procedure. At 6-month follow-up, an asymptomatic cystic recurrence was observed, which further reduced at the 1-year follow-up. Pain remained stable (VAS at 0) during all follow-ups. CT- and fluoroscopy-guided percutaneous cyst rupture associated with facet screw fixation could be an alternative to surgery in patients suffering from a symptomatic recurrent lumbar facet joint cyst.

  11. Biomechanical evaluation of the impact of various facet joint lesions on the primary stability of anterior plate fixation in cervical dislocation injuries: a cadaver study: Laboratory investigation.

    PubMed

    Oberkircher, Ludwig; Born, Sebastian; Struewer, Johannes; Bliemel, Christopher; Buecking, Benjamin; Wack, Christina; Bergmann, Martin; Ruchholtz, Steffen; Krüger, Antonio

    2014-10-01

    Injuries of the subaxial cervical spine including facet joints and posterior ligaments are common. Potential surgical treatments consist of anterior, posterior, or anterior-posterior fixation. Because each approach has its advantages and disadvantages, the best treatment is debated. This biomechanical cadaver study compared the effect of different facet joint injuries on primary stability following anterior plate fixation. Fractures and plate fixation were performed on 15 fresh-frozen intact cervical spines (C3-T1). To simulate a translation-rotation injury in all groups, complete ligament rupture and facet dislocation were simulated by dissecting the entire posterior and anterior ligament complex between C-4 and C-5. In the first group, the facet joints were left intact. In the second group, one facet joint between C-4 and C-5 was removed and the other side was left intact. In the third group, both facet joints between C-4 and C-5 were removed. The authors next performed single-level anterior discectomy and interbody grafting using bone material from the respective thoracic vertebral bodies. An anterior cervical locking plate was used for fixation. Continuous loading was performed using a servohydraulic test bench at 2 N/sec. The mean load failure was measured when the implant failed. In the group in which both facet joints were intact, the mean load failure was 174.6 ± 46.93 N. The mean load failure in the second group where only one facet joint was removed was 127.8 ± 22.83 N. In the group in which both facet joints were removed, the mean load failure was 73.42 ± 32.51 N. There was a significant difference between the first group (both facet joints intact) and the third group (both facet joints removed) (p < 0.05, Kruskal-Wallis test). In this cadaver study, primary stability of anterior plate fixation for dislocation injuries of the subaxial cervical spine was dependent on the presence of the facet joints. If the bone in one or both facet joints is damaged

  12. Factors affecting results of fluoroscopy-guided facet joint injection: Probable differences in the outcome of treatment between pure facet joint hypertrophy and concomitant diseases

    PubMed Central

    Albayrak, Akif; Ozkul, Baris; Balioglu, Mehmet Bulent; Atici, Yunus; Gultekin, Muhammet Zeki; Albayrak, Merih Dilan

    2016-01-01

    Study Design: Retrospective cohort study. Purpose: Facet joints are considered a common source of chronic low-back pain. To determine whether pathogens related to the facet joint arthritis have any effect on treatment failure. Materials and Methods: Facet joint injection was applied to 94 patients treated at our hospital between 2011 and 2012 (mean age 59.5 years; 80 women and 14 men). For the purpose of analysis, the patients were divided into two groups. Patients who only had facet hypertrophy were placed in group A (47 patients, 41 women and 6 men, mean age 55.3 years) and patients who had any additional major pathology to facet hypertrophy were placed in group B (47 patients, 39 women and 8 men, mean age 58.9 years). Injections were applied around the facet joint under surgical conditions utilizing fluoroscopy device guidance. A mixture of methylprednisolone and lidocaine was used as the injection ingredient. Results: In terms of Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, no significant difference was found between preinjection and immediate postinjection values in both groups, and the scores of group A patients were significantly lower (P < 0.005) compared with that of group B patients at the end of the third, sixth, and twelfth month. Conclusion: For low-back pain caused by facet hypertrophy, steroid injection around the facet joint is an effective treatment, but if there is an existing major pathology, it is not as effective. PMID:27041884

  13. Comparison of intra-articular lumbar facet joint pulsed radiofrequency and intra-articular lumbar facet joint corticosteroid injection for management of lumbar facet joint pain

    PubMed Central

    Do, Kyung Hee; Ahn, Sang Ho; Cho, Yun Woo; Chang, Min Cheol

    2017-01-01

    Abstract Background: This study aimed to demonstrate the effect of intra-articular (IA) lumbar facet joint (LFJ) pulsed radiofrequency (PRF) for the management of LFJ pain, and to compare the effect of IA LFJ PRF to IA corticosteroid injection (ICI). Pathology in the LFJ is a common source of lower back pain (LBP). It is responsible for chronic LBP in approximately 15% to 45% of patients. It has been reported that PRF stimulation can effectively reduce refractory joint pain. Methods: Sixty patients with LFJ pain were recruited and randomly assigned to 1 of 2 groups: the IA PRF group and the ICI group. There were 30 patients in each group. At pretreatment, 2 weeks, 1, 3, and 6 months after treatment, we assessed the severity of LBP using a numeric rating scale (NRS). Results: Compared with the pretreatment NRS scores, patients in both groups showed a significant decrease in NRS scores at 2 weeks, and 1, 3, and 6 months after each treatment. Between groups, changes in the NRS scores were significantly different over time. At 2 weeks and 1 month after each procedure, the NRS score after ICI was significantly lower than that after the PRF stimulation. However, at 3 and 6 months after the procedures, the decrements of NRS scores were not significantly different between the 2 groups. Six months after treatment, about half of patients in both groups reported successful pain relief (pain relief of ≥50%). Conclusion: In the current study, both IA PRF stimulation and ICI into the LFJ significantly relieved LFJ pain. Their effects persisted for at least 6 months after the procedure. Thus, IA PRF is a useful therapeutic option for the management of LFJ pain. PMID:28353611

  14. Calcium pyrophosphate dihydrate crystal deposition of multiple lumbar facet joints: a case report.

    PubMed

    Namazie, Mohamed Ridzwan bin Mohamed; Fosbender, Murray R

    2012-08-01

    Pseudogout of the lumbar facet joints is rare. We report on a 69-year-old woman with 2-level symptomatic synovial cysts of the facet joints caused by calcium pyrophosphate dihydrate crystal deposition. She underwent surgical decompression for sciatica and low back pain. At one-year follow-up, she had recovered completely.

  15. Magnetic resonance-guided focused ultrasound treatment of facet joint pain: summary of preclinical phase

    PubMed Central

    2014-01-01

    Study design A phantom experiment, two thermocouple experiments, three in vivo pig experiments, and a simulated treatment on a healthy human volunteer were conducted to test the feasibility, safety, and efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) for treating facet joint pain. Objective The goal of the current study was to develop a novel method for accurate and safe noninvasive facet joint ablation using MRgFUS. Summary of background data Facet joints are a common source of chronic back pain. Direct facet joint interventions include medial branch nerve ablation and intra-articular injections, which are widely used, but limited in the short and long term. MRgFUS is a breakthrough technology that enables accurate delivery of high-intensity focused ultrasound energy to create a localized temperature rise for tissue ablation, using MR guidance for treatment planning and real-time feedback. Methods We validated the feasibility, safety, and efficacy of MRgFUS for facet joint ablation using the ExAblate 2000® System (InSightec Ltd., Tirat Carmel, Israel) and confirmed the system's ability to ablate the edge of the facet joint and all terminal nerves innervating the joint. A phantom experiment, two thermocouple experiments, three in vivo pig experiments, and a simulated treatment on a healthy human volunteer were conducted. Results The experiments showed that targeting the facet joint with energies of 150–450 J provides controlled and accurate heating at the facet joint edge without penetration to the vertebral body, spinal canal, or root foramina. Treating with reduced diameter of the acoustic beam is recommended since a narrower beam improves access to the targeted areas. Conclusions MRgFUS can safely and effectively target and ablate the facet joint. These results are highly significant, given that this is the first study to demonstrate the potential of MRgFUS to treat facet joint pain. PMID:24921048

  16. [Synovial cyst in the lumbar facet joint. A rare cause of lumbar-sciatic pain].

    PubMed

    Villas, C; Leyes, M

    1997-01-01

    Synovial cysts of the facet joints are uncommon lesions which may be asymptomatic or present as low back pain, with or without radicular symptoms. They are considered to be secondary to trauma or degenerative joint disease, and they occur more frequently in patients with spondylolisthesis. Diagnosis is normally achieved with computed tomography or magnetic resonance, which show a cystic lesion located laterally adjacent to the facet joint. We review the literature and report a patient who presented with first sacral nerve root symptoms attributable to a ganglion cyst of the left L5 S1 facet joint. Treatment was curative and consisted in excision of the cyst.

  17. A prospective morphological study of facet joint integrity following intervertebral disc replacement with the CHARITE Artificial Disc.

    PubMed

    Trouillier, Hans; Kern, P; Refior, H J; Müller-Gerbl, M

    2006-02-01

    In degenerative disc disease (DDD), increased loading in the posterior column increases facet joint subchondral bone density and may lead to facet joint degeneration. While spinal fusion is commonly used to treat patients with symptomatic DDD, increased stress at the levels adjacent to fusion may accelerate facet joint and adjacent segment degeneration. Artificial disc replacements have been developed as an alternative to fusion. In this prospective study, the effects of disc replacement with the CHARITE Artificial Disc on facet joint loading and integrity were evaluated. Thirteen patients aged <50 years with symptomatic DDD were recruited. Computed tomography (CT) osteoabsorptiometry was performed prior to the implantation of the CHARITE Artificial Disc and six months after. With this technique, increases or decreases in facet joint loading and integrity are indicated by corresponding changes in subchondral bone density. Changes in the distribution of load alter the distribution of the areas of maximum bone density. Clinical outcome was also assessed at pre-operative and 6 and 12 month post-operative visits using the Visual Analogue Scale back and leg pain scores, the Oswestry Disability Index and the Short Form-36 (SF-36) questionnaire. The height of the intervertebral space at the operated level was monitored by lateral X-ray. Subchondral bone density was evaluated in the facet joints of all 13 patients at the operated level, 12 patients at the level above the operated segment, and five patients at the level below the operated segment. Quantitative measurements revealed no significant increases (> or =3%) in subchondral bone density of the facet joints at any level in any patient. Significant decreases (> or =3%) in subchondral bone density were measured at the operated level in 10/13 patients, at the level above the operated segment in 6/12 patients, and at the level below the operated segment in 3/5 patients. There were no changes in the distribution of the

  18. Lumbar juxta-facet joint cysts in association with facet joint orientation, -tropism and -arthritis: A case-control study.

    PubMed

    Ening, Genevieve; Kowoll, Annika; Stricker, Ingo; Schmieder, Kirsten; Brenke, Christopher

    2015-12-01

    To assess the association between juxta-facet-joint cysts (JFC) occurrence at the lumbar spine and Facet Joint (FJ) orientation, -tropism and -arthritis. Study group, 36 consecutive patients with JFC and the same number of controls, with degenerative diseases without JFC were match paired for demographics and spine segment. Parameter assessment was by T2-weighted axial MRI scans. JFC diagnosis was confirmed histopathologically. Group comparison was by Student's t-test for continuous variables and X(2) for categorical variables. Nineteen female and 17 male patients, aged between 45 and 85 years (mean 67.19 ± 10.3 years) had a mean JFC size of 9.26 ± 4.8mm occurring most frequently in the segment L4-L5 (75% n=25) and on the left side (61%). Mean FJ orientation of the study group was significantly more coronal compared to controls (left side 42° vs 36°, p<0.02*, 95% confidence interval: 0.9-11.5 and right side 43° vs 37°, p<0.02*, 95% confidence interval: 0.6-10.6 respectively). However, individual intersegmental analysis for study group patients showed the JFC bearing side to be significantly more sagittally oriented 40° ± 11.2° compared to 45° ± 13.2° for the side without FJC (p<0.03*, 95% confidence interval: 8.1-1.7). 50% of the study group showed FJ asymmetry compared to 30% in controls, with a trend for FJ tropism (p<0.07). Severe (grade 3) FJ arthritis was significantly more predominant in the study group 23/33 (p<0.001*) as compared to controls. Compared to a control group, JFC occurrence is associated with significant higher rates of arthritis and coronally orientated FJ. At intersegment comparison within the same patient cysts located in more sagittally orientated FJ and the asymmetric segments show a trend for FJ tropism. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Subdural empyema following lumbar facet joint injection: An exceeding rare complication.

    PubMed

    Fayeye, Oluwafikayo; Silva, Adikarige Haritha Dulanka; Chavda, Swarupsinh; Furtado, Navin Raoul

    2016-01-01

    Chronic low back pain is extremely common with a life time prevalence estimated at greater than 70%. Facet joint arthrosis is thought to be the causative aetiological substrate in approximately 25% of chronic low back pain cases. Facet joint injection is a routine intervention in the armamentarium for both the diagnostic and therapeutic management of chronic low back pain. In fact, a study by Carrino et al. reported in excess of 94,000 facet joint injection procedures were carried out in the US in 1999. Although generally considered safe, the procedure is not entirely without risk. Complications including bleeding, infection, exacerbation of pain, dural puncture headache, and pneumothorax have been described. We report a rare case of a 47-year-old female patient who developed a left L4/5 facet septic arthrosis with an associated subdural empyema and meningitis following facet joint injection. This case is unique, as to the best of our knowledge no other case of subdural empyema following facet joint injection has been reported in the literature. Furthermore this case serves to highlight the potential serious adverse sequelae of a routine and apparently innocuous intervention. The need for medical practitioners to be alert to and respond rapidly to the infective complications of facet joint injection cannot be understated.

  20. Presence and Extent of Severe Facet Joint Osteoarthritis Are Associated with Back Pain in Older Adults

    PubMed Central

    Suri, Pradeep; Hunter, David J.; Rainville, James; Guermazi, Ali; Katz, Jeffrey N.

    2014-01-01

    Objective To determine whether the presence and extent of severe lumbar facet joint osteoarthritis (OA) is associated with back pain in older adults, accounting for disc height narrowing and other covariates. Design 252 older adults from the Framingham Offspring Cohort (mean age 67 years) were studied. Participants received standardized CT assessments of lumbar facet joint OA and disc height narrowing at the L2-S1 interspaces using 4-grade semi-quantitative scales. Severe facet joint OA was defined according to the presence and/or degree of joint space narrowing, osteophytosis, articular process hypertrophy, articular erosions, subchondral cysts, and intraarticular vacuum phenomenon. Severe disc height narrowing was defined as marked narrowing with endplates almost in contact. Back pain was defined as participant report of pain on most days or all days in the past 12 months. We used multivariable logistic regression to examine associations between severe facet joint OA and back pain, adjusting for key covariates including disc height narrowing, sociodemographics, anthropometrics, and health factors. Results Severe facet joint OA was more common in participants with back pain than those without (63.2% vs. 46.7%;p=0.03). In multivariable analyses, presence of any severe facet joint OA remained significantly associated with back pain (odds ratio[OR]2.15 (95% confidence interval [CI]1.13-4.08). Each additional joint with severe OA conferred greater odds of back pain (OR per joint 1.20 (95% CI;1.02-1.41). Conclusions The presence and extent of severe facet joint OA on CT imaging is associated with back pain in community-based older adults, independent of sociodemographics, health factors, and disc height narrowing. PMID:23973131

  1. Lumbar facet joint arthritis is associated with more coronal orientation of the facet joints at the upper lumbar spine.

    PubMed

    Jentzsch, Thorsten; Geiger, James; Zimmermann, Stefan M; Slankamenac, Ksenija; Nguyen-Kim, Thi Dan Linh; Werner, Clément M L

    2013-01-01

    We retrospectively analyzed CT scans of 620 individuals, who presented to our traumatology department between 2008 and 2010. Facet joint (FJ) arthritis was present in 308 (49.7%) individuals with a mean grade of 1. It was seen in 27% of individuals ≤40 years and in 75% of individuals ≥41 years (P < 0.0001) as well as in 52% of females and 49% of males (P = 0.61). Mean FJ orientation was 30.4° at L2/3, 38.7° at L3/4, 47° at L4/5, and 47.3° at L5/S1. FJ arthritis was significantly associated with more coronal (increased degree) FJ orientation at L2/3 (P = 0.03) with a cutoff point at ≥32°. FJs were more coronally oriented (48.8°) in individuals ≤40 years and more sagittally oriented (45.6°) in individuals ≥41 years at L5/S1 (P = 0.01). Mean FJ asymmetry was 4.89° at L2/3, 6.01° at L3/4, 6.67° at L4/5, and 7.27° at L5/S1, without a significant difference for FJ arthritis. FJ arthritis is common, increases with age, and affects both genders equally. More coronally oriented FJs (≥32°) in the upper lumbar spine may be an individual risk factor for development of FJ arthritis.

  2. Effect of facet joint injection versus systemic steroids in low back pain: a randomized controlled trial.

    PubMed

    Ribeiro, Luiza Helena; Furtado, Rita Nely Vilar; Konai, Monique Sayuri; Andreo, Ana Beatriz; Rosenfeld, Andre; Natour, Jamil

    2013-11-01

    Randomized clinical trial. To compare the effectiveness of facet joint injection versus systemic steroid in patients with a diagnosis of facet joint syndrome. The term facet joint syndrome has been used to define back pain originating from the facet joints. Treatment is mainly conservative, although interventions, including intra-articular injections and medial branch nerve blocks are used to manage facet-mediated pain. Several studies have evaluated the effectiveness of these interventions. Results of facet joint injection, however, are conflicting. Sixty subjects with a diagnosis of facet joint syndrome were enrolled in the study. They were randomized into experimental and control groups. The experimental group was administered with intra-articular injection of 6 lumbar facet joints with triamcinolone hexacetonide; the control group was administered with triamcinolone acetonide intramuscular injection of 6 lumbar paravertebral points. Visits were taken at baseline and at 1, 4, 12, and 24 weeks after interventions. Outcome measures were used: pain visual analogue scale, pain visual analogue scale during extension of the spine, Likert scale, improvement percentage scale, Roland-Morris, 36-Item Short Form Health Survey, and accountability of medications taken.Homogeneity was tested using the Student t, Pearson χ, and Mann-Whitney tests. Analysis of variance was used to analyze differences in the groups over time and the Student t test to analyze differences between groups at each time evaluation. The groups were similar at baseline. Comparisons between the groups showed, in analysis of variance analysis, an improvement in the experimental group regarding diclofenac intake and quality of life, in the "role physical" profile, assessed by 36-Item Short Form Health Survey.In the analysis at each time point, an improvement in the experimental group was also found in the Roland-Morris questionnaire, in the improvement percentage scale and in the response to treatment

  3. [CORRELATION OF LUMBAR FACET JOINT DEGENERATION AND SPINE-PELVIC SAGITTAL BALANCE].

    PubMed

    Lo, Xin; Zhang, Bin; Liu, Yuan; Dai, Min

    2015-08-01

    To investigate the relationship between lumbar facet joint degeneration of each segment and spine-pelvic sagittal balance parameters. A retrospective analysis was made the clinical data of 120 patients with lumbar degenerative disease, who accorded with the inclusion criteria between June and November 2014. There were 58 males and 62 females with an average age of 53 years (range, 24-77 years). The disease duration ranged from 3 to 96 months (mean, 6.6 months). Affected segments included L3,4 in 32 cases, L4,5 in 47 cases, and L5, S1 in 52 cases. The CT and X-ray films of the lumbar vertebrae were taken. The facet joint degeneration was graded based on the grading system of Pathria. The spine-pelvic sagittal balance parameters were measured, including lumbar lordosis (LL), upper lumbar lordosis (ULL), lower lumbar lordosis (LLL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). According to normal range of PI, the patients were divided into 3 groups: group A (PI was less than normal range), group B (PI was within normal range), and group C (PI was more than normal range). The facet joint degeneration was compared; according to the facet joint degeneration degree, the patients were divided into group N (mild degeneration group) and group M (serious degeneration group) to observe the relationship of lumbar facet joint degeneration of each segment and spine-pelvic sagittal balance parameters. At L4,5 and L5, S1, facet joint degeneration showed significant difference among groups A, B, and C (P < 0.05), more serious facet joint degeneration was observed in group C; no significant difference was found in facet joint degeneration at L3,4 (P > 0.05). There was no significant difference in the other spine-pelvic sagittal balance parameters between groups N and M at each segment (P > 0.05) except for PT (P < 0.05). PI of more than normal range may lead to or aggravate lumbar facet joint degeneration at L4,5 and L5, Si; PT and PI are significantly associated

  4. Load transfer in composite bolted joints

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Perry, J. C.; Lightfoot, M. C.

    1980-01-01

    The study deals with composite bolted joints, specifically those required to transmit primary loads. Consideration is given to the ultimate load capacity of quasi-isotropic bolted joint specimens as a function of the width of the joint, the diameter of the bolt, the joint thickness, and the number of bolts. Emphasis is placed on the effect of adding a second bolt, in tandem, on the load capacity of the joint.

  5. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and...

  6. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their...

  7. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their...

  8. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier for...

  9. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier for...

  10. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier for...

  11. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier for...

  12. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier for...

  13. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their...

  14. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their...

  15. Comparison of facet joint activity on 99mTc-MDP SPECT/CT with facet joint signal change on MRI with fat suppression.

    PubMed

    Lehman, Vance T; Murphy, Robert C; Schenck, Louis A; Carter, Rickey E; Johnson, Geoffrey B; Kotsenas, Amy L; Morris, Jonathan M; Nathan, Mark A; Wald, John T; Maus, Timothy P

    2016-01-01

    We compared signal change on magnetic resonance imaging (MRI) with fat suppression and bone scan activity of lumbar facet joints to determine if these two imaging findings are correlated. We retrospectively identified all patients who underwent imaging of the lumbar spine for pain evaluation using both technetium-99m methylene disphosphonate single-photon emission computed tomography/computed tomography (99mTc-MDP SPECT/CT) and MRI with at least one fat-suppressed T2- or T1-weighted sequence with gadolinium enhancement within a 180-day interval, at our institution between 1 January 2008 and 19 February 2013. Facet joint activity on 99mTc-MDP SPECT/CT and peri-facet signal change on MRI were rated as normal or increased. Agreement between the two examination types were determined with the κ and prevalence-adjusted bias-adjusted κ (PABAK) statistics. This study included 60 patients (28 male, 47%), with a mean age of 49±19.7 years (range, 12-93 years). The κ value indicated no agreement between 99mTc-MDP SPECT/CT and MRI (κ=-0.026; 95% confidence interval: -0.051, 0.000). The PABAK values were fair to high at each spinal level, which suggests that relatively low disease prevalence lowered the κ values. Together, the κ and PABAK values indicate that there is some degree of intermodality agreement, but that it is not consistent. Overall, facet joint signal change on fat-suppressed MRI did not always correlate with increased 99mTc-MDP SPECT/CT activity. MRI and 99mTc-MDP SPECT/CT for facet joint evaluation should not be considered interchangeable examinations in clinical practice or research.

  16. Pressure measurement in the cervical spinal facet joint: considerations for maintaining joint anatomy and an intact capsule.

    PubMed

    Jaumard, Nicolas V; Bauman, Joel A; Welch, William C; Winkelstein, Beth A

    2011-07-01

    A novel noninvasive approach to measure facet joint pressure in the cervical spine was investigated using a tip-mounted transducer that can be inserted through a hole in the bony lateral mass. This technique is advantageous because it does not require resection of the joint capsule, but there are potential issues regarding its applicability that are addressed. The objective was to evaluate the effect of a tip-mounted pressure probe's position and orientation on contact pressure measurements in biomechanical experiments. Measurements of direct contact pressure in the facet joint of cadaveric spines have been obtained via pressure-sensitive films. However, that method requires the resection of the facet capsule, which can alter the overall joint's mechanical behavior and can affect the measured contact pressures. Influence of position and orientation on probe measurements was evaluated in companion surrogate and cadaveric investigations. The probe was placed in the facet of an anatomic vertebral C4/5 surrogate undergoing sagittal bending moments. Pressure-sensitive paper was used to map contact regions in the joint of the surrogate and cadaveric cervical segments (n = 3) during extension. The probe also underwent uniaxial compression in cadaveric facets to evaluate the effect of orientation relative to the contact surface on the probe signal. Although experimental and theoretical pressure profiles followed the same trends, measured maximum pressures were half of the theoretical ones. In the orientation study, maximum pressures were not different for probe orientations of 0° and 5°, but no signal was recorded at orientations greater than 15°. This approach to measure pressure was selected to provide a minimally-invasive method to quantify facet joint pressures during clinically relevant applications. Both the position and orientation of the probe are critical factors in monitoring local pressure profiles in this mobile synovial joint.

  17. Radiological and Radionuclide Imaging of Degenerative Disease of the Facet Joints

    PubMed Central

    Shur, Natalie; Corrigan, Alexis; Agrawal, Kanhaiyalal; Desai, Amidevi; Gnanasegaran, Gopinath

    2015-01-01

    The facet joint has been increasingly implicated as a potential source of lower back pain. Diagnosis can be challenging as there is not a direct correlation between facet joint disease and clinical or radiological features. The purpose of this article is to review the diagnosis, treatment, and current imaging modality options in the context of degenerative facet joint disease. We describe each modality in turn with a pictorial review using current evidence. Newer hybrid imaging techniques such as single photon emission computed tomography/computed tomography (SPECT/CT) provide additional information relative to the historic gold standard magnetic resonance imaging. The diagnostic benefits of SPECT/CT include precise localization and characterization of spinal lesions and improved diagnosis for lower back pain. It may have a role in selecting patients for local therapeutic injections, as well as guiding their location with increased precision. PMID:26170560

  18. Radiological and Radionuclide Imaging of Degenerative Disease of the Facet Joints.

    PubMed

    Shur, Natalie; Corrigan, Alexis; Agrawal, Kanhaiyalal; Desai, Amidevi; Gnanasegaran, Gopinath

    2015-01-01

    The facet joint has been increasingly implicated as a potential source of lower back pain. Diagnosis can be challenging as there is not a direct correlation between facet joint disease and clinical or radiological features. The purpose of this article is to review the diagnosis, treatment, and current imaging modality options in the context of degenerative facet joint disease. We describe each modality in turn with a pictorial review using current evidence. Newer hybrid imaging techniques such as single photon emission computed tomography/computed tomography (SPECT/CT) provide additional information relative to the historic gold standard magnetic resonance imaging. The diagnostic benefits of SPECT/CT include precise localization and characterization of spinal lesions and improved diagnosis for lower back pain. It may have a role in selecting patients for local therapeutic injections, as well as guiding their location with increased precision.

  19. Prevalence of facet joint pain in chronic spinal pain of cervical, thoracic, and lumbar regions

    PubMed Central

    Manchikanti, Laxmaiah; Boswell, Mark V; Singh, Vijay; Pampati, Vidyasagar; Damron, Kim S; Beyer, Carla D

    2004-01-01

    Background Facet joints are a clinically important source of chronic cervical, thoracic, and lumbar spine pain. The purpose of this study was to systematically evaluate the prevalence of facet joint pain by spinal region in patients with chronic spine pain referred to an interventional pain management practice. Methods Five hundred consecutive patients with chronic, non-specific spine pain were evaluated. The prevalence of facet joint pain was determined using controlled comparative local anesthetic blocks (1% lidocaine or 1% lidocaine followed by 0.25% bupivacaine), in accordance with the criteria established by the International Association for the Study of Pain (IASP). The study was performed in the United States in a non-university based ambulatory interventional pain management setting. Results The prevalence of facet joint pain in patients with chronic cervical spine pain was 55% 5(95% CI, 49% – 61%), with thoracic spine pain was 42% (95% CI, 30% – 53%), and in with lumbar spine pain was 31% (95% CI, 27% – 36%). The false-positive rate with single blocks with lidocaine was 63% (95% CI, 54% – 72%) in the cervical spine, 55% (95% CI, 39% – 78%) in the thoracic spine, and 27% (95% CI, 22% – 32%) in the lumbar spine. Conclusion This study demonstrated that in an interventional pain management setting, facet joints are clinically important spinal pain generators in a significant proportion of patients with chronic spinal pain. Because these patients typically have failed conservative management, including physical therapy, chiropractic treatment and analgesics, they may benefit from specific interventions designed to manage facet joint pain. PMID:15169547

  20. Characterization of a new animal model for evaluation and treatment of back pain due to lumbar facet joint osteoarthritis.

    PubMed

    Kim, Jae-Sung; Kroin, Jeffrey S; Buvanendran, Asokumar; Li, Xin; van Wijnen, Andre J; Tuman, Kenneth J; Im, Hee-Jeong

    2011-10-01

    Osteoarthritic (OA) degeneration of the lumbar facet joints has been implicated in low back pain. This study was undertaken to investigate the biologic links between cellular and structural alterations within facet joint components and the development of symptomatic chronic back pain. We generated an animal model of facet joint degeneration by intraarticular injection of monosodium iodoacetate (MIA) into facet joints (L3-L4, L4-L5, L5-L6) of Sprague-Dawley rats. Pain sensation due to pressure, which mimics a mechanical stimulus for facet joint injury, was measured using an algometer. Pain response was also assessed in a straight leg raising test. Cartilage alterations were assessed by biochemical evaluation and microfocal computed tomography (micro-CT). Therapeutic modulation of chronic facet joint pain with the use of various pharmacologic agents was investigated. MIA injection resulted in severely damaged facet joint cartilage, proteoglycan loss, and alterations of subchondral bone structure. Micro-CT analyses suggested that the behavioral hyperalgesia from facet joint degeneration was not associated with foraminal stenosis. The biologic and structural changes in facet joints were closely associated with sustained and robust chronic pain. Morphine and pregabalin markedly alleviated pressure hyperalgesia, while celecoxib (a selective inhibitor of cyclooxygenase 2 [COX-2]) produced moderate antihyperalgesic effects and the effect of ketorolac (an inhibitor of COX-1 and COX-2) was negligible. Our findings demonstrate that MIA injection provides a useful model for the study of OA changes in the facet joint and indicate that facet joint degeneration is a major cause of chronic low back pain. The treatment results suggest that classes of drugs that are widely used to treat OA, such as nonsteroidal antiinflammatory drugs, may have limited efficacy once joint destruction is complete. Copyright © 2011 by the American College of Rheumatology.

  1. Bipolar Intra-articular Radiofrequency Thermocoagulation of the Thoracic Facet Joints: A Case Series of a New Technique

    PubMed Central

    2014-01-01

    Background This study tests the hypothesis that of bipolar radiofrequency thermocoagulation of the thoracic facet joint capsule may provide a safe and effect method of pain control from thoracic facet origin. Methods Among patients suffering from localized mid back pain, nine patients with thoracic facet disease confirmed by magnetic resonance image and diagnostic thoracic facet block were enrolled. Bipolar radiofrequency ablation in the inferior aspect of the thoracic facet joint was done. Visual Analog Scale (VAS) was measured pre-intervention and 1 month post-intervention. Any complications and changes in amount of pain medication were recorded. Results Significant 47.6% reduction in VAS was noted at 1 month. There were no serious complications. Conclusions Intra-articular bipolarradiofrequency thermocoagulation of the thoracic facet joint may be a technically easier and valid method of treating mid back pain of thoracic facet origin. PMID:24478900

  2. Lumbar Facet Joint Motion in Patients with Degenerative Disc Disease at Affected and Adjacent Levels

    PubMed Central

    Li, Weishi; Wang, Shaobai; Xia, Qun; Passias, Peter; Kozanek, Michal; Wood, Kirkham; Li, Guoan

    2013-01-01

    Study Design Controlled laboratory study. Objective To evaluate the effect of lumbar degenerative disc diseases (DDDs) on motion of the facet joints during functional weight-bearing activities. Summary of Background Data It has been suggested that DDD adversely affects the biomechanical behavior of the facet joints. Altered facet joint motion, in turn, has been thought to associate with various types of lumbar spine pathology including facet degeneration, neural impingement, and DDD progression. However, to date, no data have been reported on the motion patterns of the lumbar facet joint in DDD patients. Methods Ten symptomatic patients of DDD at L4–S1 were studied. Each participant underwent magnetic resonance images to obtain three-dimensional models of the lumbar vertebrae (L2–S1) and dual fluoroscopic imaging during three characteristic trunk motions: left-right torsion, left-right bending, and flexion-extension. In vivo positions of the vertebrae were reproduced by matching the three-dimensional models of the vertebrae to their outlines on the fluoroscopic images. The kinematics of the facet joints and the ranges of motion (ROMs) were compared with a group of healthy participants reported in a previous study. Results In facet joints of the DDD patients, there was no predominant axis of rotation and no difference in ROMs was found between the different levels. During left-right torsion, the ROMs were similar between the DDD patients and the healthy participants. During left-right bending, the rotation around mediolateral axis at L4–L5, in the DDD patients, was significantly larger than that of the healthy participants. During flexion-extension, the rotations around anterioposterior axis at L4–L5 and around craniocaudal axis at the adjacent level (L3–L4), in the DDD patients, were also significantly larger, whereas the rotation around mediolateral axis at both L2–L3 and L3–L4 levels in the DDD patients were significantly smaller than those of the

  3. 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

  4. Activating transcription factor 4, a mediator of the integrated stress response, is increased in the dorsal root ganglia following painful facet joint distraction

    PubMed Central

    Dong, Ling; Guarino, Benjamin B.; Jordan-Sciutto, Kelly L.; Winkelstein, Beth A.

    2011-01-01

    Chronic neck pain is one of the most common musculoskeletal disorders in the US. Although biomechanical and clinical studies have implicated the facet joint as a primary source of neck pain, specific cellular mechanisms still remain speculative. The purpose of this study was to investigate whether a mediator (ATF4) of the integrated stress response (ISR) is involved in facet-mediated pain. Holtzman rats underwent C6/C7 facet joint loading that produces either painful (n=16) or nonpainful (n=8) responses. A sham group (n=9) was also included as surgical controls. Behavioral sensitivity was measured and the C6 DRGs were harvested on day 7 to evaluate the total and neuronal ATF4 expression. In separate groups, an intra-articular ketorolac injection was administered either immediately (D0 ketorolac) or 1 day (D1 ketorolac) after painful facet joint loading. Allodynia was measured at days 1 and 7 after injury to assess the effects on behavioral responses. ATF4 and BiP (an indicator of ISR activation) were separately quantified at day 7. Facet joint loading sufficient to elicit behavioral hypersensitivity produced a 3-fold increase in total and neuronal ATF4 expression in the DRG. After ketorolac treatment at the time of injury, ATF4 expression was significantly (p<0.01) reduced despite not producing any attenuation of behavioral responses. Interestingly, ketorolac treatment at day 1 significantly (p<0.001) alleviated behavioral sensitivity at day 7, but did not modify ATF4 expression. BiP expression was unchanged after either intervention time. Results suggest that ATF4-dependent activation of the ISR does not directly contribute to persistent pain, but may sensitize neurons responsible for pain initiation. These behavioral and immunohistochemical findings imply that facet-mediated pain may be sustained through other pathways of the ISR. PMID:21821103

  5. Talocalcaneal Joint Middle Facet Coalition Resection With Interposition of a Juvenile Hyaline Cartilage Graft.

    PubMed

    Tower, Dyane E; Wood, Ryan W; Vaardahl, Michael D

    2015-01-01

    Talocalcaneal joint middle facet coalition is the most common tarsal coalition, occurring in ≤2% of the population. Fewer than 50% of involved feet obtain lasting relief of symptoms after nonoperative treatment, and surgical intervention is commonly used to relieve symptoms, increase the range of motion, improve function, reconstruct concomitant pes planovalgus, and prevent future arthrosis from occurring at the surrounding joints. Several approaches to surgical intervention are available for patients with middle facet coalitions, ranging from resection to hindfoot arthrodesis. We present a series of 4 cases, in 3 adolescent patients, of talocalcaneal joint middle facet coalition resection with interposition of a particulate juvenile hyaline cartilaginous allograft (DeNovo(®) NT Natural Tissue Graft, Zimmer, Inc., Warsaw, IN). With a mean follow-up period of 42.8 ± 2.9 (range 41 to 47) months, the 3 adolescent patients in the present series were doing well with improved subtalar joint motion and decreased pain, and 1 foot showed no bony regrowth on a follow-up computed tomography scan. The use of a particulate juvenile hyaline cartilaginous allograft as interposition material after talocalcaneal middle facet coalition resection combined with adjunct procedures to address concomitant pes planovalgus resulted in good short-term outcomes in 4 feet in 3 adolescent patients.

  6. Characterization of subchondral bone histopathology of facet joint osteoarthritis in lumbar spinal stenosis.

    PubMed

    Netzer, Cordula; Urech, Karin; Hügle, Thomas; Benz, Robyn Melanie; Geurts, Jeroen; Schären, Stefan

    2016-08-01

    Facet joint osteoarthritis may be a cause of low back pain in degenerative spine diseases including lumbar spinal stenosis. Subchondral bone is regarded as a potential therapeutic target for osteoarthritis treatment. The goal of this study was to characterize subchondral bone histopathology in osteoarthritic facet joints from lumbar spinal stenosis patients. Fifteen patients with degenerative spinal stenosis scheduled for transforaminal lumbar interbody fusion surgery were recruited for this study. Osteoarthritis severity was graded on T1- and T2-weighted MRI images using Weishaupt scoring system. Dissected osteoarthritic facet joints were subjected to histological and immunohistochemistry analyses to study relative abundance of osteoblast, osteoclasts, and macrophages using van Gieson's, tartrate-resistant acid phosphatase and CD68-antibody staining, respectively. Presence of nerve fibers was evaluated by PGP9.5-antibody staining. Differential bone histopathology, independent from radiological osteoarthritis grade, was observed in facet joints. Extensive de novo bone formation was found in subchondral bone tissues of eight of fifteen specimens. Regions of bone formation showed high abundance of blood vessels and CD68-positive macrophages, but were devoid of multinucleated osteoclasts. Additional pathological changes in subchondral marrow spaces, including inflammatory infiltration and enhanced osteoclast activity, were characterized by macrophage-rich tissues. PGP9.5-positive nerve fibers were detected near arterioles, but not in regions displaying bone pathology. Individual histopathological parameters did not associate with clinical features or radiological osteoarthritis severity. Subchondral bone histopathology of facet joint osteoarthritis in lumbar spinal stenosis is characterized by marrow infiltration by macrophage-rich tissues and enhanced de novo bone formation. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34

  7. Arthrofibrosis involving the middle facet of the talocalcaneal joint in children and adolescents.

    PubMed

    El Rassi, George; Riddle, Eric C; Kumar, S Jay

    2005-10-01

    Pain over the anterolateral aspect of the ankle in a patient with a history of repeated ankle sprains and with restricted subtalar movement may be associated with a tarsal coalition. Nineteen patients presented with such a history, but conventional imaging did not reveal a cartilaginous or osseous coalition. Since symptoms persisted despite nonoperative treatment, the middle facet was explored surgically. The purpose of this study was to discuss the operative findings and to report the results of treatment. Nineteen patients (twenty-three feet) with pain over the anterolateral aspect of the ankle or a history of repeated ankle sprains had restricted subtalar joint motion and inconclusive findings on diagnostic imaging, except for bone-scanning. Their ages ranged from 9.1 to 18.5 years. The middle facet of the subtalar joint was explored surgically through a 3 to 4-cm-long incision centered over the sustentaculum tali. The results at a mean of 5.8 years were classified as good, fair, or poor on the basis of pain, talocalcaneal joint motion, and shoe wear. Routine radiographs, computed tomography, and magnetic resonance imaging revealed no major abnormality, whereas technetium-99m bone scintigraphy consistently showed slightly increased isotope uptake in the middle facet. Surgical removal of a hypervascular and thickened capsule and synovium in the area of the middle facet of the subtalar joint decreased pain and improved subtalar motion. The final result was good in seventeen patients (twenty feet) and fair in two patients (three feet). There were no poor results. A diagnosis of inflammatory arthrofibrosis should be considered when a patient with a painful rigid flatfoot has normal findings on radiographs and hematological studies but increased isotope uptake in the middle facet of the talocalcaneal joint on bone scintigraphy. Excision of the hypervascular capsule and synovium from this area can result in resolution of the symptoms. Therapeutic Level IV.

  8. In Vivo Cervical Facet Joint Capsule Deformation During Flexion-Extension

    PubMed Central

    Anderst, William J; Lee, Joon Y; Kang, James D

    2014-01-01

    Study Design Non-randomized controlled cohort. Objective To characterize subaxial cervical facet joint kinematics and facet joint capsule (FJC) deformation during in vivo, dynamic flexion-extension. To assess the effect of single-level anterior arthrodesis on adjacent segment FJC deformation. Summary of Background Data The cervical facet joint has been identified as the most common source of neck pain and it is thought to play a role in chronic neck pain related to whiplash injury. Our current knowledge of cervical facet joint kinematics is based on cadaveric mechanical testing. Methods 14 asymptomatic controls and 9 C5-C6 arthrodesis patients performed full range of motion (ROM) flexion-extension while biplane radiographs were collected at 30 Hz. A volumetric model-based tracking process determined 3D vertebral position with sub-millimeter accuracy. FJC fibers were modeled and grouped into anterior, lateral, posterior-lateral, posterior, and posterior-medial regions. FJC fiber deformations (total, shear and compression-distraction) relative to the static position were determined for each cervical motion segment (C2-C3 through C6-C7) during flexion-extension. Results No significant differences in the rate of fiber deformation in flexion were identified among motion segments (p = .159), however, significant differences were observed among fiber regions (p < .001). Significant differences in the rate of fiber deformation in extension were identified among motion segments (p < .001) and among fiber regions (p = .001). The rate of FJC deformation in extension adjacent to the arthrodesis was 45% less than in corresponding motion segments in control subjects (p = .001). Conclusion In control subjects, facet joint capsule deformations are significantly different among vertebral levels and capsule regions when vertebrae are in an extended orientation. In a flexed orientation, FJC deformations are only different among capsule regions. Single-level anterior arthrodesis is

  9. Clinical significance of postdecompression facet joint effusion after minimally invasive decompression for degenerative lumbar spinal stenosis.

    PubMed

    Pao, Jwo-Luen; Chen, Wen-Chih; Chang, Chih-Hung; Chen, Chiang-Sang; Wang, Jaw-Lin

    2014-12-01

    A retrospective case series study. To investigate the clinical significance of postdecompression facet effusion (PDFE) after microendoscopic decompressive laminotomy (MEDL). The facet joint effusion noted on magnetic resonance imaging was considered as an indicator of degeneration of the facet joints and segmental instability. PDFE occurring after MEDL might imply postdecompression segmental instability. Its clinical significance has not yet been clarified. From 2005 to 2010, 165 patients with degenerative lumbar spinal stenosis (average age: 64.5, average follow-up: 25.8 mo) who received MEDL were reviewed. We investigated the incidence of PDFE with preoperative and repetitive magnetic resonance imaging at 6 months postoperatively. The clinical data and treatment courses were reviewed. The treatment outcomes were evaluated with Oswestry Disability Index and Japanese Orthopedic Association scores. The incidence of PDFE was 17.0% (n=28), which was significantly higher in patients receiving multilevel decompression and patients with scoliosis or spondylolisthesis. The intensity of low back pain was similar between patients with and without PDFE, but "mechanical" low back pain was only noted in patients with PDFE. Of the 28 patients with PDFE, only 9 symptomatic patients required invasive treatment (5 facet joint steroid injection, 3 revision MEDL, and 1 spinal fusion). Although the postoperative Oswestry Disability Index and Japanese Orthopedic Association scores were significantly worse these 9 patients, the final outcomes were good. Progression of spondylolisthesis was noted in 2 patients without PDFE but no patients with PDFE during the follow-up period. The relatively high incidence of PDFE after MEDL suggests that injury to the integrity of facet joint is inevitable during decompression of the stenosis, even using minimally invasive techniques. However, the overall stability is well preserved with very rare progression of spondylolisthesis. Most patients with

  10. Brain-derived neurotrophic factor is upregulated in the cervical dorsal root ganglia and spinal cord and contributes to the maintenance of pain from facet joint injury in the rat.

    PubMed

    Kras, Jeffrey V; Weisshaar, Christine L; Quindlen, Julia; Winkelstein, Beth A

    2013-10-01

    The facet joint is commonly associated with neck and low back pain and is susceptible to loading-induced injury. Although tensile loading of the cervical facet joint has been associated with inflammation and neuronal hyperexcitability, the mechanisms of joint loading-induced pain remain unknown. Altered brain-derived neurotrophic factor (BDNF) levels are associated with a host of painful conditions, but the role of BDNF in loading-induced joint pain remains undefined. Separate groups of rats underwent a painful cervical facet joint distraction or a sham procedure. Bilateral forepaw mechanical hypersensitivity was assessed and BDNF mRNA and protein levels were quantified in the dorsal root ganglion (DRG) and spinal cord at days 1 and 7. Facet joint distraction induced significant (P < 0.001) mechanical hypersensitivity at both time points. Painful joint distraction did not alter BDNF mRNA in the DRG compared with sham levels but did significantly increase (P < 0.016) BDNF protein expression over sham in the DRG at day 7. Painful distraction also significantly increased BDNF mRNA (P = 0.031) and protein expression (P = 0.047) over sham responses in the spinal cord at day 7. In a separate study, intrathecal administration of the BDNF-sequestering molecule trkB-Fc on day 5 after injury partially attenuated behavioral sensitivity after joint distraction and reduced pERK in the spinal cord at day 7 (P < 0.045). Changes in BDNF after painful facet joint injury and the effect of spinal BDNF sequestration in partially reducing pain suggest that BDNF signaling contributes to the maintenance of loading-induced facet pain but that additional cellular responses are also likely involved. Copyright © 2013 Wiley Periodicals, Inc.

  11. Vertebral rotatory subluxation in degenerative scoliosis: facet joint tropism is related.

    PubMed

    Bao, Hongda; Zhu, Feng; Liu, Zhen; Bentley, Mark; Mao, Saihu; Zhu, Zezhang; Ding, Yitao; Qiu, Yong

    2014-12-15

    A cross-sectional study. To identify facet tropism as one of the possible risk factors leading to vertebral rotatory subluxation (VRS). VRS has been considered as one of the prognostic factors for degenerative scoliosis. Although several risk factors of VRS, including age and Cobb angle, have been investigated, few studies exist that have evaluated the correlation between VRS and anatomical structures of the vertebral column. This retrospective study recruited 23 patients diagnosed with degenerative lumbar scoliosis with VRS and 20 patients with degenerative scoliosis without VRS. The lateral translation on coronal radiographs was measured and 5 mm was used as the cutoff value to define rotatory subluxation. Computed tomographic scans for facet joints were made for all lumbar levels. The difference between right and left facet angles was recorded as ΔFA. Facet tropism was defined as a difference between the bilateral facet angles of more than 10°. In this study, VRS was most commonly found at the L3-L4 level (49%) and, with decreasing frequency at L2-L3 (24%), L4-L5 (20%), and L1-L2 (7%). On the convex side of the main curve, face joints at levels with VRS were more coronally oriented compared with those at levels without VRS (41.64° ± 11.65° vs. 36.30° ± 10.99°, P = 0.034). ΔFA was also significantly different between levels with and without VRS (P = 0.005). A strong correlation was found between ΔFA and lateral translation, with a coefficient of 0.33 (P < 0.001). In addition, ΔFA and a larger Cobb angle were found to be significantly associated with VRS based on binary regression analysis, with an odds ratio of 4.68 and 2.14, respectively. Facet tropism was more significantly observed at levels with VRS. On the convex side of the main curve, facet joints at levels with VRS were more coronally oriented. A larger Cobb angle and severe facet tropism in degenerative scoliosis should be considered to be related to VRS.

  12. Spinal neuronal plasticity is evident within 1 day after a painful cervical facet joint injury.

    PubMed

    Crosby, Nathan D; Weisshaar, Christine L; Winkelstein, Beth A

    2013-05-10

    Excessive stretch of the cervical facet capsular ligament induces persistent pain and spinal plasticity at later time points. Yet, it is not known when such spinal modifications are initiated following this painful injury. This study investigates the development of hyperalgesia and neuronal hyperexcitability in the spinal cord after a facet joint injury. Behavioral sensitivity was measured in a model of painful C6/C7 facet joint injury in the rat, and neuronal hyperexcitability in the spinal cord was evaluated at 6h and 1 day after injury or a sham procedure, in separate groups. Extracellular recordings of C6/C7 dorsal horn neuronal activity (229 neurons) were used to quantify spontaneous and evoked firing. Rats exhibited no change in sensitivity to mechanical stimulation of the forepaw at 6h, but did exhibit increased sensitivity at 1 day after injury (p=0.012). At 6h, both spontaneous neuronal activity and firing evoked by light brushing, pinch, and von Frey filaments (1.4-26g) applied at the forepaw were not different between sham and injury. At 1 day, spontaneous firing was noted in a greater number of neurons after injury than sham (p<0.04). Evoked firing was also increased 1 day after injury compared to normal and sham (p<0.03). Dorsal horn hyperexcitability and increased spontaneous firing developed between 6 and 24h after painful facet injury, suggesting that the development of hyperalgesia parallels dorsal horn hyperexcitability following mechanical facet joint injury, and these spinal mechanisms are initiated as early as 1 day after injury.

  13. Navigated Pin-Point Approach to Osteoid Osteoma Adjacent to the Facet Joint of Spine

    PubMed Central

    Neo, Masashi; Takemoto, Mitsuru; Nishizawa, Kazuya; Imai, Shinji

    2016-01-01

    Osteoid osteoma (OO) is a benign osteoblastic tumor. Its curative treatment is complete removal of the nidus, where intraoperative localization of the nidus governs clinical results. However, treatment can be difficult since the lesion is often invisible over the bony surface. Accordingly, establishment of an ideal less invasive surgical strategy for spinal OO remains yet unsettled. We illustrate the efficacy of a computed tomography (CT)-based navigation system in excising OO located adjacent to the facet joint of spine. In our 2 cases, complete and pin-point removal of the nidus located close to the facet joint was successfully achieved, without excessive removal of the bone potentially leading to spinal instability and possible damage of nearby neurovascular structures. We advocate a less invasive approach to spinal OO, particularly in an environment with an available CT-based navigation system. PMID:26949472

  14. 1988 Volvo award in clinical sciences. Facet joint injection in low-back pain. A prospective statistical study.

    PubMed

    Jackson, R P; Jacobs, R R; Montesano, P X

    1988-09-01

    From January 1980 through December 1984, 454 patients were evaluated with facet joint injections. All had the chief complaint of low-back pain, normal neurologic examinations and no root tension signs. Three hundred and ninety completed the protocol, which included a lumbar motion pain assessment before and after facet injection. A total of 127 variables were studied. There were 229 males and 161 females with a median age of 38. Facet joint arthrograms were performed prior to intra-articular injection of local anesthetic and cortisone. Initial mean pain relief was only 29%. Variables correlating significantly (P less than 0.05) with more postinjection pain relief were older age, prior history of low-back pain, normal gait, maximum pain on extension following forward flexion in the standing position, and the absence of leg pain, muscle spasm and aggravation of pain on Valsalva. Greatest pain relief immediately after injection was seen with lumbar extension and rotation, motions reported to stress the facet joints or aggravate pain of facet joint origin. Patients with more pain on lumbar extension and rotation as a group, however, did not get more pain relief. From this study we were not able to identify clinical facet joint syndromes or predict patients responding better to this procedure. The facet joints were not commonly the single or primary source for low-back pain in the great majority (greater than 90%) of patients studied.

  15. Intra-articular facet joint injections for low back pain: a systematic review.

    PubMed

    Vekaria, Rajni; Bhatt, Ree'thee; Ellard, David R; Henschke, Nicholas; Underwood, Martin; Sandhu, Harbinder

    2016-04-01

    Evidence supporting the use of therapeutic intra-articular facet joint injections for patients with suspected facet joint pain is sparse. A systematic review including a narrative synthesis was carried out to determine if intra-articular facet joint injections with active drug are more effective in reducing back pain and back pain-related disability than a sham procedure or a placebo/inactive injection. Secondly, to determine if intra-articular facet joint injections with active drug or placebo/inactive injection are more effective in reducing back pain and back pain-related disability than conservative treatment. Medline, EMBASE, CINAHL, CENTRAL, Index to Chiropractic Literature and the Cochrane Central Register of Controlled Trials were searched from inception through April 2015. Data were screened and single extraction with independent verification and risk of bias assessment was performed. A total of 391 records were screened, and six trials were included. The trials included were small (range 18-109 participants) and overall in terms of pain and disability outcomes most were inconclusive. Only two of the trials report any significant between-group differences in pain (mean difference -1.0, 95% CI -2.0 to -0.1) and (p = 0.032) or disability (mean difference -3.0, 95% CI -6.2 to 0.2) and (p = 0.013) outcomes. The studies found here were clinically diverse and precluded any meta-analysis. A number of methodological issues were identified. The positive results, whilst interpreted with caution, do suggest that there is a need for further high-quality work in this area.

  16. Lumbar facet joint nerve blocks in managing chronic facet joint pain: one-year follow-up of a randomized, double-blind controlled trial: Clinical Trial NCT00355914.

    PubMed

    Manchikanti, Laxmaiah; Singh, Vijay; Falco, Frank J E; Cash, Kimberly A; Pampati, Vidyasagar

    2008-01-01

    Lumbar facet joints have been implicated as the source of chronic pain in 15% to 45% of patients with chronic low back pain. Various therapeutic techniques including intraarticular injections, medial branch blocks, and radiofrequency neurotomy of lumbar facet joint nerves have been described in the alleviation of chronic low back pain of facet joint origin. The study was conducted to determine the clinical effectiveness of therapeutic local anesthetic lumbar facet joint nerve blocks with or without steroid in managing chronic function-limiting low back pain of facet joint origin. A randomized, double-blind, controlled trial. An interventional pain management setting in the United States. This study included 60 patients in Group I with local anesthetic and 60 patients in Group II with local anesthetic and steroid. The inclusion criteria was based on the positive response to the diagnostic controlled comparative local anesthetic lumbar facet joint blocks. Numeric pain scores, Oswestry Disability Index, opioid intake, and work status. All outcome assessments were performed at baseline, 3 months, 6 months, and 12 months. Significant improvement with significant pain relief (> 50%) and functional improvement (> 40%) were observed in 82% and 85% in Group I, with significant pain relief in over 82% of the patients and improvement in functional status in 78% of the patients. Based on the results of the present study, it appears that patients may experience significant pain relief 44 to 45 weeks of 1 year, requiring approximately 3 to 4 treatments with an average relief of 15 weeks per episode of treatment. Therapeutic lumbar facet joint nerve blocks, with or without steroid, may provide a management option for chronic function-limiting low back pain of facet joint origin.

  17. Unusual case of paediatric septic arthritis of the lumbar facet joints due to Kingella kingae.

    PubMed

    Le Hanneur, M; Vidal, C; Mallet, C; Mazda, K; Ilharreborde, B

    2016-11-01

    A 32-month-old boy presented with febrile limping that had developed over 6days, associated with right lumbosacral inflammatory swelling. Magnetic resonance imaging (MRI) showed joint effusion of the right L5-S1 zygapophyseal joint, complicated by destructive osteomyelitis of the L5 articular process and paraspinal abscess. Surgery was decided to evacuate the fluid accumulation and rule out differential diagnoses. The diagnosis of septic arthritis of the facet joint was confirmed intraoperatively; real-time quantitative PCR analysis identified Kingella kingae. This is the first substantiated paediatric case of zygapophyseal joint septic arthritis due to K. kingae. K. kingae is the most common pathogen responsible for invasive osteoarticular infection in children under 4years of age. Since empiric antibiotics are effective in early stages, physicians should consider the possibility of spinal infections due to K. kingae when a limping child under 4years of age presents with a fever.

  18. Melorheostosis of the tenth and eleventh thoracic vertebrae crossing the facet joint: a rare cause of back pain.

    PubMed

    McCarthy, M; Mehdian, H; Fairbairn, K J; Stevens, A

    2004-05-01

    Melorheostosis affecting the axial skeleton is a rare condition. We present a case affecting a single thoracic zygoapophyseal (facet) joint that proved to be a diagnostic challenge. CT, MRI and radionuclide imaging with surgical and histopathology findings are discussed.

  19. Evaluation of the stress distribution change at the adjacent facet joints after lumbar fusion surgery: a biomechanical study.

    PubMed

    Ma, Jianxiong; Jia, Haobo; Ma, Xinlong; Xu, Weiguo; Yu, Jingtao; Feng, Rui; Wang, Jie; Xing, Dan; Wang, Ying; Zhu, Shaowen; Yang, Yang; Chen, Yang; Ma, Baoyi

    2014-07-01

    Spinal fusion surgery has been widely applied in clinical treatment, and the spinal fusion rate has improved markedly. However, its postoperative complications, especially adjacent segment degeneration, have increasingly attracted the attention of spinal surgeons. The most common pathological condition at adjacent segments is hypertrophic degenerative arthritis of the facet joint. To study the stress distribution changes at the adjacent facet joint after lumbar fusion with pedicle screw fixation, human cadaver lumbar spines were used in the present study, and electrical resistance strain gauges were attached on L1-L4 articular processes parallel or perpendicular to the articular surface of facet joints. Subsequently, electrical resistance strain gauge data were measured using anYJ-33 static resistance strain indicator with three types of models: the intact model, the laminectomy model, and the fusion model with pedicle screw fixation. The strain changes in the measurement sites indirectly reflect the stress changes. Significant differences in strain were observed between the normal and laminectomy state at all facet joints. Significant differences in strain were observed between the normal and the pedicle screw fixation fusion state at the L1/2 and L3/4 facet joints. The increased stress on the facet joints after lumbar fusion with pedicle screw fixation may be the cause of adjacent segment degeneration.

  20. Morphometric Study of Clavicular Facet of Coracoclavicular Joint in Adult Indian Population

    PubMed Central

    Mahajan, Anita; Vasudeva, Neelam

    2016-01-01

    Introduction Anthropologists have used Coracoclavicular Joint (CCJ), a non-metric anatomical variant in population, as a marker for population migration from prehistoric times to present. Aim The aim of this osteological study was to determine the incidence and morphometry of articular facet of CCJ on conoid tubercle of clavicle in Indian population, as Indian studies are scanty and incomplete. Materials and Methods The study was done on 144 adult human clavicles (76 right and 68 left; 93 males and 51 females) collected from osteology museum in Department of Anatomy, Maulana Azad Medical College, New Delhi, India. The presence of articular facet on the conoid tubercle was determined and Maximum Antero-Posterior (MAPD) and maximum transverse diameter (MTD) was measured by digital vernier calliper. The incidence was compared on the basis of sex, side and with other osteological studies in the world. Statistical analysis was done using the Chi-Square test for nominal categorical data and student’s t-test for normally distributed continuous variables in Microsoft Excel 2007 to assess the relationship between the examined variables. Results Articular facet on conoid tubercle was found in 8 cases (5.6%). Seven (9.2%) were present on the right side and one (1.5%) on the left side. Seven cases (7.5%) were present in males and one case (2%) was found in females. The facets were generally oval, with MAPD and MTD of 12.28 and 17.17 mm respectively. A significant side variation was present with right sided facet being more common. The left sided facet was more transversely elongated than right. In males, the facets were more elongated antero-posteriorly than in females. Conclusion The Indian population showed an incidence of 5.6%, which was comparable to other ethnic groups in world population. The morphometric and side differences could be attributed to the occupational factors and range of movements associated with the CCJ. The CCJ should be borne in mind as a differential

  1. Does therapist’s attitude affect clinical outcome of lumbar facet joint injections?

    PubMed Central

    Middendorp, Marcus; Kollias, Konstantinos; Ackermann, Hanns; Splettstößer, Annina; Vogl, Thomas J; Khan, M Fawad; Maataoui, Adel

    2016-01-01

    AIM: To investigate if the clinical outcome of intra-articular lumbar facet joint injections is affected by the therapist’s attitude. METHODS: A total of 40 patients with facet joint-associated chronic low back pain were randomly divided into two groups. All patients received computed tomography-guided, monosegmental intra-articular facet joint injections. Following the therapeutic procedure, the patients of the experimental group (EG) held a conversation with the radiologist in a comfortable atmosphere. During the dialog, the patients were encouraged to ask questions and were shown four images. The patients of the control group (CG) left the clinic without any further contact with the radiologist. Outcome was assessed using a pain-based Verbal Numeric Scale at baseline, at 1 wk and at 1, 3, and 6 mo after first treatment. RESULTS: The patient demographics showed no differences between the groups. The patients of the EG received 57 interventional procedures in total, while the patients of the CG received 70 interventional procedures. In both groups, the pain scores decreased significantly over the entire observation period. Compared to the CG, the EG showed a statistically significant reduction of pain at 1 wk and 1 mo post-treatment, while at 3 and 6 mo after treatment, there were no significant differences between both groups. CONCLUSION: Our results show a significant effect on pain relief during the early post-interventional period in the EG as compared to the CG. The basic principle behind the higher efficacy might be the phenomenon of hetero-suggestion. PMID:27358691

  2. Pigmented villonodular synovitis originating from the lumbar facet joint: a case report

    PubMed Central

    Oe, Kenichi; Yoshida, Yugo; Ohnari, Hiroyuki; Iida, Hirokazu; Sakaida, Noriko; Uemura, Yoshiko

    2007-01-01

    The authors successfully treated a rare case of pigmented villonodular synovitis (PVNS) that originated from the lumbar facet joint (L4-5). A 43-year-old man presented with a complaint of left severe sciatica causing difficulty in walking. Magnetic resonance imaging (MRI) demonstrated an extradural mass on the left side at L4 and the mass compressed the dural tube and was continuous with the left L4-5 facet joint. A computed tomography myelogram revealed an extradural defect of contrast medium at the L4 level and an erosion of the L4 lamina. A total synovectomy with unilateral osteoplastic laminectomy was performed. The histological findings were a diagnosis of PVNS. The patient’s symptoms resolved completely and the MRI at postoperative 3 years demonstrated no recurrence of PVNS. It is important to totally remove the synovium, which is the origin of PVNS in order to prevent the recurrence. We think that our procedure is reasonable and adequate for lumbar PVNS. PMID:17566795

  3. Septic Arthritis of an Atlantoaxial Facet Joint with Normal Inflammatory Markers: Case Report and Literature Review.

    PubMed

    Kuyumcu, Gokhan; Simpfendorfer, Claus S; Babic, Maja; Kalfas, Iain H; Teixeira-Johnson, Lucileia; Winalski, Carl S

    2017-02-01

    Septic arthritis of the atlantoaxial facet joint is extremely rare. Contiguous spread to the median atlantoaxial joints with subsequent dens erosion can lead to atlantoaxial instability. Misleading normal inflammatory markers can result in delayed diagnosis and catastrophic consequences. A 56-year-old man presented with right-sided neck pain that had lasted for 2 days. He did not have fever or chills, and his serum C-reactive protein and erythrocyte sedimentation rate were normal. The patient was diagnosed with acute neck strain and treated conservatively. The pain continued for the next 3 weeks; cervical spine radiographs demonstrated normal findings with the exception of degenerative changes. The patient was treated with physical rehabilitation for the presumed neck strain and degenerative changes of the cervical vertebrae. Worsening neck pain and stiffness prompted a magnetic resonance imaging study obtained 5 weeks after the initial presentation, which showed an epidural collection with septic arthritis of the right facet and median atlantoaxial joints. Computed tomography demonstrated severe dens erosion. Surgical evacuation of the abscess and occipitocervical fusion were performed. Pathologic evaluation of tissue obtained during surgery demonstrated the presence of an infection, and Streptococcus anginosus grew from cultures. Infection must be considered in the differential diagnosis for neck pain when imaging findings are suggestive of an infectious process, even in an afebrile patient with normal C-reactive protein and erythrocyte sedimentation rate levels. Magnetic resonance imaging and computed tomography can play a critical role in such cases, potentially leading to a more timely diagnosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. THE PROSTAGLANDIN E2 RECEPTOR, EP2, IS UPREGULATED IN THE DRG AFTER PAINFUL CERVICAL FACET JOINT INJURY IN THE RAT

    PubMed Central

    Kras, Jeffrey V.; Dong, Ling; Winkelstein, Beth A.

    2012-01-01

    Study Design This study implemented immunohistochemistry to assay prostaglandin E2 (PGE2) receptor EP2 expression in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury. Objective The objective of this study was to identify if inflammatory cascades are induced in association with cervical facet joint distraction-induced pain by investigating the time course of EP2 expression in the DRG. Summary of Background Data The cervical facet joint is a common source of neck pain and non-physiological stretch of the facet capsular ligament can initiate pain from the facet joint via mechanical injury. PGE2 levels are elevated in painful inflamed and arthritic joints, and PGE2 sensitizes joint afferents to mechanical stimulation. Although in vitro studies suggest the EP2 receptor subtype contributes to painful joint disease the EP2 response has not been investigated for any association with painful mechanical joint injury. Methods Separate groups of male Holtzman rats underwent either a painful cervical facet joint distraction injury or sham procedure. Bilateral forepaw mechanical allodynia was assessed, and immunohistochemical techniques were used to quantify EP2 expression in the DRG at days 1 and 7. Results Facet joint distraction induced mechanical allodynia that was significant (p<0.024) at all time points. Painful joint injury also significantly elevated total EP2 expression in the DRG at day 1 (p=0.009), which was maintained also at day 7 (p<0.001). Neuronal expression of EP2 in the DRG was only increased over sham levels at day 1 (p=0.013). Conclusions Painful cervical facet joint distraction induces an immediate and sustained increase of EP2 expression in the DRG, implicating peripheral inflammation in the initiation and maintenance of facet joint pain. The transient increase in neuronal EP2 suggests, as in other painful joint conditions, that after joint injury non-neuronal cells may migrate to the DRG, some of which likely express EP2

  5. Internal morphology of human facet joints: comparing cervical and lumbar spine with regard to age, gender and the vertebral core

    PubMed Central

    Wilke, Hans-Joachim; Zanker, Daniel; Wolfram, Uwe

    2012-01-01

    Back pain constitutes a major problem in modern societies. Facet joints are increasingly recognised as a source of such pain. Knowledge about the internal morphology and its changes with age may make it possible to include the facets more in therapeutic strategies, for instance joint replacements or immobilisation. In total, 168 facets from C6/7 and L4/5 segments were scanned in a micro-computed tomography. Image analysis was used to investigate the internal morphology with regard to donor age and gender. Additional data from trabecular bone of the vertebral core allowed a semi-quantitative comparison of the morphology of the vertebral core and the facets. Porosity and pore spacing of the cortical sub-chondral bone does not appear to change with age for either males or females. In contrast, bone volume fraction decreases in females from approximately 0.4 to 0.2 , whereas it is constant in males. Trabecular thickness decreases during the ageing process in females and stays constant in males , whereas trabecular separation increases during the ageing process in both genders. The results of this study may help to improve the understanding of pathophysiological changes in the facet joints. Such results could be of value for understanding back pain and its treatment. PMID:22257304

  6. In vivo feasibility of real-time MR-US fusion imaging lumbar facet joint injections.

    PubMed

    Sartoris, Riccardo; Orlandi, Davide; Corazza, Angelo; Sconfienza, Luca Maria; Arcidiacono, Alice; Bernardi, Silvia Perugin; Schiaffino, Simone; Turtulici, Giovanni; Caruso, Pietro; Silvestri, Enzo

    2017-03-01

    Traditionally, facet joint injections (FJI) are performed under fluoroscopic or computed tomography (CT) guidance, mainly due to the deep anatomical location and the presence of bony landmarks. Fusion imaging technology, which couples the ultrasound scan with the corresponding CT or magnetic resonance (MR) image obtained from the diagnostic examination and reformatted in real time according to the ultrasound scanning plane, allows to combine the panoramic view and the elevated anatomical detail of MR or CT with the ease of use of ultrasound without patient exposure to ionizing radiation. Thirty eight patients (24 females; mean age ± SD: 64 ± 9 years) received MR fusion-assisted ultrasound-guided FJI of 1 ml of a mixture of local anaesthetic and corticosteroid using a ultrasound machine (Logiq E9, GE Healthcare) equipped with a GPS-enhanced fusion imaging technology which couples real-time B-mode images with those of the previous recent diagnostic MR examination. Low-dose CT needle positioning confirmation was performed in the first 28 patients. Patients' pain was recorded using a visual analogue scale (VAS), at baseline and at 2, 4 and 8 weeks. All fusion imaging-guided injections were performed successfully. Out of 112, 96 FJI had optimal intra-articular needle positioning (accuracy: 85.7%). Patients VAS significantly decreases after the procedure with no differences among who received CT needle positioning control and who did not receive it. No major complications were observed. Ultrasound needle guidance with MR fusion assistance allows for safe and effective injection of degenerative facet joint disease.

  7. Facet joint pain in chronic spinal pain: an evaluation of prevalence and false-positive rate of diagnostic blocks.

    PubMed

    Manchukonda, Rajeev; Manchikanti, Kavita N; Cash, Kimberly A; Pampati, Vidyasagar; Manchikanti, Laxmaiah

    2007-10-01

    A retrospective review. Evaluation of the prevalence of facet or zygapophysial joint pain in chronic spinal pain of cervical, thoracic, and lumbar origin by using controlled, comparative local anesthetic blocks and evaluation of false-positive rates of single blocks in the diagnosis of chronic spinal pain of facet joint origin. Facet or zygapophysial joints are clinically important sources of chronic cervical, thoracic, and lumbar spine pain. The previous studies have demonstrated the value and validity of controlled, comparative local anesthetic blocks in the diagnosis of facet joint pain, with a prevalence of 15% to 67% variable in lumbar, thoracic, and cervical regions. False-positive rates of single diagnostic blocks also varied from 17% to 63%. Five hundred consecutive patients receiving controlled, comparative local anesthetic blocks of medial branches for the diagnosis of facet or zygapophysial joint pain were included. Patients were investigated with diagnostic blocks using 0.5 mL of 1% lidocaine per nerve. Patients with lidocaine-positive results were further studied using 0.5 mL of 0.25% bupivacaine per nerve on a separate occasion. Medial branch blocks were performed with intermittent fluoroscopic visualization, at 2 levels to block a single joint. A positive response was considered as one with at least 80% pain relief from a block of at least 2 hours duration when lidocaine was used, and at least 3 hours or longer than the duration of relief with lidocaine when bupivacaine was used, and also the ability to perform prior painful movements. A total of 438 patients met inclusion criteria. The prevalence of facet joint pain was 39% in the cervical spine [95% confidence interval (CI), 32%-45%]; 34% (95% CI, 22%-47%) in the thoracic pain; and 27% (95% CI, 22%-33%) in the lumbar spine. The false-positive rate with a single block in the cervical region was 45%, in the thoracic region was 42%, and in the lumbar region 45%. This retrospective review once again

  8. Physiotherapy and lumbar facet joint injections as a combination treatment for chronic low back pain. A narrative review of lumbar facet joint injections, lumbar spinal mobilizations, soft tissue massage and lower back mobility exercises.

    PubMed

    Chambers, Hannah

    2013-06-01

    The aim of this study was to summarize the available evidence on lumbar facet joint injections and the physiotherapy treatments, land-based lower back mobility exercise, soft tissue massage and lumbar spinal mobilizations for chronic low back pain (CLBP). The plausibility of physiotherapy and lumbar facet joint injections as a combination treatment is discussed. Using a systematic process, an online electronic search was performed using key words utilizing all available databases and hand searching reference lists. Using a critical appraisal tool from the Critical Appraisal Skills Programme (CASP), the literature was screened to include primary research. The main aspects of the research were summarized. The evidence for lumbar facet joint injections suggests an overall short-term positive effect on CLBP. Land-based lower back mobility exercise and soft tissue massage appear to have a positive effect on CLBP in the short term and possibly in the longer term. There is insufficient evidence to draw conclusions for lumbar spinal mobilizations. The review indicates that lumbar facet joint injections create a short period when pain is reduced. Physiotherapy treatments including land-based lower back mobility exercise and soft tissue massage may be of benefit during this time to improve the longer-term outcomes of patients with CLBP. It is not possible to make generalizations or firm conclusions. The current review highlights the need for further research. A randomized controlled trial is recommended to assess the impact of physiotherapy in combination with lumbar facet joint injections on CLBP. Copyright © 2013 John Wiley & Sons, Ltd.

  9. Micro-computed tomography, scanning electron microscopy and energy X-ray spectroscopy studies of facet joint degeneration: A comparison to clinical imaging.

    PubMed

    Goehre, Felix; Ludtka, Christopher; Hamperl, Melanie; Friedmann, Andrea; Straube, Anja; Mendel, Thomas; Heilmann, Andreas; Meisel, Hans Jörg; Schwan, Stefan

    2017-09-01

    Segmental degeneration in the human lumbar spine affects both the intervertebral discs and facet joints. Facet joint degeneration not only affects the cartilage surface, but also alters the cellular properties of the cartilage tissue and the structure of the subchondral bone. The primary focus of this study is the investigation of these microstructural changes that are caused by facet joint degeneration. Microstructural analyses of degenerated facet joint samples, obtained from patients following operative lumbar interbody fusion, have not previously been extensively investigated. This study analyzes human facet joint samples from the inferior articular process using scanning electron microscopy, micro-computed tomography, and energy dispersive X-ray spectroscopy to evaluate parameters of interest in facet joint degeneration such as elemental composition, cartilage layer thickness and cell density, calcification zone thickness, subchondral bone portion, and trabecular bone porosity. These microstructural analyses demonstrate fragmentation, cracking, and destruction of the cartilage layer, a thickened calcification zone, localized calcification areas, and cell cluster formation as pathological manifestations of facet joint degeneration. The detailed description of these microstructural changes is critical for a comprehensive understanding of the pathology of facet joint degeneration, as well as the subsequent development and efficacy analysis of regenerative treatment strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Ultrasound guided, painful electrical stimulation of lumbar facet joint structures: an experimental model of acute low back pain.

    PubMed

    O'Neill, Søren; Graven-Nielsen, Thomas; Manniche, Claus; Arendt-Nielsen, Lars

    2009-07-01

    Quantitative sensory testing has indicated generalized muscle hyperalgesia in patients with chronic low back pain. The temporal development of such hyperalgesia is not well understood. The aim of the present study was to demonstrate whether generalized muscle hyperalgesia can develop within minutes of acute low back pain using a new experimental model of lumbar facet joint pain. Thirteen healthy volunteers were included and baseline pressure pain thresholds were assessed at eight separate sites, outside the area of evoked low back and referred pain. Using ultrasonography, two electrode needles were placed either side of a lumbar facet joint (right L3-4) and used to induce experimental low back pain for 10 min with continuous stimulation. Thresholds, stimulus-response relationships, distribution and quality of the electrically induced pain were recorded. Electrical facet joint stimulation induced low back pain and pain referral into the anterior leg, ipsilaterally, proximal to the knee, similar to what is observed clinically. Pressure pain thresholds did not change significantly before, during and after facet joint stimulation. In conclusion, we describe a novel model of acute experimental low back pain and demonstrate that generalized hyperalgesia did not develop within minutes of acute low back pain.

  11. A Cervico-Thoraco-Lumbar Multibody Dynamic Model for the Estimation of Joint Loads and Muscle Forces.

    PubMed

    Khurelbaatar, Tsolmonbaatar; Kim, Kyungsoo; Hyuk Kim, Yoon

    2015-11-01

    Computational musculoskeletal models have been developed to predict mechanical joint loads on the human spine, such as the forces and moments applied to vertebral and facet joints and the forces that act on ligaments and muscles because of difficulties in the direct measurement of joint loads. However, many whole-spine models lack certain elements. For example, the detailed facet joints in the cervical region or the whole spine region may not be implemented. In this study, a detailed cervico-thoraco-lumbar multibody musculoskeletal model with all major ligaments, separated structures of facet contact and intervertebral disk joints, and the rib cage was developed. The model was validated by comparing the intersegmental rotations, ligament tensile forces, facet joint contact forces, compressive and shear forces on disks, and muscle forces were to those reported in previous experimental and computational studies both by region (cervical, thoracic, or lumbar regions) and for the whole model. The comparisons demonstrated that our whole spine model is consistent with in vitro and in vivo experimental studies and with computational studies. The model developed in this study can be used in further studies to better understand spine structures and injury mechanisms of spinal disorders.

  12. The influence of facet joint orientation and tropism on the stress at the adjacent segment after lumbar fusion surgery: a biomechanical analysis.

    PubMed

    Kim, Ho-Joong; Kang, Kyoung-Tak; Son, Juhyun; Lee, Choon-Ki; Chang, Bong-Soon; Yeom, Jin S

    2015-08-01

    Facet joint orientation and tropism influence the biomechanics of the corresponding segment. Therefore, the sagittal orientation or tropism of the facet joint adjacent to the fusion segment seems a potential risk factor for adjacent segment degeneration. However, there have been no biomechanical studies regarding this issue. To investigate the association between adjacent facet orientation and facet tropism and stress in adjacent disc/facet joints using finite element (FE) analysis. An FE analysis. Four intact (F50, F55, F60, and FT [facet tropism]) and matched L3-L4 fusion (F50, F55, F60, and FT fusion) models with different facet joint orientation (50°, 55°, 60° relative to the coronal plane, and facet tropism, respectively) at both L2-L3 facet joints were simulated. In each model, intradiscal pressures and facet contact force at the L2-L3 segment were investigated under pure moments and anterior shear force. Compared with the matched-intact model, the F60 fusion model yielded the highest and largest percentage increase of intradiscal pressure at the L2-L3 segment under flexion, torsion moment, and anterior shear force among the F50, F55, and F60 fusion models. F60 fusion model also demonstrated the largest facet contact force under torsion moment among the F50, F55, and F60 fusion models. In all conditions tested, the FT fusion model demonstrated the highest intradiscal pressure and facet contact force of all the models. Facet joint orientation and tropism at the adjacent segment influences the overstress of the adjacent segment, especially under the clinical circumstance of increased anterior shear force. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Intra-articular nerve growth factor regulates development, but not maintenance, of injury-induced facet joint pain & spinal neuronal hypersensitivity.

    PubMed

    Kras, J V; Kartha, S; Winkelstein, B A

    2015-11-01

    The objective of the current study is to define whether intra-articular nerve growth factor (NGF), an inflammatory mediator that contributes to osteoarthritic pain, is necessary and sufficient for the development or maintenance of injury-induced facet joint pain and its concomitant spinal neuronal hyperexcitability. Male Holtzman rats underwent painful cervical facet joint distraction (FJD) or sham procedures. Mechanical hyperalgesia was assessed in the forepaws, and NGF expression was quantified in the C6/C7 facet joint. An anti-NGF antibody was administered intra-articularly in additional rats immediately or 1 day following facet distraction or sham procedures to block intra-articular NGF and test its contribution to initiation and/or maintenance of facet joint pain and spinal neuronal hyperexcitability. NGF was injected into the bilateral C6/C7 facet joints in separate rats to determine if NGF alone is sufficient to induce these behavioral and neuronal responses. NGF expression increases in the cervical facet joint in association with behavioral sensitivity after that joint's mechanical injury. Intra-articular application of anti-NGF immediately after a joint distraction prevents the development of both injury-induced pain and hyperexcitability of spinal neurons. Yet, intra-articular anti-NGF applied after pain has developed does not attenuate either behavioral or neuronal hyperexcitability. Intra-articular NGF administered to the facet in naïve rats also induces behavioral hypersensitivity and spinal neuronal hyperexcitability. Findings demonstrate that NGF in the facet joint contributes to the development of injury-induced joint pain. Localized blocking of NGF signaling in the joint may provide potential treatment for joint pain. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  14. Muscular response to physiologic tensile stretch of the caprine c5/6 facet joint capsule: dynamic recruitment thresholds and latencies.

    PubMed

    Azar, Nadia R; Kallakuri, Srinivasu; Chen, Chaoyang; Cavanaugh, John M

    2011-11-01

    This study examined the cervical muscle response to physiologic, high-rate (100 mm/s) tensile facet joint capsule (FJC) stretch. Six in-vivo caprine C5/6 FJC preparations were subjected to an incremental tensile loading paradigm. EMG activity was recorded from the right trapezius (TR) and multifidus (MF) muscle groups at the C5 and C6 levels; and from the sternomastoid (SM) and longus colli (LC) muscle groups bilaterally at the C5/6 level; during FJC stretch. Capsule load during the displacement applications was recorded via a miniature load cell, and 3D capsule strains (based on stereoimaging of an array of markers on the capsule surface) were reconstructed using finite element methods. EMG traces from each muscle were examined for onset of muscular activity. Capsule strains and loads at the time of EMG onset were recorded for each muscle, as was the time from the onset of FJC stretch to the onset of muscle activity. All muscles were responsive to physiologic high-rate FJC stretch. The deep muscles (MF and LC) were recruited at significantly smaller capsule loads and onset latencies than the superficial muscles (TR and SM). MF activation strain was significantly smaller than LC and TR activation strains. These data were also compared to previously published low-rate data. MF was the first muscle group to be recruited regardless of the activation criterion under consideration (i.e. strain, load, or latency) or the rate of FJC stretch. LC recruitment occurred significantly sooner under high-rate vs. low-rate FJC stretch. The results of this study provide further evidence of extensive ligamento-muscular reflex pathways between the FJC and the cervical musculature, which are responsive to both low-rate and high-rate FJC stretch. These data add to our knowledge of the dynamic response of paraspinal muscles relative to facet joint motion and provide a unique contribution to enhance the precision of computer-simulated impacts.

  15. Diagnostic Value of Lumbar Facet Joint Injection: A Prospective Triple Cross-Over Study

    PubMed Central

    Schütz, Uwe; Cakir, Balkan; Dreinhöfer, Karsten; Richter, Marcus; Koepp, Holger

    2011-01-01

    The diagnosis “lumbar facet syndrome” is common and often indicates severe lumbar spine surgery procedures. It is doubtful whether a painful facet joint (FJ) can be identified by a single FJ block. The aim of this study was to clarify the validity of a single and placebo controlled bilateral FJ blocks using local anesthetics. A prospective single blinded triple cross-over study was performed. 60 patients (31 f, 29 m, mean age 53.2 yrs (22–73)) with chronic low back pain (mean pain persistance 31 months, 6 months of conservative treatment without success) admitted to a local orthopaedic department for surgical or conservative therapy of chronic LBP, were included in the study. Effect on pain reduction (10 point rating scale) was measured. The 60 subjects were divided into six groups with three defined sequences of fluoroscopically guided bilateral monosegmental lumbar FJ test injections in “oblique needle” technique: verum-(local anaesthetic-), placebo-(sodium chloride-) and sham-injection. Carry-over and periodic effects were evaluated and a descriptive and statistical analysis regarding the effectiveness, difference and equality of the FJ injections and the different responses was performed. The results show a high rate of non-response, which documents the lack of reliable and valid predictors for a positive response towards FJ blocks. There was a high rate of placebo reactions noted, including subjects who previously or later reacted positively to verum injections. Equivalence was shown among verum vs. placebo and partly vs. sham also. With regard to test validity criteria, a single intraarticular FJ block with local anesthetics is not useful to detect the pain-responsible FJ and therefore is no valid and reliable diagostic tool to specify indication of lumbar spine surgery. Comparative FJ blocks with local anesthetics and placebo-controls have to be interpretated carefully also, because they solely give no proper diagnosis on FJ being main pain

  16. INTRA-ARTICULAR NERVE GROWTH FACTOR REGULATES DEVELOPMENT, BUT NOT MAINTENANCE, OF INJURY-INDUCED FACET JOINT PAIN & SPINAL NEURONAL HYPERSENSITIVITY

    PubMed Central

    Kras, Jeffrey V.; Kartha, Sonia; Winkelstein, Beth A.

    2015-01-01

    Objective The objective of the current study is to define whether intra-articular nerve growth factor (NGF), an inflammatory mediator that contributes to osteoarthritic pain, is necessary and sufficient for the development or maintenance of injury-induced facet joint pain and its concomitant spinal neuronal hyperexcitability. Method Male Holtzman rats underwent painful cervical facet joint distraction or sham procedures. Mechanical hyperalgesia was assessed in the forepaws, and NGF expression was quantified in the C6/C7 facet joint. An anti-NGF antibody was administered intra-articularly in additional rats immediately or 1 day following facet distraction or sham procedures to block intra-articular NGF and test its contribution to initiation and/or maintenance of facet joint pain and spinal neuronal hyperexcitability. NGF was injected into the bilateral C6/C7 facet joints in separate rats to determine if NGF alone is sufficient to induce these behavioral and neuronal responses. Results NGF expression increases in the cervical facet joint in association with behavioral sensitivity after that joint’s mechanical injury. Intra-articular application of anti-NGF immediately after a joint distraction prevents the development of both injury-induced pain and hyperexcitability of spinal neurons. Yet, intra-articular anti-NGF applied after pain has developed does not attenuate either behavioral or neuronal hyperexcitability. Intra-articular NGF administered to the facet in naïve rats also induces behavioral hypersensitivity and spinal neuronal hyperexcitability. Conclusion Findings demonstrate that NGF in the facet joint contributes to the development of injury-induced joint pain. Localized blocking of NGF signaling in the joint may provide potential treatment for joint pain. PMID:26521746

  17. Sonoanatomic indices of lumbar facet joints in patients with facetogenic back pain in comparison to healthy subjects.

    PubMed

    Rahimzadeh, Poupak; Faiz, Hamid Reza; Baghaee, Ali Reza; Nader, Nader D

    2017-02-01

    Nowadays, ultrasound is increasingly used with a great accuracy in performing nerve blocks for facet joint disease. To measure sonoanatomic characteristics for the facet joints of lumbar vertebras in patients with facetogenic pain and healthy volunteers. Cross-sectional, observational study. University-affiliated Specialty Clinic for Pain Management. Twenty patients with facet joint disease (FJD) and 40 healthy volunteers (HVGs) were matched for age and sex, height, and weight. Patients with FJD were referred with complaints of pain in the left lumbar facet joints that twice responded favorably to ultrasound guided medial branch blocks. Medial branch blocks. The interfacet joint distance (IFJD) between the third, the fourth, and the fifth lumbar vertebras and their depth from the level of skin (DFS) were measured bilaterally, using a high-resolution ultrasound in both groups. Thirty-one men and 29 women with average age of 41.5±9.5 years were enrolled. The IFJD for L3-L4 was 31.5±4.0 mm on the left side and 31.8±4.0 mm on the right side. The IFJD for L4-L5 was 31.3±4.4 mm on the left side and 31.5±4.0 mm on the right side. The IFJD was uniformly 2.2 mm shorter in the FJD group than those in the HVG group (P=.021). The measurements of DFS increased in lower vertebras (L3facet joints of L4 (P=.016), DFS measurements were similar in FJD and HVG groups. The diagnosis of facet joint disease was merely clinical and the total number of the patients was relatively small. Interfacet distances of the lumbar vertebras are smaller in patients suffering from degenerative FJD compared with HVGs. Degenerative changes of intervertebral discs and partial reduction of space between 2 adjacent vertebras may contribute to this observation. Published by Elsevier Inc.

  18. Explosive growth of facet joint interventions in the medicare population in the United States: a comparative evaluation of 1997, 2002, and 2006 data

    PubMed Central

    2010-01-01

    Background The Office of Inspector General of the Department of Health and Human Services (OIG-DHHS) issued a report which showed explosive growth and also raised questions of lack of medical necessity and/or indications for facet joint injection services in 2006. The purpose of the study was to determine trends of frequency and cost of facet joint interventions in managing spinal pain. Methods This analysis was performed to determine trends of frequency and cost of facet joint Interventions in managing spinal pain, utilizing the annual 5% national sample of the Centers for Medicare and Medicaid Services (CMS) for 1997, 2002, and 2006. Outcome measures included overall characteristics of Medicare beneficiaries receiving facet joint interventions, utilization of facet joint interventions by place of service, by specialty, reimbursement characteristics, and other variables. Results From 1997 to 2006, the number of patients receiving facet joint interventions per 100,000 Medicare population increased 386%, facet joint visits increased 446%, and facet joint interventions increased 543%. The increases were higher in patients aged less than 65 years compared to those 65 or older with patients increasing 504% vs. 355%, visits increasing 587% vs. 404%, and services increasing 683% vs. 498%. Total expenditures for facet joint interventions in the Medicare population increased from over $229 million in 2002 to over $511 million in 2006, with an overall increase of 123%. In 2006, there was a 26.8-fold difference in utilization of facet joint intervention services in Florida compared to the state with the lowest utilization - Hawaii. There was an annual increase of 277.3% in the utilization of facet joint interventions by general physicians, whereas a 99.5% annual increase was seen for nurse practitioners (NPs) and certified registered nurse anesthetists (CRNAs) from 2002 to 2006. Further, in Florida, 47% of facet joint interventions were performed by general physicians

  19. Immediate Effects of Paraspinal Dry Needling in Patients with Acute Facet Joint Lock Induced Wry Neck

    PubMed Central

    Mathias, Lawrence

    2017-01-01

    Introduction Acute facet joint lock induced wry neck (AFJL-WN) is common among adult population and it is primarily managed by medications and physiotherapy. However, the immediate recovery from pain and movements restriction caused by AFJL-WN is not documented in favour of existing interventions. Aim To evaluate the immediate effects of paraspinal dry needling (PSDN) on acute neck pain and movement deficit in patients with AFJL-WN. Materials and Methods A total of 21 patients with AFJL-WN were treated with single session of PSDN for 12-15 minutes. The Visual Analog Scale (0-100mm) and Hand Held Goniometer were used to assess the immediate, 24 hours and 1 week follow-up neck pain and cervical spine’s range of motion respectively. The mean and standard deviation was used to make inferences. Results Immediately after PSDN the pain score was reduced and cervical spine range of motion have improved. The 24 hours and 1 week follow-up pain and range of motion scores have shown the sustained improvement without deteriorations. Conclusion PSDN is effective method to achieve pain free neck movements in patients with AFJL-WN. PMID:28764281

  20. The effect of augmented reality training on percutaneous needle placement in spinal facet joint injections.

    PubMed

    Yeo, Caitlin T; Ungi, Tamas; U-Thainual, Paweena; Lasso, Andras; McGraw, Robert C; Fichtinger, Gabor

    2011-07-01

    The purpose of this study was to determine if augmented reality image overlay and laser guidance systems can assist medical trainees in learning the correct placement of a needle for percutaneous facet joint injection. The Perk Station training suite was used to conduct and record the needle insertion procedures. A total of 40 volunteers were randomized into two groups of 20. 1) The Overlay group received a training session that consisted of four insertions with image and laser guidance, followed by two insertions with laser overlay only. 2) The Control group received a training session of six classical freehand insertions. Both groups then conducted two freehand insertions. The movement of the needle was tracked during the series of insertions. The final insertion procedure was assessed to determine if there was a benefit to the overlay method compared to the freehand insertions. The Overlay group had a better success rate (83.3% versus 68.4%, p=0.002), and potential for less tissue damage as measured by the amount of needle movement inside the phantom (3077.6 mm(2) versus 5607.9 mm(2) , p =0.01). These results suggest that an augmented reality overlay guidance system can assist medical trainees in acquiring technical competence in a percutaneous needle insertion procedure. © 2011 IEEE

  1. Analysis of the Relationship between Ligamentum Flavum Thickening and Lumbar Segmental Instability, Disc Degeneration, and Facet Joint Osteoarthritis in Lumbar Spinal Stenosis

    PubMed Central

    Yoshiiwa, Toyomi; Notani, Naoki; Ishihara, Toshinobu; Kawano, Masanori; Tsumura, Hiroshi

    2016-01-01

    Study Design Cross-sectional study. Purpose To investigate the relationship between ligamentum flavum (LF) thickening and lumbar segmental instability and disc degeneration and facet joint osteoarthritis. Overview of Literature Posterior spinal structures, including LF thickness, play a major role in lumbar spinal canal stenosis pathogenesis. The cause of LF thickening is multifactorial and includes activity level, age, and mechanical stress. LF thickening pathogenesis is unknown. Methods We examined 419 patients who underwent computed tomography (CT) myelography and magnetic resonance imaging after complaints of clinical symptoms. To investigate LF hypertrophy, 57 patients whose lumbar vertebra had normal disc heights at L4–5 were selected to exclude LF buckling as a hypertrophy component. LF thickness, disc space widening angulation in flexion, segmental angulation, presence of a vacuum phenomenon, and lumbar lordosis at T12–S1 were investigated. Disc and facet degeneration were also evaluated. Facet joint orientation was measured via an axial CT scan. Results The mean LF thickness in all patients was 4.4±1.0 mm at L4–5. There was a significant correlation between LF thickness and disc degeneration; LF thickness significantly increased with severe disc degeneration and facet joint osteoarthritis. There was a tendency toward increased LF thickness in more sagittalized facet joints than in coronalized facet joints. Logistic regression analysis showed that LF thickening was influenced by segmental angulation and facet joint osteoarthritis. Patient age was associated with LF thickening. Conclusions LF hypertrophy development was associated with segmental instability and severe disc degeneration, severe facet joint osteoarthritis, and a sagittalized facet joint orientation. PMID:27994791

  2. A CT-Based Simulation Study to Compare the Risk of Facet Joint Violation by the Cervical Pedicle Screw Between Degenerative and Nondegenerative Cervical Spines.

    PubMed

    Lee, Dong-Ho; Noh, Hyounmin; Hwang, Chang Ju; Lee, Choon Sung; Abumi, Kuniyoshi; Cho, Jae Hwan

    2017-02-01

    A retrospective case-control study. This study aimed (A) to compare entry points and trajectories of the cervical pedicle screw (CPS) between degenerative and nondegenerative spines, and (B) to evaluate the risk of facet joint violation by the CPS according to the degree of facet degeneration. Entry point, trajectories, and risk of misplacement of the CPS have been widely researched; however, its application to degenerative cervical spine has to be elucidated. Sixty patients who underwent cervical surgeries at our institution were classified into two groups according to cervical facet joint degeneration. A simulation program with 0.7-mm thickness axial computed tomographic images was used to evaluate facet joint violation by the CPS from C3 to C6. Horizontal and vertical offsets of entry points were measured from two different anatomical landmarks on lateral mass, namely the lateral notch and the center of the superior ridge. The transverse and sagittal angles of the screws were also measured. Facet joint violation was evaluated and classified into either "minor" (<50% of screw diameter) or "major" (≥50% of screw diameter). The mean transverse and sagittal angles showed no difference between the two groups. However, a more superior vertical offset from the superior ridge in terms of entry point was observed in the degenerative cervical spine group at all levels (P = 0.001-0.026). In addition, facet joint violation was more frequently found in severely degenerated facet joints than in mild to moderately degenerated facet joints (P = 0.011). The entry point of CPS was moved more superiorly in the degenerative cervical spine in this study, which increased the risk of facet joint violation in our patients. Thus, surgeons need to modify the insertion technique of the CPS or to insert lateral mass screw instead of the CPS when it is considered to insert screws at the uppermost vertebra in the degenerative cervical spine. 4.

  3. Systematic review of patient history and physical examination to diagnose chronic low back pain originating from the facet joints.

    PubMed

    Maas, E T; Juch, J N S; Ostelo, R W J G; Groeneweg, J G; Kallewaard, J W; Koes, B W; Verhagen, A P; Huygen, F J P M; van Tulder, M W

    2017-03-01

    Patient history and physical examination are frequently used procedures to diagnose chronic low back pain (CLBP) originating from the facet joints, although the diagnostic accuracy is controversial. The aim of this systematic review is to determine the diagnostic accuracy of patient history and/or physical examination to identify CLBP originating from the facet joints using diagnostic blocks as reference standard. We searched MEDLINE, EMBASE, CINAHL, Web of Science and the Cochrane Collaboration database from inception until June 2016. Two review authors independently selected studies for inclusion, extracted data and assessed the risk of bias. We calculated sensitivity and specificity values, with 95% confidence intervals (95% CI). Twelve studies were included, in which 129 combinations of index tests and reference standards were presented. Most of these index tests have only been evaluated in single studies with a high risk of bias. Four studies evaluated the diagnostic accuracy of the Revel's criteria combination. Because of the clinical heterogeneity, results were not pooled. The published sensitivities ranged from 0.11 (95% CI 0.02-0.29) to 1.00 (95% CI 0.75-1.00), and the specificities ranged from 0.66 (95% CI 0.46-0.82) to 0.91 (95% CI 0.83-0.96). Due to clinical heterogeneity, the evidence for the diagnostic accuracy of patient history and/or physical examination to identify facet joint pain is inconclusive. Patient history and physical examination cannot be used to limit the need of a diagnostic block. The validity of the diagnostic facet joint block should be studied, and high quality studies are required to confirm the results of single studies.

  4. Effect of changing lumbar stiffness by single facet joint dysfunction on the responsiveness of lumbar muscle spindles to vertebral movement

    PubMed Central

    Reed, William R.; Pickar, Joel G.; Long, Cynthia R.

    2014-01-01

    Objective: Individuals experiencing low back pain often present clinically with intervertebral joint dysfunction. The purpose of this study was to determine whether relative changes in stiffness at a single spinal joint alters neural responsiveness of lumbar muscle spindles to either vertebral movement or position. Methods: Muscle spindle discharge was recorded in response to 1mm L6 ramp and hold movements (0.5mm/s) in the same animal for lumbar laminectomy-only (n=23), laminectomy & L5/6 facet screw (n=19), laminectomy & L5/6 facetectomy (n=5) conditions. Mean instantaneous frequency (MIF) was calculated for the ramp-up, hold, ramp-down and post-ramp phases during each joint condition. Results: Mean MIFs were not significantly different between the laminectomy-only and the other two types of joint dysfunction for the ramp-up, hold, ramp-down, or post-ramp phases. Conclusion: Stiffness changes caused by single facet joint dysfunction failed to alter spindle responses during slow 1mm ramp and hold movements of the L6 vertebra. PMID:24932020

  5. Significance of interfacet distance, facet joint orientation, and lumbar lordosis in spondylolysis.

    PubMed

    Chung, Sang-Bong; Lee, Sungjoon; Kim, Hoon; Lee, Sun-Ho; Kim, Eun Sang; Eoh, Whan

    2012-04-01

    The aim of this study is to reveal the association between lumbar spondylolysis and several radiologic parameters, which had been suggested to be significant. The authors examine interfacet distance (IFD), facet joint orientation (FJO), and lumbar segmental lordosis (LSL) all together on the basis of lumbar computed tomography (CT) scan of 35 patients with L5 spondylolysis and 36 unaffected control groups. Thirty-five Korean military recruits, aged 19-23 (mean 20.9 years), were diagnosed as L5 spondylolysis by lumber CT scans. As a control group, 36 male Korean military recruits, aged 18-25 (mean 21.3 years), were reconfirmed as not affected by lumbar spondylolysis by CT scan when they visited our hospital complaining of back pain. This study compares IFD, FJO, and LSL for each lumbar segment between the spondylolytic and unaffected groups. We also propose the use of normal mean data of IFD, FJO, and LSL of lumbar vertebrae from 36 Korean young military recruits because each measurement has power as an absolute value, like data from an osteologic collection in other studies. Comparison of IFD between spondylolytic and unaffected individuals reveals significant differences at the L3, L4, and L5 level (P = 0.0384, P = 0.0219, and P < 0.0001, respectively). In the group of spondylolysis, the increase of IFD from L4 to S1 was less pronounced (P < 0.0001) and the LSL at L5-S1 was more lordotic (P = 0.0203). Interfacet distance and lumbar lordosis were significantly different between patients with L5 spondylolysis and individuals without pars defect on L5. In the spondylolysis group, and the increase of IFD from L4 to S1 was less pronounced and the LSL at L5-S1 was more lordotic. Copyright © 2011 Wiley Periodicals, Inc.

  6. An investigation on the effect of improved X-rays-guided radiofrequency thermocoagulation denervation on lumbar facet joint syndrome.

    PubMed

    Zhou, Qin; Zhou, Fang; Wang, Long; Liu, Kang

    2016-09-01

    This study aims to observe the clinical efficacy and feasibility of improved X-rays-guided radiofrequency thermocoagulation denervation for treating low back pain secondary to lumbar facet joint syndrome (LFJS). Eighty LFJS patients were randomly assigned into two groups: the denervation group (n=40), treated with percutaneous radiofrequency thermocoagulation denervation on the lumbar facet joint, and the control group (n=40), injected with betamethasone and lidocaine into the lumbar facet joint. All patients underwent pain scoring using the visual analogous scale (VAS) before treatment, and again at 30 min, 1 d, 1 week, 1 month, and 6 months after treatment. The Schober index was also evaluated at 1 week, 1 month, and 6 months after treatment. The efficacy and adverse effects were also recorded. The denervation group had significantly lower VAS scores at each time point than before treatment (P<0.01). The VAS scores in the control group at 30min, 1d, 1 week, and 1 month after treatment were also significantly lower, but they returned to the pre-treatment level at 6 months after treatment. The VAS scores in the denervation group were significantly lower than that in the control group at 1 month and at 6 months after treatment (P<0.05 and P<0.01), whereas the Schober index was significantly higher (P<0.01). Moreover, the excellent to good efficacy rate in the denervation group was higher than that in the control group (P<0.01). The patients in both treatments had no side effects. Improved X-rays-guided radiofrequency thermocoagulation denervation is an effective, minimally invasive and convenient method for treating low back pain secondary to lumbar facet syndrome. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Ketorolac Reduces Spinal Astrocytic Activation and PAR1 Expression Associated with Attenuation of Pain after Facet Joint Injury

    PubMed Central

    Dong, Ling; Smith, Jenell R.

    2013-01-01

    Abstract Chronic neck pain affects up to 70% of persons, with the facet joint being the most common source. Intra-articular injection of the non-steroidal anti-inflammatory drug ketorolac reduces post-operative joint-mediated pain; however, the mechanism of its attenuation of facet-mediated pain has not been evaluated. Protease-activated receptor-1 (PAR1) has differential roles in pain maintenance depending on the type and location of painful injury. This study investigated if the timing of intra-articular ketorolac injection after painful cervical facet injury affects behavioral hypersensitivity by modulating spinal astrocyte activation and/or PAR1 expression. Rats underwent a painful joint distraction and received an injection of ketorolac either immediately or 1 day later. Separate control groups included injured rats with a vehicle injection at day 1 and sham operated rats. Forepaw mechanical allodynia was measured for 7 days, and spinal cord tissue was immunolabeled for glial fibrillary acidic protein (GFAP) and PAR1 expression in the dorsal horn on day 7. Ketorolac administered on day 1 after injury significantly reduced allodynia (p=0.0006) to sham levels, whereas injection immediately after the injury had no effect compared with vehicle. Spinal astrocytic activation followed behavioral responses and was significantly decreased (p=0.009) only for ketorolac given at day 1. Spinal PAR1 (p=0.0025) and astrocytic PAR1 (p=0.012) were significantly increased after injury. Paralleling behavioral data, astrocytic PAR1 was returned to levels in sham only when ketorolac was administered on day 1. Yet, spinal PAR1 was significantly reduced (p<0.0001) by ketorolac independent of timing. Spinal astrocyte expression of PAR1 appears to be associated with the maintenance of facet-mediated pain. PMID:23126437

  8. Ketorolac reduces spinal astrocytic activation and PAR1 expression associated with attenuation of pain after facet joint injury.

    PubMed

    Dong, Ling; Smith, Jenell R; Winkelstein, Beth A

    2013-05-15

    Chronic neck pain affects up to 70% of persons, with the facet joint being the most common source. Intra-articular injection of the non-steroidal anti-inflammatory drug ketorolac reduces post-operative joint-mediated pain; however, the mechanism of its attenuation of facet-mediated pain has not been evaluated. Protease-activated receptor-1 (PAR1) has differential roles in pain maintenance depending on the type and location of painful injury. This study investigated if the timing of intra-articular ketorolac injection after painful cervical facet injury affects behavioral hypersensitivity by modulating spinal astrocyte activation and/or PAR1 expression. Rats underwent a painful joint distraction and received an injection of ketorolac either immediately or 1 day later. Separate control groups included injured rats with a vehicle injection at day 1 and sham operated rats. Forepaw mechanical allodynia was measured for 7 days, and spinal cord tissue was immunolabeled for glial fibrillary acidic protein (GFAP) and PAR1 expression in the dorsal horn on day 7. Ketorolac administered on day 1 after injury significantly reduced allodynia (p=0.0006) to sham levels, whereas injection immediately after the injury had no effect compared with vehicle. Spinal astrocytic activation followed behavioral responses and was significantly decreased (p=0.009) only for ketorolac given at day 1. Spinal PAR1 (p=0.0025) and astrocytic PAR1 (p=0.012) were significantly increased after injury. Paralleling behavioral data, astrocytic PAR1 was returned to levels in sham only when ketorolac was administered on day 1. Yet, spinal PAR1 was significantly reduced (p<0.0001) by ketorolac independent of timing. Spinal astrocyte expression of PAR1 appears to be associated with the maintenance of facet-mediated pain.

  9. Evaluation of Lumbar Facet Joint Nerve Blocks in Managing Chronic Low Back Pain: A Randomized, Double-Blind, Controlled Trial with a 2-Year Follow-Up

    PubMed Central

    Manchikanti, Laxmaiah; Singh, Vijay; Falco, Frank J.E.; Cash, Kimberly A.; Pampati, Vidyasagar

    2010-01-01

    Study Design: A randomized, double-blind, controlled trial. Objective: To determine the clinical effectiveness of therapeutic lumbar facet joint nerve blocks with or without steroids in managing chronic low back pain of facet joint origin. Summary of Background Data: Lumbar facet joints have been shown as the source of chronic pain in 21% to 41% of low back patients with an average prevalence of 31% utilizing controlled comparative local anesthetic blocks. Intraarticular injections, medial branch blocks, and radiofrequency neurotomy of lumbar facet joint nerves have been described in the alleviation of chronic low back pain of facet joint origin. Methods: The study included 120 patients with 60 patients in each group with local anesthetic alone or local anesthetic and steroids. The inclusion criteria was based upon a positive response to diagnostic controlled, comparative local anesthetic lumbar facet joint blocks. Outcome measures included the numeric rating scale (NRS), Oswestry Disability Index (ODI), opioid intake, and work status, at baseline, 3, 6, 12, 18, and 24 months. Results: Significant improvement with significant pain relief of ≥ 50% and functional improvement of ≥ 40% were observed in 85% in Group 1, and 90% in Group II, at 2-year follow-up. The patients in the study experienced significant pain relief for 82 to 84 weeks of 104 weeks, requiring approximately 5 to 6 treatments with an average relief of 19 weeks per episode of treatment. Conclusions: Therapeutic lumbar facet joint nerve blocks, with or without steroids, may provide a management option for chronic function-limiting low back pain of facet joint origin. PMID:20567613

  10. 18F-Sodium Fluoride PET-CT Hybrid Imaging of the Lumbar Facet Joints: Tracer Uptake and Degree of Correlation to CT-graded Arthropathy

    PubMed Central

    Mabray, Marc C.; Brus-Ramer, Marcel; Behr, Spencer C.; Pampaloni, Miguel H.; Majumdar, Sharmila; Dillon, William P.; Talbott, Jason F.

    2016-01-01

    We aim to evaluate 18F-NaF uptake by facet joints with hybrid PET-CT technique. Specifically, we evaluate NaF uptake in the facet joints of the lower lumbar spine, and correlate with the morphologic grade of facet arthropathy on CT. 30 consecutive patients who underwent standard vertex to toes NaF PET-CT for re-staging of primary neoplastic disease without measurable or documented bony metastases were identified. Maximum (SUVmax) and average (SUVavg) standardized uptake values were calculated for each L3-4, L4-5, and L5-S1 facet joint (n = 180) and normalized to average uptake in the non-diseased femur. A Pathria grade (0-3) was assigned to each facet based upon the CT morphology. Spearman's rank correlation was performed for normalized SUVmax and SUVavg with Pathria grade. ANOVA was performed with Tukey-Kramer pairwise tests to evaluate differences in uptake between Pathria groups. Facet normalized SUVmax (r = 0.31, P < 0.001) and SUVavg (r = 0.28, P < 0.001) demonstrated a mild positive correlation with CT Pathria grade. There was a wide range of uptake values within each Pathria grade subgroup with statistically significant differences in uptake only between Pathria grade 3 as compared to grades 0, 1, and 2. In conclusion, NaF uptake and morphologic changes of the facet joint on CT are weakly correlated. Physiologic information provided by NaF uptake is often discrepant with structural findings on CT suggesting NaF PET may supplement conventional structural imaging for identification of pain generating facet joints. Prospective investigation into the relationship of facet joint NaF uptake with pain and response to pain interventions is warranted. PMID:27134557

  11. Calcium Carbonate Nanoplate Assemblies with Directed High-Energy Facets: Additive-Free Synthesis, High Drug Loading, and Sustainable Releasing.

    PubMed

    Zhang, Jing; Li, Yu; Xie, Hao; Su, Bao-Lian; Yao, Bin; Yin, Yixia; Li, Shipu; Chen, Fang; Fu, Zhengyi

    2015-07-29

    Developing drug delivery systems (DDSs) with high drug-loading capacity and sustainable releasing is critical for long-term chemotherapeutic efficacy, and it still remains challenging. Herein, vaterite CaCO3 nanoplate assemblies with exposed high-energy {001} facets have been synthesized via a novel, additive-free strategy. The product shows a high doxorubicin-loading capacity (65%); the best of all the CaCO3-based DDSs so far. Also, the product's sustainable releasing performance and its inhibition of the initial burst release, together, endow it with long-term drug efficacy. The work may shed light on exposing directed high-energy facets for rationally designing of a drug delivery system with long-term efficacy.

  12. Cartilage in facet joints of patients with ankylosing spondylitis (AS) shows signs of cartilage degeneration rather than chondrocyte hypertrophy: implications for joint remodeling in AS.

    PubMed

    Bleil, Janine; Sieper, Joachim; Maier, Rene; Schlichting, Uwe; Hempfing, Axel; Syrbe, Uta; Appel, Heiner

    2015-07-17

    In ankylosing spondylitis (AS), joint remodeling leading to joint ankylosis involves cartilage fusion. Here, we analyzed whether chondrocyte hypertrophy is involved in cartilage fusion and subsequent joint remodeling in AS. We assessed the expression of chondrocyte hypertrophy markers runt-related transcription factor 2 (Runx2), type X collagen (COL10), matrix metalloproteinase 13 (MMP13), osteocalcin and beta-catenin and the expression of positive bone morphogenic proteins (BMPs) and negative regulators (dickkopf-1 (DKK-1)), sclerostin, (wingless inhibitory factor 1 (wif-1)) of chondrocyte hypertrophy in the cartilage of facet joints from patients with AS or osteoarthritis (OA) and from autopsy controls (CO) by immunohistochemistry. Sex determining region Y (SRY)-box 9 (Sox9) and type II collagen (COL2) expression was assessed as indicators of chondrocyte integrity and function. The percentage of hypertrophic chondrocytes expressing Runx2, COL10, MMP13, osteocalcin or beta-catenin was significantly increased in OA but not in AS joints compared to CO joints. Frequencies of sclerostin-positive and DKK-1-positive chondrocytes were similar in AS and CO. In contrast, wif-1- but also BMP-2- and BMP-7-expressing and Sox9-expressing chondrocytes were drastically reduced in AS joints compared to CO as well as OA joints whereas the percentage of COL2-expressing chondrocytes was significantly higher in AS joints compared to CO joints. We found no evidence for chondrocyte hypertrophy within hyaline cartilage of AS joints even in the presence of reduced expression of the wnt inhibitor wif-1 suggesting that chondrocyte hypertrophy is not a predominant pathway involved in joint fusion and remodeling in AS. In contrast, the reduced expression of Sox9, BMP-2 and BMP-7 concomitantly with induced COL2 expression rather point to disturbed cartilage homeostasis promoting cartilage degeneration in AS.

  13. Joint interaction with embedded concretions: joint loading configurations inferred from propagation paths

    NASA Astrophysics Data System (ADS)

    McConaughy, David T.; Engelder, Terry

    1999-11-01

    The interaction between propagating joints and embedded concretions in a Devonian black shale near Seneca Lake, NY, permits identification of the loading configurations responsible for two joint sets of different ages striking at nearly the same orientation. The earlier set consists of systematic joints cut by later Alleghanian joints of the Appalachian Plateau. The later set consists of non-systematic curving cross joints that abut these same Alleghanian joints. Field evidence shows that concretions functioned as stiff inclusions in a compliant black shale. As a consequence of this elastic contrast, local perturbations in the remote stress field persisted around the concretions during burial, tectonic deformation, and exhumation. These stress perturbations influenced joint propagation paths of both joint sets. Our conclusions about loading configurations are based on finite-element modeling of the effect of the local stress perturbation on concretion-modified joint propagation. Modeling shows that the local stress perturbation from a thermoelastic loading was responsible for deflecting cross joints away from concretions in a curved propagation path near the concretion. This load configuration also led to arrest of cross joints before they penetrated the shale-concretion interface. At greater distances from the concretion, the propagation path of cross joints was controlled by the contemporary tectonic stress field. The interface between concretions and the surrounding shale was strongly bonded, as indicated by the crossing of the interface by some of the systematic ENE joints. Higher compressive stress levels within the concretions relative to the shale suppressed joint development in the concretion, causing the arrest of those joints once they had driven across the interface and a short distance into the concretion. Numerical modeling shows that interface penetration by the systematic ENE joints is consistent with a fluid load, the same loading configuration

  14. A Modified Posterolateral Approach for Radiofrequency Denervation of the Medial Branch of the Cervical Segmental Nerve in Cervical Facet Joint Pain Based on Anatomical Considerations.

    PubMed

    van Eerd, Maarten; Lataster, Arno; Sommer, Micha; Patijn, Jacob; van Kleef, Maarten

    2016-10-13

    The cervical facet joints, also called the zygapophyseal joints, are a potential source of neck pain (cervical facet joint pain). The cervical facet joints are innervated by the cervical medial branches (CMBs) of the cervical segmental nerves. Cervical facet joint pain has been shown to respond to multisegmental radiofrequency denervation of the cervical medial branches. This procedure is performed under fluoroscopic guidance. Currently, three approaches are described and used. Those three techniques of radiofrequency treatment of the CMBs, classified on the base of the needle trajectory toward the anatomical planes, are as follows: the posterolateral technique, the posterior technique, and the lateral technique. We describe the three techniques with their advantages and disadvantages. Anatomical studies providing a topographic anatomy of the course of the CMBs are reviewed. We developed a novel approach based on the observed strengths and weaknesses of the three currently used approaches and based on recent anatomical findings. With this fluoroscopic-guided approach, there is always bone (the facet column) in front of the needle, which makes it safer, and the insertion point is easier to determine without the risk of positioning the radiofrequency needle too dorsally.

  15. Biomechanical analysis of press-extension technique on degenerative lumbar with disc herniation and staggered facet joint.

    PubMed

    Du, Hong-Gen; Liao, Sheng-Hui; Jiang, Zhong; Huang, Huan-Ming; Ning, Xi-Tao; Jiang, Neng-Yi; Pei, Jian-Wei; Huang, Qin; Wei, Hui

    2016-05-01

    This study investigates the effect of a new Chinese massage technique named "press-extension" on degenerative lumbar with disc herniation and facet joint dislocation, and provides a biomechanical explanation of this massage technique. Self-developed biomechanical software was used to establish a normal L1-S1 lumbar 3D FE model, which integrated the spine CT and MRI data-based anatomical structure. Then graphic technique is utilized to build a degenerative lumbar FE model with disc herniation and facet joint dislocation. According to the actual press-extension experiments, mechanic parameters are collected to set boundary condition for FE analysis. The result demonstrated that press-extension techniques bring the annuli fibrosi obvious induction effect, making the central nucleus pulposus forward close, increasing the pressure in front part. Study concludes that finite element modelling for lumbar spine is suitable for the analysis of press-extension technique impact on lumbar intervertebral disc biomechanics, to provide the basis for the disease mechanism of intervertebral disc herniation using press-extension technique.

  16. Characterization of a New Animal Model for Evaluation and Treatment of Back Pain Due to Lumbar Facet Joint Osteoarthritis

    PubMed Central

    Kim, Jae-Sung; Kroin, Jeffrey S.; Buvanendran, Asokumar; Li, Xin; van Wijnen, Andre J.; Tuman, Kenneth J.; Im, Hee-Jeong

    2011-01-01

    Degeneration of lumbar facet joints (FJs) has been implicated in lower back pain. To verify the biological links between cellular and structural alterations within FJ components and development of symptomatic chronic back pain, we generated an animal model for FJ degeneration by intra-articular injection of monosodium iodoacetate (MIA) in FJs (L3/L4, L4/L5, L5/L6) of Sprague Dawley rats followed by behavioral pain tests. The degree of primary hyperalgesia was assessed by measuring pain sensation due to pressure using an algometer, which mimics a mechanical stimulus for FJ injury. Biochemical assessments and µCT imaging revealed severely damaged FJ cartilage, proteoglycan loss and alterations of subchondral bone structure by MIA injection. The µCT analyses further suggested that the behavioral hyperalgesia from FJ degeneration is not associated with foramina stenosis. These biological and structural changes in FJs are closely related to sustained and robust chronic pain. Therapeutic modulation of chronic pain using pharmaceutical drugs was investigated in the facet joint osteoarthritis animal model. Morphine and pregabalin markedly alleviate pressure hyperalgesia while celecoxib (selective inhibitor of COX-2) and ketorolac (inhibitor of COX-1 and -2) demonstrate moderate to negligible anti-hyperalgesic effects, respectively. PMID:21953085

  17. Issues related to SPR joints subjected to fatigue loads

    NASA Astrophysics Data System (ADS)

    De Luca, A.; Senatore, F.; Greco, A.

    2016-05-01

    SPR joints will represent an alternative solution to spot welding in automotive field. However, their fatigue behavior shows several critical issues. After a brief introduction of this new solution, different crack modes are described, emphasizing the parameters that characterize them, i.e. the applied loads, the geometry of the joint and other phenomenon as fretting, vibration and corrosion.

  18. Nondestructive evaluation of load transfer at rigid airport pavement joints

    NASA Astrophysics Data System (ADS)

    Hammons, Michael I.

    1995-07-01

    Current design criteria for rigid pavements for commercial and military airfields assume that 25% of the load applied to an edge of a slab is transferred through the joint to an adjacent unloaded slab. A nondestructive testing technique using a falling weight deflectometer (FWD) was used to conduct field testing at a number of sites. A transfer function, developed from an analytical study, was used to estimate load transfer from the measured joint efficiency as a function of the loaded area and the radius of relative stiffness of the pavement. This procedure, although analytically sound, lacks actual field verification at an instrumented pavement site. This procedure was used to estimate load transfer at a number of commercial and military airfields for a variety of joint types, climate conditions, and pavement structures. The results of these tests indicate that the assumption of load transfer as a constant value of 25% appears to be unconservative, especially during the winter months.

  19. Analysis of the load on the knee joint and vertebral column with changes in squatting depth and weight load.

    PubMed

    Hartmann, Hagen; Wirth, Klaus; Klusemann, Markus

    2013-10-01

    It has been suggested that deep squats could cause an increased injury risk of the lumbar spine and the knee joints. Avoiding deep flexion has been recommended to minimize the magnitude of knee-joint forces. Unfortunately this suggestion has not taken the influence of the wrapping effect, functional adaptations and soft tissue contact between the back of thigh and calf into account. The aim of this literature review is to assess whether squats with less knee flexion (half/quarter squats) are safer on the musculoskeletal system than deep squats. A search of relevant scientific publications was conducted between March 2011 and January 2013 using PubMed. Over 164 articles were included in the review. There are no realistic estimations of knee-joint forces for knee-flexion angles beyond 50° in the deep squat. Based on biomechanical calculations and measurements of cadaver knee joints, the highest retropatellar compressive forces and stresses can be seen at 90°. With increasing flexion, the wrapping effect contributes to an enhanced load distribution and enhanced force transfer with lower retropatellar compressive forces. Additionally, with further flexion of the knee joint a cranial displacement of facet contact areas with continuous enlargement of the retropatellar articulating surface occurs. Both lead to lower retropatellar compressive stresses. Menisci and cartilage, ligaments and bones are susceptible to anabolic metabolic processes and functional structural adaptations in response to increased activity and mechanical influences. Concerns about degenerative changes of the tendofemoral complex and the apparent higher risk for chondromalacia, osteoarthritis, and osteochondritis in deep squats are unfounded. With the same load configuration as in the deep squat, half and quarter squat training with comparatively supra-maximal loads will favour degenerative changes in the knee joints and spinal joints in the long term. Provided that technique is learned accurately

  20. Fluoroscopic caudal epidural injections in managing chronic axial low back pain without disc herniation, radiculitis, or facet joint pain

    PubMed Central

    Manchikanti, Laxmaiah; Cash, Kimberly A; McManus, Carla D; Pampati, Vidyasagar

    2012-01-01

    Background Chronic low back pain without disc herniation is common. Various modalities of treatments are utilized in managing this condition, including epidural injections. However, there is continued debate on the effectiveness, indications, and medical necessity of any treatment modality utilized for managing axial or discogenic pain, including epidural injections. Methods A randomized, double-blind, actively controlled trial was conducted. The objective was to evaluate the ability to assess the effectiveness of caudal epidural injections of local anesthetic with or without steroids for managing chronic low back pain not caused by disc herniation, radiculitis, facet joints, or sacroiliac joints. A total of 120 patients were randomized to two groups; one group did not receive steroids (group 1) and the other group did (group 2). There were 60 patients in each group. The primary outcome measure was at least 50% improvement in Numeric Rating Scale and Oswestry Disability Index. Secondary outcome measures were employment status and opioid intake. These measures were assessed at 3, 6, 12, 18, and 24 months after treatment. Results Significant pain relief and functional status improvement (primary outcome) defined as a 50% or more reduction in scores from baseline, were observed in 54% of patients in group 1 and 60% of patients in group 2 at 24 months. In contrast, 84% of patients in group 1 and 73% in group 2 saw significant pain relief and functional status improvement in the successful groups at 24 months. Conclusion Caudal epidural injections of local anesthetic with or without steroids are effective in patients with chronic axial low back pain of discogenic origin without facet joint pain, disc herniation, and/or radiculitis. PMID:23091395

  1. Facet-joint injections for people with persistent non-specific low back pain (FIS): study protocol for a randomised controlled feasibility trial.

    PubMed

    Sandhu, Harbinder; Ellard, David R; Achana, Felix; Antrobus, James H L; Balasubramanian, Shyam; Brown, Sally; Cairns, Melinda; Griffiths, Frances; Haywood, Kirstie; Hutchinson, Charles; Lall, Ranjit; Petrou, Stavros; Stallard, Nigel; Tysall, Colin; Walsh, David A; Underwood, Martin

    2015-12-24

    The role of injections of therapeutic substances into the back as treatment for low back pain is unclear. Facet joint injections are widely used despite the absence of evidence of sustained benefit. We hypothesise that facet joint injections might facilitate engagement with physiotherapist-led, best usual care (a combined physical and psychological programme) and is a clinically and cost-effective treatment for people with suspected low back pain of facet joint origin. We present here the protocol for a randomised controlled feasibility trial for a main trial to test the above hypotheses. Patients referred to secondary care with persistent non-specific low back pain will be screened and invited to take part in the study. Those who meet the eligibility criteria will be invited for a physiotherapy assessment to confirm trial eligibility and for baseline data collection. All participants (n = 150) will be offered the best usual care package with physical and psychological components. Those randomised into the intervention arm (n = 75) will, in addition, receive intra-articular facet joint injections with local anaesthetic and steroids. Primary outcome data will be collected using daily and then weekly text messaging service for a pain score on a 0-10 scale. Questionnaire follow-up will be at 3, 6, and 12 months. Evaluation of trial processes and health economic analyses, including a value of information analysis, will be undertaken. The process evaluation will be mixed methods and will include the views of all stakeholders. Whilst this trial is a feasibility study it is currently one of the largest trials in this area. The outcomes will provide some evidence on the use of facet joint injections for patients with clinically diagnosed facet joint pain. EudraCT identifier 2014-000682-50, (registered on 12 February 14). ISRCTN registry number: ISRCTN93184143 DOI 10.1186/ISRCTN93184143 (registered on 27 February 2014).

  2. Subtalar Joint Instability and Calcaneal Spurs Associated with the Configuration of the Articular Facets of Adult Human Calcaneum in Indian Population

    PubMed Central

    Garg, Shilpi; Vasudeva, Neelam

    2016-01-01

    Introduction Morphological variations of articular facets of calcaneum may predispose people to joint instability, ligamentous laxity and development of arthritic changes in the subtalar joint. Knowledge of such variations is essential for treatment and diagnostic procedures in orthopaedic surgeries. Aim The aim of this study was to determine patterns of articular facets of calcanei and to establish its correlation with calcaneal spurs. Materials and Methods The study was conducted on 580 adult calcanei of Indian origin at Maulana Azad Medical College and pattern of articular facets were observed and classified according to five patterns described in literature. A digital vernier calliper was used to measure separation between anterior and middle facet. Degree of intersecting angle between anterior and medial facets was calculated using UTHSCSA Image Tool software. The calcaneal spurs were observed by visual inspection. Results Out of 580 calcanei, 66.55% had fused anterior and middle facets (Pattern I), 27.59% had all three facets separate (Pattern II), 5.52% had absence of anterior facet (Pattern III), 0.17% had all three facets fused (Pattern IV) and 0.17% had fused middle and posterior facets (Pattern V). A significant side variation was present in Pattern III with predominance on left side. Mean angle of intersection was 147.700 in Pattern I and 133.340 in Pattern II calcaneum. Calcaneal spurs were found in 61.38% out of which it was associated with Pattern I in 43.62%, Pattern II in 14.66% and Pattern III in 2.76%. Conclusion Individuals with Pattern I and III calcaneum were found to be at a greater risk of subtalar joint instability than individuals with Pattern II. Angle of intersection was obtuse in Pattern I which resulted in ligament laxity and unstable joint. Pattern I was more common in Indian population and this fact necessitates modifications of the western surgical techniques to suit the Indian scenario. An association between the presence of spur

  3. Estimating total knee replacement joint load ratios from kinematics.

    PubMed

    Fitzpatrick, Clare K; Rullkoetter, Paul J

    2014-09-22

    Accurate prediction of loads acting at the joint in total knee replacement (TKR) patients is key to developing experimental or computational simulations which evaluate implant designs under physiological loading conditions. In vivo joint loads have been measured for a small number of telemetric TKR patients, but in order to assess device performance across the entire patient population, a larger patient cohort is necessary. This study investigates the accuracy of predicting joint loads from joint kinematics. Specifically, the objective of the study was to assess the accuracy of internal-external (I-E) and anterior-posterior (A-P) joint load predictions from I-E and A-P motions under a given compressive load, and to evaluate the repeatability of joint load ratios (I-E torque to compressive force (I-E:C), and A-P force to compressive force (A-P:C)) for a range of compressive loading profiles. A tibiofemoral finite element model was developed and used to simulate deep knee bend, chair-rise and step-up activities for five patients. Root-mean-square (RMS) differences in I-E:C and A-P:C load ratios between telemetric measurements and model predictions were less than 1.10e-3 Nm/N and 0.035 N/N for all activities. I-E:C and A-P:C load ratios were consistently reproduced regardless of the compressive force profile applied (RMS differences less than 0.53e-3 Nm/N and 0.010 N/N, respectively). When error in kinematic measurement was introduced to the model, joint load predictions were forgiving to kinematic measurement error when conformity between femoral and tibial components was low. The prevalence of kinematic data, in conjunction with the analysis presented here, facilitates determining the scope of A-P and I-E joint loading ratios experienced by the TKR population. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Hip joint load and muscular activation during rising exercises.

    PubMed

    Németh, G; Ekholm, J; Arborelius, U P; Schüldt, K; Harms-Ringdahl, K

    1984-01-01

    The load on the hip joint and activation of the gluteus maximus, hamstrings, adductor magnus and rectus femoris muscles during rising exercises including different adaptive adjustments were investigated in nine healthy subjects. The joint load was calculated from forces recorded with a force-measuring platform and pictures on cine-film. Levels of muscular activity were recorded with rectified, low-pass filtered, time-averaged and normalized EMGs. The loading moment about the hip joint was about 45 Nm during the initial part of the rising exercise, decreasing with smaller hip angle. Increase of the backward inclination of the trunk increased the load moment, which was maintained at about the same level during the rising exercise. Two adaptive adjustments lowered the joint load: foot position further backward and reduced resistance from the device. Foot position further forward increased the joint load. The levels of muscular activity in the hip extensors were low to medium and were slightly increased by posterior foot position and increased resistance from the device. Increased backward trunk inclination increased the activity in the final part of the rising exercise.

  5. Load distribution along length of joints with segmented splines

    SciTech Connect

    Abdullaev, A.I.; Akhundova, S.M.; Bodrykh, I.G.; Kornev, T.N.

    1986-07-01

    The load distribution over the length of joints with segmented splines of a different structural use were studied on a special developed apparatus which simulates the operation of the joints. A figure of the apparatus used to determine nonuniformity of load along length of joints with segmented splines is shown. Wire resistant-type strain gages were used for strain measurement. The maximum twisting moment on the shaft was determined by an equation was created by a dynamometric wrench. The results obtained indicate that nonuniform distribution of relative deformation occurs over the length of the spline. A certain effective length of the segmented splines takes part in the load transfer. Owing to the flexibility of the ends of the segmented splines recommended for structural use, the maximum stress concentration across their length is somewhat smaller than that across the length of the standard splines; this exerts a favorable influence on the uniformity of the load distribution.

  6. Stud Reinforcement in Beam-Column Joints under Seismic Loads

    NASA Astrophysics Data System (ADS)

    Ibrahim, Hatem Hassan Ali

    Current codes recommend large amounts of shear reinforcement for reinforced concrete beam-column joints causing significant congestion. This research aims at investigating experimentally and numerically the efficiency of using studs with a head at each end in lieu of conventional closed hoops in reinforced concrete beam-column joints. The proposed reinforcement reduces congestion and ensures easier assembly of the reinforcing cage, saving labour cost and enhancing performance of the joint. Based on this research, a recommended arrangement and detailing of headed studs and their design for exterior beam-column joint are presented. The experimental investigation consisted of testing ten full-scale beam-column joint specimens under quasi-static cyclic loading. The specimens represented an exterior beam-column joint subassembly isolated at the points of contra-flexure from a typical multi-storey, multi-bay reinforced concrete frame. A test setup was developed to simulate the lateral inter-storey drift. The test parameters included: the type, arrangement and amount of shear reinforcement, the load history and rate of loading, and the amount of reinforcement for out-of-plane confinement of the joint. Envelopes of the hysteretic behaviour of the specimens and the joint deformation under shear stress are presented. The stiffness degradation, the strain levels in the joint reinforcement, the contribution of joint, beam, and column to the inter-storey drift, and the energy dissipation were compared. All the test specimens reinforced with headed studs in the joint achieved considerable enhancement in their behaviour under cyclic loads and exhibited a performance close to that of a joint reinforced with closed hoops and cross ties according to the code. All the specimens with adequate out-of-plane confinement had an equivalent behaviour compared with the code-based specimen and achieved a desirable mode of failure. Use of double-headed studs proved to be a viable option for

  7. Percutaneous radiofrequency facet joint denervation with monitoring of compound muscle action potential of the multifidus muscle group for treating chronic low back pain: a preliminary report.

    PubMed

    Kanchiku, Tsukasa; Imajo, Yasuaki; Suzuki, Hidenori; Yoshida, Yuichiro; Nishida, Norihiro; Taguchi, Toshihiko

    2014-10-01

    A retrospective review. The aim of this study was to study the effectiveness of percutaneous radiofrequency neurotomy of facet joints by monitoring compound muscle action potentials (CMAPs) of the multifidus muscle group as an objective index of treatment efficacy. Percutaneous radiofrequency neurotomy of the medial branches of the dorsal rami of the lumbar nerves is a widely accepted treatment for chronic lumbar intervertebral joint pain. However, its success rate has varied in different studies because an objective method for evaluating the facet joint denervation is lacking. Fifty-five patients (age range, 19-76 y; mean age, 55 y) with low back pain persisting for ≥3 months, in whom facet block and/or block of the medial branch of the dorsal ramus were only temporarily effective, were included. The Japanese Orthopaedic Association (JOA) scoring system for back pain was used for clinical assessment. JOA scores were measured before treatment and 1 week, 3 months, 6 months, and 12 months afterward. The improvement rate was calculated with ≥40% improvement rate defined as successful, and the success rate was subsequently evaluated. The patient success rate was 75% (41/55) at 1 week, 71% (39/55) at 3 months, 60% (33/55) at 6 months, and 51% (28/55) at 12 months after treatment. Two cases had minor postoperative complications, which were localized burning pain lasting <1 week at the site of electrode insertion. Our results suggest that percutaneous radiofrequency facet joint denervation with CMAPs monitoring is a safe, long-lasting, and effective treatment for chronic facet joint pain. CMAP monitoring may be useful as an objective index for facet denervation.

  8. Muscular loading of joints triggers cellular secretion of PRG4 into the joint fluid.

    PubMed

    Abusara, Z; Krawetz, R; Steele, B; DuVall, M; Schmidt, T; Herzog, W

    2013-04-26

    We developed a novel testing system that allows quantification of joint loading and permits analysis of changes in total protein and PRG4 contents in joint fluid of intact knees in live mice. A sequence of 15 repeat, isometric muscular contractions of "low" intensity (less than 50% of the maximal isometric muscular force), and "high" intensity (greater than 55% of maximal) were applied repeatedly (up to five times with a 15 min rest between contractions) to the mouse knee. Increases in knee joint loading were accompanied with significant increases in total protein (p<0.0001) and PRG4 concentrations in the synovial fluid. Total protein and PRG4 concentrations decreased with repeated "high" intensity loading. However, the addition of cell secretion inhibitors to the knee prior to muscular loading resulted in PRG4 levels that remained below the detection limit for all loading conditions. These results suggest that changes in synovial fluid proteins and PRG4 concentrations upon joint loading are mediated by cells within the joint, and that these changes may be used as quantitative indicators for the intensity and duration of acute joint loading, and might serve as a powerful clinical tool to assess the effectiveness of rehabilitation and prevention exercise programs.

  9. Does aquatic exercise reduce hip and knee joint loading? In vivo load measurements with instrumented implants

    PubMed Central

    Kutzner, Ines; Dymke, Jörn; Damm, Philipp; Duda, Georg N.; Günzl, Reiner; Bergmann, Georg

    2017-01-01

    Aquatic exercises are widely used for rehabilitation or preventive therapies in order to enable mobilization and muscle strengthening while minimizing joint loading of the lower limb. The load reducing effect of water due to buoyancy is a main advantage compared to exercises on land. However, also drag forces have to be considered that act opposite to the relative motion of the body segments and require higher muscle activity. Due to these opposing effects on joint loading, the load-reducing effect during aquatic exercises remains unknown. The aim of this study was to quantify the joint loads during various aquatic exercises and to determine the load reducing effect of water. Instrumented knee and hip implants with telemetric data transfer were used to measure the resultant joint contact forces in 12 elderly subjects (6x hip, 6x knee) in vivo. Different dynamic, weight-bearing and non-weight-bearing activities were performed by the subjects on land and in chest-high water. Non-weight-bearing hip and knee flexion/extension was performed at different velocities and with additional Aquafins. Joint forces during aquatic exercises ranged between 32 and 396% body weight (BW). Highest forces occurred during dynamic activities, followed by weight-bearing and slow non-weight-bearing activities. Compared to the same activities on land, joint forces were reduced by 36–55% in water with absolute reductions being greater than 100%BW during weight-bearing and dynamic activities. During non-weight-bearing activities, high movement velocities and additional Aquafins increased the joint forces by up to 59% and resulted in joint forces of up to 301%BW. This study confirms the load reducing effect of water during weight-bearing and dynamic exercises. Nevertheless, high drag forces result in increased joint contact forces and indicate greater muscle activity. By the choice of activity, movement velocity and additional resistive devices joint forces can be modulated individually in

  10. Does aquatic exercise reduce hip and knee joint loading? In vivo load measurements with instrumented implants.

    PubMed

    Kutzner, Ines; Richter, Anja; Gordt, Katharina; Dymke, Jörn; Damm, Philipp; Duda, Georg N; Günzl, Reiner; Bergmann, Georg

    2017-01-01

    Aquatic exercises are widely used for rehabilitation or preventive therapies in order to enable mobilization and muscle strengthening while minimizing joint loading of the lower limb. The load reducing effect of water due to buoyancy is a main advantage compared to exercises on land. However, also drag forces have to be considered that act opposite to the relative motion of the body segments and require higher muscle activity. Due to these opposing effects on joint loading, the load-reducing effect during aquatic exercises remains unknown. The aim of this study was to quantify the joint loads during various aquatic exercises and to determine the load reducing effect of water. Instrumented knee and hip implants with telemetric data transfer were used to measure the resultant joint contact forces in 12 elderly subjects (6x hip, 6x knee) in vivo. Different dynamic, weight-bearing and non-weight-bearing activities were performed by the subjects on land and in chest-high water. Non-weight-bearing hip and knee flexion/extension was performed at different velocities and with additional Aquafins. Joint forces during aquatic exercises ranged between 32 and 396% body weight (BW). Highest forces occurred during dynamic activities, followed by weight-bearing and slow non-weight-bearing activities. Compared to the same activities on land, joint forces were reduced by 36-55% in water with absolute reductions being greater than 100%BW during weight-bearing and dynamic activities. During non-weight-bearing activities, high movement velocities and additional Aquafins increased the joint forces by up to 59% and resulted in joint forces of up to 301%BW. This study confirms the load reducing effect of water during weight-bearing and dynamic exercises. Nevertheless, high drag forces result in increased joint contact forces and indicate greater muscle activity. By the choice of activity, movement velocity and additional resistive devices joint forces can be modulated individually in the

  11. A critical evaluation of subtalar joint arthrosis associated with middle facet talocalcaneal coalition in 21 surgically managed patients: a retrospective computed tomography review. Investigations involving middle facet coalitions-part III.

    PubMed

    Kernbach, Klaus J; Barkan, Howard; Blitz, Neal M

    2010-01-01

    Symptomatic middle facet talocalcaneal coalition is frequently associated with rearfoot arthrosis that is often managed surgically with rearfoot fusion. However, no objective method for classifying the extent of subtalar joint arthrosis exists. No study has clearly identified the extent of posterior facet arthrosis present in a large cohort treated surgically for talocalcaneal coalition through preoperative computerized axial tomography. The authors conducted a retrospective review of 21 patients (35 feet) with coalition who were surgically treated over a 12-year period for coalition on at least 1 foot. Using a predefined original staging system, the extent of the arthrosis was categorized into normal or mild (Stage I), moderate (Stage II), and severe (Stage III) arthrosis. The association of stage and age is statistically significant. All of the feet with Stage III arthrosis had fibrous coalitions. No foot with osseous coalition had Stage III arthrosis. The distribution of arthrosis staging differs between fibrous and osseous coalitions. Only fibrous coalitions had the most advanced arthrosis (Stage III), whereas osseous coalitions did not. This suggests that osseous coalitions may have a protective effect in the prevention of severe degeneration of the subtalar joint. Concomitant subtalar joint arthrosis severity progresses with age; surgeons may want to consider earlier surgical intervention to prevent arthrosis progression in patients with symptomatic middle facet talocalcaneal coalition.

  12. Temporomandibular joint loads in subjects with and without disc displacement

    PubMed Central

    Iwasaki, Laura R.; Crosby, Michael J.; Gonzalez, Yoly; McCall, Willard D.; Marx, David B.; Ohrbach, Richard; Nickel, Jeffrey C.

    2009-01-01

    The likelihood of development of degenerative joint disease (DJD) of the temporomandibular joint (TMJ) is related to the integrity of the TMJ disc. Predilection for mechanical failure of the TMJ disc may reflect inter-individual differences in TMJ loads. Nine females and eight males in each of normal TMJ disc position and bilateral disc displacement diagnostic groups consented to participate in our study. Disc position was determined by bilateral magnetic resonance images of the joints. Three-dimensional (3D) anatomical geometry of each subject was used in a validated computer-assisted numerical model to calculate ipsilateral and contralateral TMJ loads for a range of biting positions (incisor, canine, molar) and angles (1–13). Each TMJ load was a resultant vector at the anterosuperior-most mediolateral midpoint on the condyle and characterized in terms of magnitude and 3D orientation. Analysis of variance (ANOVA) was used to test for effects of biting position and angle on TMJ loads. Mean TMJ loads in subjects with disc displacement were 9.5–69% higher than in subjects with normal disc position. During canine biting, TMJ loads in subjects with disc displacement were 43% (ipsilateral condyle,p=0.029) and 49% (contralateral condyle,p=0.015) higher on average than in subjects with normal disc position. Biting angle effects showed that laterally directed forces on the dentition produced ipsilateral joint loads, which on average were 69% higher (p=0.002) compared to individuals with normal TMJ disc position. The data reported here describe large differences in TMJ loads between individuals with disc displacement and normal disc position. The results support future investigations of inter-individual differences in joint mechanics as a variable in the development of DJD of the TMJ. PMID:20890385

  13. Lumbar Facet Joint Compressive Injury Induces Lasting Changes in Local Structure, Nociceptive Scores, and Inflammatory Mediators in a Novel Rat Model

    PubMed Central

    Henry, James L.; Yashpal, Kiran; Vernon, Howard; Kim, Jaesung; Im, Hee-Jeong

    2012-01-01

    Objective. To develop a novel animal model of persisting lumbar facet joint pain. Methods. Sprague Dawley rats were anaesthetized and the right lumbar (L5/L6) facet joint was exposed and compressed to ~1 mm with modified clamps applied for three minutes; sham-operated and naïve animals were used as control groups. After five days, animals were tested for hind-paw sensitivity using von Frey filaments and axial deep tissue sensitivity by algometer on assigned days up to 28 days. Animals were sacrificed at selected times for histological and biochemical analysis. Results. Histological sections revealed site-specific loss of cartilage in model animals only. Tactile hypersensitivity was observed for the ipsi- and contralateral paws lasting 28 days. The threshold at which deep tissue pressure just elicited vocalization was obtained at three lumbar levels; sensitivity at L1 > L3/4 > L6. Biochemical analyses revealed increases in proinflammatory cytokines, especially TNF-α, IL-1α, and IL-1β. Conclusions. These data suggest that compression of a facet joint induces a novel model of local cartilage loss accompanied by increased sensitivity to mechanical stimuli and by increases in inflammatory mediators. This new model may be useful for studies on mechanisms and treatment of lumbar facet joint pain and osteoarthritis. PMID:22966427

  14. Lumbar disc degeneration was not related to spine and hip bone mineral densities in Chinese: facet joint osteoarthritis may confound the association.

    PubMed

    Pan, Jianjiang; Lu, Xuan; Yang, Ge; Han, Yongmei; Tong, Xiang; Wang, Yue

    2017-12-01

    A sample of 512 Chinese was studied and we observed that greater disc degeneration on MRI was associated with greater spine DXA BMD. Yet, this association may be confounded by facet joint osteoarthritis. BMD may not be a risk factor for lumbar disc degeneration in Chinese.

  15. Evaluation of a Robotic Assistance-System For Percutaneous Computed Tomography-Guided (CT-Guided) Facet Joint Injection: A Phantom Study

    PubMed Central

    Beyer, Lukas Philipp; Michalik, Katharina; Niessen, Christoph; da Silva, Natascha Platz Batista; Wiesinger, Isabell; Stroszczynski, Christian; Wiggermann, Philipp

    2016-01-01

    Background The aim of this study was to compare robotic assisted and freehand facet joint puncture on a phantom model in regards to time requirements and puncture accuracy. Material/Methods Forty facet joints were punctured, 20 using a robotic guidance system and 20 using a freehand procedure. Side and height of the facet joints were randomized and identical for both groups. Procedural accuracy, defined as axial and sagittal deviation, as well as the number of corrections were assessed. Procedure times for each step were documented and time requirements for pre-positioning, reconstruction, planning, and total intervention were calculated. Results Total procedure time for robotic guidance was 259±111 seconds versus 119±77 seconds for freehand procedure (p=1.0). Procedural accuracy for robotic guidance was significantly higher with 0 corrections versus 1.3 corrections for freehand procedure (p=0.02). Needle deviation in the robotics arm was 0.35±1.1 mm in the axial and 2.15±1.2 mm in the sagittal reconstruction. Conclusions Robotic assisted puncture of the facet joint allowed accurate positioning of the needle with a lower number of needle readjustments. Higher procedural accuracy was marginally offset by a slightly longer intervention time. PMID:27648509

  16. Evaluation of a Robotic Assistance-System For Percutaneous Computed Tomography-Guided (CT-Guided) Facet Joint Injection: A Phantom Study.

    PubMed

    Beyer, Lukas Philipp; Michalik, Katharina; Niessen, Christoph; Platz Batista da Silva, Natascha; Wiesinger, Isabell; Stroszczynski, Christian; Wiggermann, Philipp

    2016-09-20

    BACKGROUND The aim of this study was to compare robotic assisted and freehand facet joint puncture on a phantom model in regards to time requirements and puncture accuracy. MATERIAL AND METHODS Forty facet joints were punctured, 20 using a robotic guidance system and 20 using a freehand procedure. Side and height of the facet joints were randomized and identical for both groups. Procedural accuracy, defined as axial and sagittal deviation, as well as the number of corrections were assessed. Procedure times for each step were documented and time requirements for pre-positioning, reconstruction, planning, and total intervention were calculated. RESULTS Total procedure time for robotic guidance was 259±111 seconds versus 119±77 seconds for freehand procedure (p=1.0). Procedural accuracy for robotic guidance was significantly higher with 0 corrections versus 1.3 corrections for freehand procedure (p=0.02). Needle deviation in the robotics arm was 0.35±1.1 mm in the axial and 2.15±1.2 mm in the sagittal reconstruction. CONCLUSIONS Robotic assisted puncture of the facet joint allowed accurate positioning of the needle with a lower number of needle readjustments. Higher procedural accuracy was marginally offset by a slightly longer intervention time.

  17. Indian Hedgehog signaling pathway members are associated with magnetic resonance imaging manifestations and pathological scores in lumbar facet joint osteoarthritis

    NASA Astrophysics Data System (ADS)

    Shuang, Feng; Zhou, Ying; Hou, Shu-Xun; Zhu, Jia-Liang; Liu, Yan; Zhang, Chun-Li; Tang, Jia-Guang

    2015-05-01

    Indian Hedgehog (HH) has been shown to be involved in osteoarthritis (OA) in articular joints, where there is evidence that Indian HH blockade could ameliorate OA. It seems to play a prominent role in development of the intervertebral disc (IVD) and in postnatal maintenance. There is little work on IHH in the IVD. Hence the aim of the current study was to investigate the role of Indian Hedgehog in the pathology of facet joint (FJ) OA. 24 patients diagnosed with lumbar intervertebral disk herniation or degenerative spinal stenosis were included. Preoperative magnetic resonance imaging (MRI) and Osteoarthritis Research Society International (OARSI) histopathology grading system was correlated to the mRNA levels of GLI1, PTCH1, and HHIP in the FJs. The Weishaupt grading and OARSI scores showed high positive correlation (r = 0.894) (P < 0.01). MRI Weishaupt grades showed positive correlation with GLI1 (r = 0.491), PTCH1 (r = 0.444), and HHIP (r = 0.654) mRNA levels (P < 0.05 in each case). OARSI scores were also positively correlated with GLI1 (r = 0. 646), PTCH1 (r = 0. 518), and HHIP (r = 0.762) mRNA levels (P < 0.01 in each case). Cumulatively our findings indicate that Indian HH signaling is increased in OA and is perhaps a key component in OA pathogenesis and progression.

  18. Steel Lattice Tower Under Ultimate Load - Chosen Joint Analysis

    NASA Astrophysics Data System (ADS)

    Szafran, Jacek; Rykaluk, Kazimierz

    2017-06-01

    The main objective of the presented paper is to discuss chosen lattice tower joint behavior under structure ultimate load. Joint numerical modelling considerations are enriched with comparison to the full-scale tower pushover test results. Two independent load cases were examined: 1) where the L-sections (diagonal bracings) are loaded by the axial force only and that forces are applied in the center of the member cross section, 2) where the L-sections are loaded by the axial force and the bending moment that reproduce the effect of the eccentric connection to the gusset plates by the one leg of the angle section is added. Differences in equivalent stresses state for two independent design situations allow for conclusion that additional bending moments should be taken into account, especially for thin-walled members.

  19. The Alternating Surface Segmented Lap Joint: a Design for Thin Highly Loaded Joints

    NASA Technical Reports Server (NTRS)

    Watkins, V. E., Jr.; Firth, G. C.

    1985-01-01

    The combination of thin airfoil sections and high aerodynamic loads on many wind tunnel models presents a major problem for attachment of flap elements. Conventional methods of attaching fixed control elements such as lap and tongue-in-groove joints are not rigid enough to provide surface continuity required in high Reynolds number research. For the extreme cases, the solution has been to fabricate separate wings for each flap setting with the flap element being and integral part of the wing. Here an attractive solution to this problem, the alternating surface segmented lap joint, is discussed. This joint provides increased rigidity and lower stress levels than conventional joints. Additionally, attachment fastener loading is low and the joint can be designed to accommodate high shear levels due to bending without the use of dowel pins.

  20. Development Of an Experimental Animal Model For Lower Back Pain By Percutaneous Injury-Induced Lumbar Facet Joint Osteoarthritis

    PubMed Central

    Kim, Jae-Sung; Ahmadinia, Kasra; Li, Xin; Hamilton, John L; Andrews, Steven; Haralampus, Chris A.; Xiao, Guozhi; Sohn, Hong-Moon; You, Jae-Won; Seo, Yo-Seob; Stein, Gary S.; Wijnen, Andre J Van; Kim, Su-Gwan; Im, Hee-Jeong

    2015-01-01

    We report generation and characterization of pain-related behavior in a minimally-invasive facet joint degeneration (FJD) animal model in rats. FJD was produced by a non-open percutaneous puncture-induced injury on the right lumbar FJs at three consecutive levels. Pressure hyperalgesia in the lower back was assessed by measuring the vocalization response to pressure from a force transducer. After hyperalgesia was established, pathological changes in lumbar FJs and alterations of intervertebral foramen size were assessed by histological and imaging analyses. To investigate treatment options for lumber FJ osteoarthritis-induced pain, animals with established hyperalgesia were administered with analgesic drugs, such as morphine, a selective COX-2 inhibitor, a non-steroidal anti-inflammatory drug (NSAID) (ketorolac), or pregabalin. Effects were assessed by behavioral pain responses. One week after percutaneous puncture-induced injury of the lumbar FJs, ipsilateral primary pressure hyperalgesia developed and was maintained for at least 12 weeks without foraminal stenosis. Animals showed decreased spontaneous activity, but no secondary hyperalgesia in the hind paws. Histopathological and microfocus X-ray computed tomography analyses demonstrated that the percutaneous puncture injury resulted in osteoarthritis-like structural changes in the FJs cartilage and subchondral bone. Pressure hyperalgesia was completely reversed by morphine. The administration of celecoxib produced moderate pain reduction with no statistical significance while the administration of ketorolac and pregabalin produced no analgesic effect on FJ osteoarthritis-induced back pain. Our animal model of non-open percutanous puncture-induced injury of the lumbar FJs in rats shows similar characteristics of low back pain produced by human facet arthropathy. PMID:25858171

  1. 654 nm broad area lasers for QCW operation with a maximal facet load of 76 mW/μm

    NASA Astrophysics Data System (ADS)

    Sumpf, B.; Pohl, M.; Pittroff, W.; Staske, R.; Erbert, G.; Tränkle, G.

    2013-03-01

    Compared to diode lasers emitting in the near infrared, the development of high power diode lasers in the red spectral range is more challenging due to the applicable compound semiconductors, the limited stability of the laser facets, and the small barrier heights for electrons and holes. For CW applications, their mounting requires excellent heat removal or expansion matched submounts. For QCW operation with small duty cycles and about 2 W per 100 μm stripe width emitter, like for the pumping of Q-switched alexandrite (Cr3+:BeAl2O4) lasers at 654 nm, a compromise is the application of aluminum nitride as heat sink. The presented broad area (BA) lasers are based on a GaInP single quantum well embedded in AlGaInP waveguide layers. The structure provides a vertical far field angle of 31° (FWHM). The material data can be compiled as follows: transparency current density jT = 220 A/cm2, internal efficiency ƞi = 0.83, internal losses αi = 1.0 cm-1. BA lasers with a stripe width of 100 μm and a length of 1.5 mm were fabricated, facet coated including a passivation procedure, and mounted on AlN submounts. In QCW operation (100 μs, 35 Hz) at 15°C, the devices had threshold currents of about 600 mA, slope efficiencies up to 1.3 W/A and conversion efficiencies of 0.36. A maximal output of 6.3 W was measured. At lower temperatures of -10°C the maximal peak power was determined to 7.6 W, i.e. a facet load of 76 mW/μm. The devices showed reliable operation over 1,000 h at a peak power of 2.7 W.

  2. Early Afferent Activity from the Facet Joint after Painful Trauma to its Capsule Potentiates Neuronal Excitability and Glutamate Signaling in the Spinal Cord

    PubMed Central

    Crosby, Nathan D.; Gilliland, Taylor M.; Winkelstein, Beth A.

    2014-01-01

    Cervical facet joint injury induces persistent pain and central sensitization. Preventing the peripheral neuronal signals that initiate sensitization attenuates neuropathic pain. Yet, there is no clear relationship between facet joint afferent activity, development of central sensitization, and pain, which may be hindering effective treatments for this pain syndrome. This study investigates how afferent activity from the injured cervical facet joint affects induction of behavioral sensitivity and central sensitization. Intra-articular bupivacaine was administered to transiently suppress afferent activity immediately or 4 days after facet injury. Mechanical hyperalgesia was monitored after injury, and spinal neuronal hyperexcitability and spinal expression of proteins that promote neuronal excitability were measured on day 7. Facet injury with saline vehicle treatment induced significant mechanical hyperalgesia (p<0.027), dorsal horn neuronal hyperexcitability (p<0.026), upregulation of pERK1/2, pNR1, mGluR5, GLAST, and GFAP, and downregulation of GLT1 (p<0.032). However, intra-articular bupivacaine immediately after injury significantly attenuated hyperalgesia (p<0.0001), neuronal hyperexcitability (p<0.004), and dysregulation of excitatory signaling proteins (p<0.049). In contrast, intra-articular bupivacaine at day 4 had no effect on these outcomes. Silencing afferent activity during the development of neuronal hyperexcitability (4hr, 8hr, 1 day) attenuated hyperalgesia and neuronal hyperexcitability (p<0.045) only for the treatment given 4 hours after injury. This study suggests that early afferent activity from the injured facet induces development of spinal sensitization via spinal excitatory glutamatergic signaling. Peripheral intervention blocking afferent activity is only effective over a short period of time early after injury and before spinal modifications develop, and is independent of modulating spinal glial activation. PMID:24978827

  3. Cervical Facet Joint Infection and Associated Epidural Abscess with Streptococcus intermedius from a Dental Infection Origin A Case Report and Review.

    PubMed

    Kaye, Ian David; Protopsaltis, Themistocles S

    2016-09-01

    Pyogenic cervical facet joint infections are rare and such infections from a dental origin are even less common. Of these few cases, none have described infection with Streptococcus intermedius as the pathogen. A 65-year-old orthopaedic surgeon complained of fevers, right-sided radiating neck pain, stiffness, swelling, erythema, and right upper extremity weakness one month after he had broken a crown over his right mandibular premolar, a continued source of pain. Imaging of the cervical spine showed a right C4-C5 facet inflammatory arthropathy and a small epidural abscess that was cultured and initially treated with intravenous antibiotics. The oral maxillofacial surgery team performed an extraction of the infected, symptomatic tooth. For continued right upper extremity weakness, the patient underwent C4-C5 laminoforaminotomy and irrigation and debridement of the right C4-C5 facet joint. After 6 weeks of intravenous antibiotics, the patient's infectious and inflammatory markers had normalized. By 4 months, he had regained full strength at his upper extremity and a painless and full range of motion of his cervical spine.Pyogenic cervical facet joint infection is very rare and potentially dangerous. A high clinical suspicion and appropriate imaging, including magnetic resonance imaging, are important for correct diagnosis. Prompt medical and surgical treatment may avert complications, and although the patient presented made a complete recovery, patients may be left with neurological compromise.

  4. Differences Regarding Branded HA in Italy, Part 2: Data from Clinical Studies on Knee, Hip, Shoulder, Ankle, Temporomandibular Joint, Vertebral Facets, and Carpometacarpal Joint

    PubMed Central

    Migliore, A.; Bizzi, E.; De Lucia, O.; Delle Sedie, A.; Tropea, S.; Bentivegna, M.; Mahmoud, A.; Foti, C.

    2016-01-01

    OBJECTIVES The aim of the current study is to collect scientific data on all branded hyaluronic acid (HA) products in Italy that are in use for intra-articular (IA) injection in osteoarthritis (OA) compared with that reported in the leaflet. METHODS An extensive literature research was performed for all articles reporting data on the IA use of HA in OA. Selected studies were taken into consideration only if they are related to products based on HAs that are currently marketed in Italy with the specific joint indication for IA use in patients affected by OA. RESULTS Sixty-two HA products are marketed in Italy: 30 products are indicated for the knee but only 8 were proved with some efficacy; 9 products were effective for the hip but only 6 had hip indication; 7 products proved to be effective for the shoulder but only 3 had the indication; 5 products proved effective for the ankle but only one had the indication; 6 products were effective for the temporomandibular joint but only 2 had the indication; only 2 proved effective for vertebral facet joints but only 1 had the indication; and 5 products proved effective for the carpometacarpal joint but only 2 had the indication. CONCLUSIONS There are only a few products with some evidences, while the majority of products remain without proof. Clinicians and regulators should request postmarketing studies from pharmaceuticals to corroborate with that reported in the leaflet and to gather more data, allowing the clinicians to choose the adequate product for the patient. PMID:27279754

  5. Enhanced visible-light-driven photocatalytic H2-production activity of CdS-loaded TiO2 microspheres with exposed (001) facets

    NASA Astrophysics Data System (ADS)

    Gao, Bifen; Yuan, Xia; Lu, Penghui; Lin, Bizhou; Chen, Yilin

    2015-12-01

    CdS-loaded TiO2 microspheres with highly exposed (001) facets were prepared by hydrothermal treatment of a TiF4-HCl-H2O mixed solution followed by a chemical bath deposition of CdS onto TiO2 microspheres. The crystal structure, surficial micro-structure and photo-absorption property of the samples were characterized by XRD, FE-SEM, TEM and UV-vis diffuse reflectance spectroscopy, etc. The as-prepared samples exhibited superior visible-light-driven photocatalytic H2-production activity from lactic acid aqueous solution in comparison with CdS-sensitized TiO2 nanoparticles, whose surface was dominated by (101) facets. Photoelectrochemical measurement confirmed that (001) facet is beneficial for the transfer of photo-generated electron from CdS to TiO2 microsphere, which led to the unexpected high photocatalytic activity of CdS-loaded TiO2 microspheres.

  6. Is lumbar facet joint tropism developmental or secondary to degeneration? An international, large-scale multicenter study by the AOSpine Asia Pacific Research Collaboration Consortium.

    PubMed

    Samartzis, Dino; Cheung, Jason Pui Yin; Rajasekaran, Shanmuganathan; Kawaguchi, Yoshiharu; Acharya, Shankar; Kawakami, Mamoru; Satoh, Shigenobu; Chen, Wen-Jer; Park, Chun-Kun; Lee, Chong-Suh; Foocharoen, Thanit; Nagashima, Hideki; Kuh, Sunguk; Zheng, Zhaomin; Condor, Richard; Ito, Manabu; Iwasaki, Motoki; Jeong, Je Hoon; Luk, Keith D K; Prijambodo, Bambang; Rege, Amol; Jahng, Tae-Ahn; Luo, Zhuojing; Tassanawipas, Warat Anant; Acharya, Narayana; Pokharel, Rohit; Shen, Yong; Ito, Takui; Zhang, Zhihai; Aithala P, Janardhana; Kumar, Gomatam Vijay; Jabir, Rahyussalim Ahmad; Basu, Saumyajit; Li, Baojun; Moudgil, Vishal; Goss, Ben; Sham, Phoebe; Williams, Richard

    2016-01-01

    Facet joint tropism is asymmetry in orientation of the bilateral facets. Some studies have shown that tropism may increase the risk of disc degeneration and herniations, as well as degenerative spondylolisthesis (DS). It remains controversial whether tropism is a pre-existing developmental phenomena or secondary to progressive remodeling of the joint structure due to degenerative changes. As such, the following study addressed the occurrence of tropism of the lower lumbar spine (i.e. L3-S1) in a degenerative spondylolisthesis patient model. An international, multi-center cross-sectional study that consisted of 349 patients with single level DS recruited from 33 spine institutes in the Asia Pacific region was performed. Axial MRI/CT from L3-S1 were utilized to assess left and right facet joint sagittal angulation in relation to the coronal plane. The angulation difference between the bilateral facets was obtained. Tropism was noted if there was 8° or greater angulation difference between the facet joints. Tropism was noted at levels of DS and compared to immediate adjacent and distal non-DS levels, if applicable, to the index level. Age, sex-type and body mass index (BMI) were also noted and assessed in relation to tropism. Of the 349 subjects, there were 63.0 % females, the mean age was 61.8 years and the mean BMI was 25.6 kg/m(2). Overall, 9.7, 76.5 and 13.8 % had L3-L4, L4-L5 and L5-S1 DS, respectively. Tropism was present in 47.1, 50.6 and 31.3 % of L3-L4, L4-L5 and L5-S1 of levels with DS, respectively. Tropism involved 33.3 to 50.0 % and 33.3 to 58.8 % of the immediate adjacent and most distal non-DS levels from the DS level, respectively. Patient demographics were not found to be significantly related to tropism at any level (p > 0.05). To the authors' knowledge, this is one of the largest studies conducted, in particular in an Asian population, addressing facet joint tropism. Although levels with DS were noted to have tropism, immediate adjacent

  7. Early Osteoarthritis of the Trapeziometacarpal Joint Is Not Associated With Joint Instability during Typical Isometric Loading

    PubMed Central

    Halilaj, Eni; Moore, Douglas C.; Patel, Tarpit K.; Ladd, Amy L.; Weiss, Arnold-Peter C.; Crisco, Joseph J.

    2015-01-01

    The saddle-shaped trapeziometacarpal (TMC) joint contributes importantly to the function of the human thumb. A balance between mobility and stability is essential in this joint, which experiences high loads and is prone to osteoarthritis (OA). Since instability is considered a risk factor for TMC OA, we assessed TMC joint instability during the execution of three isometric functional tasks (key pinch, jar grasp, and jar twist) in 76 patients with early TMC OA and 44 asymptomatic controls. Computed tomography images were acquired while subjects held their hands relaxed and while they applied 80% of their maximum effort for each task. Six degree-of-freedom rigid body kinematics of the metacarpal with respect to the trapezium from the unloaded to the loaded task positions were computed in terms of a TMC joint coordinate system. Joint instability was expressed as a function of the metacarpal translation and the applied force. We found that the TMC joint was more unstable during a key pinch task than during a jar grasp or a jar twist task. Sex, age, and early OA did not have an effect on TMC joint instability, suggesting that instability during these three tasks is not a predisposing factor in TMC OA. PMID:25941135

  8. [Panlongqi tablet (Chinese characters) combined with lumbar facet joint release for the treatment of lumbar spinal stenosis of Fengshi Bizu (Chinese characters)].

    PubMed

    Deng, Xiao-chuan; Yang, Ao-fei; He, Cheng-jian

    2014-10-01

    To investigate the clinical efficacy of Panlongqi tablet (Chinese characters) combined with lumbar facet joint release for lumbar spinal stenosis of type Fengshi Bizu (Chinese characters). Since February 2012 to February 2013, 120 patients with lumbar spinal stenosis of Fengshi Bizu (Chinese characters) syndrome were retrospectively studied. According to different treatment methods, 120 patients with lumbar spinal stenosis were divided into Panlongqi tablet (Chinese characters)group and control groups, respectively. In Panlongqi tablet (Chinese characters)group, 60 patients were treated by Panlongqi tablet (Chinese characters) combined with lumbar facet joints release solution including 26 males and 34 females with an average age of (60.40±3.36) years old ranging from 46 to 65 ; the course of the disease was 2 to 15 years (averaged 7.6 years). In control group the other 60 patients were treated with lumbar facet joint release including 24 males and 36 females with an average age of (61.20±2.47) years old ranging from 48 to 63; the course was 3 to 14 years (averaged 6.9 years). The clinical effect of patients were evaluated by JOA and ODI score before treatment, at 4 weeks and 3 months after treatment. All patients were followed up for 4 to 7 months (means 5.6 months). After 3 months,7 cases in control group recurrenced symptoms,only 1 case in Panlongqi tablet (Chinese characters) group recurrenced. At 4 weeks and 3 months of follow-up, ODI score and JOA score of Panlongqi tablet group were much better than those of the control group. For lumbar spinal stenosis of type Fengshi Bizu (Chinese characters),which were treated with lumbar facet joint release with Panlongqi tablet(Chinese characters), supplemented by back muscle exercise, in relieving waist and low back pain symptoms and improving functional status of lower lumbar spine, can obtain satisfactory clinical outcome, is a good method of conservative treatment for such diseases.

  9. A New CT Method for Assessing 3D Movements in Lumbar Facet Joints and Vertebrae in Patients before and after TDR

    PubMed Central

    Svedmark, Per; Berg, Svante; Noz, Marilyn E.; Zeleznik, Michael P.; Nemeth, Gunnar; Olivecrona, Henrik

    2015-01-01

    This study describes a 3D-CT method for analyzing facet joint motion and vertebral rotation in the lumbar spine after TDR. Ten patients were examined before and then three years after surgery, each time with two CT scans: provoked flexion and provoked extension. After 3D registration, the facet joint 3D translation and segmental vertebral 3D rotation were analyzed at the operated level (L5-S1) and adjacent level (L4-L5). Pain was evaluated using VAS. The median (±SD) 3D movement in the operated level for the left facet joint was 3.2 mm (±1.9 mm) before and 3.5 mm (±1.7 mm) after surgery and for the right facet joint was 3.0 mm (±1.0 mm) before and 3.6 mm (±1.4 mm) after surgery. The median vertebral rotation in the sagittal plane at the operated level was 5.4° (±2.3°) before surgery and 6.8° (±1.7°) after surgery and in the adjacent level was 7.7° (±4.0°) before and 9.2° (±2.7°) after surgery. The median VAS was reduced from 6 (range 5–8) to 3 (range 2–8) in extension and from 4 (range 2–6) to 2 (range 1–3) in flexion. PMID:26587533

  10. Joint loads in marsupial ankles reflect habitual bipedalism versus quadrupedalism.

    PubMed

    Carlson, Kristian J; Jashashvili, Tea; Houghton, Kimberley; Westaway, Michael C; Patel, Biren A

    2013-01-01

    Joint surfaces of limb bones are loaded in compression by reaction forces generated from body weight and musculotendon complexes bridging them. In general, joints of eutherian mammals have regions of high radiodensity subchondral bone that are better at resisting compressive forces than low radiodensity subchondral bone. Identifying similar form-function relationships between subchondral radiodensity distribution and joint load distribution within the marsupial postcranium, in addition to providing a richer understanding of marsupial functional morphology, can serve as a phylogenetic control in evaluating analogous relationships within eutherian mammals. Where commonalities are established across phylogenetic borders, unifying principles in mammalian physiology, morphology, and behavior can be identified. Here, we assess subchondral radiodensity patterns in distal tibiae of several marsupial taxa characterized by different habitual activities (e.g., locomotion). Computed tomography scanning, maximum intensity projection maps, and pixel counting were used to quantify radiodensity in 41 distal tibiae of bipedal (5 species), arboreal quadrupedal (4 species), and terrestrial quadrupedal (5 species) marsupials. Bipeds (Macropus and Wallabia) exhibit more expansive areas of high radiodensity in the distal tibia than arboreal (Dendrolagus, Phascolarctos, and Trichosurus) or terrestrial quadrupeds (Sarcophilus, Thylacinus, Lasiorhinus, and Vombatus), which may reflect the former carrying body weight only through the hind limbs. Arboreal quadrupeds exhibit smallest areas of high radiodensity, though they differ non-significantly from terrestrial quadrupeds. This could indicate slightly more compliant gaits by arboreal quadrupeds compared to terrestrial quadrupeds. The observed radiodensity patterns in marsupial tibiae, though their statistical differences disappear when controlling for phylogeny, corroborate previously documented patterns in primates and xenarthrans

  11. Joint Loads in Marsupial Ankles Reflect Habitual Bipedalism versus Quadrupedalism

    PubMed Central

    Carlson, Kristian J.; Jashashvili, Tea; Houghton, Kimberley; Westaway, Michael C.; Patel, Biren A.

    2013-01-01

    Joint surfaces of limb bones are loaded in compression by reaction forces generated from body weight and musculotendon complexes bridging them. In general, joints of eutherian mammals have regions of high radiodensity subchondral bone that are better at resisting compressive forces than low radiodensity subchondral bone. Identifying similar form-function relationships between subchondral radiodensity distribution and joint load distribution within the marsupial postcranium, in addition to providing a richer understanding of marsupial functional morphology, can serve as a phylogenetic control in evaluating analogous relationships within eutherian mammals. Where commonalities are established across phylogenetic borders, unifying principles in mammalian physiology, morphology, and behavior can be identified. Here, we assess subchondral radiodensity patterns in distal tibiae of several marsupial taxa characterized by different habitual activities (e.g., locomotion). Computed tomography scanning, maximum intensity projection maps, and pixel counting were used to quantify radiodensity in 41 distal tibiae of bipedal (5 species), arboreal quadrupedal (4 species), and terrestrial quadrupedal (5 species) marsupials. Bipeds (Macropus and Wallabia) exhibit more expansive areas of high radiodensity in the distal tibia than arboreal (Dendrolagus, Phascolarctos, and Trichosurus) or terrestrial quadrupeds (Sarcophilus, Thylacinus, Lasiorhinus, and Vombatus), which may reflect the former carrying body weight only through the hind limbs. Arboreal quadrupeds exhibit smallest areas of high radiodensity, though they differ non-significantly from terrestrial quadrupeds. This could indicate slightly more compliant gaits by arboreal quadrupeds compared to terrestrial quadrupeds. The observed radiodensity patterns in marsupial tibiae, though their statistical differences disappear when controlling for phylogeny, corroborate previously documented patterns in primates and xenarthrans

  12. Shear fracture of jointed steel plates of bolted joints under impact load

    NASA Astrophysics Data System (ADS)

    Daimaruya, M.; Fujiki, H.; Ambarita, H.; Kobayashi, H.; Shin, H.-S.

    2013-07-01

    The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of bolted joints used in a car body, which contributes to crash simulations by CAE. We focus our attention on the shear fracture of the jointed steel plates of lap-bolted joints in the suspension of a car under impact load. Members of lap-bolted joints are modelled as a pair of steel plates connected by a bolt. One of the plates is a specimen subjected to plastic deformation and fracture and the other is a jig subjected to elastic deformation only. Three kinds of steel plate specimens are examined, i.e., a common steel plate with a tensile strength of 270 MPa and high tensile strength steel plates of 440 and 590 MPa used for cars. The impact shear test was performed using the split Hopkinson bar technique for tension impact, together with the static test using a universal testing machine INSTRON 5586. The behaviour of the shear stress and deformation up to rupture taking place in the joint was discussed. The obtained results suggest that a stress-based fracture criterion may be developed for the impact fracture of jointed steel plates of a lap-bolted joint.

  13. Load distributions in photoeleastic bolted-joint models

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Liu, D.

    1982-01-01

    An attempt is made to study the stresses in multiple-bolt connectors, focusing on the stress distribution in a two-pin connector, the two pins being in line and in parallel with the direction of the applied load. The photoelastic modeling approach with two-dimensional transmission photoelasticity is used. The joint models and model fringe patterns are discussed, with special attention given to the existence of a photoelastic isotropic point and to the separation of stresses.

  14. Clinical effects of computed tomography-guided lumbosacral facet joint, transforaminal epidural, and translaminar epidural injections of methylprednisolone acetate in healthy dogs.

    PubMed

    Liotta, Annalisa P; Girod, Maud; Peeters, Dominique; Sandersen, Charlotte; Couvreur, Thierry; Bolen, Géraldine

    2016-10-01

    OBJECTIVE To determine clinical effects of CT-guided lumbosacral facet joint, transforaminal epidural, and translaminar epidural injections of methylprednisolone acetate in healthy dogs. ANIMALS 15 healthy Beagles. PROCEDURES Dogs were randomly assigned to 3 groups (5 dogs/group) and received a single CT-guided lumbosacral facet joint, transforaminal epidural, or translaminar epidural injection of methylprednisolone acetate (0.1 mg/kg). Contrast medium was injected prior to injection of methylprednisolone to verify needle placement. Neurologic examinations were performed 1, 3, 7, and 10 days after the injection. In dogs with neurologic abnormalities, a final neurologic examination was performed 24 days after the procedure. RESULTS Methylprednisolone injections were successfully performed in 14 of the 15 dogs. In 1 dog, vascular puncture occurred, and the methylprednisolone injection was not performed. No major or minor complications were identified during or immediately after the procedure, other than mild transient hyperthermia. During follow-up neurologic examinations, no motor, sensory, or postural deficits were identified, other than mild alterations in the patellar, withdrawal, cranial tibial, and perineal reflexes in some dogs. Overall, altered reflexes were observed in 11 of the 14 dogs, during 27 of 65 neurologic examinations. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that CT-guided lumbosacral facet joint, transforaminal epidural, and translaminar epidural injections of methylprednisolone acetate were associated with few complications in healthy dogs. However, the number of dogs evaluated was small, and additional studies are needed to assess clinical efficacy and safety of these procedures.

  15. Predictors of knee joint loading after anterior cruciate ligament reconstruction.

    PubMed

    Wellsandt, Elizabeth; Khandha, Ashutosh; Manal, Kurt; Axe, Michael J; Buchanan, Thomas S; Snyder-Mackler, Lynn

    2017-03-01

    Anterior cruciate ligament (ACL) injury results in altered knee joint mechanics which frequently continue even after ACL reconstruction. The persistence of altered mechanical loading of the knee is of concern due to its likely role in the development of post-traumatic osteoarthritis (OA). Joint contact forces are associated with post-traumatic OA development, but evaluation of factors influencing the magnitude of contact forces after ACL injury is needed to advance current strategies aimed at preventing post-traumatic OA. Therefore, the purpose of this study was to identify predictive factors of knee joint contact forces after ACL reconstruction. Thirty athletes completed standard gait analysis with surface electromyography 6 months after ACL reconstruction. An electromyographic-driven musculoskeletal model was used to estimate joint contact forces. External knee adduction moment was a significant predictor of medial compartment contact forces in both limbs, while vertical ground reaction force and co-contraction only contributed significantly in the uninvolved limb. The large influence of the knee adduction moment on joint contact forces provides mechanistic clues to understanding the mechanical pathway of post-traumatic OA after ACL injury. Statement of Clinical Significance: This study provides critical information in improving the understanding of mechanisms influencing the development of post-traumatic OA after ACL injury. Further work is needed to identify additional driving factors of joint loading in the ACL-injured limb and develop treatment strategies to avert the deleterious consequences of post-traumatic OA. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:651-656, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  16. Finite Element Analysis of Sacroiliac Joint Fixation under Compression Loads

    PubMed Central

    Bruna-Rosso, Claire; Arnoux, Pierre-Jean; Bianco, Rohan-Jean; Godio-Raboutet, Yves; Fradet, Léo

    2016-01-01

    Background Sacroiliac joint (SIJ) is a known chronic pain-generator. The last resort of treatment is the arthrodesis. Different implants allow fixation of the joint, but to date there is no tool to analyze their influence on the SIJ biomechanics under physiological loads. The objective was to develop a computational model to biomechanically analyze different parameters of the stable SIJ fixation instrumentation. Methods A comprehensive finite element model (FEM) of the pelvis was built with detailed SIJ representation. Bone and sacroiliac joint ligament material properties were calibrated against experimentally acquired load-displacement data of the SIJ. Model evaluation was performed with experimental load-displacement measurements of instrumented cadaveric SIJ. Then six fixation scenarios with one or two implants on one side with two different trajectories (proximal, distal) were simulated and assessed with the FEM under vertical compression loads. Results The simulated S1 endplate displacement reduction achieved with the fixation devices was within 3% of the experimentally measured data. Under compression loads, the uninstrumented sacrum exhibited mainly a rotation motion (nutation) of 1.38° and 2.80° respectively at 600 N and 1000 N, with a combined relative translation (0.3 mm). The instrumentation with one screw reduced the local displacement within the SIJ by up to 62.5% for the proximal trajectory vs. 15.6% for the distal trajectory. Adding a second implant had no significant additional effect. Conclusion A comprehensive finite element model was developed to assess the biomechanics of SIJ fixation. SIJ devices enable to reduce the motion, mainly rotational, between the sacrum and ilium. Positioning the implant farther from the SIJ instantaneous rotation center was an important factor to reduce the intra-articular displacement. Clinical relevance Knowledge provided by this biomechanical study enables improvement of SIJ fixation through optimal implant

  17. Incorporation of lower neck shear forces to predict facet joint injury risk in low-speed automotive rear impacts.

    PubMed

    Stemper, Brian D; Storvik, Steven G

    2010-06-01

    Lower neck shear force remains a viable candidate for a low-velocity automotive rear-impact injury criterion. Data were previously reported to demonstrate high correlations between the magnitude of lower neck shear force and lower cervical spine facet joint motions. The present study determined the ability of lower neck shear force to predict soft-tissue injury risk in simulated automotive rear impacts. Rear-impact tests were conducted at two velocities and with two seatback orientations using a Hybrid III anthropomorphic test device (ATD) and stock automobile seats from 2007 model year vehicles. Higher velocities and more vertical seatback orientations were associated with higher injury risk based on computational modeling simulations performed in this study. Six cervical spine injury criteria including NIC, Nij, Nkm, LNL, and lower neck shear force and bending moment, increased with impact velocity. NIC, Nij, and shear force were most sensitive to changes in impact velocity. Four metrics, including Nkm, LNL, and lower neck shear force and bending moment, increased for tests with more vertical seatback orientations. Shear force was most sensitive to changes in seatback orientation. Peak values for shear force, NIC, and Nij occurred approximately at the time of head restraint contact for all four test conditions. Therefore, of the six investigated metrics, lower neck shear force was the only metric to demonstrate consistency with regard to injury risk and timing of peak magnitudes. These results demonstrate the ability of lower neck shear force to predict injury risk during low velocity automotive rear impacts and warrant continued investigation into the sensitivity and applicability of this metric for other rear-impact conditions.

  18. Solid Rocket Booster Hydraulic Pump Port Cap Joint Load Testing

    NASA Technical Reports Server (NTRS)

    Gamwell, W. R.; Murphy, N. C.

    2004-01-01

    The solid rocket booster uses hydraulic pumps fabricated from cast C355 aluminum alloy, with 17-4 PH stainless steel pump port caps. Corrosion-resistant steel, MS51830 CA204L self-locking screw thread inserts are installed into C355 pump housings, with A286 stainless steel fasteners installed into the insert to secure the pump port cap to the housing. In the past, pump port cap fasteners were installed to a torque of 33 Nm (300 in-lb). However, the structural analyses used a significantly higher nut factor than indicated during tests conducted by Boeing Space Systems. When the torque values were reassessed using Boeing's nut factor, the fastener preload had a factor of safety of less than 1, with potential for overloading the joint. This paper describes how behavior was determined for a preloaded joint with a steel bolt threaded into steel inserts in aluminum parts. Finite element models were compared with test results. For all initial bolt preloads, bolt loads increased as external applied loads increased. For higher initial bolt preloads, less load was transferred into the bolt, due to external applied loading. Lower torque limits were established for pump port cap fasteners and additional limits were placed on insert axial deformation under operating conditions after seating the insert with an initial preload.

  19. The effect of different design concepts in lumbar total disc arthroplasty on the range of motion, facet joint forces and instantaneous center of rotation of a L4-5 segment.

    PubMed

    Schmidt, Hendrik; Midderhoff, Stefan; Adkins, Kyle; Wilke, Hans-Joachim

    2009-11-01

    Although both unconstrained and constrained core lumbar artificial disc designs are in clinical use, the effect of their design on the range of motion, center of rotations, and facet joint forces is not well understood. It is assumed that the constrained configuration causes a fixed center of rotation with high facet forces, while the unconstrained configuration leads to a moving center of rotation with lower loaded facets. The authors disagree with both assumptions and hypothesized that the two different designs do not lead to substantial differences in the results. For the different implant designs, a three-dimensional finite element model was created and subsequently inserted into a validated model of a L4-5 lumbar spinal segment. The unconstrained design was represented by two implants, the Charité disc and a newly developed disc prosthesis: Slide-Disc. The constrained design was obtained by a modification of the Slide-Disc whereby the inner core was rigidly connected to the lower metallic endplate. The models were exposed to an axial compression preload of 1,000 N. Pure unconstrained moments of 7.5 Nm were subsequently applied to the three anatomical main planes. Except for extension, the models predicted only small and moderate inter-implant differences. The calculated values were close to those of the intact segment. For extension, a large difference of about 45% was calculated between both Slide-Disc designs and the Charité disc. The models predicted higher facet forces for the implants with an unconstrained core compared to an implant with a constrained core. All implants caused a moving center of rotation. Except for axial rotation, the unconstrained and constrained configurations mimicked the intact situation. In axial rotation, only the Slide- Disc with mobile core reproduced the intact behavior. Results partially support our hypothesis and imply that different implant designs do not lead to strong differences in the range of motion and the location

  20. The efficacy of conventional radiofrequency denervation in patients with chronic low back pain originating from the facet joints: a meta-analysis of randomized controlled trials.

    PubMed

    Lee, Chang-Hyun; Chung, Chun Kee; Kim, Chi Heon

    2017-05-30

    Radiofrequency denervation is commonly used for the treatment of chronic facet joint pain that has been refractory to more conservative treatments, although the evidence supporting this treatment has been controversial. We aimed to elucidate the precise effects of radiofrequency denervation in patients with low back pain originating from the facet joints relative to those obtained using control treatments, with particular attention to consistency in the denervation protocol. A meta-analysis of randomized controlled trials was carried out. Adult patients undergoing radiofrequency denervation or control treatments (sham or epidural block) for facet joint disease of the lumbar spine comprised the patient sample. Visual analog scale (VAS) pain scores were measured and stratified by response of diagnostic block procedures. We searched PubMed, Embase, Web of Science, and the Cochrane Database for randomized controlled trials regarding radiofrequency denervation and control treatments for back pain. Changes in VAS pain scores of the radiofrequency group were compared with those of the control group as well as the minimal clinically important difference (MCID) for back pain VAS. Meta-regression model was developed to evaluate the effect of radiofrequency treatment according to responses of diagnostic block while controlling for other variables. We then calculated mean differences and 95% confidence intervals (CIs) using random-effects models. We included data from seven trials involving 454 patients who had undergone radiofrequency denervation (231 patients) and control treatments such as sham or epidural block procedures (223 patients). The radiofrequency group exhibited significantly greater improvements in back pain score when compared with the control group for 1-year follow-up. Although the average improvement in VAS scores exceeded the MCID, the lower limit of the 95% CI encompassed the MCID. A subgroup of patients who responded very well to diagnostic block

  1. Prediction and Validation of Load-Dependent Behavior of the Tibiofemoral and Patellofemoral Joints During Movement

    PubMed Central

    Lenhart, Rachel L.; Kaiser, Jarred; Smith, Colin R.; Thelen, Darryl G.

    2016-01-01

    The study objective was to construct and validate a subject-specific knee model that can simulate full six degree of freedom tibiofemoral and patellofemoral joint behavior in the context of full body movement. Segmented MR images were used to reconstruct the geometry of 14 ligament bundles and articular cartilage surfaces. The knee was incorporated into a lower extremity musculoskeletal model, which was then used to simulate laxity tests, passive knee flexion, active knee flexion, and human walking. Simulated passive and active knee kinematics were shown to be consistent with subject-specific measures obtained via dynamic MRI. Anterior tibial translation and internal tibial rotation exhibited the greatest variability when uncertainties in ligament properties were considered. When used to simulate walking, the model predicted knee kinematic patterns that differed substantially from passive joint behavior. Predictions of mean knee cartilage contact pressures during normal gait reached 6.2 and 2.8 MPa on the medial tibial plateau and patellar facets, respectively. Thus, the dynamic modeling framework can be used to simulate the interaction of soft tissue loads and cartilage contact during locomotion activities, and therefore provides a basis to simulate the effects of soft tissue injury and surgical treatment on functional knee mechanics. PMID:25917122

  2. Effects of Enzymatic Degradation after Loading in Temporomandibular Joint

    PubMed Central

    Asakawa-Tanne, Y.; Su, S.; Kunimatsu, R.; Hirose, N.; Mitsuyoshi, T.; Okamoto, Y.; Tanaka, E.; Tanne, K.

    2015-01-01

    Synovial fluid of the joint decreases friction between the cartilage surfaces and reduces cartilage wear during articulation. Characteristic changes of synovial fluid have been shown in patients with osteoarthritis (OA) in the temporomandibular joint (TMJ). OA is generally considered to be induced by excessive mechanical stress. However, whether the changes in synovial fluid precede the mechanical overloading or vice versa remains unclear. In the present study, our purpose was to examine if the breakdown of joint lubrication affects the frictional properties of mandibular condylar cartilage and leads to subsequent degenerative changes in TMJ. We measured the frictional coefficient in porcine TMJ by a pendulum device after digestion with hyaluronidase (HAase) or trypsin. Gene expressions of interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), matrix metalloproteinases (MMPs), type II collagen, and histology were examined after prolonged cyclic loading by an active pendulum system. The results showed that the frictional coefficient increased significantly after HAase (35%) or trypsin (74%) treatment. Gene expression of IL-1β, COX-2, and MMPs-1, -3, and -9 increased significantly in enzyme-treated TMJs after cyclic loading. The increase in the trypsin-treated group was greater than that in the HAase-treated group. Type II collagen expression was reduced in both enzyme-treated groups. Histology revealed surface fibrillation and increased MMP-1 in the trypsin-treated group, as well as increased IL-1β in both enzyme-treated groups after cyclic loading. The findings demonstrated that the compromised lubrication in TMJ is associated with altered frictional properties and surface wear of condylar cartilage, accompanied by release of pro-inflammatory and matrix degradation mediators under mechanical loading. PMID:25503611

  3. Ultimate strength of high-load-capacity composite bolted joints

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Lightfoot, M. C.

    1979-01-01

    Presented are the results of a series of tests initiated to obtain baseline data on the load-carrying capacity of bolted joints designed to carry large loads, specifically up to 222 kN (50 kips). The major testing purposes were to determine the load carrying capacity as a function of the width and thickness of the joint and the diameter and number of bolts, and to observe the failure mode. A total of 100 tests were conducted on three different specimen configurations. The specimens were fabricated from a T300/5208 fiber/resin system in a quasi-isotropic lay-up. The results presented indicate that for a given ratio of specimen width to hole diameter, the specimens with the smaller holes sustained a higher net-section tensile stress before failure. In addition, for a given ratio of specimen width to hole diameter, the thinner specimens withstood a higher net-section stress. No attempt has been made to correlate the results with theoretical predictions.

  4. Development of fracture facets from a crack loaded in mode I+III: Solution and application of a model 2D problem

    NASA Astrophysics Data System (ADS)

    Leblond, Jean-Baptiste; Frelat, Joël

    2014-03-01

    It is experimentally well-known that a crack loaded in mode I+III propagates through formation of discrete fracture facets inclined at a certain tilt angle on the original crack plane, depending on the ratio of the mode III to mode I initial stress intensity factors. Pollard et al. (1982) have proposed to calculate this angle by considering the tractions on all possible future infinitesimal facets and assuming shear tractions to be zero on that which will actually develop. In this paper we consider the opposite case of well-developed facets; the stress field near the lateral fronts of such facets becomes independent of the initial crack and essentially 2D in a plane perpendicular to the main direction of crack propagation. To determine this stress field, we solve the model 2D problem of an infinite plate containing an infinite periodic array of cracks inclined at some angle on a straight line, and loaded through uniform stresses at infinity. This is done first analytically, for small values of this angle, by combining Muskhelishvili's (1953) formalism and a first-order perturbation procedure. The formulae found for the 2D stress intensity factors are then extended in an approximate way to larger angles by using another reference solution, and finally assessed through comparison with some finite element results. To finally illustrate the possible future application of these formulae to the prediction of the stationary tilt angle, we introduce the tentative assumption that the 2D mode II stress intensity factor is zero on the lateral fronts of the facets. An approximate formula providing the tilt angle as a function of the ratio of the mode III to mode I stress intensity factors of the initial crack is deduced from there. This formula, which slightly depends on the type of loading imposed, predicts somewhat smaller angles than that of Pollard et al. (1982).

  5. Modeling of Anisotropic Rock Joints Under Cyclic Loading (Invited)

    NASA Astrophysics Data System (ADS)

    White, J. A.

    2013-12-01

    This work describes a constitutive framework for modeling the behavior of rough joints under cyclic loading. Particular attention is paid to the intrinsic links between dilatancy, surface degradation, and mobilized shear strength. The framework also accounts for the important effect of shear-induced anisotropy. Both the governing formulation and an algorithm for implicit numerical integration are presented. While the proposed methods are general, we also postulate a specific model that is compared with experimental data. It employs relatively few free parameters, but shows good agreement with laboratory tests.

  6. The frictional coefficient of the temporomandibular joint and its dependency on the magnitude and duration of joint loading.

    PubMed

    Tanaka, E; Kawai, N; Tanaka, M; Todoh, M; van Eijden, T; Hanaoka, K; Dalla-Bona, D A; Takata, T; Tanne, K

    2004-05-01

    In synovial joints, friction between articular surfaces leads to shear stress within the cartilaginous tissue, which might result in tissue rupture and failure. Joint friction depends on synovial lubrication of the articular surfaces, which can be altered due to compressive loading. Therefore, we hypothesized that the frictional coefficient of the temporomandibular joint (TMJ) is affected by the magnitude and duration of loading. We tested this by measuring the frictional coefficient in 20 intact porcine TMJs using a pendulum-type friction tester. The mean frictional coefficient was 0.0145 (SD 0.0027) after a constant loading of 50 N during 5 sec. The frictional coefficient increased with the length of the preceding loading duration and exceeded 0.0220 (SD 0.0014) after 1 hr. Application of larger loading (80 N) resulted in significantly larger frictional coefficients. In conclusion, the frictional coefficient in the TMJ was proportional to the magnitude and duration of joint loading.

  7. A review of percutaneous techniques for low back pain and neuralgia: current trends in epidural infiltrations, intervertebral disk and facet joint therapies

    PubMed Central

    Kelekis, Alexis

    2016-01-01

    Low back pain and neuralgia due to spinal pathology are very common symptoms debilitating numerous patients with peak prevalence at ages between 45 and 60 years. Intervertebral discs and facet joints act as pain sources in the vast majority of the cases. Diagnosis is based on the combination of clinical examination and imaging studies. Therapeutic armamentarium for low back pain and neuralgia due to intervertebral discs and/or facet joints includes conservative therapy, injections, percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments which can be performed as outpatient procedures. In cases of facet joint syndrome, they include, apart from injections, neurolysis with radiofrequency/cryoablation, MR-guided high-intensity focused ultrasound and percutaneous fixation techniques. In case of discogenic pain, apart from infiltrations, therapeutic techniques can be classified in to two main categories: decompression (mechanical, thermal, chemical) techniques and biomaterials implantation/disc cell therapies. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. This article will report clinical and imaging findings for each pathology type and the association with treatment decision. In addition, we will describe in detail all possible treatment techniques for low back pain and neuralgia, and we will report recently published results of these techniques summarizing the data concerning safety and effectiveness as well as the level of evidence. Finally, we will try to provide a rational approach for the therapy of low back pain and neuralgia by means of minimally invasive imaging-guided percutaneous techniques. PMID:26463233

  8. A review of percutaneous techniques for low back pain and neuralgia: current trends in epidural infiltrations, intervertebral disk and facet joint therapies.

    PubMed

    Filippiadis, Dimitrios K; Kelekis, Alexis

    2016-01-01

    Low back pain and neuralgia due to spinal pathology are very common symptoms debilitating numerous patients with peak prevalence at ages between 45 and 60 years. Intervertebral discs and facet joints act as pain sources in the vast majority of the cases. Diagnosis is based on the combination of clinical examination and imaging studies. Therapeutic armamentarium for low back pain and neuralgia due to intervertebral discs and/or facet joints includes conservative therapy, injections, percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments which can be performed as outpatient procedures. In cases of facet joint syndrome, they include, apart from injections, neurolysis with radiofrequency/cryoablation, MR-guided high-intensity focused ultrasound and percutaneous fixation techniques. In case of discogenic pain, apart from infiltrations, therapeutic techniques can be classified in to two main categories: decompression (mechanical, thermal, chemical) techniques and biomaterials implantation/disc cell therapies. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. This article will report clinical and imaging findings for each pathology type and the association with treatment decision. In addition, we will describe in detail all possible treatment techniques for low back pain and neuralgia, and we will report recently published results of these techniques summarizing the data concerning safety and effectiveness as well as the level of evidence. Finally, we will try to provide a rational approach for the therapy of low back pain and neuralgia by means of minimally invasive imaging-guided percutaneous techniques.

  9. Critical Values of Facet Joint Angulation and Tropism in the Development of Lumbar Degenerative Spondylolisthesis: An International, Large-Scale Multicenter Study by the AOSpine Asia Pacific Research Collaboration Consortium

    PubMed Central

    Samartzis, Dino; Cheung, Jason Pui Yin; Rajasekaran, Shanmuganathan; Kawaguchi, Yoshiharu; Acharya, Shankar; Kawakami, Mamoru; Satoh, Shigenobu; Chen, Wen-Jer; Park, Chun-Kun; Lee, Chong-Suh; Foocharoen, Thanit; Nagashima, Hideki; Kuh, Sunguk; Zheng, Zhaomin; Condor, Richard; Ito, Manabu; Iwasaki, Motoki; Jeong, Je Hoon; Luk, Keith D. K.; Prijambodo, Bambang; Rege, Amol; Jahng, Tae-Ahn; Luo, Zhuojing; Tassanawipas, Warat; Acharya, Narayana; Pokharel, Rohit; Shen, Yong; Ito, Takui; Zhang, Zhihai; Aithala P, Janardhana; Kumar, Gomatam Vijay; Jabir, Rahyussalim Ahmad; Basu, Saumyajit; Li, Baojun; Moudgil, Vishal; Goss, Ben; Sham, Phoebe; Williams, Richard

    2015-01-01

    Study Design  An international, multicenter cross-sectional image-based study performed in 33 institutions in the Asia Pacific region. Objective  The study addressed the role of facet joint angulation and tropism in relation to L4–L5 degenerative spondylolisthesis (DS). Methods  The study included 349 patients (63% females; mean age: 61.8 years) with single-level DS; 82 had no L4–L5 DS (group A) and 267 had L4–L5 DS (group B). Axial computed tomography and magnetic resonance imaging were utilized to assess facet joint angulations and tropism (i.e., asymmetry between facet joint angulations) between groups. Results  There was a statistically significant difference between group A (left mean: 46.1 degrees; right mean: 48.2 degrees) and group B (left mean: 55.4 degrees; right mean: 57.5 degrees) in relation to bilateral L4–L5 facet joint angulations (p < 0.001). The mean bilateral angulation difference was 7.4 and 9.6 degrees in groups A and B, respectively (p = 0.025). A critical value of 58 degrees or greater significantly increased the likelihood of DS if unilateral (adjusted OR: 2.5; 95% CI: 1.2 to 5.5; p = 0.021) or bilateral facets (adjusted OR: 5.9; 95% CI: 2.7 to 13.2; p < 0.001) were involved. Facet joint tropism was found to be relevant between 16 and 24 degrees angulation difference (adjusted OR: 5.6; 95% CI: 1.2 to 26.1; p = 0.027). Conclusions  In one of the largest studies assessing facet joint orientation in patients with DS, greater sagittal facet joint angulation was associated with L4-L5 DS, with a critical value of 58 degrees or greater increasing the likelihood of the condition for unilateral and bilateral facet joint involvement. Specific facet joint tropism categories were noted to be associated with DS. PMID:27433424

  10. Interaction of Bearing and Tensile Loads on Creep Properties of Joints

    NASA Technical Reports Server (NTRS)

    Bodine, E G; Carlson, R L; Manning, G K

    1956-01-01

    The interaction of bearing and tensile loads on the creep behavior of joints was studied. A specimen was designed for this study which possessed some of the general features of pin and rivet joint connections and an apparatus was constructed to apply both bearing and tensile loads to the joint model. Deformation measurements were made by use of a photogrid printed on the joint model.

  11. An International Multicenter Study Assessing the Role of Ethnicity on Variation of Lumbar Facet Joint Orientation and the Occurrence of Degenerative Spondylolisthesis in Asia Pacific: A Study from the AOSpine Asia Pacific Research Collaboration Consortium

    PubMed Central

    Williams, Richard; Cheung, Jason Pui Yin; Goss, Ben; Rajasekaran, Shanmuganathan; Kawaguchi, Yoshiharu; Acharya, Shankar; Kawakami, Mamoru; Satoh, Shigenobu; Chen, Wen-Jer; Park, Chun-Kun; Lee, Chong-Suh; Foocharoen, Thanit; Nagashima, Hideki; Kuh, Sunguk; Zheng, Zhaomin; Condor, Richard; Ito, Manabu; Iwasaki, Motoki; Jeong, Je Hoon; Luk, Keith D. K.; Prijambodo, Bambang; Rege, Amol; Jahng, Tae-Ahn; Luo, Zhuojing; Tassanawipas, Warat; Acharya, Narayana; Pokharel, Rohit; Shen, Yong; Ito, Takui; Zhang, Zhihai; Aithala P, Janardhana; Kumar, Gomatam Vijay; Jabir, Rahyussalim Ahmad; Basu, Saumyajit; Li, Baojun; Moudgil, Vishal; Sham, Phoebe; Samartzis, Dino

    2015-01-01

    Study Design A multinational, multiethnic, cross-sectional image-based study was performed in 33 institutions, representing 10 countries, which were part of the AOSpine Asia Pacific Research Collaboration Consortium. Objective Lumbar facet joint orientation has been reported to be associated with the development of degenerative spondylolisthesis (DS). The role of ethnicity regarding facet joint orientation remains uncertain. As such, the following study was performed across a wide-ranging population base to assess the role of ethnicity in facet joint orientation in patients with DS in the Asia Pacific region. Methods Lateral standing X-rays and axial magnetic resonance imaging scans were obtained for patients with lumbar DS. The DS parameters and facet joint angulations were assessed from L3–S1. Sex, age, body mass index (BMI), and ethnicity were also noted. Results The study included 371 patients with known ethnic origin (mean age: 62.0 years; 64% males, 36% females). The mean BMI was 25.6 kg/m2. The level of DS was most prevalent at L4–L5 (74.7%). There were 28.8% Indian, 28.6% Japanese, 18.1% Chinese, 8.6% Korean, 6.5% Thai, 4.9% Caucasian, 2.7% Filipino, and 1.9% Malay patients. Variations in facet joint angulations were noted from L3 to S1 and between patients with and without DS (p < 0.05). No differences were noted with regards to sex and overall BMI to facet joint angulations (p > 0.05); however, increasing age was found to increase the degree of angulation throughout the lumbar spine (p < 0.05). Accounting for age and the presence or absence of DS at each level, no statistically significant differences between ethnicity and degree of facet joint angulations from L3–L5 were noted (p > 0.05). Ethnic variations were noted in non-DS L5–S1 facet joint angulations, predominantly between Caucasian, Chinese, and Indian ethnicities (p < 0.05). Conclusions This study is the first to suggest that ethnicity may not play a role in

  12. An International Multicenter Study Assessing the Role of Ethnicity on Variation of Lumbar Facet Joint Orientation and the Occurrence of Degenerative Spondylolisthesis in Asia Pacific: A Study from the AOSpine Asia Pacific Research Collaboration Consortium.

    PubMed

    Williams, Richard; Cheung, Jason Pui Yin; Goss, Ben; Rajasekaran, Shanmuganathan; Kawaguchi, Yoshiharu; Acharya, Shankar; Kawakami, Mamoru; Satoh, Shigenobu; Chen, Wen-Jer; Park, Chun-Kun; Lee, Chong-Suh; Foocharoen, Thanit; Nagashima, Hideki; Kuh, Sunguk; Zheng, Zhaomin; Condor, Richard; Ito, Manabu; Iwasaki, Motoki; Jeong, Je Hoon; Luk, Keith D K; Prijambodo, Bambang; Rege, Amol; Jahng, Tae-Ahn; Luo, Zhuojing; Tassanawipas, Warat; Acharya, Narayana; Pokharel, Rohit; Shen, Yong; Ito, Takui; Zhang, Zhihai; Aithala P, Janardhana; Kumar, Gomatam Vijay; Jabir, Rahyussalim Ahmad; Basu, Saumyajit; Li, Baojun; Moudgil, Vishal; Sham, Phoebe; Samartzis, Dino

    2016-02-01

    Study Design A multinational, multiethnic, cross-sectional image-based study was performed in 33 institutions, representing 10 countries, which were part of the AOSpine Asia Pacific Research Collaboration Consortium. Objective Lumbar facet joint orientation has been reported to be associated with the development of degenerative spondylolisthesis (DS). The role of ethnicity regarding facet joint orientation remains uncertain. As such, the following study was performed across a wide-ranging population base to assess the role of ethnicity in facet joint orientation in patients with DS in the Asia Pacific region. Methods Lateral standing X-rays and axial magnetic resonance imaging scans were obtained for patients with lumbar DS. The DS parameters and facet joint angulations were assessed from L3-S1. Sex, age, body mass index (BMI), and ethnicity were also noted. Results The study included 371 patients with known ethnic origin (mean age: 62.0 years; 64% males, 36% females). The mean BMI was 25.6 kg/m(2). The level of DS was most prevalent at L4-L5 (74.7%). There were 28.8% Indian, 28.6% Japanese, 18.1% Chinese, 8.6% Korean, 6.5% Thai, 4.9% Caucasian, 2.7% Filipino, and 1.9% Malay patients. Variations in facet joint angulations were noted from L3 to S1 and between patients with and without DS (p < 0.05). No differences were noted with regards to sex and overall BMI to facet joint angulations (p > 0.05); however, increasing age was found to increase the degree of angulation throughout the lumbar spine (p < 0.05). Accounting for age and the presence or absence of DS at each level, no statistically significant differences between ethnicity and degree of facet joint angulations from L3-L5 were noted (p > 0.05). Ethnic variations were noted in non-DS L5-S1 facet joint angulations, predominantly between Caucasian, Chinese, and Indian ethnicities (p < 0.05). Conclusions This study is the first to suggest that ethnicity may not play a role in facet

  13. Fluoroscopic cervical epidural injections in chronic axial or disc-related neck pain without disc herniation, facet joint pain, or radiculitis

    PubMed Central

    Manchikanti, Laxmaiah; Cash, Kimberly A; Pampati, Vidyasagar; Malla, Yogesh

    2012-01-01

    Background While chronic neck pain is a common problem in the adult population, with a typical 12-month prevalence of 30%–50%, there is a lack of consensus regarding its causes and treatment. Despite limited evidence, cervical epidural injections are one of the commonly performed nonsurgical interventions in the management of chronic neck pain. Methods A randomized, double-blind, active, controlled trial was conducted to evaluate the effectiveness of cervical interlaminar epidural injections of local anesthetic with or without steroids for the management of chronic neck pain with or without upper extremity pain in patients without disc herniation, radiculitis, or facet joint pain. Results One hundred and twenty patients without disc herniation or radiculitis and negative for facet joint pain by means of controlled diagnostic medial branch blocks were randomly assigned to one of two treatment groups, ie, injection of local anesthetic only (group 1) or local anesthetic mixed with nonparticulate betamethasone (group 2). The primary outcome of significant pain relief and improvement in functional status (≥50%) was demonstrated in 72% of group 1 and 68% of group 2. The overall average number of procedures per year was 3.6 in both groups with an average total relief per year of 37–39 weeks in the successful group over a period of 52 weeks. Conclusion Cervical interlaminar epidural injections of local anesthetic with or without steroids may be effective in patients with chronic function-limiting discogenic or axial pain. PMID:22826642

  14. Antibiotic-loaded bone cement and periprosthetic joint infection.

    PubMed

    Chen, Antonia F; Parvizi, Javad

    2014-01-01

    Antibiotic-loaded bone cement (ALBC) is commonly used for antibiotic delivery during total joint arthroplasty (TJA) for prevention or treatment of periprosthetic joint infection (PJI). ALBC is commonly used in two-stage exchange arthroplasty with static and dynamic spacers, beads, rods, and other custom spacers. The use of commercially available or hand-made ALBC for primary and revision TJA to prevent infection has also been studied. Commonly used antibiotics include gentamicin, tobramycin, and vancomycin powder, and these antibiotics can be used alone or in combination, depending on the organism present. ALBC can be prepared by hand mixing to increase porosity and improve antibiotic elution or by vacuum-mixing to improve tensile fatigue strength. Vacuum-mixed cement is predominantly used in primary TJA, whereas hand-mixed cement is often used in two-stage exchange arthroplasty for shaping spacers and beads. Inadequate strength of ALBC spacers can result in mechanical failure, including fracture or dislocation of spacers. Additionally, studies have demonstrated that the use of antibiotics in cement, especially aminoglycosides like gentamicin and tobramycin that can elute into the bloodstream, may result in acute renal failure. Using antibiotics in ALBC can also theoretically increase antibiotic resistance and the likelihood of obtaining a negative culture if subsequent aspirations are performed. Overall, ALBC is an effective medical implant tool that can be used for treating and preventing PJI.

  15. Virtual reality imaging with real-time ultrasound guidance for facet joint injection: a proof of concept.

    PubMed

    Clarke, Collin; Moore, John; Wedlake, Christopher; Lee, Donald; Ganapathy, Su; Salbalbal, Maher; Wilson, Timothy; Peters, Terry; Bainbridge, Daniel

    2010-05-01

    Facet interventions continue to be used in pain management. Computed tomographic (CT) images can be registered into a virtual world that includes images generated by an ultrasound (US) probe tracked in real time, permitting guidance of tracked needles. We acquired CT-generated 3-dimensional (3D) images of 2 models and a cadaver. Three-dimensional representations of a US probe and needle were generated. A magnetic system tracked the needle and US probe. Using the US, 3D CT images were registered to the model/cadaver. Images were fused on a single interface. Facet injections were performed in the models and cadaver with radio-opaque markers. A postprocedure CT image determined appropriate placement. The virtual reality system described demonstrates technical innovations that may lead to future advancements in the area of percutaneous interventions in the management of pain.

  16. [Dynamic loads at knee joint of trans-tibial amputee on different terrains].

    PubMed

    Jia, Xiaohong; Zhang, Ming; Fan, Yubo; Wang, Rencheng

    2005-04-01

    Dynamic loads at knee joint of amputee are fundamental for rehabilitation of knee injury and prosthesis design. In this paper, a 3-D model for calculation of dynamic load at knee joint of trans-tibial amputee was developed. Gait analysis was done on three terrains including normal level walking, upstairs and downstairs. Dynamic loads at knee joint were calculated during one gait cycle. The results show that gait patterns and dynamic loads at knee joint were different among these three terrains. Although the general waveforms were about the same, the motion range of knee joint, ground reaction forces and loads at knee joint when walking upstairs or downstairs were larger than those in a normal level walking. The quantitative findings provide the theoretical basis of gait analysis and prosthesis design for trans-tibial amputee.

  17. Medial and lateral foot loading and its effect on knee joint loading.

    PubMed

    Schwachmeyer, Verena; Kutzner, Ines; Bornschein, Jan; Bender, Alwina; Dymke, Jörn; Bergmann, Georg

    2015-10-01

    The medial knee contact force may be lowered by modified foot loading to prevent the progression of unilateral gonarthrosis but the real effects of such gait modifications are unknown. This study investigates how walking with a more medial or lateral rollover of the foot influences the in vivo measured knee contact forces. Five subjects with telemeterized knee implants walked on a treadmill with pronounced lateral or medial foot loading. Acoustic feedback of peak foot pressure was used to facilitate the weight bearing shift. The resultant contact force, Fres, the medial contact force, Fmed, and the force distribution Fmed/Fres across the tibial plateau were computed from the measured joint contact loads. During lateral foot loading, the two maxima of Fres during the stance phase, Peak 1 and Peak 2, increased by an average of 20% and 12%, respectively. The force distribution was changed by only -3%/+2%. As a result, Fmed increased by +16%/+17%. Medial foot loading, on the other hand, changed Fres only slightly, but decreased the distribution by -18%/-11%. This led to average reductions of Fmed by -18%/-18%. The reductions were realized by kinematic adaptations, such as increases of ankle eversion, step width and foot progression angle. Medial foot loading consistently reduced the medial knee compartment, and may be a helpful gait modification for patients with pronounced medial gonarthrosis. The increase of Fmed during lateral foot loading was most likely caused by muscular co-contractions. Long-term training may lead to more efficient gait and reduce co-contractions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Normal dynamic deformation characteristics of non-consecutive jointed rock masses under impact loads

    NASA Astrophysics Data System (ADS)

    Zeng, Sheng; Jiang, Bowei; Sun, Bing

    2017-08-01

    In order to study deformation characteristics of non-consecutive single jointed rock masses under impact loads, we used the cement mortar materials to make simulative jointed rock mass samples, and tested the samples under impact loads by the drop hammer. Through analyzing the time-history signal of the force and the displacement, first we find that the dynamic compression displacement of the jointed rock mass is significantly larger than that of the intact jointless rock mass, the compression displacement is positively correlated with the joint length and the impact height. Secondly, the vertical compressive displacement of the jointed rock mass is mainly due to the closure of opening joints under small impact loads. Finally, the peak intensity of the intact rock mass is larger than that of the non-consecutive jointed rock mass and negatively correlated with the joint length under the same impact energy.

  19. Ultrasonic measurement and monitoring of loads in bolts used in structural joints

    NASA Astrophysics Data System (ADS)

    Koshti, Ajay M.

    2015-04-01

    The paper is an overview of work by the author in measuring and monitoring loads in bolts using an ultrasonic extensometer. A number of cases of bolted joints are covered. These include, a clamped joint with clearance fit between the bolt and hole, a clamped joint with bolt in an interference fit with the hole, a flanged joint which allows the flange and bolt to bend; and a shear joint in a clevis and tang configuration. These applications were initially developed for measuring and monitoring preload in National Aeronautics and Space Administration (NASA) Space Shuttle Orbiter critical joints but are also applicable for monitoring loads in other critical bolted joints of structures such as transportation bridges and other aerospace structures. The papers cited here explain how to set-up a model to estimate the ultrasonic load factor and accuracy for the ultrasonic preload application in a clamped joint with clearance fit. The ultrasonic preload application for clamped joint with bolt in an interference fit can also be used to measure diametrical interference between the bolt shank and hole, as well as interference pressure on the bolt shank. Results of simulation and experimental data are given to demonstrate use of ultrasonic measurements in a shear joint. A bolt in a flanged joint experiences both tensile and bending loads. This application involves measurement of bending and tensile preload in a bolt. The ultrasonic beam bends due to bending load on the bolt. Results of a numerical technique to compute the trace of ultrasonic ray are presented.

  20. Ultrasonic Measurement and Monitoring of Loads in Bolts used in Structural Joints

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay

    2015-01-01

    The paper is an overview of work by the author in measuring and monitoring loads in bolts using an ultrasonic extensometer. A number of cases of bolted joints are covered. These include, a clamped joint with clearance fit between the bolt and hole, a clamped joint with the bolt in an interference fit with the hole, a flanged joint which allows the flange and bolt to bend; and a shear joint in a clevis and tang configuration. These applications were initially developed for measuring and monitoring preload in the NASA Space Shuttle Orbiter critical joints but are also applicable for monitoring loads in other critical bolted joints of structures such as transportation bridges and other aerospace structures. The paper explains how to set-up a model to estimate the load factor and accuracy for the ultrasonic preload application in a clamped joint with clearance fit. The ultrasonic preload application for clamped joint with bolt in an interference fit can also be used to measure diametrical interference between the bolt shank and hole; and interference pressure on the bolt shank. Model and experimental data are given to demonstrate use of ultrasonic measurements in a shear joint. A bolt in a flanged joint experiences both tensile and bending loads. This application involves measurement of bending and tensile preload in a bolt. The ultrasonic beam bends due to the bending load on the bolt. A numerical technique to compute the trace of ultrasonic ray is presented.

  1. Synthesis of Pt-Loaded Self-Interspersed Anatase TiO2 with a Large Fraction of (001) Facets for Efficient Photocatalytic Nitrobenzene Degradation.

    PubMed

    Wang, Wei-Kang; Chen, Jie-Jie; Li, Wen-Wei; Pei, Dan-Ni; Zhang, Xing; Yu, Han-Qing

    2015-09-16

    TiO2 is capable of directly utilizing solar energy for sustainable energy harvest and water purification. Facet-dependent performance of TiO2 has attracted enormous interests due to its tunable photocatalytic activity toward photoredox transformations, but information about the noble-metal-loaded TiO2 for its facet-dependent photocatalytic performance, especially in pollutant degradation systems, is limited. In this work, inspired by our previous theoretical calculations about the roles of the crystal surface in Pt-loaded TiO2 in its enhanced photocatalytic capacity, TiO2 nanocrystals with interspersed polyhedron nanostructures and coexposed (001) and (101) surfaces as a support of Pt nanoparticles are prepared in a simple and relatively green route. Also, their performance for photocatalytic degradation of nitrobenzene (NB), a model organic pollutant, is explored. The experimental results demonstrate that the NB photodegradation and photoconversion efficiencies are significantly enhanced by uniformly loading Pt nanoparticles on the crystal surfaces, but the Pt nanoparticles deposited on only the (101) surface have no contribution to the improved NB photodegradation. Furthermore, the liquid chromatography mass spectrometry results also show that NB photodegradation tends to proceed on the (001) surface of Pt/TiO2 for the generation of nitrophenol intermediates through the photooxidation pathway. This work provides a new route to design and construct advanced photocatalysts toward pollutant photoredox conversions and deepens our fundamental understanding about crystal surface engineering.

  2. Photonic Waveguide Choke Joint with Non-Absorptive Loading

    NASA Technical Reports Server (NTRS)

    Wollack, Edward J. (Inventor); U-Yen, Kongpop (Inventor); Chuss, David T. (Inventor)

    2016-01-01

    A waveguide choke joint includes a first array of pillars positioned on a substrate, each pillar in the first array of pillars having a first size and configured to receive an input plane wave at a first end of the choke joint. The choke joint has a second end configured to transmit the input plane wave away from the choke joint. The choke joint further includes a second array of pillars positioned on the substrate between the first array of pillars and the second end of the choke joint. Each pillar in the second array of pillars has a second size. The choke joint also has a third array of pillars positioned on the substrate between the second array and the second end of the choke joint. Each pillar in the third array of pillars has a third size.

  3. Numerical Modeling of Jointed Rock Under Compressive Loading Using X-ray Computerized Tomography

    NASA Astrophysics Data System (ADS)

    Yu, Qinglei; Yang, Shengqi; Ranjith, P. G.; Zhu, Wancheng; Yang, Tianhong

    2016-03-01

    As jointed rocks consist of joints embedded within intact rock blocks, the presence and geometrical fabric of joints have a great influence on the mechanical behavior of rock. With consideration of the actual spatial shape of joints, a numerical model is proposed to investigate the fracture evolution mechanism of jointed rocks. In the proposed model, computerized tomography (CT) scanning is first used to capture the microstructure of a jointed sandstone specimen, which is artificially fabricated by loading the intact sample until the residual strength, and then digital image processing (DIP) techniques are applied to characterize the geometrical fabric of joints from the CT images. A simple vectorization method is used to convert the microstructure based on a cross-sectional image into a layer of 3-D vectorized microstructure and the overall 3-D model of the jointed sandstone including the real spatial shape of the joints is established by stacking the layers in a specific sequence. The 3-D model is then integrated into a well-established code [three-dimensional Rock Failure Process Analysis, (RFPA3D)]. Using the proposed model, a uniaxial compression test of the jointed sandstone is simulated. The results show that the presence of joints can produce tensile stress zones surrounding them, which result in the fracture of jointed rocks under a relatively small external load. In addition, the spatial shape of the joints has a great influence on the fracture process of jointed rocks.

  4. Can extra-articular strains be used to measure facet contact forces in the lumbar spine? An in-vitro biomechanical study.

    PubMed

    Zhu, Q A; Park, Y B; Sjovold, S G; Niosi, C A; Wilson, D C; Cripton, P A; Oxland, T R

    2008-02-01

    Experimental measurement of the load-bearing patterns of the facet joints in the lumbar spine remains a challenge, thereby limiting the assessment of facet joint function under various surgical conditions and the validation of computational models. The extra-articular strain (EAS) technique, a non-invasive measurement of the contact load, has been used for unilateral facet joints but does not incorporate strain coupling, i.e. ipsilateral EASs due to forces on the contralateral facet joint. The objectives of the present study were to establish a bilateral model for facet contact force measurement using the EAS technique and to determine its effectiveness in measuring these facet joint contact forces during three-dimensional flexibility tests in the lumbar spine. Specific goals were to assess the accuracy and repeatability of the technique and to assess the effect of soft-tissue artefacts. In the accuracy and repeatability tests, ten uniaxial strain gauges were bonded to the external surface of the inferior facets of L3 of ten fresh lumbar spine specimens. Two pressure-sensitive sensors (Tekscan) were inserted into the joints after the capsules were cut. Facet contact forces were measured with the EAS and Tekscan techniques for each specimen in flexion, extension, axial rotation, and lateral bending under a +/- 7.5 N m pure moment. Four of the ten specimens were tested five times in axial rotation and extension for repeatability. These same specimens were disarticulated and known forces were applied across the facet joint using a manual probe (direct accuracy) and a materials-testing system (disarticulated accuracy). In soft-tissue artefact tests, a separate set of six lumbar spine specimens was used to document the virtual facet joint contact forces during a flexibility test following removal of the superior facet processes. Linear strain coupling was observed in all specimens. The average peak facet joint contact forces during flexibility testing was greatest in

  5. Synthesis and photocatalytic properties of Palladium-loaded three dimensional flower-like anatase TiO2 with dominant {001} facets.

    PubMed

    Bai, Xue; Lv, Lingling; Zhang, Xiaoyuan; Hua, Zulin

    2016-04-01

    Palladium-loaded (Pd-loaded) anatase TiO2 with dominant {001} facets used as photocatalysts was prepared by a two-step process. Three dimensional flower-like structures of anatase TiO2 with exposed {001} facets were synthesized by solvothermal method, and then Pd nanoparticles were photodeposited onto the {101} surface of TiO2 by UV reduction. The resulting Pd/TiO2 was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectra. Characterization results indicated that the flower-like structures of anatase TiO2 were assembled by two dimensional nanosheets with a thickness of approximately 10nm and a length of approximately 1.0μm. The Pd/TiO2 nanocomposites with improved visible-light-harvesting capability, high charge-hole mobility, and low electron-hole recombination exhibited improved photocatalytic performance in degrading bisphenol A. This study provided new insights into the fabrication and practical application of high-performance photocatalysts in degrading organic pollutants. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Low-Friction, High-Stiffness Joint for Uniaxial Load Cell

    NASA Technical Reports Server (NTRS)

    Lewis, James L.; Le, Thang; Carroll, Monty B.

    2007-01-01

    A universal-joint assembly has been devised for transferring axial tension or compression to a load cell. To maximize measurement accuracy, the assembly is required to minimize any moments and non-axial forces on the load cell and to exhibit little or no hysteresis. The requirement to minimize hysteresis translates to a requirement to maximize axial stiffness (including minimizing backlash) and a simultaneous requirement to minimize friction. In practice, these are competing requirements, encountered repeatedly in efforts to design universal joints. Often, universal-joint designs represent compromises between these requirements. The improved universal-joint assembly contains two universal joints, each containing two adjustable pairs of angular-contact ball bearings. One might be tempted to ask why one could not use simple ball-and-socket joints rather than something as complex as universal joints containing adjustable pairs of angularcontact ball bearings. The answer is that ball-and-socket joints do not offer sufficient latitude to trade stiffness versus friction: the inevitable result of an attempt to make such a trade in a ball-and-socket joint is either too much backlash or too much friction. The universal joints are located at opposite ends of an axial subassembly that contains the load cell. The axial subassembly includes an axial shaft, an axial housing, and a fifth adjustable pair of angular-contact ball bearings that allows rotation of the axial housing relative to the shaft. The preload on each pair of angular-contact ball bearings can be adjusted to obtain the required stiffness with minimal friction, tailored for a specific application. The universal joint at each end affords two degrees of freedom, allowing only axial force to reach the load cell regardless of application of moments and non-axial forces. The rotational joint on the axial subassembly affords a fifth degree of freedom, preventing application of a torsion load to the load cell.

  7. Modeling of Rock Joints Under Cyclic Loading Conditions Using Discontinuous Deformation Analysis

    NASA Astrophysics Data System (ADS)

    Ma, Shuqi; He, Chuan; Zhao, Zhiye; Nie, Wen; Zhu, Xing; Zhang, Zhenyu

    2017-05-01

    The shear strength of rock joints is an important factor to be considered when analyzing the stability of jointed rock mass. Rock joints tend to have smaller shear resistances in the reverse shearing than that of the forward shearing. A conceptual model describing the general shear behavior of rock joints under cyclic loading and the Barton-Bandis joint model considering the surface roughness degradation are implemented into the two-dimensional discontinuous deformation analysis (DDA) model. The modified DDA model is empirically validated by cyclic shear tests on two types of rock joints. Numerical simulations agree well with the experimental results, indicating that the DDA model is capable of describing the varying shear behaviors of rock joints subjected to cyclic loading conditions.

  8. Shape, Loading, and Motion in the Bioengineering Design, Fabrication, and Testing of Personalized Synovial Joints

    PubMed Central

    Williams, Gregory M.; Chan, Elaine F.; Temple-Wong, Michele M.; Bae, Won C.; Masuda, Koichi; Bugbee, William D.; Sah, Robert L.

    2009-01-01

    With continued development and improvement of tissue engineering therapies for small articular lesions, increased attention is being focused on the challenge of engineering partial or whole synovial joints. Joint-scale constructs could have applications in the treatment of large areas of articular damage or in biological arthroplasty of severely degenerate joints. This review considers the roles of shape, loading and motion in synovial joint mechanobiology and their incorporation into the design, fabrication, and testing of engineered partial or whole joints. Incidence of degeneration, degree of impairment, and efficacy of current treatments are critical factors in choosing a target for joint bioengineering. The form and function of native joints may guide the design of engineered joint-scale constructs with respect to size, shape, and maturity. Fabrication challenges for joint-scale engineering include controlling chemo-mechano-biological microenvironments to promote the development and growth of multiple tissues with integrated interfaces or lubricated surfaces into anatomical shapes, and joint-scale bioreactors which nurture and stimulate the tissue with loading and motion. Finally, evaluation of load-bearing and tribological properties can range from tissue to joint scale and can focus on biological structure at present or after adaptation. PMID:19815214

  9. Local Dynamic Joint Stability During Human Treadmill Walking in Response to Lower Limb Segmental Loading Perturbations.

    PubMed

    Beaudette, Shawn M; Worden, Timothy A; Kamphuis, Megan; Vallis, Lori Ann; Brown, Stephen H M

    2015-09-01

    Our purpose was to quantify changes in local dynamic stability (LDS) of the lumbar spine, hip, knee, and ankle in response to changes in lower limb segment mass, as well as to quantify temporal adaptations to segment loading during treadmill walking. Results demonstrate that increased mass distal to a joint yields either the maintenance of, or increased stabilization of, that particular joint relative to the unloaded condition. Increased mass proximal to a particular joint resulted in joint destabilization. The hip and ankle LDS were observed to change temporally, independent of segment loading condition, suggesting adaptation to walking on a treadmill interface.

  10. A Revolute Joint With Linear Load-Displacement Response for Precision Deployable Structures

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Warren, Peter A.; Peterson, Lee D.

    1996-01-01

    NASA Langley Research center is developing key structures and mechanisms technologies for micron-accuracy, in-space deployment of future space instruments. Achieving micron-accuracy deployment requires significant advancements in deployment mechanism design such as the revolute joint presented herein. The joint presented herein exhibits a load-cycling response that is essentially linear with less than two percent hysteresis, and the joint rotates with less than one in.-oz. of resistance. A prototype reflector metering truss incorporating the joint exhibits only a few microns of kinematic error under repeated deployment and impulse loading. No other mechanically deployable structure found in literature has been demonstrated to be this kinematically accurate.

  11. Hip joint contact loads in older adults during recovery from forward loss of balance by stepping.

    PubMed

    Graham, David F; Modenese, Luca; Trewartha, Grant; Carty, Christopher P; Constantinou, Maria; Lloyd, David G; Barrett, Rod S

    2016-09-06

    Hip joint contact loads during activities of daily living are not generally considered high enough to cause acute bone or joint injury. However there is some evidence that hip joint loads may be higher in stumble recovery from loss of balance. A common laboratory method used to evaluate balance recovery performance involves suddenly releasing participants from various static forward lean magnitudes (perturbation intensities). Prior studies have shown that when released from the same perturbation intensity, some older adults are able to recover with a single step, whereas others require multiple steps. The main purpose of this study was to use a musculoskeletal model to determine the effect of three balance perturbation intensities and the use of single versus multiple recovery steps on hip joint contact loads during recovery from forward loss of balance in community dwelling older adults (n=76). We also evaluated the association of peak hip contact loads with perturbation intensity, step length and trunk flexion angle at foot contact at each participant׳s maximum recoverable lean angle (MRLA). Peak hip joint contact loads were computed using muscle force estimates obtained using Static Optimisation and increased as lean magnitude was increased and were on average 32% higher for Single Steppers compared to Multiple Steppers. At the MRLA, peak hip contact loads ranged from 4.3 to 12.7 body weights and multiple linear stepwise regression further revealed that initial lean angle, step length and trunk angle at foot contact together explained 27% of the total variance in hip joint contact load. Overall findings indicated that older adults experience peak hip joint contact loads during maximal balance recovery by stepping that in some cases exceeded loads reported to cause mechanical failure of cadaver femurs. While step length and trunk flexion angle are strong predictors of step recovery performance they are at best moderate predictors of peak hip joint loading

  12. Heavily loaded joints for assembling aerobrake support trusses

    NASA Technical Reports Server (NTRS)

    Bandel, Hannskarl; Olsson, Nils; Levintov, Boris

    1990-01-01

    The major emphasis was to develop erectable joints for large aerobrake support trusses. The truss joints must be able to withstand the large forces experienced by the truss during the aero-pass, as well as be easily assembled and disassembled on orbit by astronauts or robots. Other important design considerations include; strength, stiffness, and allowable error in strut length. Six mechanical joint designs, as well as a seventh joint design, where a high strength epoxy is injected to make the connection rigid, are presented.

  13. In vivo hip joint loads and pedal forces during ergometer cycling.

    PubMed

    Damm, P; Dymke, J; Bender, A; Duda, G; Bergmann, G

    2017-07-26

    The rising prevalence of osteoarthritis and an increase in total hip replacements calls for attention to potential therapeutic activities. Cycling is considered as a low impact exercise for the hip joint and hence recommended. However, there are limited data about hip joint loading to support this claim. The aim of this study was to measure synchronously the in vivo hip joint loads and pedal forces during cycling. The in vivo hip joint loads were measured in 5 patients with instrumented hip implants. Data were collected at several combinations of power and cadence, at two saddle heights. Joint loads and pedal forces showed strong linear correlation with power. So the relationship between the external pedal forces and internal joint forces was shown. While cycling at different cadences the minimum joint loads were acquired at 60RPM. The lower saddle height configuration results in an approximately 15% increase compared to normal saddle height. The results offered new insights into the actual effects of cycling on the hip joint and can serve as useful tools while developing an optimum cycling regimen for individuals with coxarthrosis or following total hip arthroplasty. Due to the relatively low contact forces, cycling at a moderate power level of 90W at a normal saddle height is suitable for patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Analysis of Operation of Arch Frictional Joint Loaded with the Impact of Freely Falling Mass

    NASA Astrophysics Data System (ADS)

    Brodny, Jarosław

    2013-03-01

    Yielding support, commonly applied to secure dog headings, is made of carrying elements in the form of steel frames and friction props. Yielding capacity of this support is realized in frictional joints, which due to their geometry can be divided to straight and arch joints. Occurring in steel frames arch frictional joints are characterized with more complex loading state than straight joints used in friction props. In the article, there is presented an analysis of the state of stress and deformation of the arch frictional joint, which was carried out on the model of these joints using finite element method. The scope of the analysis included two methods of loading of arch frictional joint, namely its axial compression and bending. In both cases, joints were loaded dynamically with the impact of freely falling mass. Arch joints with and without passive pressure were submitted to an axial compression. Physical model of the frictional joint was developed on the basis of a system applied during the stand tests. To solve mathematical model an explicit integration method was used. As a result of analyses carried out, temporal courses of force transmitted through the frictional joint, and displacements of section sliding down were determined. On the basis of the temporal courses, dependences between maximum value of force transmitted through the frictional joint and the height from which the impact mass falls down were determined. Distributions of reduced stresses in elements of frictional joint were also determined and the state of deformation was described. In order to emphasize the difference between straight and arch frictional joints, also an analysis of internal forces in arch frictional joint depending on its geometrical parameters without and with passive pressure was presented.

  15. Patellofemoral joint loading during stair ambulation in people with patellofemoral osteoarthritis.

    PubMed

    Fok, Laurence A; Schache, Anthony G; Crossley, Kay M; Lin, Yi-Chung; Pandy, Marcus G

    2013-08-01

    To determine whether people with patellofemoral (PF) joint osteoarthritis (OA) ascend and descend stairs with different PF joint loading, knee joint moments, lower limb kinematics, and muscle forces compared to healthy people. We recruited 17 participants with isolated PF joint OA, 13 participants with concurrent PF joint OA and tibiofemoral (TF) joint OA, and 21 age-matched controls. Joint kinematics and ground reaction forces were measured while participants ascended and descended stairs at a self-selected speed. Musculoskeletal computer modeling was used to determine lower limb muscle forces and the PF joint reaction force, and these parameters were compared between groups by analysis of variance. Compared to their healthy counterparts, participants with isolated PF joint OA and participants with concurrent PF and TF joint OA ascended and descended stairs with lower knee extension moments, lower quadriceps muscle forces, lower PF joint reaction forces, and increased anterior pelvic tilt. Participants with OA also ascended stairs with increased hip flexion angles and descended stairs with smaller knee flexion angles and smaller hip abductor muscle forces. No differences were evident between the two groups with OA. Compared to their healthy counterparts, people with PF joint OA (with or without concurrent TF joint OA) exhibit lower PF joint reaction forces during stair ascent and descent, in conjunction with lower knee extension moments and lower quadriceps muscle forces. Copyright © 2013 by the American College of Rheumatology.

  16. Multiaxial fatigue behavior of tubular joints under variable amplitude loading conditions

    SciTech Connect

    Abel, A.; Wu, S.; Yu, X.

    1994-12-31

    An analytical approach has been developed for the study of fatigue life of tubular joints used in offshore structures when random loading conditions are applied. The method is based on linear elastic fracture mechanics and surface fatigue crack propagation. Using the line-spring element method, stress intensity factors of a part-through surface crack are computed. Crack propagation under random loading conditions with distribution parameters is calculated leading to fatigue life prediction if the statistical characteristics of random loading conditions are known. This method can be also used in predicting the remaining lives of tubular joints when cracks are detected and random loading conditions are applied.

  17. Increased joint loads during walking--a consequence of pain relief in knee osteoarthritis.

    PubMed

    Henriksen, Marius; Simonsen, Erik B; Alkjaer, Tine; Lund, Hans; Graven-Nielsen, Thomas; Danneskiold-Samsøe, Bente; Bliddal, Henning

    2006-12-01

    Joint pain is a primary symptom in knee osteoarthritis (OA), but the effect of pain and pain relief on the knee joint mechanics of walking is not clear. In this study, the effects of local knee joint analgesia on knee joint loads during walking were studied in a group of knee osteoarthritis patients. A group of healthy subjects was included as a reference group. The joint loads were calculated from standard gait analysis data obtained with standardised walking speed (4 km/h). The gait analyses were performed before and after pain relief by intra-articular injections of 10 mL lidocaine (1%). Pre-injection measurements revealed lower joint loads in the OA group compared to the reference group. Following injections pain during walking decreased significantly and the joint loads increased in the OA group during the late single support phase to a level comparable to the reference group. Although the patients walked with less compressive knee joint forces compared to the reference group, the effects of pain relief may accelerate the degenerative changes.

  18. Patellofemoral Joint and Achilles Tendon Loads During Overground and Treadmill Running.

    PubMed

    Willy, Richard W; Halsey, Lisa; Hayek, Andrew; Johnson, Holly; Willson, John D

    2016-08-01

    Study Design Level 4, controlled laboratory study. Background Little is known regarding how the potential differences between treadmill and overground running may affect patellofemoral joint and Achilles tendon loading characteristics. Objectives To compare measures of loading of the patellofemoral joint and Achilles tendon across treadmill and overground running in healthy, uninjured runners. Methods Eighteen healthy runners ran at their self-selected speed on an instrumented treadmill and overground, while 3-D running mechanics were sampled. A musculoskeletal model derived peak load, rate of loading, and estimated cumulative load per 1 km of continuous running for the patellofemoral joint and Achilles tendon for each condition. Data were analyzed via paired t tests and Pearson correlations to detect differences and assess relationships, respectively, between the 2 running mediums. Results No differences (P>.05) were found between treadmill and overground running for peak load, rate of loading, or estimated cumulative patellofemoral joint stress per 1 km of continuous running. However, treadmill running resulted in 12.5% greater peak Achilles tendon force (P<.001), 15.6% greater loading rate of Achilles tendon force (P<.001), and 14.2% greater estimated cumulative Achilles tendon force per 1 km of continuous running (P<.001) compared with overground running. There were strong (r>0.70) and moderate agreements (r>0.50) for most patellofemoral joint and Achilles measures, respectively, between treadmill and overground running. Conclusion No differences were observed in loading characteristics to the patellofemoral joint between running mediums; however, treadmill running resulted in greater Achilles tendon loading compared with overground running. Future investigations should examine whether sudden bouts of treadmill running may increase the risk of mechanical overload of the Achilles tendon in runners who habitually train overground. J Orthop Sports Phys Ther 2016

  19. Effect of walking speed on lower extremity joint loading in graded ramp walking.

    PubMed

    Schwameder, Hermann; Lindenhofer, Elke; Müller, Erich

    2005-07-01

    Lower extremity joint loading during walking is strongly affected by the steepness of the slope and might cause pain and injuries in lower extremity joint structures. One feasible measure to reduce joint loading is the reduction of walking speed. Positive effects have been shown for level walking, but not for graded walking or hiking conditions. The aim of the study was to quantify the effect of walking speed (separated into the two components, step length and cadence) on the joint power of the hip, knee and ankle and to determine the knee joint forces in uphill and downhill walking. Ten participants walked up and down a ramp with step lengths of 0.46, 0.575 and 0.69 m and cadences of 80, 100 and 120 steps per minute. The ramp was equipped with a force platform and the locomotion was filmed with a 60 Hz video camera. Loading of the lower extremity joints was determined using inverse dynamics. A two-dimensional knee model was used to calculate forces in the knee structures during the stance phase. Walking speed affected lower extremity joint loading substantially and significantly. Change of step length caused much greater loading changes for all joints compared with change of cadence; the effects were more distinct in downhill than in uphill walking. The results indicate that lower extremity joint loading can be effectively controlled by varying step length and cadence during graded uphill and downhill walking. Hikers can avoid or reduce pain and injuries by reducing walking speed, particularly in downhill walking.

  20. Bearing-Bypass Loading On Bolted Composite Joints

    NASA Technical Reports Server (NTRS)

    Crews, John H.; Naik, Rajiv-Vikas A.

    1989-01-01

    Unexpected interaction between effects of bypass and bearing loads reported. Combined experimental and analytical study described in NASA technical memorandum conducted to investigate effects of simultaneous bearing and bypass loading on graphite/epoxy laminate. Results important in emerging technology of composites for use in wide range of applications. Includes applications in aircraft, boats, and automobiles, in which bolted connections to composites increasingly important.

  1. Joint Procrustes Analysis for Simultaneous Nonsingular Transformation of Component Score and Loading Matrices

    ERIC Educational Resources Information Center

    Adachi, Kohei

    2009-01-01

    In component analysis solutions, post-multiplying a component score matrix by a nonsingular matrix can be compensated by applying its inverse to the corresponding loading matrix. To eliminate this indeterminacy on nonsingular transformation, we propose Joint Procrustes Analysis (JPA) in which component score and loading matrices are simultaneously…

  2. The Effects of Load Carriage and Muscle Fatigue on Lower-Extremity Joint Mechanics

    ERIC Educational Resources Information Center

    Wang, He; Frame, Jeff; Ozimek, Elicia; Leib, Daniel; Dugan, Eric L.

    2013-01-01

    Military personnel are commonly afflicted by lower-extremity overuse injuries. Load carriage and muscular fatigue are major stressors during military basic training. Purpose: To examine effects of load carriage and muscular fatigue on lower-extremity joint mechanics during walking. Method: Eighteen men performed the following tasks: unloaded…

  3. The Effects of Load Carriage and Muscle Fatigue on Lower-Extremity Joint Mechanics

    ERIC Educational Resources Information Center

    Wang, He; Frame, Jeff; Ozimek, Elicia; Leib, Daniel; Dugan, Eric L.

    2013-01-01

    Military personnel are commonly afflicted by lower-extremity overuse injuries. Load carriage and muscular fatigue are major stressors during military basic training. Purpose: To examine effects of load carriage and muscular fatigue on lower-extremity joint mechanics during walking. Method: Eighteen men performed the following tasks: unloaded…

  4. The Relationship between Knee Joint Loading Rate During Walking and Degenerative Changes on Magnetic Resonance Imaging

    PubMed Central

    Morgenroth, David C.; Medverd, Jonathan R.; Seyedali, Mahyo; Czerniecki, Joseph M.

    2014-01-01

    Background While animal study and cadaveric study have demonstrated an association between knee joint loading rate and joint degeneration, the relationship between knee joint loading rate during walking and osteoarthritis has not yet been sufficiently studied in humans. Methods Twenty-eight participants (14 transfemoral amputees and 14 age and body mass matched controls) underwent knee MRI with subsequent assessment using the semiquantitative Whole-Organ Magnetic Resonance Image Score. Each subject also underwent gait analysis in order to determine knee adduction moment loading rate, peak, and impulse and an exploratory measure, knee adduction moment rate*magnitude. Findings Significant correlations were found between medial tibiofemoral joint degeneration and knee adduction moment peak (slope = 0.42 [SE 0.20]; P=.037), loading rate (slope = 12.3 [SE 3.2]; P=.0004), and rate*magnitude (slope = 437 [SE 100]; P<.0001). These relationships continued to be significant after adjusting for body mass or subject type. The relationship between medial knee semiquantitative MRI score and knee adduction moment loading rate and rate*magnitude continued to be significant even after adjusting for peak moment (P<.0001), however, the relationship between medial knee semiquantitative MRI score and peak moment was no longer significant after adjusting for either loading rate or rate*magnitude (P>.2 in both cases). Interpretation This study suggests an independent relationship between knee adduction moment loading rate and medial tibiofemoral joint degeneration. Our results support the hypothesis that rate of loading, represented by the knee adduction moment loading rate, is strongly associated with medial tibiofemoral joint degeneration independent of knee adduction moment peak and impulse. PMID:24820134

  5. Loading Analysis of Composite Wind Turbine Blade for Fatigue Life Prediction of Adhesively Bonded Root Joint

    NASA Astrophysics Data System (ADS)

    Salimi-Majd, Davood; Azimzadeh, Vahid; Mohammadi, Bijan

    2015-06-01

    Nowadays wind energy is widely used as a non-polluting cost-effective renewable energy resource. During the lifetime of a composite wind turbine which is about 20 years, the rotor blades are subjected to different cyclic loads such as aerodynamics, centrifugal and gravitational forces. These loading conditions, cause to fatigue failure of the blade at the adhesively bonded root joint, where the highest bending moments will occur and consequently, is the most critical zone of the blade. So it is important to estimate the fatigue life of the root joint. The cohesive zone model is one of the best methods for prediction of initiation and propagation of debonding at the root joint. The advantage of this method is the possibility of modeling the debonding without any requirement to the remeshing. However in order to use this approach, it is necessary to analyze the cyclic loading condition at the root joint. For this purpose after implementing a cohesive interface element in the Ansys finite element software, one blade of a horizontal axis wind turbine with 46 m rotor diameter was modelled in full scale. Then after applying loads on the blade under different condition of the blade in a full rotation, the critical condition of the blade is obtained based on the delamination index and also the load ratio on the root joint in fatigue cycles is calculated. These data are the inputs for fatigue damage growth analysis of the root joint by using CZM approach that will be investigated in future work.

  6. Bearing-Bypass Loading on Bolted Composite Joints

    NASA Technical Reports Server (NTRS)

    Crews, J. H., Jr.; Naik, R. A.

    1988-01-01

    A combined experimental and analytical study has been conducted to investigate the effects of simultaneous bearing and bypass loading on a graphite/epoxy (T300/5208) laminate. Tests were conducted with a test machine that allows the bearing-bypass load ratio to be controlled while a single-fastener coupon is loaded to failure in either tension or compression. Test coupons consisted of 16-ply quasi-isotropic graphite/epoxy laminates with a centrally-located 6.35 mm bolt having a clearance fit. Onset-damage and ultimate strengths were determined for each test case. Next, a finite element stress analysis was conducted for each test case. The computed local stresses were used with appropriate failure criteria to analyze the observed failure modes and strengths. An unexpected interaction of the effect of the bypass and bearing loads was found for the onset of compression-reacted bearing damage. This interaction was caused by a decrease in the bolt-hole contact arc and a corresponding increase in the severity of the bearing loads. The amount of bolt-hole contact had a significant effect on local stresses and, thus, on the calculated damage-onset and ultimate strengths. An offset-compressible failure mode was identified for laminate failure under compression bearing-bypass loading. This failure mode appears to be unique to compression bearing-bypass loading and, therefore, cannot be predicted from simple tests.

  7. The Reliability of Adhesive Joints Under Piezomechanical Loading

    DTIC Science & Technology

    2006-10-04

    actuation was established. Experiments were conducted on Lead Zirconium Titanate ( PZT ) substrates bonded by Lead-Tin eutectic solders. Some experiments were...piezo-mechanical joint consists of a three layer, double lap joint piezo-stack using lead-zirconate-titanate ( PZT ) 5H and solder alloy, as shown in...eliminating bending of the piezo- stack. "+VDC D C PZT +VA C/-VA C Solder -VD PZT 25.4 pm (1 mil) Solder , 190.5 pm (7.5 mils) -VA c/+VA c PZT 4 6.35 mm (0.25

  8. Study of the dynamic behavior of a bolted joint under heavy loadings

    NASA Astrophysics Data System (ADS)

    Daouk, Sami; Louf, François; Cluzel, Christophe; Dorival, Olivier; Champaney, Laurent; Audebert, Sylvie

    2017-03-01

    In structural dynamics, the quantification of the quality and reliability of numerical models remains a relevant issue. While the behavior of structures such as beams and plates is generally understood, a large number of industrial structures are bolted assemblies of many components with connections that are not well understood. The main reason for this lack of understanding is that the dynamical behavior of the whole assembly depends critically upon joint conditions, especially under heavy loadings. For the purpose of improving our understanding and the development of pertinent models, a dynamic test bed, based on a bolted structure, is designed and modal testing is performed. The configuration of the bolted joint and the level of the loading are the relevant parameters, related to joint conditions, that are considered in this study. The results of the experimental campaign show the variation of the dissipation in a bolted joint and its apparent stiffness as a function of joint conditions.

  9. MSAT boom joint testing and load absorber design

    NASA Technical Reports Server (NTRS)

    Klinker, D. H.; Shuey, K.; St.clair, D. R.

    1994-01-01

    Through a series of component and system-level tests, the torque margin for the MSAT booms is being determined. The verification process has yielded a number of results and lessons that can be applied to many other types of deployable spacecraft mechanisms. The MSAT load absorber has proven to be an effective way to provide high energy dissipation using crushable honeycomb. Using two stages of crushable honeycomb and a fusible link, a complex crush load profile has been designed and implemented. The design features of the load absorber lend themselves to use in other spacecraft applications.

  10. Lamb Wave-Based Structural Health Monitoring on Composite Bolted Joints under Tensile Load

    PubMed Central

    Yang, Bin; Xuan, Fu-Zhen; Xiang, Yanxun; Li, Dan; Zhu, Wujun; Tang, Xiaojun; Xu, Jichao; Yang, Kang; Luo, Chengqiang

    2017-01-01

    Online and offline monitoring of composite bolted joints under tensile load were investigated using piezoelectric transducers. The relationships between Lamb wave signals, pre-tightening force, the applied tensile load, as well as the failure modes were investigated. Results indicated that S0/A0 wave amplitudes decrease with the increasing of load. Relationships between damage features and S0/A0 mode were built based on the finite element (FE) simulation and experimental results. The possibility of application of Lamb wave-based structure health monitoring in bolted joint-like composite structures was thus achieved. PMID:28773014

  11. Bearing-bypass loading on bolted composite joints

    NASA Technical Reports Server (NTRS)

    Crews, J. H., Jr.; Naik, R. A.

    1987-01-01

    The effects of simultaneous bearing and bypass loading on a graphite-epoxy (T300/5208) laminate were investigated. Onset damage and ultimate strengths were determined for each test case. A finite element stress analysis was conducted for each test case. The computed local stresses were used with appropriate failure criteria to analyze the observed failure modes and strengths. An unexpected interaction of the effect of the bypass and bearing loads was found for the onset of compression reacted bearing damage. The interaction was caused by a decrease in the bolt-hole contact arc and a corresponding increase in the severity of the bearing loads. The amount of bolt-hole contact had a significant effect on local stresses and, thus, on the calculated damage-onset and ultimate strengths. An offset-compression failure mode was identified for laminate failure under compression bearing-bypass loading.

  12. Structural Joint with Multi-Axis Load Carrying Capability

    NASA Technical Reports Server (NTRS)

    Wu, K. Chauncey (Inventor); Martin, Robert A. (Inventor); Stewart, Brian K. (Inventor)

    2017-01-01

    A structural joint is formed of a mandrel having a plurality of bumps and dimples formed thereon which is fitted into a sleeve. The bumps and dimples form a non-circular geometry at all points along the length of the mandrel. The bumps are defined by surfaces which have 1st and 2nd derivatives which are continuous.

  13. The influence of footwear on knee joint loading during walking--in vivo load measurements with instrumented knee implants.

    PubMed

    Kutzner, Ines; Stephan, Daniel; Dymke, Jörn; Bender, Alwina; Graichen, Friedmar; Bergmann, Georg

    2013-02-22

    Since footwear is commonly used every day, its influence on knee joint loading and thereby on the development and progression of osteoarthritis may be crucial. So far the influence of footwear has been examined only indirectly. The aim of this study was to directly measure the effect of footwear on tibiofemoral contact loads during walking. Instrumented knee implants with telemetric data transmission were used to measure the tibiofemoral contact forces and moments in six subjects. The loads during walking with four different shoes (basic running shoes, advanced running shoes, classical dress shoes and shoes with a soft rounded sole in the sagittal plane (MBT)) were compared to those during barefoot walking. Peak values of all six load components were analyzed. In general, footwear tended to increase knee joint loading slightly, with the dress shoe being the most unfavorable type of footwear. At the early stance phase all load components were increased by all shoe types. The resultant force rose by 2-5%, the internal adduction moment by 7-12% and the forces on the medial compartment by 3-5%. Significant reductions of the resultant force were solely observed for the advanced running shoe (-6%) and the MBT (-9%) shoe at late stance. Also the medial compartment force was slightly yet non-significantly reduced by 2-5% with the two shoes. It is questionable whether such small load changes have an influence on the progression of gonarthrosis. Future research is necessary to examine which factors regarding the shoe design, such as heel height, arch support or flexibility are most decisive for a reduction of knee joint loading. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement

    PubMed Central

    Rasnick, Robert; Standifird, Tyler; Reinbolt, Jeffrey A.; Cates, Harold E.

    2016-01-01

    Total knee replacement (TKR) is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF) and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (p<0.05). No differences were observed for peak joint compressive forces between groups. Some muscle force compensatory strategies appear to be present in both the loading and push-off phases. Evidence from knee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups. PMID:27258086

  15. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement.

    PubMed

    Rasnick, Robert; Standifird, Tyler; Reinbolt, Jeffrey A; Cates, Harold E; Zhang, Songning

    2016-01-01

    Total knee replacement (TKR) is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF) and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (p<0.05). No differences were observed for peak joint compressive forces between groups. Some muscle force compensatory strategies appear to be present in both the loading and push-off phases. Evidence from knee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups.

  16. Resection or degeneration of uncovertebral joints altered the segmental kinematics and load-sharing pattern of subaxial cervical spine: A biomechanical investigation using a C2-T1 finite element model.

    PubMed

    Wang, Zhong; Zhao, Hui; Liu, Ji-Ming; Tan, Li-Wen; Liu, Peng; Zhao, Jian-Hua

    2016-09-06

    The uncovertebral joint (UJ) is an important load-bearing structure in the subaxial cervical spine (SCS) and the medial wall of the intervertebral foramen (IVF). To investigate the UJ׳s role in load distribution and transmission under physiological loading, we developed and validated a detailed finite element model (C2-T1). Based on the initial model, two additional models were modified to simulate surgical resection and degeneration of UJs, to evaluate their influence on SCS kinematics and load distribution. The three models were subjected to 2Nm pure moment (flexion, extension, lateral bending, and axial rotation). Foraminal narrowing and potential nerve compression were evaluated. In the initial model, contact forces provided by the UJ were apparent in lateral bending and axial rotation. In axial rotation, the UJs and contralateral facet joints participated in joint activity, implying a possible restraint/counterbalance mechanism of these two joints. Peak vertebral stress was observed in the pedicle of vertebrae and was higher in the uncovertebral region than in the facet region. Resection of uncinate processes led to an apparent range of motion increase in lateral bending and axial rotation, while sagittal kinematics is influenced slightly. The load on other structures was slightly increased, but in axial rotation, resection of UJs changed the load distribution pattern. Degeneration of UJs significantly increased SCS stiffness and shielded other load-bearing structures. Peak IVF narrowing, but no nerve compression, was observed in axial rotation of the resection model. Thus, resection did not induce apparent secondary foraminal stenosis when other structures were still functional.

  17. Stress analysis method for clearance-fit joints with bearing-bypass loads

    NASA Technical Reports Server (NTRS)

    Naik, R. A.; Crews, J. H., Jr.

    1989-01-01

    Within a multi-fastener joint, fastener holes may be subjected to the combined effects of bearing loads and loads that bypass the hole to be reacted elsewhere in the joint. The analysis of a joint subjected to search combined bearing and bypass loads is complicated by the usual clearance between the hole and the fastener. A simple analysis method for such clearance-fit joints subjected to bearing-bypass loading has been developed in the present study. It uses an inverse formulation with a linear elastic finite-element analysis. Conditions along the bolt-hole contact arc are specified by displacement constraint equations. The present method is simple to apply and can be implemented with most general purpose finite-element programs since it does not use complicated iterative-incremental procedures. The method was used to study the effects of bearing-bypass loading on bolt-hole contact angles and local stresses. In this study, a rigid, frictionless bolt was used with a plate having the properties of a quasi-isotropic graphite/epoxy laminate. Results showed that the contact angle as well as the peak stresses around the hole and their locations were strongly influenced by the ratio of bearing and bypass loads. For single contact, tension and compression bearing-bypass loading had opposite effects on the contact angle. For some compressive bearing-bypass loads, the hole tended to close on the fastener leading to dual contact. It was shown that dual contact reduces the stress concentration at the fastener and would, therefore, increase joint strength in compression. The results illustrate the general importance of accounting for bolt-hole clearance and contact to accurately compute local bolt-hole stresses for combined bearings and bypass loading.

  18. Reflex Responses to Ligament Loading: Implications for Knee Joint Stability

    DTIC Science & Technology

    2007-11-02

    American Volume. 63(5): p. 780-7, 1981. [21] Y.C. Fung, Biomechanics : Mechanical Properties of living tissue. 2nd ed. 1993: Springer-Verlag. [22...To quantify the input (abduction angle)/output (NR) properties of the sustained response, an exponential regression model was used given as (3...joint stiffness through co-contraction [22], and (b) selective activation based on the efficient biomechanical role of muscles. In the context of

  19. Effects of changing speed on knee and ankle joint load during walking and running.

    PubMed

    de David, Ana Cristina; Carpes, Felipe Pivetta; Stefanyshyn, Darren

    2015-01-01

    Joint moments can be used as an indicator of joint loading and have potential application for sports performance and injury prevention. The effects of changing walking and running speeds on joint moments for the different planes of motion still are debatable. Here, we compared knee and ankle moments during walking and running at different speeds. Data were collected from 11 recreational male runners to determine knee and ankle joint moments during different conditions. Conditions include walking at a comfortable speed (self-selected pacing), fast walking (fastest speed possible), slow running (speed corresponding to 30% slower than running) and running (at 4 m · s(-1) ± 10%). A different joint moment pattern was observed between walking and running. We observed a general increase in joint load for sagittal and frontal planes as speed increased, while the effects of speed were not clear in the transverse plane moments. Although differences tend to be more pronounced when gait changed from walking to running, the peak moments, in general, increased when speed increased from comfortable walking to fast walking and from slow running to running mainly in the sagittal and frontal planes. Knee flexion moment was higher in walking than in running due to larger knee extension. Results suggest caution when recommending walking over running in an attempt to reduce knee joint loading. The different effects of speed increments during walking and running should be considered with regard to the prevention of injuries and for rehabilitation purposes.

  20. Lower extremity biomechanics during weightlifting exercise vary across joint and load.

    PubMed

    Kipp, Kristof; Harris, Chad; Sabick, Michelle B

    2011-05-01

    The purpose of this study was to determine the effect of load on lower extremity biomechanics during the pull phase of the clean. Kinematic and kinetic data of the 3 joints of the lower extremity were collected while participants performed multiple sets of cleans at 3 percentages: 65, 75, and 85% of 1 repetition maximum (1RM). General linear models with repeated measures were used to assess the influence of load on angular velocities, net torques, powers, and rates of torque development at the ankle, knee, and hip joint. The results suggest that the biomechanical demands required from the lower extremities change with the lifted load and to an extent depend on the respective joint. Most notably, the hip and knee extended significantly faster than the ankle independent of load, whereas the hip and ankle generally produced significantly higher torques than the knee did. Torque, rate of torque development (RTD), and power were maximimal at 85% of 1RM for the ankle joint and at 75% of 1RM for the knee joint. Torque and RTD at the hip were maximal at loads >75% of 1RM. This study provides important novel information about the mechanical demands of a weightlifting exercise and should be heeded in the design of resistance training programs.

  1. Impact of Generalized Joint Laxity on Plantar Loading Patterns in Young Females.

    PubMed

    Aydın, Elif; Metin Tellioğlu, Ayfer; Kurt Ömürlü, Imran; Turan, Yasemin

    2017-08-01

    Generalized joint laxity is often associated with gait deviations. The aim of this study was to investigate the static and dynamic loading pattern of the foot with increasing joint mobility and to discuss the potential impact of this condition on the plantar loading patterns. Seventy female participants between ages of 18 and 30 were included in this cross-sectional survey. The Beighton-Horan Joint Mobility Index scores were assessed and participants divided into 3 categories: no hypermobility (NH) group, scores 0 to 2; moderate hypermobility (MH) group, scores 3 to 4; distinct hypermobility (DH) group, scores 5 to 9. Pedobarographic analysis was performed both in static and walking conditions. Dynamic foot loading examined in 10 anatomic zones. Contact areas of forefoot, midfoot, and rearfoot were recorded. In the dynamic pedobarographic analysis, individuals with distinct joint hypermobility displayed higher peak pressure and maximum force values under the hallux, compared with other groups ( P < .05). The maximum force value of the second metatarsal was higher in the DH group than in the MH group ( P < .05). Our study results suggest that plantar loading pattern differs with increasing degrees of the hypermobility score. Differences in plantar loading parameters in people with severe joint mobility scores may be useful in interpreting the foot pathologies of these individuals.

  2. Lower extremity joint loading during level walking with Masai barefoot technology shoes in overweight males.

    PubMed

    Buchecker, M; Wagner, H; Pfusterschmied, J; Stöggl, T L; Müller, E

    2012-06-01

    The purpose of this study was to evaluate the effects of Masai barefoot technology (MBT) shoes on lower extremity joint loading in overweight males during level walking. Therefore, lower extremity kinematics, kinetics, and muscle electromyographic signals of the vastus lateralis (VL), biceps femoris (BF), and gastrocnemius medialis (GM) were recorded in 10 overweight males at a self-chosen walking speed with MBT shoes and conventional shoes. Selected peak joint moments, maximal joint force loading rates, mean muscle intensities, and co-activation indices of the VL/BF, as well as of the VL/GM were analyzed and compared for the two shoe conditions using paired Student's t-tests (α=0.05). Results showed that walking with MBT shoes reduced first peak knee adduction moments in overweight subjects. During midstance and terminal stance, increases in VL/GM co-activation, accompanied by increases in VL and GM (only terminal stance) intensities were found for the MBT situation. Kinetic variables analyzed to assess ankle and hip joint loading did not exhibit any statistical differences. These results suggest that using MBT shoes diminishes medial compartment loads at the knee without overloading hip or ankle joints in overweight males. However, the additional muscle loading should not be overlooked, and warrants further investigation.

  3. Analysis of the Constraint Joint Loading in the Thumb During Pipetting

    PubMed Central

    Sinsel, Erik W.; Zhao, Kristin D.; An, Kai-Nan; Buczek, Frank L.

    2015-01-01

    Dynamic loading on articular joints is essential for the evaluation of the risk of the articulation degeneration associated with occupational activities. In the current study, we analyzed the dynamic constraint loading for the thumb during pipetting. The constraint loading is considered as the loading that has to be carried by the connective tissues of the joints (i.e., the cartilage layer and the ligaments) to maintain the kinematic constraints of the system. The joint loadings are solved using a classic free-body approach, using the external loading and muscle forces, which were obtained in an inverse dynamic approach combined with an optimization procedure in anybody. The constraint forces in the thumb joint obtained in the current study are compared with those obtained in the pinch and grasp tests in a previous study (Cooney and Chao, 1977, “Biomechanical Analysis of Static Forces in the Thumb During Hand Function,” J. Bone Joint Surg. Am., 59(1), pp. 27–36). The maximal compression force during pipetting is approximately 83% and 60% greater than those obtained in the tip pinch and key pinch, respectively, while substantially smaller than that obtained during grasping. The maximal lateral shear force is approximately six times, 32 times, and 90% greater than those obtained in the tip pinch, key pinch, and grasp, respectively. The maximal dorsal shear force during pipetting is approximately 3.2 and 1.4 times greater than those obtained in the tip pinch and key pinch, respectively, while substantially smaller than that obtained during grasping. Our analysis indicated that the thumb joints are subjected to repetitive, intensive loading during pipetting, compared to other daily activities. PMID:25839321

  4. Analysis of the Constraint Joint Loading in the Thumb During Pipetting.

    PubMed

    Wu, John Z; Sinsel, Erik W; Zhao, Kristin D; An, Kai-Nan; Buczek, Frank L

    2015-08-01

    Dynamic loading on articular joints is essential for the evaluation of the risk of the articulation degeneration associated with occupational activities. In the current study, we analyzed the dynamic constraint loading for the thumb during pipetting. The constraint loading is considered as the loading that has to be carried by the connective tissues of the joints (i.e., the cartilage layer and the ligaments) to maintain the kinematic constraints of the system. The joint loadings are solved using a classic free-body approach, using the external loading and muscle forces, which were obtained in an inverse dynamic approach combined with an optimization procedure in anybody. The constraint forces in the thumb joint obtained in the current study are compared with those obtained in the pinch and grasp tests in a previous study (Cooney and Chao, 1977, "Biomechanical Analysis of Static Forces in the Thumb During Hand Function," J. Bone Joint Surg. Am., 59(1), pp. 27-36). The maximal compression force during pipetting is approximately 83% and 60% greater than those obtained in the tip pinch and key pinch, respectively, while substantially smaller than that obtained during grasping. The maximal lateral shear force is approximately six times, 32 times, and 90% greater than those obtained in the tip pinch, key pinch, and grasp, respectively. The maximal dorsal shear force during pipetting is approximately 3.2 and 1.4 times greater than those obtained in the tip pinch and key pinch, respectively, while substantially smaller than that obtained during grasping. Our analysis indicated that the thumb joints are subjected to repetitive, intensive loading during pipetting, compared to other daily activities.

  5. The Physiological Basis of Cervical Facet-Mediated Persistent Pain: Basic Science and Clinical Challenges.

    PubMed

    Ita, Meagan E; Zhang, Sijia; Holsgrove, Timothy P; Kartha, Sonia; Winkelstein, Beth A

    2017-07-01

    Synopsis Chronic neck pain is a common condition and a primary clinical symptom of whiplash and other spinal injuries. Loading-induced neck injuries produce abnormal kinematics between the vertebrae, with the potential to injure facet joints and the afferent fibers that innervate the specific joint tissues, including the capsular ligament. Mechanoreceptive and nociceptive afferents that innervate the facet have their peripheral terminals in the capsule, cell bodies in the dorsal root ganglia, and terminal processes in the spinal cord. As such, biomechanical loading of these afferents can initiate nociceptive signaling in the peripheral and central nervous systems. Their activation depends on the local mechanical environment of the joint and encodes the neural processes that initiate pain and lead to its persistence. This commentary reviews the complex anatomical, biomechanical, and physiological consequences of facet-mediated whiplash injury and pain. The clinical presentation of facet-mediated pain is complex in its sensory and emotional components. Yet, human studies are limited in their ability to elucidate the physiological mechanisms by which abnormal facet loading leads to pain. Over the past decade, however, in vivo models of cervical facet injury that reproduce clinical pain symptoms have been developed and used to define the complicated and multifaceted electrophysiological, inflammatory, and nociceptive signaling cascades that are involved in the pathophysiology of whiplash facet pain. Integrating the whiplash-like mechanics in vivo and in vitro allows transmission of pathophysiological mechanisms across scales, with the hope of informing clinical management. Yet, despite these advances, many challenges remain. This commentary further describes and highlights such challenges. J Orthop Sports Phys Ther 2017;47(7):450-461. Epub 16 Jun 2017. doi:10.2519/jospt.2017.7255.

  6. Constitutive Modelling of Joints under Cyclic Loading. Part 1. Modelling and Testing of Idealized Rock Joints

    DTIC Science & Technology

    1988-07-31

    Crawford and Curran (1981) developed a direct-shear device to examine the effect of shear rate on the shear resistance of smooth artificial joints in dif... Artificial rock joint surfaces were prepared by casting concrete against a structured surface. The structured surface had a "sawtooth" shaped pattern...parameter n, and the constants a and b in the growth function must be determined for the reverse pass. The value of y for the reverse pass is = womb 167

  7. A revolute joint with linear load-displacement response for a deployable lidar telescope

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Warren, Peter A.; Peterson, Lee D.

    1996-01-01

    NASA Langley Research Center is developing concepts for an advanced spacecraft, called LidarTechSat, to demonstrate key structures and mechanisms technologies necessary to deploy a segmented telescope reflector. Achieving micron-accuracy deployment requires significant advancements in deployment mechanism design, such as the revolute joint presented herein. The joint exhibits load-cycling response that is essentially linear with less than 2% hysteresis, and the joint rotates with less than 7 mN-m (1 in-oz) of resistance. A prototype reflector metering truss incorporating the joint exhibits only a few microns of kinematic error under repected deployment and impulse loading. No other mechanically deployment structure found in the literature has been demonstrated to be this kinematically accurate.

  8. A Wolff in sheep's clothing: trabecular bone adaptation in response to changes in joint loading orientation.

    PubMed

    Barak, Meir M; Lieberman, Daniel E; Hublin, Jean-Jacques

    2011-12-01

    This study tests Wolff's law of trabecular bone adaptation by examining if induced changes in joint loading orientation cause corresponding adjustments in trabecular orientation. Two groups of sheep were exercised at a trot, 15 min/day for 34 days on an inclined (7°) or level (0°) treadmills. Incline trotting caused the sheep to extend their tarsal joints by 3-4.5° during peak loading (P<0.01) but has no effect on carpal joint angle (P=0.984). Additionally, tarsal joint angle in the incline group sheep were maintained more extended throughout the day using elevated platform shoes on their forelimbs. A third "sedentary group" group did not run but wore platform shoes throughout the day. As predicted by Wolff's law, trabecular orientation in the distal tibia (tarsal joint) were more obtuse by 2.7 to 4.3° in the incline group compared to the level group; trabecular orientation was not significantly different in the sedentary and level groups. In addition, trabecular orientations in the distal radius (carpal joint) of the sedentary, level and incline groups did not differ between groups, and were aligned almost parallel to the radius long axis, corresponding to the almost straight carpal joint angle at peak loading. Measurements of other trabecular bone parameters revealed additional responses to loading, including significantly higher bone volume fraction (BV/TV), Trabecular number (Tb.N) and trabecular thickness (Tb.Th), lower trabecular spacing (Tb.Sp), and less rod-shaped trabeculae (higher structure model index, SMI) in the exercised than sedentary sheep. Overall, these results demonstrate that trabecular bone dynamically adjusts and realigns itself in very precise relation to changes in peak loading direction, indicating that Wolff's law is not only accurate but also highly sensitive.

  9. Effects of Carbon Nanomaterial Reinforcement on Composite Joints Under Cyclic and Impact Loading

    DTIC Science & Technology

    2012-03-01

    Molding ( VARTM ) technique with 7.5g/m2 of MWCNTs or CNFs dispersed at the joint interface ahead of the crack tip. The test coupons were loaded in 3...fabricated via Vacuum Assisted Resin Transfer Molding ( VARTM ) technique with 7.5g/m 2 of MWCNTs or CNFs dispersed at the joint interface ahead of... VARTM setup in the laboratory ........................................................................9 Figure 7. Arrangement of the various layers

  10. Strengthening of beam - column joint with steel fibre reinforced concrete under seismic loading

    NASA Astrophysics Data System (ADS)

    Prasanna, K.; Ramasubramani, R.; Anandh, K. S.; Saisabarish; Krupaker Maddu, Vijay

    2017-07-01

    Earthquakes not only kill the human beings but the structures too. Considering this above fact, there is a necessity to take care of the beam column joint region in a structure. Under seismic excitation, the bar segment joint district is subjected to even and the vertical shear force extents are normally commonly greater than those in the adjoining bits of the structural segments. In the event that the joint is not precisely nitty gritty, the shaft segment joint may end up plainly frail. To keep this, an adequate control ought to be given in the joint area. The seismic examination and outline technique ought to be utilised as a part of the plan of the building structures and their segments ought to be recommended in the segment. The building structures incorporate finish sidelong and vertical drive opposing frameworks fit for giving satisfactory quality. Stiffness and the vitality dissemination ability to withstand the outline ground movements inside the recommended furthest reaches of twisting and quality request. The plan ground movements are accepted to happen along any even headings of a building structure. This work focuses on behaviour of M20 concrete in beam-column joint subjected to seismic loading, by using steel fibre (1.5%). The specimens detailed as per IS: 456-2000 and IS: 13920-1993 were casted and tested under cyclic and reverse cyclic loading. The parameters analysed were ductility, energy dissipation, load v/s displacement curve, beam-column reinforcement strain and crack pattern. From the experimental investigation, it is found that the fibre reinforced beam-column joint with fibre (1.50% of steel fibre) performs better ductility, load carrying capacity, energy dissipation and strength by 10% more than conventional reinforced beam-column joint.

  11. Medial knee joint loading during stair ambulation and walking while carrying loads.

    PubMed

    Hall, Michelle; Boyer, Elizabeth R; Gillette, Jason C; Mirka, Gary A

    2013-03-01

    Carrying loads while walking or using stairs is a common activity of daily living. Knee osteoarthritis is associated with increased external knee adduction moment (KAM) during walking, so understanding how the additional challenges of stairs and carrying loads impact these moments is of value. Sixteen healthy individuals performed three types of MOTION (walking, stair ascent, stair descent) under three LOAD conditions (no load, carrying a 13.6kg front load, carrying 13.6kg load in a backpack). Three-dimensional gait analysis was used to measure KAM. Results of ANOVA showed a significant main effect of both MOTION and LOAD on peak KAM (p<0.001), but no significant MOTION×LOAD interaction (p=0.250). Peak KAM during stair ascent was about two-times those seen in stair descent (p<0.001) and was significantly higher than those seen in walking (p<0.001). Conditions with LOAD generated significantly greater KAM as compared to the no-LOAD conditions (p<0.001). These findings suggest that carrying a load of moderate magnitude while climbing stairs significantly increases the peak KAM - a risk factor associated with knee osteoarthritis. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Mechanical Behaviour of Bolted Joints Under Impact Rates of Loading

    DTIC Science & Technology

    2012-01-01

    lost during testing. Experimental results show 95% confidence error bars for 4 specimens. The FEM results show an average of five calculations of...the same e/d configuration to reduce the bias of human calculation of takeoff and landing of incident, reflected, and transmission waves. The FEM ...the loading rate of the specimen as shown in Figure 2.3. Five FEM simulations for e/d of 1, 2, 3, 4 were run using ABAQUS and averaged to smooth any

  13. Facets: Ersatz, Resource and Tag

    ERIC Educational Resources Information Center

    Frické, Martin H.

    2013-01-01

    Introduction: Faceted classification appears to be of utmost importance. Ersatz facets, resource faceting and tag faceting: The distinctions are drawn between facets and ersatz facets, and between faceted resources and faceted tags. Single tag resource faceting and multiple tag information object faceting: The basic features are explored of single…

  14. Focal cartilage defect compromises fluid-pressure dependent load support in the knee joint.

    PubMed

    Dabiri, Yaghoub; Li, LePing

    2015-06-01

    A focal cartilage defect involves tissue loss or rupture. Altered mechanics in the affected joint may play an essential role in the onset and progression of osteoarthritis. The objective of the present study was to determine the compromised load support in the human knee joint during defect progression from the cartilage surface to the cartilage-bone interface. Ten normal and defect cases were simulated with a previously tested 3D finite element model of the knee. The focal defects were considered in both condyles within high load-bearing regions. Fluid pressurization, anisotropic fibril-reinforcement, and depth-dependent mechanical properties were considered for the articular cartilages and menisci. The results showed that a small cartilage defect could cause 25% reduction in the load support of the knee joint due to a reduced capacity of fluid pressurization in the defect cartilage. A partial-thickness defect could cause a fluid pressure decrease or increase in the remaining underlying cartilage depending on the defect depth. A cartilage defect also increased the shear strain at the cartilage-bone interface, which was more significant with a full-thickness defect. The effect of cartilage defect on the fluid pressurization also depended on the defect sites and contact conditions. In conclusion, a focal cartilage defect causes a fluid-pressure dependent load reallocation and a compromised load support in the joint, which depend on the defect depth, site, and contact condition.

  15. Urinary CTX‐II levels are associated with radiographic subtypes of osteoarthritis in hip, knee, hand, and facet joints in subject with familial osteoarthritis at multiple sites: the GARP study

    PubMed Central

    Meulenbelt, I; Kloppenburg, M; Kroon, H M; Houwing‐Duistermaat, J J; Garnero, P; Graverand, M‐P Hellio Le; DeGroot, J; Slagboom, P E

    2006-01-01

    Objective To assess the relation between the urinary concentrations of type II collagen C‐telopeptide (UCTX‐II) and radiographic signs of osteoarthritis (ROA) in the GARP (Genetics, Arthrosis and Progression) study. Methods UCTX‐II levels were measured in GARP study participants, who are sibling pairs predominantly with symptomatic osteoarthritis at multiple sites. Kellgren and Lawrence scores were used to assess ROA in the knees, hips, hands, and vertebral facet joints, and spinal disc degeneration. A proportionate score was made for each joint location, based on the number of joints with ROA. The sum total ROA score represents a measure of cartilage abnormalities within each patient. By using linear mixed models the total ROA score and the joint site specific ROA scores were correlated with the UCTX‐II level. Results In 302 subjects the mean (SD) and median (range) for UCTX‐II were 265 (168) and 219 (1346) ng/mmol creatine, respectively. There was a significant association between the total ROA score and UCTX‐II levels. Subsequent multivariate analysis showed that the joint site specific ROA score at all joint sites, except for spinal disc degeneration, contributed independently to this association. Conclusions The total ROA score of GARP patients, representing cartilage abnormalities at the most prevalent ROA joint locations, showed an excellent correlation with UCTX‐II levels. The specific ROA scores at the hip, hand, facet, and knee joints additively and independently explained this association. Even in patients with osteoarthritis at multiple sites, UCTX‐II may be a sensitive quantitative marker of ROA. PMID:16079167

  16. Quantification of finger joint loadings using musculoskeletal modelling clarifies mechanical risk factors of hand osteoarthritis.

    PubMed

    Goislard de Monsabert, Benjamin; Vigouroux, Laurent; Bendahan, David; Berton, Eric

    2014-02-01

    Owing to limited quantitative data related to the loadings (forces and pressures) acting upon finger joints, several clinical observations regarding mechanical risk factors of hand osteoarthritis remain misunderstood. To improve the knowledge of this pathology, the present study used musculoskeletal modelling to quantify the forces and pressures acting upon hand joints during two grasping tasks. Kinematic and grip force data were recorded during both a pinch and a power grip tasks. Three-dimensional magnetic resonance imaging measurements were conducted to quantify joint contact areas. Using these datasets as input, a musculoskeletal model of the hand and wrist, including twenty-three degrees of freedom and forty-two muscles, has been developed to estimate joint forces and joint pressures. When compared with the power grip task, the pinch grip task resulted in two to eight times higher joint loadings whereas the grip forces exerted on each finger were twice lower. For both tasks, joint forces and pressures increased along a disto-proximal direction for each finger. The quantitative dataset provided by the present hand model clarified two clinical observations about osteoarthritis development which were not fully understood, i.e., the strong risk associated to pinch grip tasks and the high frequency of thumb-base osteoarthritis. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  17. Seismic load tests on reinforced concrete beam-column sandwich joints with strengthening measures

    NASA Astrophysics Data System (ADS)

    Yang, Zhi-hong; Li, Ying-min; Liu, Jian-wei

    2010-03-01

    Reinforced concrete high-rise buildings with high strength concrete (HSC) column and normal strength concrete (NSC) floor are popular nowadays. For these structures, it is ineffective to construct beam-column joint with high strength concrete. So beam-column joints with normal strength concrete attract abundant attention and are strongly recommended in china recent years. In this paper, we refer to this type of joints as sandwich joints. In order to improve seismic behavior of sandwich joints with high stress, strengthening measures including addition of vertical dowels, addition of diagonal bars, and enhancement of joint constraint were proposed to apply to engineering practice recent years. In this paper, 6 full scale sandwich joint specimens were test under cyclic load to investigate the validity of strengthening measures. Tested specimens were consist of 1 specimen with additional vertical dowels, 2 specimens with additional diagonal bars, and 1 specimen with additional lateral beams, compared with 2 specimens without strengthening measures. Integrated seismic performances of these specimens were studied, such as load resistance behavior, deflection performance, ductility, energy dissipation behavior, beam bars anchorage capacity and so on. Based on the experimental results, the effect and mechanical behavior of strengthening measures were analyzed.

  18. Seismic load tests on reinforced concrete beam-column sandwich joints with strengthening measures

    NASA Astrophysics Data System (ADS)

    Yang, Zhi-Hong; Li, Ying-Min; Liu, Jian-Wei

    2009-12-01

    Reinforced concrete high-rise buildings with high strength concrete (HSC) column and normal strength concrete (NSC) floor are popular nowadays. For these structures, it is ineffective to construct beam-column joint with high strength concrete. So beam-column joints with normal strength concrete attract abundant attention and are strongly recommended in china recent years. In this paper, we refer to this type of joints as sandwich joints. In order to improve seismic behavior of sandwich joints with high stress, strengthening measures including addition of vertical dowels, addition of diagonal bars, and enhancement of joint constraint were proposed to apply to engineering practice recent years. In this paper, 6 full scale sandwich joint specimens were test under cyclic load to investigate the validity of strengthening measures. Tested specimens were consist of 1 specimen with additional vertical dowels, 2 specimens with additional diagonal bars, and 1 specimen with additional lateral beams, compared with 2 specimens without strengthening measures. Integrated seismic performances of these specimens were studied, such as load resistance behavior, deflection performance, ductility, energy dissipation behavior, beam bars anchorage capacity and so on. Based on the experimental results, the effect and mechanical behavior of strengthening measures were analyzed.

  19. Mathematical modelling as a tool to assessment of loads in volleyball player's shoulder joint during spike.

    PubMed

    Jurkojć, Jacek; Michnik, Robert; Czapla, Krzysztof

    2017-06-01

    This article deals with kinematic and kinetic conditions in volleyball attack and identifies loads in the shoulder joint. Joint angles and velocities of individual segments of upper limb were measured with the use of the motion capture system XSENS. Muscle forces and loads in skeletal system were calculated by means of mathematical model elaborated in AnyBody system. Spikes performed by players in the best and worst way were compared with each other. The relationships were found between reactions in shoulder joint and flexion/extension, abduction/adduction and rotation angles in the same joint and flexion/extension in the elbow joint. Reactions in shoulder joint varied from 591 N to 2001 N (in relation to body weight [BW] 83-328%). The analysis proved that hand velocity at the moment of the ball hit (which varied between 6.8 and 13.3 m s(-1)) influences on the value of reaction in joints, but positions of individual segments relative to each other are also crucial. It was also proved in objective way, that position of the upper limb during spike can be more or less harmful assuming that bigger reaction increases possibility of injury, what can be an indication for trainers and physiotherapists how to improve injury prevention.

  20. Daptomycin-loaded polymethylmethacrylate bone cement for joint arthroplasty surgery.

    PubMed

    Hsu, Yuan-Ming; Liao, Chun-Hsing; Wei, Yu-Hong; Fang, Hsu-Wei; Hou, Hsiang-Huan; Chen, Chia-Chun; Chang, Chih-Hung

    2014-06-01

    Antibiotic-loaded acrylic bone cement has been frequently used as an infection prophylaxis or antibiotic-loaded spacer in infected arthroplasty. In addition, daptomycin has been used recently against broad spectrum Gram-positive organisms. The goal of this in vitro study is to investigate the bacteriacidal and mechanical properties of daptomycin-incorporated polymethylmethacrylate (PMMA) bone cement and evaluate its feasibility for clinical use. Daptomycin (0.5, 1, or 2 g) was premixed with 40 g of PMMA bone cement powder before curing. The mechanical properties of the daptomycin-loaded acrylic bone cement (DLABC) were estimated following standard guidance, and the release profile and kinetics of daptomycin from PMMA were analyzed. The antimicrobial efficacy of DLABC was determined with a zone of inhibition (ZOI) assay against Staphylococcus aureus, Staphylococcus epidermis, Enterococcus faecalis, and Enterococcus faecium, respectively. The results showed that the compressive strength, of PMMA bone cement, which was higher than 100 MPa in all groups, was sufficient according to ISO 5833 after incorporation of daptomycin. The encapsulated daptomycin was released for 2 weeks with a 9.59 ± 0.85%, 15.25 ± 0.69%, and 20.64 ± 20.33% released percentage on the first day in the low, mid, and high groups, respectively. According to the calculated release kinetics, incorporated daptomycin should be 3.3 times the original dose to double its release. Although all recipes of DLABC had a microbial inhibitory effect, the effect with a higher encapsulated amount of daptomycin was more significant. Therefore, we believe that daptomycin can be locally delivered from PMMA bone cement at the surgical site as a prophylactic or treatment for osteomyelitis against Gram-positive organisms with intact cement function.

  1. Gabapentin alleviates facet-mediated pain in the rat through reduced neuronal hyperexcitability and astrocytic activation in the spinal cord

    PubMed Central

    Dong, Ling; Crosby, Nathan D.; Winkelstein, Beth A.

    2013-01-01

    Although joint pain is common, its mechanism(s) remain undefined, with little known about the spinal neuronal responses that contribute to this type of pain. Afferent activity and sustained spinal neuronal hyperexcitability correlate to facet joint loading and the extent of behavioral sensitivity induced after painful facet injury, suggesting spinal neuronal plasticity is induced in association with facet-mediated pain. This study used a rat model of painful C6/C7 facet joint stretch, together with intrathecal administration of gabapentin, to investigate the effects of one aspect of spinal neuronal function on joint pain. Gabapentin or saline vehicle was given via lumbar puncture prior to and at 1 day after painful joint distraction. Mechanical hyperalgesia was measured in the forepaw for 7 days. Extracellular recordings of neuronal activity and astrocytic and microglial activation in the cervical spinal cord were evaluated at day 7. Gabapentin significantly (p=0.0001) attenuated mechanical hyperalgesia and the frequency of evoked neuronal firing also significantly decreased (p<0.047) with gabapentin treatment. Gabapentin also decreased (p<0.04) spinal GFAP expression. Although spinal Iba1 expression was doubled over sham, gabapentin did not reduce it. Facet joint-mediated pain appears to be sustained through spinal neuronal modifications that are also associated with astrocytic activation. PMID:24094695

  2. Joint loading modality: its application to bone formation and fracture healing.

    PubMed

    Zhang, P; Malacinski, G M; Yokota, H

    2008-07-01

    Sports-related injuries such as impact and stress fractures often require a rehabilitation programme to stimulate bone formation and accelerate fracture healing. This review introduces a recently developed joint loading modality and evaluates its potential applications to bone formation and fracture healing in post-injury rehabilitation. Bone is a dynamic tissue whose structure is constantly altered in response to its mechanical environments. Indeed, many loading modalities can influence the bone remodelling process. The joint loading modality is, however, able to enhance anabolic responses and accelerate wound healing without inducing significant in situ strain at the site of bone formation or fracture healing. This review highlights the unique features of this loading modality and discusses its potential underlying mechanisms as well as possible clinical applications.

  3. Numerical and experimental analysis on load sharing & optimization of the joint parameters of polymer composite multi bolted joints

    NASA Astrophysics Data System (ADS)

    Latha Shankar, B.; Sudeep Kumar, T.; Shiva Shankar, G. S.

    2016-09-01

    In the present work, the bearing failure of composite bolted connections of composite laminates was analysed both experimentally and numerically. The glass fiber woven mat 600GSM/ epoxy composite laminates were prepared using wet-layup technique. The process parameters were taken care during preparation of laminates. Examination is done for various estimations of edge-to-hole diameter and width-to-hole diameter proportion. Stress is evaluated in laminates by utilizing Hart-Smith criteria. Ideal estimation of e/d proportion, d/w proportion is recommended for most extreme effectiveness. A numerical technique is utilized for the rough determination of a load shared by bolts in a numerous "bolted" joints loaded in tension were investigated experimentally and numerically. The effect of un-evenness in load shearing is suggested.

  4. Load Variation Influences on Joint Work During Squat Exercise in Reduced Gravity

    NASA Technical Reports Server (NTRS)

    DeWitt, John K.; Fincke, Renita S.; Logan, Rachel L.; Guilliams, Mark E.; Ploutz-Snyder, Lori L.

    2011-01-01

    Resistance exercises that load the axial skeleton, such as the parallel squat, are incorporated as a critical component of a space exercise program designed to maximize the stimuli for bone remodeling and muscle loading. Astronauts on the International Space Station perform regular resistance exercise using the Advanced Resistive Exercise Device (ARED). Squat exercises on Earth entail moving a portion of the body weight plus the added bar load, whereas in microgravity the body weight is 0, so all load must be applied via the bar. Crewmembers exercising in microgravity currently add approx.70% of their body weight to the bar load as compensation for the absence of the body weight. This level of body weight replacement (BWR) was determined by crewmember feedback and personal experience without any quantitative data. The purpose of this evaluation was to utilize computational simulation to determine the appropriate level of BWR in microgravity necessary to replicate lower extremity joint work during squat exercise in normal gravity based on joint work. We hypothesized that joint work would be positively related to BWR load.

  5. Effects of imbalanced muscle loading on hip joint development and maturation.

    PubMed

    Ford, Caleb A; Nowlan, Niamh C; Thomopoulos, Stavros; Killian, Megan L

    2017-05-01

    The mechanical loading environment influences the development and maturation of joints. In this study, the influence of imbalanced muscular loading on joint development was studied using localized chemical denervation of hip stabilizing muscle groups in neonatal mice. It was hypothesized that imbalanced muscle loading, targeting either gluteal muscles or quadriceps muscles, would lead to bilateral hip joint asymmetry, as measured by acetabular coverage, femoral head volume and bone morphometry, and femoral-acetabular shape. The contralateral hip joints as well as age-matched, uninjected mice were used as controls. Altered bone development was analyzed using micro-computed tomography, histology, and image registration techniques at postnatal days (P) 28, 56, and 120. This study found that unilateral muscle unloading led to reduced acetabular coverage of the femoral head, lower total volume, lower bone volume ratio, and lower mineral density, at all three time points. Histologically, the femoral head was smaller in unloaded hips, with thinner triradiate cartilage at P28 and thinner cortical bone at P120 compared to contralateral hips. Morphological shape changes were evident in unloaded hips at P56. Unloaded hips had lower trabecular thickness and increased trabecular spacing of the femoral head compared to contralateral hips. The present study suggests that decreased muscle loading of the hip leads to altered bone and joint shape and growth during postnatal maturation. Statement of Clinical Significance: Adaptations from altered muscle loading during postnatal growth investigated in this study have implications on developmental hip disorders that result from asymmetric loading, such as patients with limb-length inequality or dysplasia. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1128-1136, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  6. The influence of cyclic concentric and eccentric submaximal muscle loading on cell viability in the rabbit knee joint.

    PubMed

    Horisberger, Monika; Fortuna, Rafael; Leonard, Timothy R; Valderrabano, Victor; Herzog, Walter

    2012-03-01

    Cartilage loading is associated with the onset and progression of osteoarthritis and cell death may play an important role in these processes. Although much is known about cell death in joint impact loading, there is no information on joints loaded by muscular contractions. The aim of this study was to evaluate the influence of muscle generated eccentric and concentric submaximal joint loading on chondrocyte viability. We hypothesised that eccentric muscle activation leads to increased cell death rates compared to concentric loading and to controls. 16 rabbits received either 50 min of uni-lateral, cyclic eccentric (n=8) or concentric (n=8) knee loading. Muscle activation for these dynamic conditions was equivalent to an activation level that produced 20% of maximum isometric force. Contralateral joints served as unloaded controls. Cell viability was assessed using confocal microscopy. Eccentric contractions produced greater knee loading than concentric contractions. Sub-maximal contractions caused a significant increase in cell death in the loaded knees compared to the unloaded controls, and eccentric loading caused significantly more cell death than concentric loading. Cyclic sub-maximal muscle loading of the knee caused increased chondrocyte death in rabbits. These findings suggest that low levels of joint loading for prolonged periods, as occurs in endurance exercise or physical labour, may cause chondrocyte death, thereby predisposing joints to degeneration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Generalized Joint Laxity Associated With Increased Medial Foot Loading in Female Athletes

    PubMed Central

    Barber Foss, Kim D; Ford, Kevin R; Myer, Gregory D; Hewett, Timothy E

    2009-01-01

    Context: The relationship between generalized joint laxity and plantar pressure distribution of the foot and the potential implications for lower extremity injury have not been studied. Objective: To determine the relationship between generalized joint laxity and dynamic plantar pressure distribution. We hypothesized that individuals with greater generalized joint laxity, or hypermobility, would have greater dynamic medial midfoot pressure and loading during walking than nonhypermobile individuals. Design: Case control. Setting: Institutional biomechanics laboratory. Patients or Other Participants: Participants included 112 female soccer players between 11 and 21 years of age. Main Outcome Measure(s): Each participant was tested for generalized joint laxity using the Beighton and Horan Joint Mobility Index (BHJMI; range, 0–9) and was categorized as having either high (BHJMI score ≥4) or low (BHJMI score <4) generalized joint laxity. Peak pressure and maximum force were calculated from a dynamic, barefoot plantar pressure distribution system. Results: Peak pressure and maximum force were greater in the 27 participants categorized as having high generalized joint laxity than in the 85 participants categorized as having low generalized joint laxity. The midfoot region exhibited greater loading in participants with high generalized joint laxity than in the other participants. We found an effect of BHJMI classification in the medial midfoot; peak pressure in the dominant (F1,109  =  11.262, P  =  .001) and nondominant (F1,109  =  14.32, P < .001) sides and maximum force in the dominant (F1,109  =  7.88, P  =  .006) and nondominant (F1,109  =  9.18, P  =  .003) sides were greater in the high generalized joint laxity group than in the low generalized joint laxity group. Conclusions: Athletes classified as having high generalized joint laxity demonstrated increased midfoot loading. Delineation of risk factors for medial collapse of the foot

  8. Failure Predictions of Out-of-Autoclave Sandwich Joints with Delaminations under Flexure Loads

    NASA Technical Reports Server (NTRS)

    Nordendale, Nikolas; Goyal, Vinay; Lundgren, Eric; Patel, Dhruv; Farrokh, Babak; Jones, Justin; Fischetti, Grace; Segal, Kenneth

    2015-01-01

    An analysis and a test program was conducted to investigate the damage tolerance of composite sandwich joints. The joints contained a single circular delamination between the face-sheet and the doubler. The coupons were fabricated through out-of-autoclave (OOA) processes, a technology NASA is investigating for joining large composite sections. The four-point bend flexure test was used to induce compression loading into the side of the joint where the delamination was placed. The compression side was chosen since it tends to be one of the most critical loads in launch vehicles. Autoclave cure was used to manufacture the composite sandwich sections, while the doubler was co-bonded onto the sandwich face-sheet using an OOA process after sandwich panels were cured. A building block approach was adopted to characterize the mechanical properties of the joint material, including the fracture toughness between the doubler and facesheet. Twelve four-point-bend samples were tested, six in the sandwich core ribbon orientation and six in sandwich core cross-ribbon direction. Analysis predicted failure initiation and propagation at the pre-delaminated location, consistent with experimental observations. A building block approach using fracture analyses methods predicted failure loads in close agreement with tests. This investigation demonstrated a small strength reduction due to a flaw of significant size compared to the width of the sample. Therefore, concerns of bonding an OOA material to an in-autoclave material was mitigated for the geometries, materials, and load configurations considered.

  9. Failure Predictions of Out-of-Autoclave Sandwich Joints with Delaminations Under Flexure Loads

    NASA Technical Reports Server (NTRS)

    Nordendale, Nikolas; Goyal, Vinay; Lundgren, Eric; Patel, Dhruv; Farrokh, Babak; Jones, Justin; Fischetti, Grace; Segal, Kenneth

    2015-01-01

    An analysis and a test program was conducted to investigate the damage tolerance of composite sandwich joints. The joints contained a single circular delamination between the face-sheet and the doubler. The coupons were fabricated through out-of-autoclave (OOA) processes, a technology NASA is investigating for joining large composite sections. The four-point bend flexure test was used to induce compression loading into the side of the joint where the delamination was placed. The compression side was chosen since it tends to be one of the most critical loads in launch vehicles. Autoclave cure was used to manufacture the composite sandwich sections, while the doubler was co-bonded onto the sandwich face-sheet using an OOA process after sandwich panels were cured. A building block approach was adopted to characterize the mechanical properties of the joint material, including the fracture toughness between the doubler and face-sheet. Twelve four-point-bend samples were tested, six in the sandwich core ribbon orientation and six in sandwich core cross-ribbon direction. Analysis predicted failure initiation and propagation at the pre-delaminated location, consistent with experimental observations. Fracture analyses methods predicted failure loads in close agreement with tests. This investigation demonstrated a strength reduction of 10 percent due to a flaw of significant size compared to the width of the sample. Therefore, concerns of bonding an OOA material to an in-autoclave material was mitigated for the geometries, materials, and load configurations considered.

  10. Failure Predictions of Out-of-Autoclave Sandwich Joints with Delaminations Under Flexure Loads

    NASA Technical Reports Server (NTRS)

    Nordendale, Nikolas A.; Goyal, Vinay K.; Lundgren, Eric C.; Patel, Dhruv N.; Farrokh, Babak; Jones, Justin; Fischetti, Grace; Segal, Kenneth N.

    2015-01-01

    An analysis and a test program was conducted to investigate the damage tolerance of composite sandwich joints. The joints contained a single circular delamination between the face-sheet and the doubler. The coupons were fabricated through out-of-autoclave (OOA) processes, a technology NASA is investigating for joining large composite sections. The four-point bend flexure test was used to induce compression loading into the side of the joint where the delamination was placed. The compression side was chosen since it tends to be one of the most critical loads in launch vehicles. Autoclave cure was used to manufacture the composite sandwich sections, while the doubler was co-bonded onto the sandwich face-sheet using an OOA process after sandwich panels were cured. A building block approach was adopted to characterize the mechanical properties of the joint material, including the fracture toughness between the doubler and face-sheet. Twelve four-point-bend samples were tested, six in the sandwich core ribbon orientation and six in sandwich core cross-ribbon direction. Analysis predicted failure initiation and propagation at the pre-delaminated location, consistent with experimental observations. A building block approach using fracture analyses methods predicted failure loads in close agreement with tests. This investigation demonstrated a small strength reduction due to a flaw of significant size compared to the width of the sample. Therefore, concerns of bonding an OOA material to an in-autoclave material was mitigated for the geometries, materials, and load configurations considered.

  11. Bolted Double-Lap Composite Joints Under Mechanical and Thermal Loading

    NASA Technical Reports Server (NTRS)

    Kradinov, V.; Barut, A.; Madenci, E.; Walker, Sandra P. (Technical Monitor)

    2000-01-01

    This study concerns the determination of the contact stresses and contact region around bolt holes and the bolt load distribution in single- and double-lap joints of composite laminates with arbitrarily located bolts under general mechanical loading conditions and uniform temperature change. The unknown contact stress distribution and contact region between the bolt and laminates and the interaction among the bolts require the bolt load distribution, as well as the contact stresses, to be as part of the solution. The present method is based on the complex potential theory and the variational formulation in order to account for bolt stiffness, bolt-hole clearance, and finite geometry of the composite laminates.

  12. On hip and lumbar biomechanics. A study of joint load and muscular activity.

    PubMed

    Németh, G

    1984-01-01

    Loading moment of force about the hip and lumbo-sacral joints during straight and flexed knee lifting was calculated at regular intervals during the lifts, using a computerized sagittal plane model. Lift with flexed knees and burden moved close to the body was found to induce lower load. Important parameters influencing the induced joint load are discussed. EMG levels from three trunk and seven hip muscles were recorded with surface electrodes and normalized, i.e. expressed as a percentage of the recorded level of each muscle during an isometric voluntary contraction. The erector spinae, gluteus maximus and adductor magnus muscles were more activated initially in the flexed knee lifts than in the straight knee lift, while the hamstrings were more and earlier activated in the flexed knee lifts. In order to estimate what proportion of the maximum hip extensor muscle moment was used to counteract the induced load moments about the hip, assessments of maximum hip extensor muscle moments were made: the highest extensor muscle moment was exerted at 90 degrees hip flexion, decreasing with decreasing hip angle. The knee angle did not significantly influence the muscle moments exerted by the hip extensor muscles. To calculate the magnitude and direction of the hip compressive load from known load moments, the length of the moment arms of three hip extensors was determined at every fifth degree of flexion at hip flexion angles between 0 degrees and 90 degrees by combining data from autopsy specimens and patients, the latter examined by computed tomography. There were significant differences in moment arm length between men and women but there was low correlation between subject's height and length of muscular moment arms. The calculated compressive force during the lifts was about three times body weight and the direction of the compressive force passed through the area described by others as having the most severe osteoarthrotic lesions on the femoral head. Hip joint load

  13. FacetGist: Collective Extraction of Document Facets in Large Technical Corpora

    PubMed Central

    Siddiqui, Tarique; Ren, Xiang; Parameswaran, Aditya; Han, Jiawei

    2017-01-01

    Given the large volume of technical documents available, it is crucial to automatically organize and categorize these documents to be able to understand and extract value from them. Towards this end, we introduce a new research problem called Facet Extraction. Given a collection of technical documents, the goal of Facet Extraction is to automatically label each document with a set of concepts for the key facets (e.g., application, technique, evaluation metrics, and dataset) that people may be interested in. Facet Extraction has numerous applications, including document summarization, literature search, patent search and business intelligence. The major challenge in performing Facet Extraction arises from multiple sources: concept extraction, concept to facet matching, and facet disambiguation. To tackle these challenges, we develop FacetGist, a framework for facet extraction. Facet Extraction involves constructing a graph-based heterogeneous network to capture information available across multiple local sentence-level features, as well as global context features. We then formulate a joint optimization problem, and propose an efficient algorithm for graph-based label propagation to estimate the facet of each concept mention. Experimental results on technical corpora from two domains demonstrate that Facet Extraction can lead to an improvement of over 25% in both precision and recall over competing schemes. PMID:28210517

  14. FacetGist: Collective Extraction of Document Facets in Large Technical Corpora.

    PubMed

    Siddiqui, Tarique; Ren, Xiang; Parameswaran, Aditya; Han, Jiawei

    2016-10-01

    Given the large volume of technical documents available, it is crucial to automatically organize and categorize these documents to be able to understand and extract value from them. Towards this end, we introduce a new research problem called Facet Extraction. Given a collection of technical documents, the goal of Facet Extraction is to automatically label each document with a set of concepts for the key facets (e.g., application, technique, evaluation metrics, and dataset) that people may be interested in. Facet Extraction has numerous applications, including document summarization, literature search, patent search and business intelligence. The major challenge in performing Facet Extraction arises from multiple sources: concept extraction, concept to facet matching, and facet disambiguation. To tackle these challenges, we develop FacetGist, a framework for facet extraction. Facet Extraction involves constructing a graph-based heterogeneous network to capture information available across multiple local sentence-level features, as well as global context features. We then formulate a joint optimization problem, and propose an efficient algorithm for graph-based label propagation to estimate the facet of each concept mention. Experimental results on technical corpora from two domains demonstrate that Facet Extraction can lead to an improvement of over 25% in both precision and recall over competing schemes.

  15. Analytical and experiment study of clearance and bearing-bypass load effects in composite bolted joints

    SciTech Connect

    Naik, R.V.A.

    1986-01-01

    A combined analytical and experimental study is conducted to determine the effects of clearance and bearing-bypass loading for mechanically fastened joints in composites. A simple method of analysis is developed to account for the nonlinear effects of bolt-hole clearance. The nonlinear load-contact variations for clearance-fit fasteners are also measured using specially instrumented fastener. For a quasi-isotropic graphite/epoxy laminate, results show that the contact arc as well as the peak stresses around the hole and their locations are strongly influenced by the clearance. After a slight initial nonlinearity, the peak stresses vary linearly with applied load. The typical clearance levels are shown to have only a minor influence on the overall joint stiffness. Quasi-isotropic graphite/epoxy laminates (T300/5208) were tested under combined bearing and bypass loading to study failure modes and strengths. Radiographs were made after damage onset and after ultimate load to examine the failure criteria to analyze the test data. The near the bolt-hole are calculated for each test condition, and then used with appropriate failure criteria to analyze the test data. The tension data show a linear interaction for combined bearing and bypass loading with damage developing the net-tension mode and growing to failure in the same mode. Failure modes are more complex in compression.

  16. Prediction of In Vivo Knee Joint Loads Using a Global Probabilistic Analysis

    PubMed Central

    Navacchia, Alessandro; Myers, Casey A.; Rullkoetter, Paul J.; Shelburne, Kevin B.

    2016-01-01

    Musculoskeletal models are powerful tools that allow biomechanical investigations and predictions of muscle forces not accessible with experiments. A core challenge modelers must confront is validation. Measurements of muscle activity and joint loading are used for qualitative and indirect validation of muscle force predictions. Subject-specific models have reached high levels of complexity and can predict contact loads with surprising accuracy. However, every deterministic musculoskeletal model contains an intrinsic uncertainty due to the high number of parameters not identifiable in vivo. The objective of this work is to test the impact of intrinsic uncertainty in a scaled-generic model on estimates of muscle and joint loads. Uncertainties in marker placement, limb coronal alignment, body segment parameters, Hill-type muscle parameters, and muscle geometry were modeled with a global probabilistic approach (multiple uncertainties included in a single analysis). 5–95% confidence bounds and input/output sensitivities of predicted knee compressive loads and varus/valgus contact moments were estimated for a gait activity of three subjects with telemetric knee implants from the “Grand Challenge Competition.” Compressive load predicted for the three subjects showed confidence bounds of 333 ± 248 N, 408 ± 333 N, and 379 ± 244 N when all the sources of uncertainty were included. The measured loads lay inside the predicted 5–95% confidence bounds for 77%, 83%, and 76% of the stance phase. Muscle maximum isometric force, muscle geometry, and marker placement uncertainty most impacted the joint load results. This study demonstrated that identification of these parameters is crucial when subject-specific models are developed. PMID:26720096

  17. Prediction of In Vivo Knee Joint Loads Using a Global Probabilistic Analysis.

    PubMed

    Navacchia, Alessandro; Myers, Casey A; Rullkoetter, Paul J; Shelburne, Kevin B

    2016-03-01

    Musculoskeletal models are powerful tools that allow biomechanical investigations and predictions of muscle forces not accessible with experiments. A core challenge modelers must confront is validation. Measurements of muscle activity and joint loading are used for qualitative and indirect validation of muscle force predictions. Subject-specific models have reached high levels of complexity and can predict contact loads with surprising accuracy. However, every deterministic musculoskeletal model contains an intrinsic uncertainty due to the high number of parameters not identifiable in vivo. The objective of this work is to test the impact of intrinsic uncertainty in a scaled-generic model on estimates of muscle and joint loads. Uncertainties in marker placement, limb coronal alignment, body segment parameters, Hill-type muscle parameters, and muscle geometry were modeled with a global probabilistic approach (multiple uncertainties included in a single analysis). 5-95% confidence bounds and input/output sensitivities of predicted knee compressive loads and varus/valgus contact moments were estimated for a gait activity of three subjects with telemetric knee implants from the "Grand Challenge Competition." Compressive load predicted for the three subjects showed confidence bounds of 333 ± 248 N, 408 ± 333 N, and 379 ± 244 N when all the sources of uncertainty were included. The measured loads lay inside the predicted 5-95% confidence bounds for 77%, 83%, and 76% of the stance phase. Muscle maximum isometric force, muscle geometry, and marker placement uncertainty most impacted the joint load results. This study demonstrated that identification of these parameters is crucial when subject-specific models are developed.

  18. Eccentric loading and range of knee joint motion effects on performance enhancement in vertical jumping.

    PubMed

    Moran, Kieran A; Wallace, Eric S

    2007-12-01

    The aim of the study was to determine the effects of variations in eccentric loading and knee joint range of motion on performance enhancement associated with the stretch-shortening cycle in vertical jumping. Seventeen male elite volleyball players performed three variations of the vertical jump which served as the research model: the squat jump (SJ), countermovement jump (CMJ) and drop jump from a height of 30 cm (DJ30). Knee joint angle (70 degrees and 90 degrees of flexion) at the commencement of the propulsive phase for each jump type was experimentally controlled, with the trunk kept as erect as possible. Force and motion data were recorded for each performance and used to compute a range of kinematic and kinetic variables, including hip, knee and ankle angles, angular velocities, work done, net joint moments and a number of temporal variables. The average of 12 trials for each participant was used in a series of repeated measures ANOVA's (jump xk nee, alpha=.05). From both knee joint angles, an increase in eccentric loading resulted in a significant increase in jump height (DJ30>CMJ>SJ; p<.05). These enhancements were significantly greater (p<.05) for 70 degrees in comparison to 90 degrees of knee flexion. From 70 degrees of knee flexion, these enhancements were due to significant increases in work done at all three joints; while from 90 degrees of knee flexion, only the hip and ankle joints appeared to contribute (p<.05). The amount of enhancement associated with employing the SSC in jumping is dependent upon the interaction of the magnitude of eccentric loading and the range of motion used.

  19. Analysis of IL-17+ cells in facet joints of patients with spondyloarthritis suggests that the innate immune pathway might be of greater relevance than the Th17-mediated adaptive immune response

    PubMed Central

    2011-01-01

    Introduction In this study, we analysed the number of IL-17+ cells in facet joints, in the peripheral blood (PB) and synovial fluid (SF) of spondyloarthritis (SpA) patients and compared these results with those of patients with other rheumatic diseases and controls. Methods Immunohistochemical analysis of IL-17+ cells was performed in facet joints of 33 ankylosing spondylitis (AS) patients and compared with data from 20 osteoarthritis (OA) patients. The frequency of IL-17+CD4+ T cells in PB and SF of SpA patients (PB n = 30, SF n = 11), rheumatoid arthritis (RA) patients (PB n = 14, SF n = 7), OA patients (PB n = 10) and healthy controls (PB n = 12) was analysed after stimulation with Staphylococcus aureus Enterotoxin B and phorbol 12-myristate 13-acetate/ionomycin and quantified by flow cytometry. Results In AS facet joints, the frequency of IL-17-secreting cells was significantly higher than in samples obtained from OA patients (P < 0.001), with a slight predominance of IL-17+ cells among the mononuclear cells (61.5% ± 14.9%) compared to cells with polysegmental nuclei. Immunofluorescence microscopy revealed that the majority of IL-17+ cells were myeloperoxidase-positive (35.84 ± 13.06/high-power field (HPF) and CD15+ neutrophils (24.25 ± 10.36/HPF), while CD3+ T cells (0.51 ± 0.49/HPF) and AA-1+ mast cells (2.28 ± 1.96/HPF) were less often IL-17-positive. The frequency of IL-17+CD4+ T cells in the PB and SF of SpA patients did not differ significantly compared to RA patients, OA patients or healthy controls. Conclusions Our data suggest an important role for IL-17 in the inflammatory processes in AS. However, the innate immune pathway might be of greater relevance than the Th17-mediated adaptive immune response. PMID:21689402

  20. Biomechanics of the incudo-malleolar-joint - Experimental investigations for quasi-static loads.

    PubMed

    Ihrle, S; Gerig, R; Dobrev, I; Röösli, C; Sim, J H; Huber, A M; Eiber, A

    2016-10-01

    Under large quasi-static loads, the incudo-malleolar joint (IMJ), connecting the malleus and the incus, is highly mobile. It can be classified as a mechanical filter decoupling large quasi-static motions while transferring small dynamic excitations. This is presumed to be due to the complex geometry of the joint inducing a spatial decoupling between the malleus and incus under large quasi-static loads. Spatial Laser Doppler Vibrometer (LDV) displacement measurements on isolated malleus-incus-complexes (MICs) were performed. With the malleus firmly attached to a probe holder, the incus was excited by applying quasi-static forces at different points. For each force application point the resulting displacement was measured subsequently at different points on the incus. The location of the force application point and the LDV measurement points were calculated in a post-processing step combining the position of the LDV points with geometric data of the MIC. The rigid body motion of the incus was then calculated from the multiple displacement measurements for each force application point. The contact regions of the articular surfaces for different load configurations were calculated by applying the reconstructed motion to the geometry model of the MIC and calculate the minimal distance of the articular surfaces. The reconstructed motion has a complex spatial characteristic and varies for different force application points. The motion changed with increasing load caused by the kinematic guidance of the articular surfaces of the joint. The IMJ permits a relative large rotation around the anterior-posterior axis through the joint when a force is applied at the lenticularis in lateral direction before impeding the motion. This is part of the decoupling of the malleus motion from the incus motion in case of large quasi-static loads.

  1. L5 – S1 Segmental Kinematics After Facet Arthroplasty

    PubMed Central

    Voronov, Leonard I.; Havey, Robert M.; Rosler, David M.; Sjovold, Simon G.; Rogers, Susan L.; Carandang, Gerard; Ochoa, Jorge A.; Yuan, Hansen; Webb, Scott

    2009-01-01

    .9 degrees, P < .017). The load-displacement curves after the facet arthroplasty system implantation at L5-S1 were sigmoidal, and quality of motion measures were similar to intact, demonstrating graded resistance to angular motion in F-E, LB and AR. Conclusions The facet arthroplasty system was able to restore stability to the lumbosacral segment after complete laminectomy and bilateral facetectomy, while also allowing near-normal kinematics in all planes. While F-E ROM after the facet arthroplasty system implantation was smaller than the intact value, it was within the physiologic norms for L5-S1. These results are consistent with previous studies of facet arthroplasty at L3-L4 and L4-L5 and demonstrate that TFAS technology can be adapted to the lumbosacral joint with functionality comparable to its application in superior lumbar levels. PMID:25802628

  2. The effect of valgus braces on medial compartment load of the knee joint - in vivo load measurements in three subjects.

    PubMed

    Kutzner, Ines; Küther, Steffen; Heinlein, Bernd; Dymke, Jörn; Bender, Alwina; Halder, Andreas M; Bergmann, Georg

    2011-04-29

    Knee osteoarthritis occurs predominately at the medial compartment. To unload the affected compartment, valgus braces are used which induce an additional valgus moment in order to shift the load more laterally. Until now the biomechanical effect of braces was mainly evaluated by measuring changes in external knee adduction moments. The aim of this study was to investigate if and to which extent the medial compartment load is reduced in vivo when wearing valgus braces. Six components of joint contact load were measured in vivo in three subjects, using instrumented, telemeterized knee implants. From the forces and moments the medio-lateral force distribution was calculated. Two braces, MOS Genu (Bauerfeind AG) and Genu Arthro (Otto Bock) were investigated in neutral, 4° and 8° valgus adjustment during walking, stair ascending and descending. During walking with the MOS brace in 4°/8° valgus adjustment, medial forces were reduced by 24%/30% on average at terminal stance. During walking with the GA in the 8° valgus position, medial forces were reduced by only 7%. During stair ascending/descending significant reductions of 26%/24% were only observed with the MOS (8°). The load reducing ability of the two investigated valgus braces was confirmed in three subjects. However, the load reduction depends on the brace stiffness and its valgus adjustment and varies strongly inter-individually. Valgus adjustments of 8° might, especially with the MOS brace, not be tolerated by patients for a long time. Medial load reductions of more than 25% can therefore probably not be expected in clinical practise. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Sagittal plane joint loading is related to knee flexion in osteoarthritic gait.

    PubMed

    Creaby, Mark W; Hunt, Michael A; Hinman, Rana S; Bennell, Kim L

    2013-10-01

    High mechanical loading has been consistently linked with medial tibiofemoral osteoarthritis, and is considered to play a central role in the pathogenesis of the disease. Evidence from healthy adults indicates that knee flexion kinematics may influence knee load. The purpose of this study therefore, was to investigate the association between knee flexion kinematics and indicators of joint loading during walking (peak moments and vertical ground reaction force), in individuals with medial tibiofemoral osteoarthritis. In this cross-sectional study, 89 participants with painful medial tibiofemoral osteoarthritis completed three-dimensional walking gait analysis to measure stance phase ground reaction forces, knee joint moments, and knee flexion kinematics. In stepwise regression, greater knee flexion excursion was associated with higher peak vertical ground reaction force, accounting for 10% of its variance (B=0.62 [95% CI 0.34, 0.89], P<0.001). Greater peak knee flexion was associated with a higher flexion moment, accounting for 44% of its variance (B=0.12 [95% CI 0.09, 0.15], P<0.001). No association was found between the knee adduction moment and knee flexion kinematics during walking. Our data suggest that greater knee flexion is associated with higher joint loads in the sagittal plane (i.e. a higher peak knee flexion moment). However, knee flexion kinematics were not associated with the knee adduction moment - a proxy measure of medial compartment knee load. Thus, high knee flexion should be considered an undesirable gait characteristic with respect to knee load in individuals with medial tibiofemoral osteoarthritis. © 2013.

  4. Effects of Cyclic Loading on the Shear Behaviour of Infilled Rock Joints Under Constant Normal Stiffness Conditions

    NASA Astrophysics Data System (ADS)

    Mirzaghorbanali, Ali; Nemcik, Jan; Aziz, Naj

    2014-07-01

    The variation of the shear strength of infilled rock joints under cyclic loading and constant normal stiffness conditions is studied. To simulate the joints, triangular asperities inclined at angles of 9.5° and 18.5° to the shear movement were cast using high-strength gypsum plaster and infilled with clayey sand. These joints were sheared cyclically under constant normal stiffness conditions. It was found that, for a particular normal stiffness, the shear strength is a function of the initial normal stress, initial asperity angle, joint surface friction angle, infill thickness, infill friction angle, loading direction and number of loading cycles. Based on the experimental results, a mathematical model is proposed to evaluate the shear strength of infilled rock joints in cyclic loading conditions. The proposed model takes into consideration different initial asperity angles, initial normal stresses and ratios of infill thickness to asperity height.

  5. Unilateral hip osteoarthritis: The effect of compensation strategies and anatomic measurements on frontal plane joint loading.

    PubMed

    Schmidt, André; Meurer, Andrea; Lenarz, Katharina; Vogt, Lutz; Froemel, Dara; Lutz, Frederick; Barker, John; Stief, Felix

    2017-08-01

    In order to reduce pain caused by the affected hip joint, unilateral hip osteoarthritis patients (HOAP) adopt characteristic gait patterns. However, it is unknown if the knee and hip joint loading in the non-affected (limbnon-affected ) and the affected (limbaffected ) limb differ from healthy controls (HC) and which gait parameters correlate with potential abnormal joint loading. Instrumented 3D-gait analysis was performed on 18 HOAP and 18 sex, age, and height matched HC. The limbnon-affected showed greater first and second peak external hip adduction moments (first HAM: +15%, p = 0.014; second HAM: +15%, p = 0.021, respectively), than seen in HC. In contrast, the second peak external knee adduction moment (KAM) in the limbaffected is reduced by about 23% and 30% compared to the limbnon-affected and HC, respectively. Furthermore, our patients showed characteristic gait compensation strategies including reduced peak vertical forces (pvF), a greater foot progression angle (FPA), and reduced knee range of motion (ROM) in the limbaffected . The limbaffected was 5.6 ± 3.8 mm shorter than the limbnon-affected . Results of stepwise regression analyses showed that increased first pvF explain 16% of first HAM alterations, whereas knee ROM and FPA explain 39% of second KAM alterations. We therefore expect an increased rate of progression of OA in the hip joint of the limbnon-affected and suggest that the shift in the medial-to-lateral knee joint load distribution may impact the rate of progression of OA in the limbaffected . The level of evidence is III. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1764-1773, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  6. A three-dimensional ankle kinetostatic model to simulate loaded and unloaded joint motion.

    PubMed

    Forlani, Margherita; Sancisi, Nicola; Parenti-Castelli, Vincenzo

    2015-06-01

    A kinetostatic model able to replicate both the natural unloaded motion of the tibiotalar (or ankle) joint and the joint behavior under external loads is presented. The model is developed as the second step of a sequential procedure, which allows the definition of a kinetostatic model as a generalization of a kinematic model of the joint defined at the first step. Specifically, this kinematic model taken as the starting point of the definition procedure is a parallel spatial mechanism which replicates the ankle unloaded motion. It features two rigid bodies (representing the tibia-fibula and the talus-calcaneus complexes) interconnected by five rigid binary links, that mimic three articular contacts and two nearly isometric fibers (IFs) of the tibiocalcaneal ligament (TiCaL) and calcaneofibular ligament (CaFiL). In the kinetostatic model, the five links are considered as compliant; moreover, further elastic structures are added to represent all the main ankle passive structures of the joint. Thanks to this definition procedure, the kinetostatic model still replicates the ankle unloaded motion with the same accuracy as the kinematic model. In addition, the model can replicate the behavior of the joint when external loads are applied. Finally, the structures that guide these motions are consistent with the anatomical evidence. The parameters of the model are identified for two specimens from both subject-specific and published data. Loads are then applied to the model in order to simulate two common clinical tests. The model-predicted ankle motion shows good agreement with results from the literature.

  7. The friction coefficient of shoulder joints remains remarkably low over 24 h of loading.

    PubMed

    Jones, Brian K; Durney, Krista M; Hung, Clark T; Ateshian, Gerard A

    2015-11-05

    The frictional response of whole human joints over durations spanning activities of daily living has not been reported previously. This study measured the friction of human glenohumeral joints during 24 h of reciprocal loading in a pendulum testing device, at moderate (0.2 mm/s, 4320 cycles) and low (0.02 mm/s, 432 cycles) sliding speeds, under a 200 N load. The effect of joint congruence was also investigated by testing human humeral heads against significantly larger mature bovine glenoids. Eight human joints and six bovine joints were tested in four combinations: human joints tested at moderate (hHCMS, n=6) and low speed (hHCLS, n=3), human humeral heads tested against bovine glenoids at moderate speed (LCMS, n=3), and bovine joints tested at moderate speed (bHCMS, n=3). In the first half hour the mean±standard deviation of the friction coefficient was hHCMS: 0.0016±0.0011, hHCLS: 0.0012±0.0002, LCMS: 0.0008±0.0002 and bHCMS: 0.0024±0.0008; in the last four hours it was hHCMS: 0.0057±0.0025, hHCLS: 0.0047±0.0017, LCMS: 0.0012±0.0003 and bHCMS: 0.0056±0.0016. The initial value was lower than the final value (p<0.0001). The value in LCMS was significantly lower than in hHCMS and bHCMS (p<0.01). No visual damage was observed in any of the specimens. These are the first results to demonstrate that the friction coefficient of natural human shoulders remains remarkably low (averaging as little as 0.0015 and no greater than 0.006) for up to 24 h of continuous loading. The sustained low friction coefficients observed in incongruent joints (~0.001) likely represent rolling rather than sliding friction. Copyright © 2015. Published by Elsevier Ltd.

  8. [Comments on the lateral load capacity of the phalangeal joints (author's transl)].

    PubMed

    Dahmen, G; Dost, G

    1979-02-01

    The article compares the load capacity of the collateral ligaments of the metacarpo-phalangeal and interphalangeal joints exposed to a laterally applied force. The tests were performed in vivo with 50 each female and male volunteers. It was found that the average load capacity of the metacarpo-phalangeal and interphalangeal joints in women was 5.8 kp and in men 12.3 kp. Furthermore, the bones of the long fingers with the preserved joint capsules and collateral ligaments of ten corpses were also examined, and the collateral ligaments exposed to a load which was increased to the point of their destruction. The average values found in this manner were 26.5 kp for the metacarpo-phalangeal collateral ligaments and 15.4 kp for the interphalangeal collateral ligaments. This means that the pain threshold is usually below the destruction limit, so that generally there will be no spontaneous overloading. It is important for the construction of endoprostheses that their stability level should always be above that of the pain threshold and should attain at least the values of the tear tests, since otherwise these endoprotheses will not function properly. These basic prerequisites enable a comparative study of endoprostheses, the results of which will be presented at a later date.

  9. Influences of Alignment and Obesity on Knee Joint Loading in Osteoarthritic Gait

    PubMed Central

    Messier, Stephen P.; Pater, Mackenzie; Beavers, Daniel P.; Legault, Claudine; Loeser, Richard F.; Hunter, David J.; DeVita, Paul

    2014-01-01

    Objective To determine the influences of frontal plane knee alignment and obesity on knee joint loads in older, overweight and obese adults with knee osteoarthritis. Methods Cross-sectional investigation of alignment and obesity on knee joint loads using community dwelling older adults (age ≥ 55 yrs.; 27 kg·m−2 ≥ BMI ≤ 41 kg·m−2; 69% female) with radiographic knee osteoarthritis that were a subset of participants (157 out of 454) enrolled in the Intensive Diet and Exercise for Arthritis (IDEA) clinical trial. Results A higher BMI was associated with greater (p = 0.0006) peak knee compressive forces [overweight, 2411 N (2182, 2639), class 1 obesity, 2772 N (2602, 2943), class 2+ obesity, 2993 N (2796, 3190)] and greater (p = 0.004) shear forces [overweight, 369 N (322, 415), class 1 obesity, 418 N (384, 453), class 2+ obesity, 472 N (432, 513)], independent of alignment, and varus alignment was associated (p < 0.0001) with greater peak external knee adduction moments, independent of BMI [valgus, 18.7 Nm (15.1, 22.4), neutral, 27.7 Nm (24.0, 31.4), varus, 37.0 Nm (34.4, 39.7)]. Conclusion BMI and alignment were associated with different joint loading measures; alignment was more closely associated with the asymmetry or imbalance of loads across the medial and lateral knee compartments as reflected by the frontal plane external adduction moment, while BMI was associated with the magnitude of total tibio-femoral force. These data may be useful in selecting treatment options for knee osteoarthritis patients (e.g., diet to reduce compressive loads or bracing to change alignment). PMID:24857973

  10. Influences of alignment and obesity on knee joint loading in osteoarthritic gait.

    PubMed

    Messier, S P; Pater, M; Beavers, D P; Legault, C; Loeser, R F; Hunter, D J; DeVita, P

    2014-07-01

    To determine the influences of frontal plane knee alignment and obesity on knee joint loads in older, overweight and obese adults with knee osteoarthritis (OA). Cross-sectional investigation of alignment and obesity on knee joint loads using community dwelling older adults (age ≥ 55 years; 27 kg m(-2) ≥ body mass or body mass index (BMI) ≤ 41 kg m(-2); 69% female) with radiographic knee OA that were a subset of participants (157 out of 454) enrolled in the Intensive Diet and Exercise for Arthritis (IDEA) clinical trial. A higher BMI was associated with greater (P = 0.0006) peak knee compressive forces [overweight, 2411 N (2182, 2639), class 1 obesity, 2772 N (2602, 2943), class 2+ obesity, 2993 N (2796, 3190)] and greater (P = 0.004) shear forces [overweight, 369 N (322, 415), class 1 obesity, 418 N (384, 453), class 2+ obesity, 472 N (432, 513)], independent of alignment, and varus alignment was associated (P < 0.0001) with greater peak external knee adduction moments, independent of BMI [valgus, 18.7 Nm (15.1, 22.4), neutral, 27.7 Nm (24.0, 31.4), varus, 37.0 Nm (34.4, 39.7)]. BMI and alignment were associated with different joint loading measures; alignment was more closely associated with the asymmetry or imbalance of loads across the medial and lateral knee compartments as reflected by the frontal plane external adduction moment, while BMI was associated with the magnitude of total tibiofemoral force. These data may be useful in selecting treatment options for knee OA patients (e.g., diet to reduce compressive loads or bracing to change alignment). Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  11. In Vivo Dynamic Deformation of Articular Cartilage in Intact Joints Loaded by Controlled Muscular Contractions

    PubMed Central

    Abusara, Ziad; Von Kossel, Markus; Herzog, Walter

    2016-01-01

    When synovial joints are loaded, the articular cartilage and the cells residing in it deform. Cartilage deformation has been related to structural tissue damage, and cell deformation has been associated with cell signalling and corresponding anabolic and catabolic responses. Despite the acknowledged importance of cartilage and cell deformation, there are no dynamic data on these measures from joints of live animals using muscular load application. Research in this area has typically been done using confined and unconfined loading configurations and indentation testing. These loading conditions can be well controlled and allow for accurate measurements of cartilage and cell deformations, but they have little to do with the contact mechanics occurring in a joint where non-congruent cartilage surfaces with different material and functional properties are pressed against each other by muscular forces. The aim of this study was to measure in vivo, real time articular cartilage deformations for precisely controlled static and dynamic muscular loading conditions in the knees of mice. Fifty and 80% of the maximal knee extensor muscular force (equivalent to approximately 0.4N and 0.6N) produced average peak articular cartilage strains of 10.5±1.0% and 18.3±1.3% (Mean ± SD), respectively, during 8s contractions. A sequence of 15 repeat, isometric muscular contractions (0.5s on, 3.5s off) of 50% and 80% of maximal muscular force produced cartilage strains of 3.0±1.1% and 9.6±1.5% (Mean ± SD) on the femoral condyles of the mouse knee. Cartilage thickness recovery following mechanical compression was highly viscoelastic and took almost 50s following force removal in the static tests. PMID:26807930

  12. In Vivo Dynamic Deformation of Articular Cartilage in Intact Joints Loaded by Controlled Muscular Contractions.

    PubMed

    Abusara, Ziad; Von Kossel, Markus; Herzog, Walter

    2016-01-01

    When synovial joints are loaded, the articular cartilage and the cells residing in it deform. Cartilage deformation has been related to structural tissue damage, and cell deformation has been associated with cell signalling and corresponding anabolic and catabolic responses. Despite the acknowledged importance of cartilage and cell deformation, there are no dynamic data on these measures from joints of live animals using muscular load application. Research in this area has typically been done using confined and unconfined loading configurations and indentation testing. These loading conditions can be well controlled and allow for accurate measurements of cartilage and cell deformations, but they have little to do with the contact mechanics occurring in a joint where non-congruent cartilage surfaces with different material and functional properties are pressed against each other by muscular forces. The aim of this study was to measure in vivo, real time articular cartilage deformations for precisely controlled static and dynamic muscular loading conditions in the knees of mice. Fifty and 80% of the maximal knee extensor muscular force (equivalent to approximately 0.4N and 0.6N) produced average peak articular cartilage strains of 10.5±1.0% and 18.3±1.3% (Mean ± SD), respectively, during 8s contractions. A sequence of 15 repeat, isometric muscular contractions (0.5s on, 3.5s off) of 50% and 80% of maximal muscular force produced cartilage strains of 3.0±1.1% and 9.6±1.5% (Mean ± SD) on the femoral condyles of the mouse knee. Cartilage thickness recovery following mechanical compression was highly viscoelastic and took almost 50s following force removal in the static tests.

  13. Comparison of Joint Loading in Badminton Lunging between Professional and Amateur Badminton Players

    PubMed Central

    Fu, Lin

    2017-01-01

    The knee and ankle are the two most injured joints associated with the sport of badminton. This study evaluates biomechanical factors between professional and amateur badminton players using an injury mechanism model. The aim of this study was to investigate the kinematic motion and kinetic loading differences of the right knee and ankle while performing a maximal right lunge. Amateur players exhibited greater ankle range of motion (p < 0.05, r = 0.89) and inversion joint moment (p < 0.05, r = 0.54) in the frontal plane as well as greater internal joint rotation moment (p < 0.05, r = 0.28) in the horizontal plane. In contrast, professional badminton players presented a greater knee joint moment in the sagittal (p < 0.05, r = 0.59) and frontal (p < 0.05, r = 0.37) planes, which may be associated with increased knee ligamentous injury risk. To avoid injury, the players need to forcefully extend the knee with internal rotation, strengthen the muscles around the ankle ligament, and maximise joint coordination during training. The injuries recorded and the forces responsible for the injuries seem to have developed during training activity. Training programmes and injury prevention strategies for badminton players should account for these findings to reduce potential injury to the ankle and knee. PMID:28694684

  14. Comparison of Joint Loading in Badminton Lunging between Professional and Amateur Badminton Players.

    PubMed

    Fu, Lin; Ren, Feng; Baker, Julien S

    2017-01-01

    The knee and ankle are the two most injured joints associated with the sport of badminton. This study evaluates biomechanical factors between professional and amateur badminton players using an injury mechanism model. The aim of this study was to investigate the kinematic motion and kinetic loading differences of the right knee and ankle while performing a maximal right lunge. Amateur players exhibited greater ankle range of motion (p < 0.05, r = 0.89) and inversion joint moment (p < 0.05, r = 0.54) in the frontal plane as well as greater internal joint rotation moment (p < 0.05, r = 0.28) in the horizontal plane. In contrast, professional badminton players presented a greater knee joint moment in the sagittal (p < 0.05, r = 0.59) and frontal (p < 0.05, r = 0.37) planes, which may be associated with increased knee ligamentous injury risk. To avoid injury, the players need to forcefully extend the knee with internal rotation, strengthen the muscles around the ankle ligament, and maximise joint coordination during training. The injuries recorded and the forces responsible for the injuries seem to have developed during training activity. Training programmes and injury prevention strategies for badminton players should account for these findings to reduce potential injury to the ankle and knee.

  15. Knee joint loading during lineman-specific movements in American football players.

    PubMed

    Lambach, Rebecca L; Young, Jay W; Flanigan, David C; Siston, Robert A; Chaudhari, Ajit M

    2015-06-01

    Linemen are at high risk for knee cartilage injuries and osteoarthritis. High-intensity movements from squatting positions (eg, 3-point stance) may produce high joint loads, increasing the risk for cartilage damage. We hypothesized that knee moments and joint reaction forces during lineman-specific activities would be greater than during walking or jogging. Data were collected using standard motion analysis techniques. Fifteen NCAA linemen (mean ± SD: height = 1.86 ± 0.07 m, mass = 121.45 ± 12.78 kg) walked, jogged, and performed 3 unloaded lineman-specific blocking movements from a 3-point stance. External 3-dimensional knee moments and joint reaction forces were calculated using inverse dynamics equations. MANOVA with subsequent univariate ANOVA and post hoc Tukey comparisons were used to determine differences in peak kinetic variables and the flexion angles at which they occurred. All peak moments and joint reaction forces were significantly higher during jogging than during all blocking drills (all P < .001). Peak moments occurred at average knee flexion angles > 70° during blocking versus < 44° in walking or jogging. The magnitude of moments and joint reaction forces when initiating movement from a 3-point stance do not appear to increase risk for cartilage damage, but the high flexion angles at which they occur may increase risk on the posterior femoral condyles.

  16. Shoulder joint loading in the high performance flat and kick tennis serves

    PubMed Central

    Reid, Machar; Elliott, Bruce; Alderson, Jacque

    2007-01-01

    Objective To quantify and compare the full body kinematics and shoulder joint kinetics during the high‐performance tennis flat (FS) and kick serves (KS). Methods A 12‐camera 250 Hz, Vicon motion analysis system recorded the three‐dimensional FS and KS of 12 high‐performance male players. A total of 22 paired Student's t tests, with an accompanying partial Bonferroni correction (p<0.01), determined statistically significant differences between the variables of interest in both serves. Results Higher peak horizontal, vertical and absolute racquet velocities were developed during the FS, while higher lateral velocities characterised the KS. Similar shoulder joint kinematics and kinetics punctuated both serves, but with some variation in trunk and lower limb mechanics. Conclusions Similar shoulder joint kinetics assisted the development of varying three‐dimensional racquet velocities in the FS and KS. The comparable shoulder joint loading conditions point to the repetitive, long‐term performance of either serve as relevant in shoulder joint injury pathologies. PMID:17513331

  17. Predicting dynamic knee joint load with clinical measures in people with medial knee osteoarthritis.

    PubMed

    Hunt, Michael A; Bennell, Kim L

    2011-08-01

    Knee joint loading, as measured by the knee adduction moment (KAM), has been implicated in the pathogenesis of knee osteoarthritis (OA). Given that the KAM can only currently be accurately measured in the laboratory setting with sophisticated and expensive equipment, its utility in the clinical setting is limited. This study aimed to determine the ability of a combination of four clinical measures to predict KAM values. Three-dimensional motion analysis was used to calculate the peak KAM at a self-selected walking speed in 47 consecutive individuals with medial compartment knee OA and varus malalignment. Clinical predictors included: body mass; tibial angle measured using an inclinometer; walking speed; and visually observed trunk lean toward the affected limb during the stance phase of walking. Multiple linear regression was performed to predict KAM magnitudes using the four clinical measures. A regression model including body mass (41% explained variance), tibial angle (17% explained variance), and walking speed (9% explained variance) explained a total of 67% of variance in the peak KAM. Our study demonstrates that a set of measures easily obtained in the clinical setting (body mass, tibial alignment, and walking speed) can help predict the KAM in people with medial knee OA. Identifying those patients who are more likely to experience high medial knee loads could assist clinicians in deciding whether load-modifying interventions may be appropriate for patients, whilst repeated assessment of joint load could provide a mechanism to monitor disease progression or success of treatment.

  18. The Load Distribution in Bolted or Riveted Joints in Light-Alloy Structures

    NASA Technical Reports Server (NTRS)

    Vogt, F.

    1947-01-01

    This report contains a theoretical discussion of the load distribution in bolted or riveted joints in light-alloy structures which is applicable not only for loads below the limit of proportionality but also for loads above this limit. The theory is developed for double and single shear joints. The methods given are illustrated by numerical examples and the values assumed for the bolt (or rivet) stiffnesses are based partly on theory and partly on known experimental values. It is shown that the load distribution does not vary greatly with the bolt (or rivet) stiffnesses and that for design purposes it is usually sufficient to know their order of magnitude. The theory may also be directly used for spot-welded structures and, with small modifications, for seam-welded structures, The computational work involved in the methods described is simple and may be completed in a reasonable time for most practical problems. A summary of earlier theoretical and experimental investigations on the subject is included in the report.

  19. Experimental characterization of damage at countersunk bolted joints tested under quasi-static bearing loads

    NASA Astrophysics Data System (ADS)

    Popescu, Alexandru Paul

    The use of composite materials in aerospace vehicles has allowed for creation of lighter structures that provide excellent stiffness. Although they allow for easy disassembly and inspection of critical assemblies, bolted joints are common damage initiation sites in composite structures. In order for aging aircraft to be considered for life extension programs, the damage at these locations must be characterized and well-understood. Failure studies require that data be provided through experimental tests. The drawback of the present test standard for bolted composite joints is that it was initially designed for testing polymers. This thesis discusses deficiencies in the measurement of bearing strength as a result of this shortcoming, although the battery of bearing tests is modeled after this established test standard. The goal of the present work is to characterize the bearing load induced damage in laminates with pin bearing and countersunk fasteners through a series of bearing tests on laminated composites using a new modified ASTM D5961 fixture designed for testing countersunk bolted joints. This thesis examines variations in measurement of bearing strength that comes with using different test fixtures. The reliability of each test fixture to represent real conditions is evaluated using test fixtures that represent real joint configurations. Results for damage conditions and joint responses are compared. This thesis presents a study of the damage initiation and accumulation in composite specimens loaded in bearing using three different test fixtures: Procedure A, Procedure C, and Procedure A Modified. Procedure A, which is used to load the test specimen in double-shear via a straight pin, is a well known test fixture that comes from ASTM D5961. Procedure C has a countersunk fastener that loads the test specimen in single-shear. These types of fasteners are preferred in the aerospace industry over traditional bolts in order to maintain a smooth aerodynamic profile

  20. Joint Seasonal ARMA Approach for Modeling of Load Forecast Errors in Planning Studies

    SciTech Connect

    Hafen, Ryan P.; Samaan, Nader A.; Makarov, Yuri V.; Diao, Ruisheng; Lu, Ning

    2014-04-14

    To make informed and robust decisions in the probabilistic power system operation and planning process, it is critical to conduct multiple simulations of the generated combinations of wind and load parameters and their forecast errors to handle the variability and uncertainty of these time series. In order for the simulation results to be trustworthy, the simulated series must preserve the salient statistical characteristics of the real series. In this paper, we analyze day-ahead load forecast error data from multiple balancing authority locations and characterize statistical properties such as mean, standard deviation, autocorrelation, correlation between series, time-of-day bias, and time-of-day autocorrelation. We then construct and validate a seasonal autoregressive moving average (ARMA) model to model these characteristics, and use the model to jointly simulate day-ahead load forecast error series for all BAs.

  1. A Stacked-Shell Finite Element Approach for Modelling a Dynamically Loaded Composite Bolted Joint Under in-Plane Bearing Loads

    NASA Astrophysics Data System (ADS)

    Pearce, G. M. K.; Johnson, A. F.; Hellier, A. K.; Thomson, R. S.

    2013-12-01

    This paper presents the results of a study into a novel application of the "stacked-shell" laminate modelling approach to dynamically loaded bolted composite joints using the explicit finite element code PAM-CRASH. The stacked-shell approach provides medium-high fidelity resolution of the key joint failure modes, but is computationally much more efficient than full 3D modelling. For this work, a countersunk bolt in a composite laminate under in-plane bearing loading was considered. The models were able to predict the onset of damage, failure modes and the ultimate load of the joint. It was determined that improved debris models are required in order to accurately capture the progressive bearing damage after the onset of joint failure.

  2. Determination of three-dimensional joint loading within the lower extremities in snowboarding.

    PubMed

    Krüger, Andreas; McAlpine, Paul; Borrani, Fabio; Edelmann-Nusser, Jürgen

    2012-02-01

    In the biomechanical literature only a few studies are available focusing on the determination of joint loading within the lower extremities in snowboarding. These studies are limited to analysis in a restricted capture volume due to the use of optical video-based systems. To overcome this restriction the aim of the present study was to develop a method to determine net joint moments within the lower extremities in snowboarding for complete measurement runs. An experienced snowboarder performed several runs equipped with two custom-made force plates as well as a full-body inertial measurement system. A rigid, multi-segment model was developed to describe the motion and loads within the lower extremities. This model is based on an existing lower-body model and designed to be run by the OpenSim software package. Measured kinetic and kinematic data were imported into the OpenSim program and inverse dynamic calculations were performed. The results illustrate the potential of the developed method for the determination of joint loadings within the lower extremities for complete measurement runs in a real snowboarding environment. The calculated net joint moments of force are reasonable in comparison to the data presented in the literature. A good reliability of the method seems to be indicated by the low data variation between different turns. Due to the unknown accuracy of this method the application for inter-individual studies as well as studies of injury mechanisms may be limited. For intra-individual studies comparing different snowboarding techniques as well as different snowboard equipment the method seems to be beneficial. The validity of the method needs to be studied further.

  3. Development and validation of a 3-D model to predict knee joint loading during dynamic movement.

    PubMed

    McLean, S G; Su, A; van den Bogert, A J

    2003-12-01

    The purpose of this study was to develop a subject-specific 3-D model of the lower extremity to predict neuromuscular control effects on 3-D knee joint loading during movements that can potentially cause injury to the anterior cruciate ligament (ACL) in the knee. The simulation consisted of a forward dynamic 3-D musculoskeletal model of the lower extremity, scaled to represent a specific subject. Inputs of the model were the initial position and velocity of the skeletal elements, and the muscle stimulation patterns. Outputs of the model were movement and ground reaction forces, as well as resultant 3-D forces and moments acting across the knee joint. An optimization method was established to find muscle stimulation patterns that best reproduced the subject's movement and ground reaction forces during a sidestepping task. The optimized model produced movements and forces that were generally within one standard deviation of the measured subject data. Resultant knee joint loading variables extracted from the optimized model were comparable to those reported in the literature. The ability of the model to successfully predict the subject's response to altered initial conditions was quantified and found acceptable for use of the model to investigate the effect of altered neuromuscular control on knee joint loading during sidestepping. Monte Carlo simulations (N = 100,000) using randomly perturbed initial kinematic conditions, based on the subject's variability, resulted in peak anterior force, valgus torque and internal torque values of 378 N, 94 Nm and 71 Nm, respectively, large enough to cause ACL rupture. We conclude that the procedures described in this paper were successful in creating valid simulations of normal movement, and in simulating injuries that are caused by perturbed neuromuscular control.

  4. Fluid load support and contact mechanics of hemiarthroplasty in the natural hip joint.

    PubMed

    Pawaskar, Sainath Shrikant; Ingham, Eileen; Fisher, John; Jin, Zhongmin

    2011-01-01

    The articular cartilage covering the ends of the bones of diarthrodial synovial joints is thought to have evolved so that the loads are transferred under different and complex conditions, with a very high degree of efficiency and without compromising the structural integrity of the tissue for the life of an individual. These loading conditions stem from different activities such as walking, and standing. The integrity of cartilage may however become compromised due to congenital disease, arthritis or trauma. Hemiarthroplasty is a potentially conservative treatment when only the femoral cartilage is affected as in case of femoral neck fractures. In hemiarthroplasty, a metallic femoral prosthesis is used to articulate against the natural acetabular cartilage. It has also been hypothesized that biphasic lubrication is the predominant mechanism protecting the cartilage through a very high fluid load support which lowers friction. This may be altered due to hemiarthroplasty and have a direct effect on the frictional shear stresses and potentially cartilage degradation and wear. This study modelled nine activities of daily living and investigated the contact mechanics of a hip joint with a hemiarthroplasty, focussing particularly on the role of the fluid phase. It was shown that in most of the activities studied the peak contact stresses and peak fluid pressures were in the superior dome or lateral roof of the acetabulum. Total fluid load support was very high (~90%) in most of the activities which would shield the solid phase from being subjected to very high contact stresses. This was dependent not only on the load magnitude but also the direction and hence on the location of the contact area with respect to the cartilage coverage. Lower fluid load support was found when the contact area was nearer the edges where the fluid drained easily.

  5. Mechanics of the knee. A study of joint and muscle load with clinical applications.

    PubMed

    Nisell, R

    1985-01-01

    The load moment of force about the knee joint during machine milking and when lifting a 12.8 kg box was quantified using a computerized static sagittal plane body model. Surface electromyography of quadriceps and hamstrings muscles was normalized and expressed as a percentage of an isometric maximum voluntary test contraction. Working with straight knees and the trunk flexed forwards induced extending knee load moments of maximum 55 Nm. Lifting the box with flexed knees gave flexing moments of 50 Nm at the beginning of the lift, irrespective of whether the burden was between or in front of the feet. During machine milking, a level difference between operator and cow of 0.70 m - 1.0 m significantly lowered the knee extending moments. To quantify the force magnitudes acting in the tibio-femoral and patello-femoral joints, a local biomechanical model of the knee was developed using a combination of cadaver knee dissections and lateral knee radiographs of healthy subjects. The moment arm of the knee extensor was significantly shorter for women than for men, which resulted in higher knee joint forces in women if the same moment was produced. A diagram for quantifying patellar forces was worked out. The force magnitudes given by the knee joint biomechanical model correlated well with experimentally forces measured by others. During the parallel squat in powerlifting, the maximum flexing knee load moment was estimated to 335-550 Nm when carrying a 382.5 kg burden and the in vivo force of a complete quadriceps tendon-muscle rupture to between 10,900 and 18,300 N. During isokinetic knee extension, the tibio-femoral compressive force reached peak magnitudes of 9 times body weight and the anteroposterior shear force was close to 1 body weight at knee angles straighter than 60 degrees, indicating that high forces stress the anterior cruciate ligament. A proximal resistance pad position decreased the shear force considerably, and this position is recommended in early

  6. Parametric Study of Single Bolted Composite Bolted Joint Subjected to Static Tensile Loading

    NASA Astrophysics Data System (ADS)

    Awadhani, L. V.; Bewoor, Anand, Dr.

    2017-08-01

    The use of composites is increasing in the engineering applications in order to reduce the weight, building energy efficient systems, designing a suitable material according to the requirements of the application. But at the same time, building a structure is possible only by bonding or bolting or combination of them. There are limitations for the bonding methods and problems with the bolting such as stress concentration near the neighborhood of the bolt hole, tensile or shear failure, delamination etc. Hence the design of a composite bolted structure needs a special attention. This paper focuses on the performance of the composite bolted joint under static tensile loading and the effect of variation in the parameters such as the bolt pitch, plate width, thickness, bolt tightening torque, composite material, coefficient of friction between the bolt and plate etc. A simple spring mass model is used to study the single bolted composite bolted joint. The influencing parameters are identified through the developed model and compared with the results from the literature. The best geometric parameters for the applied load are identified for the composite bolted joints.

  7. FACET ORIENTATION AND TROPISM: ASSOCIATION WITH ACCELERATED DEGENERATION OF STABILIZING STRUCTURES IN LOWER LUMBAR SPINE.

    PubMed

    Jelec, Vjekoslav; Turner, Rajka; Franić, Miljenko; Korušić, Anđelko; Rotim, Krešimir

    2016-03-01

    The influence of facet orientation and tropism on the process of spinal degeneration has been extensively studied during the last few decades, but there are still many controversies and conflicting results in this field of research. The biomechanical cause of accelerated degeneration of stabilizing structures in lower lumbar spine lies within the combination of several factors, but two most important ones are compressive load and more coronal facet orientation that offers less resistance against torsional loading. Axial rotation of lower lumbar spine is undoubtedly associated with higher strain in disc annulus, and enhanced range of secondary rotational movements may be even more significant for the progression of annular degeneration. Accordingly, more pronounced facet tropism could be having part in faster progression of disc degeneration in lower lumbar spine, as indicated by a number of recent studies. More sagittal facet orientation in patients with a higher facet osteoarthritis score at lower lumbar segments is very likely related to arthritic remodeling commonly seen in other synovial joints. There is also a possibility that it could be associated with the adaptation to partial loss of lumbar lordosis, as both coincide with advanced age.

  8. The Effects of Common Footwear on Joint Loading in Osteoarthritis of the Knee

    PubMed Central

    Shakoor, Najia; Sengupta, Mondira; Foucher, Kharma C.; Wimmer, Markus A.; Fogg, Louis F.; Block, Joel A.

    2010-01-01

    Objective Elevated joint loads during walking have been associated with the severity and progression of osteoarthritis (OA) of the knee. Footwear may have the potential to alter these loads. This study compared the effects of several common shoe types on knee loading in subjects with OA of the knee. Methods 31 subjects (10 men, 21 women) with radiographic and symptomatic knee OA underwent gait analyses using an optoelectronic camera system and multi-component force plate. In each case, gait was evaluated barefoot and while wearing 4 different shoes: 1) clogs (Dansko®), 2) stability shoes (Brooks Addiction®), 3) flat walking shoes (Puma H Street®), and 4) flip-flops. Peak knee loads were compared between the different footwear conditions. Results Overall, the clogs and stability shoes, resulted in a significantly higher peak knee adduction moment (3.1±0.7 and 3.0±0.7 %BW*ht, respectively, ~15% higher, p<0.05)) compared with that of flat walking shoes (2.8±0.7%BW*ht), flip-flops (2.7±0.8%BW*ht) and barefoot walking (2.7±0.7%BW*ht). There were no statistically significant differences in knee loads with the flat walking shoes and flip-flops compared to barefoot walking. Conclusions These data confirm that footwear may have significant effects on knee loads during walking in subjects with OA of the knee. Flexibility and heel height may be important differentiating characteristics of shoes which affect knee loads. In light of the strong relationship between knee loading and OA, the design and biomechanical effects of modern footwear should be more closely evaluated in terms of their effects on the disease. PMID:20191571

  9. Design and validation of a cadaveric knee joint loading device compatible with magnetic resonance imaging and computed tomography.

    PubMed

    Chen, Larry; Gordon, Karen; Hurtig, Mark

    2014-10-01

    Design and validation of a magnetic resonance and computed tomography compatible device capable of applying physiologically relevant muscle forces to cadaveric knee joints with high levels of repeatability and reproducibility. Repeatability and reproducibility were assessed with two porcine stifle joints. Load was applied to joints at full extension, five and 15 degrees of flexion through two cables simulating the lines of action of the quadriceps and hamstrings muscles. Five repeatability and five reproducibility trials were performed at each flexion angle. Standard deviations (SDs) of joint angle and load were recorded. For repeatability, the maximum SDs for joint angle were 1.26° (flexion), 1.54° (ab/adduction) and 0.90° (in/external rotation). The maximum SDs for joint load were 4.60 N (anterior/posterior), 7.36 N (medial/lateral), and 42.6N (axial). For reproducibility, the maximum SDs for joint angle were 0.84° (flexion), 0.66° (ab/adduction) and 0.92° (in/external rotation). The maximum SDs for joint load were 6.40 N (anterior/posterior), 11.7 N (medial/lateral), and 39.7 N (axial). This level of repeatability and reproducibility is within intra-subject variability of measured gait kinematics. Therefore, this device is considered to be an effective tool for in vitro testing of knee soft tissue repair. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  10. Real time monitoring of spot-welded joints under service load using lead zirconate titanate (PZT) transducers

    NASA Astrophysics Data System (ADS)

    Yao, Ping; Zheng, Botong; Dawood, Mina; Huo, Linsheng; Song, Gangbing

    2017-03-01

    This paper proposes a nondestructive method to evaluate the health status of resistance spot-welded (RSW) joint under service load using lead zirconate titanate (PZT) active sensing system, in which the PZT transducers were used as both actuator and sensor. The physical principle of the approach was validated through a numerical analysis showing that an opening between the faying faces at the welded joint occurred under tension load. The opening decreased the contact area hence reduced the amplitude of the stress wave received by the PZT sensor. Therefore, by comparing the energy index of the signals before and after the loading, the health condition of the joint can be evaluated. Five ST14 steel single lap joint specimens were tested under tension load while being monitored by the PZT sensing system and digital image correlation (DIC) system in real time. The data obtained from the DIC system validated the numerical results. By comparing the energy index of the signal obtained from the PZT sensing system before and after unloading, it was concluded that the RSW joint was intact after being loaded to the service load. The proposed method is promising in evaluating the health condition of RSW joint nondestructively.

  11. Fracture behavior under monotonic and low cycle loadings in carbon steel pipes and welded pipe joints with a defect

    SciTech Connect

    Miyazaki, Katsumasa; Kanno, Satoshi; Hayashi, Makoto; Ishiwata, Masayuki; Gotoh, Nobuho; Miura, Naoki; Fujioka, Terutaka; Kashima, Koichi

    1996-12-01

    To evaluate the structural integrity of power plant piping during earthquakes, fracture behavior under monotonic and low cycle loadings was examined, using 4-inch carbon steel pipes made of base metal and welded pipe joints with a circumferential defect at room and elevated temperatures in air. In the monotonic bending tests, the maximum loads increased slightly with the loading rates for base metal pipes and welded pipe joints. The maximum loads in welded pipe joints were about 10% higher than those in base metal pipes for various displacement rate. In the cyclic bending tests, the number of cycles to failure, N{sub f} was closely correlated with the ratio of the load amplitude, Pa to the maximum load, Pmax obtained in the monotonic bending tests, in spite of the difference in the maximum loads for base metal pipes and welded pipe joints. The number of loading cycles during an earthquake was assumed as about 100 cycles in design. The relationship between Pa/Pmax and the number of cycles to failure showed that the allowable load amplitude ratio was estimated as about 0.7.

  12. 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.

  13. Soldier-relevant body borne loads increase knee joint contact force during a run-to-stop maneuver.

    PubMed

    Ramsay, John W; Hancock, Clifford L; O'Donovan, Meghan P; Brown, Tyler N

    2016-12-08

    The purpose of this study was to understand the effects of load carriage on human performance, specifically during a run-to-stop (RTS) task. Using OpenSim analysis tools, knee joint contact force, grounds reaction force, leg stiffness and lower extremity joint angles and moments were determined for nine male military personnel performing a RTS under three load configurations (light, ~6kg, medium, ~20kg, and heavy, ~40kg). Subject-based means for each biomechanical variable were submitted to repeated measures ANOVA to test the effects of load. During the RTS, body borne load significantly increased peak knee joint contact force by 1.2 BW (p<0.001) and peak vertical (p<0.001) and anterior-posterior (p=0.002) ground reaction forces by 0.6 BW and 0.3 BW, respectively. Body borne load also had a significant effect on hip (p=0.026) posture with the medium load and knee (p=0.046) posture with the heavy load. With the heavy load, participants exhibited a substantial, albeit non-significant increase in leg stiffness (p=0.073 and d=0.615). Increases in joint contact force exhibited during the RTS were primarily due to greater GRFs that impact the soldier with each incremental addition of body borne load. The stiff leg, extended knee and large braking force the soldiers exhibited with the heavy load suggests their injury risk may be greatest with that specific load configuration. Further work is needed to determine if the biomechanical profile exhibited with the heavy load configuration translates to unsafe shear forces at the knee joint and consequently, a higher likelihood of injury. Published by Elsevier Ltd.

  14. Optimum design of bolted composite lap joints under mechanical and thermal loading

    NASA Astrophysics Data System (ADS)

    Kradinov, Vladimir Yurievich

    A new approach is developed for the analysis and design of mechanically fastened composite lap joints under mechanical and thermal loading. Based on the combined complex potential and variational formulation, the solution method satisfies the equilibrium equations exactly while the boundary conditions are satisfied by minimizing the total potential. This approach is capable of modeling finite laminate planform dimensions, uniform and variable laminate thickness, laminate lay-up, interaction among bolts, bolt torque, bolt flexibility, bolt size, bolt-hole clearance and interference, insert dimensions and insert material properties. Comparing to the finite element analysis, the robustness of the method does not decrease when modeling the interaction of many bolts; also, the method is more suitable for parametric study and design optimization. The Genetic Algorithm (GA), a powerful optimization technique for multiple extrema functions in multiple dimensions search spaces, is applied in conjunction with the complex potential and variational formulation to achieve optimum designs of bolted composite lap joints. The objective of the optimization is to acquire such a design that ensures the highest strength of the joint. The fitness function for the GA optimization is based on the average stress failure criterion predicting net-section, shear-out, and bearing failure modes in bolted lap joints. The criterion accounts for the stress distribution in the thickness direction at the bolt location by applying an approach utilizing a beam on an elastic foundation formulation.

  15. Adhesive-bonded double-lap joints. [analytical solutions for static load carrying capacity

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.

    1973-01-01

    Explicit analytical solutions are derived for the static load carrying capacity of double-lap adhesive-bonded joints. The analyses extend the elastic solution Volkersen and cover adhesive plasticity, adherend stiffness imbalance and thermal mismatch between the adherends. Both elastic-plastic and bi-elastic adhesive representations lead to the explicit result that the influence of the adhesive on the maximum potential bond strength is defined uniquely by the strain energy in shear per unit area of bond. Failures induced by peel stresses at the ends of the joint are examined. This failure mode is particularly important for composite adherends. The explicit solutions are sufficiently simple to be used for design purposes

  16. Do counteracting external frontal plane moments alter the intraarticular contact force distribution in the loaded human tibiofemoral joint?

    PubMed

    Engel, Karsten; Brüggemann, Gert-Peter; Heinrich, Kai; Potthast, Wolfgang; Liebau, Christian

    2015-03-01

    There are strong indications that asymmetric medio-lateral load distribution in the knee joint is a risk factor for osteoarthritis. Externally applied frontal plane moments (adduction and abduction) might affect the distribution of knee joint compartment loading. However, this is not confirmed through intraarticular measurements in loaded human knee joints. The purpose of the study was to determine the force distribution and the movement of the centre of pressure in the loaded tibiofemoral joint as a function of varied externally applied counteracting frontal plane moments and in dependence of the knee flexion angle. Adduction and abduction moments of 2.5 Nm and 5 Nm were applied to six cadaveric knees exhibiting varus, valgus and normal alignments. The joints were mounted in a knee joint loading simulator. During simulated muscle-driven extension-flexion cycles, intraarticular forces were determined using capacitive pressure sensors inserted into the medial and lateral knee joint compartments. Motion of femur and tibia were assessed by a motion analysis system. Externally applied frontal plane moments altered the intraarticular force distribution and caused shifts in the centre of pressure up to 4.3mm in all knee joints. Larger redistribution effects were found in higher knee flexion angles. The medial compartment load increased during the flexion in all investigated knee joints. The application of counteracting frontal plane moments for the conservative treatment of osteoarthritis can redistribute the forces and might slow down the progression of the disease. The findings of this study offer novel insights to guide the development and optimization of mechanical aids for the treatment of osteoarthritic knees. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Does an Antibiotic-Loaded Hydrogel Coating Reduce Early Post-Surgical Infection After Joint Arthroplasty?

    PubMed Central

    Romanò, Carlo Luca; Malizos, Kostantinos; Capuano, Nicola; Mezzoprete, Riccardo; D'Arienzo, Michele; Van Der Straeten, Catherine; Scarponi, Sara; Drago, Lorenzo

    2016-01-01

    Background: Infection remains among the main reasons for joint prosthesis failure. Preclinical reports have suggested that antibacterial coatings of implants may prevent bacterial adhesion and biofilm formation. This study presents the results of the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating (Defensive Antibacterial Coating, DAC®) in patients undergoing hip or knee prosthesis. Methods: In this multicenter, randomized prospective study, a total of 380 patients, scheduled to undergo primary (n=270) or revision (n=110) total hip (N=298) or knee (N=82) joint replacement with a cementless or a hybrid implant, were randomly assigned, in six European orthopedic centers, to receive an implant either with the antibiotic-loaded DAC coating (treatment group) or without coating (control group). Pre- and postoperative assessment of clinical scores, wound healing, laboratory tests, and x-ray exams were performed at fixed time intervals. Results: Overall, 373 patients were available at a mean follow-up of 14.5 ± 5.5 months (range 6 to 24). On average, wound healing, laboratory and radiographic findings showed no significant difference between the two groups. Eleven early surgical site infections were observed in the control group and only one in the treatment group (6% vs. 0.6%; p=0.003). No local or systemic side effects related to the DAC hydrogel coating were observed, and no detectable interference with implant osteointegration was noted. Conclusions: The use of a fast-resorbable, antibiotic-loaded hydrogel implant coating can reduce the rate of early surgical site infections, without any detectable adverse events or side effects after hip or knee joint replacement with a cementless or hybrid implant. PMID:28529851

  18. Numerical simulation of the low-cyclic loading of new-type assembled integral beam-column joints

    NASA Astrophysics Data System (ADS)

    Wu, Jiangchuan; Zhang, Jiwen; Yin, Wanyun; Jin, Rencai

    2017-04-01

    In this paper, the low-cycle cyclic loading test and the elasto-plastic numerical simulation by OpenSEES of assembled integral beam-column joints of the three new prefabricated prestressed concrete beams are carried out. The key technologies such as unit selection, material model selection and prestressing in the numerical simulation of the new assembly-type beam-column joint is studied deeply. The results show that the relative model and parameters of the OpenSEES software can be used to simulate the hysteresis performance of the low-cycle cyclic loading of the new-type assembled integral beam-column joints.

  19. An observational feasibility study to assess the safety and effectiveness of intranasal fentanyl for radiofrequency ablations of the lumbar facet joints

    PubMed Central

    Bartoszek, Michael W; McCoart, Amy; Hong, Kyung-soo Jason; Haley, Chelsey; Highland, Krista Beth; Plunkett, Anthony R

    2017-01-01

    Purpose The purpose of the present observational, feasibility study is to assess the preliminary safety and effectiveness of intranasal fentanyl for lumbar facet radiofrequency ablation procedures. Patients and methods This cohort observational study included 23 adult patients. Systolic and diastolic blood pressures, heart rate, oxygen saturation percent, Pasero Opioid-Induced Sedation Scale score, and the Defense and Veterans Pain Rating Scale pain score were assessed prior to the procedure and intranasal fentanyl (100 μg) administration and every 15 minutes after administration, up to 60 minutes post administration. Follow-up of patient satisfaction with pain control and treatment was assessed 24 hours after discharge. The primary outcome was safety as evidenced by adverse events. Secondary outcomes included the above-mentioned vital signs and pain ratings. Results No adverse events occurred in the present study and all participants maintained an acceptable level of awareness throughout the assessment period. One-way repeated measures analyses of covariance tests with Bonferroni-adjusted means indicated that oxygen saturation, blood pressure, and heart rate changed from baseline, whereas pain scores were lower at post-administration levels compared with baseline. Finally, the majority of participants reported being satisfied with pain control and treatment. Conclusion Preliminary evidence indicates that intranasal fentanyl is safe and effective for lumbar facet radiofrequency ablation procedures. Future rigorous randomized control trials are needed to confirm the present results and to examine the effects of intranasal fentanyl on intraoperative and postoperative opioid use. PMID:28243139

  20. Relationship between leg extensor muscle strength and knee joint loading during gait before and after total knee arthroplasty.

    PubMed

    Vahtrik, Doris; Gapeyeva, Helena; Ereline, Jaan; Pääsuke, Mati

    2014-01-01

    The aim of the present study was to evaluate an isometric maximal voluntary contraction (MVC) force of the leg extensor muscles and its relationship with knee joint loading during gait prior and after total knee arthroplasty (TKA). Custom-made dynamometer was used to assess an isometric MVC force of the leg extensor muscles and 3-D motion analysis system was used to evaluate the knee joint loading during gait in 13 female patients (aged 49-68 years) with knee osteoarthritis. Patients were evaluated one day before, and three and six months following TKA in the operated and non-operated leg. Six months after TKA, MVC force of the leg extensor muscles for the operated leg did not differ significantly as compared to the preoperative level, whereas it remained significantly lower for the non-operated leg and controls. The knee flexion moment and the knee joint power during mid stance of gait was improved six months after TKA, remaining significantly lowered compared with controls. Negative moderate correlation between leg extensor muscles strength and knee joint loading for the operated leg during mid stance was noted three months after TKA. The correlation analysis indicates that due to weak leg extensor muscles, an excessive load is applied to knee joint during mid stance of gait in patients, whereas in healthy subjects stronger knee-surrounding muscles provide stronger knee joint loading during gait. III (correlational study). Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Injury tolerance and moment response of the knee joint to combined valgus bending and shear loading.

    PubMed

    Bose, Dipan; Bhalla, Kavi S; Untaroiu, Costin D; Ivarsson, B Johan; Crandall, Jeff R; Hurwitz, Shepard

    2008-06-01

    Valgus bending and shearing of the knee have been identified as primary mechanisms of injuries in a lateral loading environment applicable to pedestrian-car collisions. Previous studies have reported on the structural response of the knee joint to pure valgus bending and lateral shearing, as well as the estimated injury thresholds for the knee bending angle and shear displacement based on experimental tests. However, epidemiological studies indicate that most knee injuries are due to the combined effects of bending and shear loading. Therefore, characterization of knee stiffness for combined loading and the associated injury tolerances is necessary for developing vehicle countermeasures to mitigate pedestrian injuries. Isolated knee joint specimens (n=40) from postmortem human subjects were tested in valgus bending at a loading rate representative of a pedestrian-car impact. The effect of lateral shear force combined with the bending moment on the stiffness response and the injury tolerances of the knee was concurrently evaluated. In addition to the knee moment-angle response, the bending angle and shear displacement corresponding to the first instance of primary ligament failure were determined in each test. The failure displacements were subsequently used to estimate an injury threshold function based on a simplified analytical model of the knee. The validity of the determined injury threshold function was subsequently verified using a finite element model. Post-test necropsy of the knees indicated medial collateral ligament injury consistent with the clinical injuries observed in pedestrian victims. The moment-angle response in valgus bending was determined at quasistatic and dynamic loading rates and compared to previously published test data. The peak bending moment values scaled to an average adult male showed no significant change with variation in the superimposed shear load. An injury threshold function for the knee in terms of bending angle and shear

  2. Effects of Specialized Footwear on Joint Loads in Osteoarthritis of the Knee

    PubMed Central

    Shakoor, Najia; Lidtke, Roy H.; Sengupta, Mondira; Fogg, Louis F.; Block, Joel A.

    2013-01-01

    Objective Elevated dynamic joint loads have been associated with the severity and progression of osteoarthritis (OA) of the knee. This study compared the effects of a specialized shoe (the mobility shoe) designed to lower dynamic loads at the knee with self-chosen conventional walking shoes and with a commercially available walking shoe as a control. Methods Subjects with knee OA were evaluated in 2 groups. Group A (n = 28) underwent gait analyses with both their self-chosen walking shoes and the mobility shoes. Group B (n = 20) underwent gait analyses with a control shoe and the mobility shoe. Frontal plane knee loads were compared between the different footwear conditions. Results Group A demonstrated an 8% reduction in the peak external knee adduction moment with the mobility shoe compared with self-chosen walking shoes (mean ± SD 49 ± 0.80 versus 2.71 ± 0.84 %BW × H; P < 0.05). Group B demonstrated a 12% reduction in the peak external knee adduction moment with the mobility shoe compared with the control shoe (mean ± SD 2.66 ± 0.69 versus 3.07 ± 0.75 %BW × H; P < 0.05). Conclusion Specialized footwear can effectively reduce joint loads in subjects with knee OA, compared with self-chosen shoes and control walking shoes. Footwear may represent a therapeutic target for the treatment of knee OA. The types of shoes worn by subjects with knee OA should be evaluated more closely in terms of their effects on the disease. PMID:18759313

  3. Heavy vs Light Load Single-Joint Exercise Performance with Different Rest Intervals.

    PubMed

    Senna, Gilmar Weber; Rodrigues, Bernardo Minelli; Sandy, Daniel; Scudese, Estevão; Bianco, Antonino; Dantas, Estélio Henrique Martin

    2017-09-01

    The aim of the study was to compare the effect of three distinct rest period lengths between sets of upper body single-joint exercise with different load zones and volume designed for either endurance or hypertrophy (50% or 80% of 1-RM). Sixteen trained men (20.75 ± 2.54 years; 76.35 ± 5.03 kg; 176.75 ± 3.33 cm, 24.53 ± 1.47 kg/m2) performed a test and retest of 1-RM on non-consecutive days. Forty-eight hours after load testing, the participants were randomly assigned to six sessions consisting of four sets of the triceps pull-down, combining different intensities with distinct rest periods between sets. The shorter 1 minute rest promoted a significant reduction in the total repetition number compared to 3 minute rest for both workloads. There was a difference between 3 and 5 minute conditions for the 50% of 1-RM that did not occur for the 80% of 1-RM condition. Both intensities presented significant interaction values for the rest conditions vs. each set (50% p = 0.0001; 80% p = 0.0001). Additionally, significant values were found for the main effect of the performance of subsequent sets (50% p = 0.003; 80% p = 0.001) and rest conditions (50% p = 0.0001; 80% p = 0.0001). In conclusion, for heavier loads (80%) to fatigue, longer rest of 3 to 5 minutes seems to allow for better recovery between sets and thus, promotes a greater volume. However, when training with lighter loads (50%), the magnitude of the rest seems to directly affect the performance of subsequent sets, and also presents a correlation with total volume achieved for the upper body single-joint exercise scheme.

  4. Heavy vs Light Load Single-Joint Exercise Performance with Different Rest Intervals

    PubMed Central

    Senna, Gilmar Weber; Rodrigues, Bernardo Minelli; Sandy, Daniel; Scudese, Estevão; Dantas, Estélio Henrique Martin

    2017-01-01

    Abstract The aim of the study was to compare the effect of three distinct rest period lengths between sets of upper body single-joint exercise with different load zones and volume designed for either endurance or hypertrophy (50% or 80% of 1-RM). Sixteen trained men (20.75 ± 2.54 years; 76.35 ± 5.03 kg; 176.75 ± 3.33 cm, 24.53 ± 1.47 kg/m2) performed a test and retest of 1-RM on non-consecutive days. Forty-eight hours after load testing, the participants were randomly assigned to six sessions consisting of four sets of the triceps pull-down, combining different intensities with distinct rest periods between sets. The shorter 1 minute rest promoted a significant reduction in the total repetition number compared to 3 minute rest for both workloads. There was a difference between 3 and 5 minute conditions for the 50% of 1-RM that did not occur for the 80% of 1-RM condition. Both intensities presented significant interaction values for the rest conditions vs. each set (50% p = 0.0001; 80% p = 0.0001). Additionally, significant values were found for the main effect of the performance of subsequent sets (50% p = 0.003; 80% p = 0.001) and rest conditions (50% p = 0.0001; 80% p = 0.0001). In conclusion, for heavier loads (80%) to fatigue, longer rest of 3 to 5 minutes seems to allow for better recovery between sets and thus, promotes a greater volume. However, when training with lighter loads (50%), the magnitude of the rest seems to directly affect the performance of subsequent sets, and also presents a correlation with total volume achieved for the upper body single-joint exercise scheme. PMID:28828090

  5. Patellofemoral Joint Loads During Running at the Time of Return to Sport in Elite Athletes With ACL Reconstruction.

    PubMed

    Herrington, Lee; Alarifi, Saud; Jones, Richard

    2017-10-01

    Patellofemoral joint pain and degeneration are common in patients who undergo anterior cruciate ligament reconstruction (ACLR). The presence of patellofemoral joint pain significantly affects the patient's ability to continue sport participation and may even affect participation in activities of daily living. The mechanisms behind patellofemoral joint pain and degeneration are unclear, but previous research has identified altered patellofemoral joint loading in individuals with patellofemoral joint pain when running. It is unclear whether this process occurs after ACLR. To assess the patellofemoral joint stresses during running in ACLR knees and compare the findings to the noninjured knee and matched control knees. Controlled laboratory study. Thirty-four elite sports practitioners who had undergone ACLR and 34 age- and sex-matched controls participated in the study. The participants' running gait was assessed via 3D motion capture, and knee loads and forces were calculated by use of inverse dynamics. A significance difference was found in knee extensor moment, knee flexion angles, patellofemoral contact force (about 23% greater), and patellofemoral contact pressure (about 27% greater) between the ACLR and the noninjured limb ( P ≤ .04) and between the ACLR and the control limb ( P ≤ .04); no significant differences were found between the noninjured and control limbs ( P ≥ .44). Significantly greater levels of patellofemoral joint stress and load were found in the ACLR knee compared with the noninjured and control knees. Altered levels of patellofemoral stress in the ACLR knee during running may predispose individuals to patellofemoral joint pain.

  6. Effect of compensatory trunk movements on knee and hip joint loading during gait in children with different orthopedic pathologies.

    PubMed

    Stief, Felix; Böhm, Harald; Ebert, Carsten; Döderlein, Leonhard; Meurer, Andrea

    2014-03-01

    Ipsilateral trunk lean toward the affected stance limb has been identified as a compensatory mechanism to unload the hip joint. However, this altered gait pattern increases the lever arm around the knee joint by shifting the ground reaction vector more lateral to the knee joint center, which could be sufficient to deform the lateral compartment of the knee. The purpose of the present study was to show the effect of ipsilateral trunk lean on hip and knee joint moments in the frontal plane in 132 young patients with different orthopedic diagnosis. Linear correlations between ipsilateral trunk lean and the external knee and/or hip adduction moment were detected for patients with Legg-Calvé-Perthes disease (LCPD), arthrogryposis multiplex congenita, myelomeningocele, and unilateral cerebral palsy (CP). In contrast, children with bilateral CP did not show such a relationship due to an increased internal foot placement. In comparison to the hip joint, the effect of ipsilateral trunk lean in patients with LCPD is obviously more pronounced in the knee joint. The valgus thrust of the knee could initiate degenerative changes by placing altered loads on regions of the articular cartilage that were previously conditioned for different load levels. The results suggest that the ipsilateral trunk lean should not be considered and recommended as unloading mechanism for the hip joint on its own but also as a potential increased joint loading of the lateral knee compartment. Therefore, an acceptable therapy concept for limping patients should aim for an inconspicuous gait pattern with a reduced trunk movement.

  7. Decreased Knee Joint Loading Associated With Early Knee Osteoarthritis After Anterior Cruciate Ligament Injury.

    PubMed

    Wellsandt, Elizabeth; Gardinier, Emily S; Manal, Kurt; Axe, Michael J; Buchanan, Thomas S; Snyder-Mackler, Lynn

    2016-01-01

    Anterior cruciate ligament (ACL) injury predisposes individuals to early-onset knee joint osteoarthritis (OA). Abnormal joint loading is apparent after ACL injury and reconstruction. The relationship between altered joint biomechanics and the development of knee OA is unknown. Altered knee joint kinetics and medial compartment contact forces initially after injury and reconstruction are associated with radiographic knee OA 5 years after reconstruction. Case-control study; Level of evidence, 3. Individuals with acute, unilateral ACL injury completed gait analysis before (baseline) and after (posttraining) preoperative rehabilitation and at 6 months, 1 year, and 2 years after reconstruction. Surface electromyographic and knee biomechanical data served as inputs to an electromyographically driven musculoskeletal model to estimate knee joint contact forces. Patients completed radiographic testing 5 years after reconstruction. Differences in knee joint kinetics and contact forces were compared between patients with and those without radiographic knee OA. Patients with OA walked with greater frontal plane interlimb differences than those without OA (nonOA) at baseline (peak knee adduction moment difference: 0.00 ± 0.08 N·m/kg·m [nonOA] vs -0.15 ± 0.09 N·m/kg·m [OA], P = .014; peak knee adduction moment impulse difference: -0.001 ± 0.032 N·m·s/kg·m [nonOA] vs -0.048 ± 0.031 N·m·s/kg·m [OA], P = .042). The involved limb knee adduction moment impulse of the group with osteoarthritis was also lower than that of the group without osteoarthritis at baseline (0.087 ± 0.023 N·m·s/kg·m [nonOA] vs 0.049 ± 0.018 N·m·s/kg·m [OA], P = .023). Significant group differences were absent at posttraining but reemerged 6 months after reconstruction (peak knee adduction moment difference: 0.02 ± 0.04 N·m/kg·m [nonOA] vs -0.06 ± 0.11 N·m/kg·m [OA], P = .043). In addition, the OA group walked with lower peak medial compartment contact forces of the involved limb

  8. Experimental and Simulative Investigations of Laser Assisted Plastic-metal-joints Considering Different Load Directions

    NASA Astrophysics Data System (ADS)

    Engelmann, Christoph; Eckstaedt, Johannes; Olowinsky, Alexander; Aden, Mirko; Mamuschkin, Viktor

    Particularly in the automotive industry, the combination of dissimilar materials presents manufacturing engineering with major challenges. Notably, the adapted use of plastic and metal opens up further potential for weight savings. Directly and firmly bonding the two materials together fails, however, on account of the chemical and physical dissimilarity of plastic and metal. Since joining of plastics and metals nowadays is based on adhesive bonding, the joint is weak and underlies ageing processes. A promising approach to overcome these problems is a laser based two-step process. In the first process step laser radiation is applied to generate microstructures on the surface of the metallic joining partner. In the subsequent laser joining process, the plastic is molten and interlocked into the microstructures after curing. The mechanical strength of the joint depends strongly on the load direction and can be influenced by the geometry and arrangement of microstructures. These influencing factors are investigated for three different load directions (tensile shear, tensile and peel) by experiments and by structural mechanics simulations.

  9. Cumulative loads increase at the knee joint with slow-speed running compared to faster running: a biomechanical study.

    PubMed

    Petersen, Jesper; Sørensen, Henrik; Nielsen, Rasmus Østergaard

    2015-04-01

    Biomechanical cross-sectional study. To investigate the hypothesis that the cumulative load at the knee during running increases as running speed decreases. The knee joint load per stride decreases as running speed decreases. However, by decreasing running speed, the number of strides per given distance is increased. Running a given distance at a slower speed may increase the cumulative load at the knee joint compared with running the same distance at a higher speed, hence increasing the risk of running-related injuries in the knee. Kinematic and ground reaction force data were collected from 16 recreational runners, during steady-state running with a rearfoot strike pattern at 3 different speeds (mean ± SD): 8.02 ± 0.17 km/h, 11.79 ± 0.21 km/h, and 15.78 ± 0.22 km/h. The cumulative load (cumulative impulse) over a 1000-m distance was calculated at the knee joint on the basis of a standard 3-D inverse-dynamics approach. Based on a 1000-m running distance, the cumulative load at the knee was significantly higher at a slow running speed than at a high running speed (relative difference, 80%). The mean load per stride at the knee increased significantly across all biomechanical parameters, except impulse, following an increase in running speed. Slow-speed running decreases knee joint loads per stride and increases the cumulative load at the knee joint for a given running distance compared to faster running. The primary reason for the increase in cumulative load at slower speeds is an increase in number of strides needed to cover the same distance.

  10. Response of a structural health monitoring fastener to fatigue crack growth and loads in metallic joints

    NASA Astrophysics Data System (ADS)

    Rakow, Alexi S.; Chang, Fu-Kuo

    2009-03-01

    Fatigue cracks initiating at fastener hole locations in metallic structure are among the most common form of airframe damage. Current methods for inspecting airframes for these cracks are manual, whereby inspectors rely on nondestructive inspection equipment or hand-held probes to scan over areas to be monitored. Use of this equipment often demands disassembly of the airframe to search appropriate hole locations for cracks, which elevates the complexity and cost of maintenance inspections. In this study an Additive, Interleaved, Multi-layer Electromagnetic (AIME) sensor was developed and integrated with the shank of a fastener to form a Structural Health Monitoring Fastener, a new technology targeted at insitu detection of fastener hole cracks. The major advantages of the Structural Health Monitoring (SHM) Fastener over other SHM technologies are its installation, which does not require joint layer disassembly, its capability to detect inner layer cracks in a multi-layer joint, and its capability to operate in a continuous monitoring mode. The AIME sensor design, SHM Fastener, and complete SHM system are presented along with experimental results from a series of single-layer and bolted double lap-joint aluminum specimens to validate the capability of these sensors to monitor metallic joints for fastener hole cracks and loads. Fatigue cracks were successfully tracked to over 0.7 inches from the fastener hole in these tests. Sensor output obtained from single-layer fatigue specimens was compared with analytical predictions for fatigue crack growth versus cycle number showing a good correlation in trend between sensor output and predicted crack size.

  11. Mechanical loading leads to osteoarthritis-like changes in the hypofunctional temporomandibular joint in rats.

    PubMed

    Ikeda, Yuhei; Yonemitsu, Ikuo; Takei, Maki; Shibata, Shunichi; Ono, Takashi

    2014-12-01

    Temporomandibular joint (TMJ) hypofunction secondary to feeding a liquid diet in the growing period leads to morphological hypoplasia. However, few studies have evaluated the results of mechanical loading on the hypoplastic TMJ. This study investigated whether TMJ hypofunction in rats causes osteoarthritis (OA)-like changes when exposed to mechanical loading. Male 21-day-old Wistar rats were divided into four groups. The first group (C) served as the control. In the second group (W), mechanical loading was applied to the TMJ by continuous steady mouth opening (3h/day for 5 days) from 63 days of age. A jaw-opening device was used to hold the mandible open in the maximal mouth-opening position with a cobalt-chromium (Co-Cr) wire (φ: 0.9mm). Groups C and W both received a normal hard diet. The third group (L) and fourth group (LW) were fed a liquid diet and group LW were subjected to the same loading as group W. We evaluated the TMJ using micro-CT, toluidine blue staining and immunohistochemistry of matrix metalloproteinase (MMP)-13. In group LW in the superior and posterior regions of the condyle, bone volume fraction, trabecular thickness and trabecular number were significantly decreased and trabecular spacing was significantly increased. The ratio of MMP-13 immunopositive cells was significantly higher than in the other groups. OA-like changes were also observed, including reduced thickness of the cartilage, irregularities in the chondrocytic layer, and cell-free areas. TMJ hypofunction in rats is likely to lead to OA-like changes when exposed to mechanical loading. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Evaluation of a subject-specific finite-element model of the equine metacarpophalangeal joint under physiological load.

    PubMed

    Harrison, Simon M; Whitton, R Chris; Kawcak, Chris E; Stover, Susan M; Pandy, Marcus G

    2014-01-03

    The equine metacarpophalangeal (MCP) joint is frequently injured, especially by racehorses in training. Most injuries result from repetitive loading of the subchondral bone and articular cartilage rather than from acute events. The likelihood of injury is multi-factorial but the magnitude of mechanical loading and the number of loading cycles are believed to play an important role. Therefore, an important step in understanding injury is to determine the distribution of load across the articular surface during normal locomotion. A subject-specific finite-element model of the MCP joint was developed (including deformable cartilage, elastic ligaments, muscle forces and rigid representations of bone), evaluated against measurements obtained from cadaver experiments, and then loaded using data from gait experiments. The sensitivity of the model to force inputs, cartilage stiffness, and cartilage geometry was studied. The FE model predicted MCP joint torque and sesamoid bone flexion angles within 5% of experimental measurements. Muscle-tendon forces, joint loads and cartilage stresses all increased as locomotion speed increased from walking to trotting and finally cantering. Perturbations to muscle-tendon forces resulted in small changes in articular cartilage stresses, whereas variations in joint torque, cartilage geometry and stiffness produced much larger effects. Non-subject-specific cartilage geometry changed the magnitude and distribution of pressure and the von Mises stress markedly. The mean and peak cartilage stresses generally increased with an increase in cartilage stiffness. Areas of peak stress correlated qualitatively with sites of common injury, suggesting that further modelling work may elucidate the types of loading that precede joint injury and may assist in the development of techniques for injury mitigation.

  13. Implementation of a gait cycle loading into healthy and meniscectomised knee joint models with fibril-reinforced articular cartilage.

    PubMed

    Mononen, Mika E; Jurvelin, Jukka S; Korhonen, Rami K

    2015-01-01

    Computational models can be used to evaluate the functional properties of knee joints and possible risk locations within joints. Current models with fibril-reinforced cartilage layers do not provide information about realistic human movement during walking. This study aimed to evaluate stresses and strains within a knee joint by implementing load data from a gait cycle in healthy and meniscectomised knee joint models with fibril-reinforced cartilages. A 3D finite element model of a knee joint with cartilages and menisci was created from magnetic resonance images. The gait cycle data from varying joint rotations, translations and axial forces were taken from experimental studies and implemented into the model. Cartilage layers were modelled as a fibril-reinforced poroviscoelastic material with the menisci considered as a transversely isotropic elastic material. In the normal knee joint model, relatively high maximum principal stresses were specifically predicted to occur in the medial condyle of the knee joint during the loading response. Bilateral meniscectomy increased stresses, strains and fluid pressures in cartilage on the lateral side, especially during the first 50% of the stance phase of the gait cycle. During the entire stance phase, the superficial collagen fibrils modulated stresses of cartilage, especially in the medial tibial cartilage. The present computational model with a gait cycle and fibril-reinforced biphasic cartilage revealed time- and location-dependent differences in stresses, strains and fluid pressures occurring in cartilage during walking. The lateral meniscus was observed to have a more significant role in distributing loads across the knee joint than the medial meniscus, suggesting that meniscectomy might initiate a post-traumatic process leading to osteoarthritis at the lateral compartment of the knee joint.

  14. Joint effects of inbreeding and local adaptation on the evolution of genetic load after fragmentation.

    PubMed

    Lopez, Sébastien; Rousset, François; Shaw, Frank H; Shaw, Ruth G; Ronce, Ophélie

    2009-12-01

    Disruption of gene flow among demes after landscape fragmentation can facilitate local adaptation but increase the effect of genetic drift and inbreeding. The joint effects of these conflicting forces on the mean fitness of individuals in a population are unknown. Through simulations, we explored the effect of increased isolation on the evolution of genetic load over the short and long term when fitness depends in part on local adaptation. We ignored genetic effects on demography. We modeled complex genomes, where a subset of the loci were under divergent selection in different localities. When a fraction of the loci were under heterogeneous selection, isolation increased mean fitness in larger demes made up of hundreds of individuals because of improved local adaptation. In smaller demes of tens of individuals, increased isolation improved local adaptation very little and reduced overall fitness. Short-term improvement of mean fitness after fragmentation may not be indicative of the long-term evolution of fitness. Whatever the deme size and potential for local adaptation, migration of one or two individuals per generation minimized the genetic load in general. The slow dynamics of mean fitness following fragmentation suggests that conservation measures should be implemented before the consequences of isolation on the genetic load become of concern.

  15. Percutaneous radiofrequency facet capsule denervation as an alternative target in lumbar facet syndrome.

    PubMed

    Moussa, Wael Mohamed Mohamed; Khedr, Wael

    2016-11-01

    Percutaneous radiofrequency denervation of the medial dorsal branch is often used in chronic low back pain of intervertebral facet etiology, which is sometimes difficult to perform and recurrence of pain often ensues. We theorized that shifting the target of RF coagulation to the facet joint capsule would provide an easier target and a longer-lived pain relieving response. A prospective randomized controlled trial where 120 patients diagnosed with CLBP of a confirmed facet origin were randomly divided into three equal groups, the first was submitted to percutaneous radiofrequency coagulation of the facet joint capsule, the second underwent percuataneous denervation of the medial dorsal branch and the third did not receive radiofrequency lesioning. All the three groups received local injection of a mixture of local anesthetic and steroid. Cases were followed for up to 3 years. 87(72.5%) patients were females. By 3 months' post procedure, improvement in VAS was significantly better than pretreatment levels in all groups (p<0.05). The control group lost improvement by 1-year follow-up (p=0.017). At 2 years' follow-up, the joint capsule denervation group maintained significant improvement (p=0.033) whereas the medial branch denervation group lost its significant effect (p=0.479). By the end of follow-up period, only joint capsule denervation group kept significant improvement (p=0.026). In CLBP of facet origin, shifting the target of percutaneous radiofrequency to the facet joint capsule provides an easier technique with an extended period of pain relief compared to the medial dorsal branch of the facet joint. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Computational biomechanics of a lumbar motion segment in pure and combined shear loads.

    PubMed

    Schmidt, Hendrik; Bashkuev, Maxim; Dreischarf, Marcel; Rohlmann, Antonius; Duda, Georg; Wilke, Hans-Joachim; Shirazi-Adl, Aboulfazl

    2013-09-27

    Anterior shear has been implicated as a risk factor in spinal injuries. A 3D nonlinear poroelastic finite element model study of a lumbar motion segment L4-L5 was performed to predict the temporal shear response under various single and combined shear loads. Effects of nucleotomy and facetectomy as well as changes in the posture and facet gap distance were analyzed as well. Comparison of the predicted anterior displacement and stiffness response with available measurements indicates satisfactory agreement. Under shear loads up to 400 N, the model predicted an almost linear displacement response. With increasing shear load and/or compressive preload, the stiffening behavior becomes evident, primarily due to stretched collagen fibers and greater facet interactions. Removal of the facets markedly decreases the segmental stiffness in shear and thus highlights the importance of the facets in resisting shear force; 61-87% of the applied shear force is transmitted through the facets depending on the magnitude of the applied shear and compressive preload. Fluid exudation during the day as well as reduced facet gap distance and a more extended posture yielded higher facet joint forces. The shear resistance of the motion segment remains almost the same with time despite the transfer of load sharing from the disc to facets. Large forces on facet joints are computed especially under greater compression preloads, shear forces and extension rotations, as time progresses and with smaller gap distances. The disc contribution on the other hand increases under larger shear loads, smaller compression preloads, flexed postures, larger facet gap distances and at transient periods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Plasma Wakefield Experiments at FACET

    SciTech Connect

    Hogan, M.J.; England, R.J.; Frederico, J.; Hast, C.; Li, S.Z.; Litos, M.; Walz, D.; An, W.; Clayton, C.E.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.; Tochitsky, S.; Muggli, P.; Pinkerton, S.; Shi, Y.; /Southern California U.

    2011-08-19

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to {approx}20{micro}m long and focused to {approx}10{micro}m wide. The intense fields of the FACET bunches will be used to field ionize neutral lithium or cesium vapor produced in a heat pipe oven. Previous experiments at the SLAC FFTB facility demonstrated 50GeV/m gradients in an 85cm field ionized lithium plasma where the interaction distance was limited by head erosion. Simulations indicate the lower ionization potential of cesium will decrease the rate of head erosion and increase single stage performance. The initial experimental program will compare the performance of lithium and cesium plasma sources with single and double bunches. Later experiments will investigate improved performance with a pre-ionized cesium plasma. The status of the experiments and expected performance are reviewed. The FACET Facility is being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration. The facility will begin commissioning in summer 2011 and conduct an experimental program over the coming five years to study electron and positron beam driven plasma acceleration with strong wake loading in the non-linear regime. The FACET experiments aim to demonstrate high-gradient acceleration of electron and positron beams with high efficiency and negligible emittance growth.

  18. Joint loads resulting in ACL rupture: Effects of age, sex, and body mass on injury load and mode of failure in a mouse model.

    PubMed

    Blaker, Carina L; Little, Christopher B; Clarke, Elizabeth C

    2016-09-07

    Anterior cruciate ligament (ACL) tears are a common knee injury with a known but poorly understood association with secondary joint injuries and post-traumatic osteoarthritis (OA). Female sex and age are known risk factors for ACL injury but these variables are rarely explored in mouse models of injury. This study aimed to further characterize a non-surgical ACL injury model to determine its clinical relevance across a wider range of mouse specifications. Cadaveric and anesthetized C57BL/6 mice (9-52 weeks of age) underwent joint loading to investigate the effects of age, sex, and body mass on ACL injury mechanisms. The ACL injury load (whole joint load required to rupture the ACL) was measured from force-displacement data, and mode of failure was assessed using micro-dissection and histology. ACL injury load was found to increase with body mass and age (p < 0.001) but age was not significant when controlling for mass. Sex had no effect. In contrast, the mode of ACL failure varied with both age and sex groups. Avulsion fractures (complete or mixed with mid-substance tears) were common in all age groups but the proportion of mixed and mid-substance failures increased with age. Females were more likely than males to have a major avulsion relative to a mid-substance tear (p < 0.01). This data compliments studies in human cadaveric knees, and provides a basis for determining the severity of joint injury relative to a major ACL tear in mice, and for selecting joint loading conditions in future experiments using this model. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  19. Three-dimensional knee joint loading in alpine skiing: a comparison between a carved and a skidded turn.

    PubMed

    Klous, Miriam; Müller, Erich; Schwameder, Hermann

    2012-12-01

    Limited data exists on knee biomechanics in alpine ski turns despite the high rate of injuries associated with this maneuver. The purpose of the current study was to compare knee joint loading between a carved and a skidded ski turn and between the inner and outer leg. Kinetic data were collected using Kistler mobile force plates. Kinematic data were collected with five synchronized, panning, tilting, and zooming cameras. Inertial properties of the segments were calculated using an extended version of the Yeadon model. Knee joint forces and moments were calculated using inverse dynamics analysis. The obtained results indicate that knee joint loading in carving is not consistently greater than knee joint loading in skidding. In addition, knee joint loading at the outer leg is not always greater than at the inner leg. Differentiation is required between forces and moments, the direction of the forces and moments, and the phase of the turn that is considered. Even though the authors believe that the analyzed turns are representative, results have to be interpreted with caution due to the small sample size.

  20. Vehicle Routing with Three-dimensional Container Loading Constraints—Comparison of Nested and Joint Algorithms

    NASA Astrophysics Data System (ADS)

    Koloch, Grzegorz; Kaminski, Bogumil

    2010-10-01

    In the paper we examine a modification of the classical Vehicle Routing Problem (VRP) in which shapes of transported cargo are accounted for. This problem, known as a three-dimensional VRP with loading constraints (3D-VRP), is appropriate when transported commodities are not perfectly divisible, but they have fixed and heterogeneous dimensions. In the paper restrictions on allowable cargo positionings are also considered. These restrictions are derived from business practice and they extended the baseline 3D-VRP formulation as considered by Koloch and Kaminski (2010). In particular, we investigate how additional restrictions influence relative performance of two proposed optimization algorithms: the nested and the joint one. Performance of both methods is compared on artificial problems and on a big-scale real life case study.

  1. Relationship between foot function and medial knee joint loading in people with medial compartment knee osteoarthritis

    PubMed Central

    2013-01-01

    Background Dynamic joint loading, particularly the external knee adduction moment (KAM), is an important surrogate measure for the medio-lateral distribution of force across the knee joint in people with knee osteoarthritis (OA). Foot motion may alter the load on the medial tibiofemoral joint and hence affect the KAM. Therefore, this study aimed to investigate the relationship between tibia, rearfoot and forefoot motion in the frontal and transverse planes and the KAM in people with medial compartment knee OA. Method Motion of the knee, tibia, rearfoot and forefoot and knee moments were evaluated in 32 patients with clinically and radiographically-confirmed OA, predominantly in the medial compartment. Pearson’s correlation coefficient was used to investigate the association between peak values of tibia, rearfoot and forefoot motion in the frontal and transverse planes and 1st peak KAM, 2nd peak KAM, and the knee adduction angular impulse (KAAI). Results Lateral tilt of the tibia was significantly associated with increased 1st peak KAM (r = 0.60, p < 0.001), 2nd peak KAM (r = 0.67, p = 0.001) and KAAI (r = 0.82, p = 0.001). Increased peak rearfoot eversion was significantly correlated with decreased 2nd peak KAM (r = 0.59, p < 0.001) and KAAI (r = 0.50, p = 0.004). Decreased rearfoot internal rotation was significantly associated with increased 2nd peak KAM (r = −0.44, p = 0.01) and KAAI (r = −0.38, p = 0.02), while decreased rearfoot internal rotation relative to the tibia was significantly associated with increased 2nd peak KAM (r = 0.43, p = 0.01). Significant negative correlations were found between peak forefoot eversion relative to the rearfoot and 2nd peak KAM (r = −0.53, p = 0.002) and KAAI (r = −0.51, p = 0.003) and between peak forefoot inversion and 2nd peak KAM (r = −0.54, p = 0.001) and KAAI (r = −0.48, p = 0.005). Conclusion Increased rearfoot

  2. Numerical and experimental behaviour of adhesive joints subjected to peeling load

    NASA Astrophysics Data System (ADS)

    De Luca, A.; Senatore, F.; Greco, A.

    2016-05-01

    In this paper, a numerical model, based on finite element theory, useful to model the stress-strain state for a bonded single lap joint under peeling load has been presented. The numerical FE model has been developed by means of Abaqus® code in order to reproduce some experimental tests. For FE model validation purpose, the numerical results have been compared with the experimental ones and a good correlation has been achieved. In more detail, the adhesive layer has been modeled by means of cohesive elements. Such elements present some numerical difficulties related to the dependence from the own element size. So, a procedure useful to solve such mesh-dependence has been proposed.

  3. The mechanical and tribological properties of UHMWPE loaded ALN after mechanical activation for joint replacements.

    PubMed

    Gong, Kemeng; Qu, Shuxin; Liu, Yumei; Wang, Jing; Zhang, Yongchao; Jiang, Chongxi; Shen, Ru

    2016-08-01

    Ultra-high molecular weight polyethylene (UHMWPE) loaded with alendronate sodium (ALN) has tremendous potential as an orthopeadic biomaterial for joint replacements. However, poor mechanical and tribological properties of UHMWPE-ALN are still obstacle for further application. The purpose of this study was to investigate the effect and mechanism of mechanical activation on mechanical and tribological properties of 1wt% ALN-loaded UHMWPE (UHMWPE-ALN-ma). In this study, tensile test, small punch test and reciprocating sliding wear test were applied to characterize the mechanical and tribological properties of UHMWPE-ALN-ma. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) were employed to characterize UHMWPE-ALN-ma. Tensile test and small punch test showed that Young׳s modulus, tensile strength and work-to-failure (WTF) of UHMWPE-ALN-ma increased significantly compared to those of UHMWPE-ALN. The friction coefficients and wear factors of UHMWPE-ALN-ma both decreased significantly compared to those of UHMWPE-ALN. Mechanical activation obviously reduced type 1 (void) and type 2 (the disconnected and dislocated machining marks) fusion defects of UHMWPE-ALN-ma, which were revealed by SEM images of freeze fracture surfaces after etching and lateral surfaces of specimens after extension to fracture, respectively. It was attributed to peeled-off layers and chain scission of molecular chains of UHMWPE particles after mechanical activation, which were revealed by SEM images and FTIR spectra of UHMWPE-ALN-ma and UHMWPE-ALN, respectively. Moreover, EDS spectra revealed the more homogeneous distribution of ALN in UHMWPE-ALN-ma compared to that of UHMWPE-ALN. The present results showed that mechanical activation was a potential strategy to improve mechanical and tribological properties of UHMWPE-ALN-ma as an orthopeadic biomaterial for joint replacements. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Lateral wedges alter mediolateral load distributions at the knee joint in obese individuals.

    PubMed

    Russell, Elizabeth M; Miller, Ross H; Umberger, Brian R; Hamill, Joseph

    2013-05-01

    Obesity is the primary risk factor for knee osteoarthritis (OA). Greater external knee adduction moments, surrogate measures for medial compartment loading, are present in Obese individuals and may predispose them to knee OA. Laterally wedged insoles decrease the magnitude of the external adduction moment in Obese individuals but it is unknown how they alter the center of pressure on the tibial plateau. A gait analysis was performed on 14 Obese (avg. 29.3 years; BMI range: 30.3-51.6 kg/m(2) ) and 14 lean women (avg. 26.1 years; BMI range: 20.9-24.6 kg/m(2) ) with and without a full-length, wedged insole. Computed joint angles, joint moments, and knee extensor strength values were input into a musculoskeletal model to estimate center of pressure of the contact force on the tibial plateau. Statistical significance was assessed using a two-way ANOVA to compare the main effects of group and insole condition (α = 0.05). The insole resulted in a significant (p < 0.01) lateral shift in the center of pressure location in both the Obese and Control groups (mean: 2.9 ± 0.7 and 1.5 ± 0.7 mm, respectively). The insole also significantly reduced the peak external knee adduction moment 1.88 ± 1.82 N m in the Control group (p < 0.01) and 3.62 ± 3.90 N m in the Obese group (p < 0.01). The results of this study indicate the effects of a prophylactic wedged insole for reducing the magnitude of the load on the knee's medial compartment in Obese women who are at risk for knee OA development.

  5. Gender Dimorphic ACL Strain In Response to Combined Dynamic 3D Knee Joint Loading: Implications for ACL Injury Risk

    PubMed Central

    Mizuno, Kiyonori; Andrish, Jack T.; van den Bogert, Antonie J.; McLean, Scott G.

    2009-01-01

    While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as a function of the combined 6 DOF knee loads. Following individual model verifications, generalized gender-specific models were generated and subjected to 6 DOF external load scenarios consistent with both a clinical examination and a dynamic sports maneuver. The ensuing model-based strain predictions were subsequently examined for gender-based discrepancies. Male and female specimen specific models predicted ACL strain within 0.51% ± 0.10% and 0.52% ± 0.07% of the measured data respectively, and explained more than 75% of the associated variance in each case. Predicted female ACL strains were also significantly larger than respective male values for both of simulated 6 DOF load scenarios. Outcomes suggest that the female ACL will rupture in response to comparatively smaller external load applications. Future work must address the underlying anatomical/laxity contributions to knee joint mechanical and resultant ACL loading, ultimately affording prevention strategies that may cater to individual joint vulnerabilities. PMID:19464897

  6. KNEE-JOINT LOADING IN KNEE OSTEOARTHRITIS: INFLUENCE OF ABDOMINAL AND THIGH FAT

    PubMed Central

    Messier, Stephen P.; Beavers, Daniel P.; Loeser, Richard F.; Carr, J. Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J.; Hunter, David J.; DeVita, Paul

    2014-01-01

    Purpose Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee-joint loads in older overweight and obese adults with knee osteoarthritis (OA). Methods Fat depots were quantified using computed tomography and total lean and fat mass determined with dual energy x-ray absorptiometry in 176 adults (age = 66.3 yr., BMI = 33.5 kg·m−2) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Results Higher total body mass was significantly associated (p ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (p < 0.0001), patellofemoral forces (p< 0.006), and knee extensor moments (p = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (p = 0.0001), shear (p < 0.001), and patellofemoral forces (p = 0.01) and knee extension moment (p = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (p = 0.002). A regression model that included total thigh and total abdominal fat found both were significantly associated with knee compressive and shear forces (p ≤ 0.04). Thigh fat was associated with the knee abduction (p = 0.03) and knee extension moment (p = 0.02). Conclusions Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA. PMID:25133996

  7. Temporomandibular joint in miniature pigs: anatomy, cell replication, and relation to loading.

    PubMed

    Herring, Susan W; Decker, Jay D; Liu, Zi-Jun; Ma, Tsun

    2002-03-01

    The mechanical environment is a regulator of growth and adaptation of the musculoskeletal system, including joints. Although pigs (Sus scrofa) are used frequently as models for temporomandibular joint (TMJ) dysfunction, no systematic description of microanatomy exists for this species. We injected the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) into 10- to 11-month-old miniature pigs that were undergoing measurements of TMJ bone strain. Ten hr later, the animals were sacrificed and their heads were perfused. Histological sections were used to map the distribution of replicating cells. Additional observations were made on gross dissections of jaw joints obtained from an abattoir. The pig TMJ is better supported than that of humans laterally and medially, but more vulnerable posteriorly. The posterior attachment area of the intra-articular disc is fibro-fatty rather than vascular, as in humans. Cartilage lines the articular eminence as well as the condylar surface. At the posterosuperior region of the condyle, the cartilage ends abruptly and is replaced by an invaginating, actively replicating periosteum. Almost all of the BrdU-labeled cells resided in the prechondroblastic zones. The condyle had more replicating cells than did the eminence (P < 0.02), but lateral and medial locations did not differ in either element. In sagittal sections, the condyle had more replicating cells posteriorly (P < 0.001), but no A-P differences were seen in the eminence. Comparisons of these data with data on bone strain indicate that increased loading is negatively associated with cell replication. Copyright 2002 Wiley-Liss, Inc.

  8. Knee joint loading in knee osteoarthritis: influence of abdominal and thigh fat.

    PubMed

    Messier, Stephen P; Beavers, Daniel P; Loeser, Richard F; Carr, J Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J; Hunter, David J; Devita, Paul

    2014-09-01

    Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee joint loads in older overweight and obese adults with knee osteoarthritis (OA). Fat depots were quantified using computed tomography, and total lean and fat mass were determined with dual energy x-ray absorptiometry in 176 adults (age, 66.3 yr; body mass index, 33.5 kg·m) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Higher total body mass was significantly associated (P ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (P < 0.0001), patellofemoral forces (P < 0.006), and knee extensor moments (P = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (P = 0.0001), shear (P < 0.001), and patellofemoral forces (P = 0.01) and knee extension moment (P = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (P = 0.002). A regression model that included total thigh and total abdominal fat found that both were significantly associated with knee compressive and shear forces (P ≤ 0.04). Thigh fat was associated with knee abduction (P = 0.03) and knee extension moment (P = 0.02). Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA.

  9. Minimization of the knee shear joint load in leg-extension equipment.

    PubMed

    Biscarini, A

    2008-10-01

    We developed an analytical biomechanical model for leg-extension equipment and the associated knee-extension/flexion exercises. The shear component, phi(t), of the tibiofemoral joint load was calculated taking into account all the fundamental elements of the equipment mechanics (resistance pad placement, cam/pulley system geometry, selected weight stack, etc.) and the instantaneous values of the relevant kinematical parameters (knee-flexion angle (theta(f)), angular velocity, and angular acceleration). The optimal distance (a(R))(OPT) between the knee-flexion/extension axis and the resistance pad placement point was derived by minimizing phi(t). (a(R))(OPT) is nearly independent of joint angular velocity and, for appreciably high resistance torques, becomes nearly independent of resistance level and cam/pulley geometry: for theta(f)>40 degrees , phi(t) is minimized by placing the resistance pad distally along the lower leg; for theta(f)joint protection. This work establishes the rational basis for the design and clinical use of a leg-extension equipment that minimizes phi(t).

  10. The effect of glenosphere diameter in reverse shoulder arthroplasty on muscle force, joint load, and range of motion.

    PubMed

    Langohr, G Daniel G; Giles, Joshua W; Athwal, George S; Johnson, James A

    2015-06-01

    Little is known about the effects of glenosphere diameter on shoulder joint loads. The purpose of this biomechanical study was to investigate the effects of glenosphere diameter on joint load, load angle, and total deltoid force required for active abduction and range of motion in internal/external rotation and abduction. A custom, instrumented reverse shoulder arthroplasty implant system capable of measuring joint load and varying glenosphere diameter (38 and 42 mm) and glenoid offset (neutral and lateral) was implanted in 6 cadaveric shoulders to provide at least 80% power for all variables. A shoulder motion simulator was used to produce active glenohumeral and scapulothoracic motion. All implant configurations were tested with active and passive motion with joint kinematics, loads, and moments recorded. At neutral and lateralized glenosphere positions, increasing diameter significantly increased joint load (+12 ± 21 N and +6 ± 9 N; P < .01) and deltoid load required for active abduction (+9 ± 22 N and +11 ± 15 N; P < .02), whereas joint load angle was unaffected (P > .8). Passive internal rotation was reduced with increased diameter at both neutral and lateralized glenosphere positions (-6° ± 6° and -12° ± 6°; P < .002); however, external rotation was not affected (P > .05). At neutral glenosphere position, increasing diameter increased the maximum angles of both adduction (+1° ± 1°; P = .03) and abduction (+8° ± 9°; P < .05). Lateralization also increased abduction range of motion compared with neutral (P < .01). Although increasing glenosphere diameter significantly increased joint load and deltoid force, the clinical impact of these changes is presently unclear. Internal rotation, however, was reduced, which contradicts previous bone modeling studies, which we postulate is due to increased posterior capsular tension as it is forced to wrap around a larger 42 mm implant assembly. Copyright © 2015 Journal of

  11. Generation of physiological parameter sets for hip joint motions and loads during daily life activities for application in wear simulators of the artificial hip joint.

    PubMed

    Fabry, Christian; Herrmann, Sven; Kaehler, Michael; Klinkenberg, Ernst-Dieter; Woernle, Christoph; Bader, Rainer

    2013-01-01

    At present, wear investigations of total hip replacements are performed in accordance with the ISO standard 14242, which is based on simplified kinematic and force data of the gait cycle. The aim of this analytical study was to generate parameter sets of daily life activities in order to replicate more realistic joint load situations in wear testing. Hence, published in vivo motion and force data of daily life activities were evaluated and adjusted using analytical techniques. The created kinematically and dynamically consistent parameter sets comprised time trajectories of three Cardan angles to describe the motion of the femur with respect to the pelvis and time trajectories of three force components, representing the hip joint contact force. The parameter sets include the activities of walking, knee bending, stair climbing and a combined load case of sitting down and standing up. Additionally, a motion sequence following the frequency of daily life activities was presented. Differences of the evaluated angular motions and joint contact forces in comparison to the ISO standard 14242-1 were pointed out. The results of this study offer the possibility to extend the kinematics and dynamics of the ISO standard test protocol and to support the loading conditions of hip wear simulators with a comprehensive set of motions and loads close to reality. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. The effects of axial and multi-plane loading of the extensor mechanism on the patellofemoral joint.

    PubMed

    Powers, Christopher M.; Lilley, James C.; Lee, Thay Q.

    1998-12-01

    OBJECTIVE: To compare the effects of axial loading, and anatomically based multi-plane loading of the extensor mechanism on the patellofemoral joint. DESIGN: Repeated measures design using an in-vitro cadaver model. BACKGROUND: Since the extensor mechanism is the primary contributor to the patellofemoral joint reaction force and can affect patellar kinematics, it is essential that the forces produced by this musculature be accurately represented in a simulation model. METHODS: Patellar kinematics (magnetic tracking device), contact pressures and areas (pressure sensitive film) were measured from 6 cadaver knees under two different loading conditions: 1) axial (rectus femoris loaded in the frontal plane), and 2) multiplane (individual components of the quadriceps loaded along their respective fiber directions in both the frontal and sagittal planes). Specimens were mounted in a custom knee jig, with muscle forces being simulated using a pulley system and weight. Data were collected at 0 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees and 90 degrees of knee flexion. RESULTS: Compared to the axial loading condition, multi-plane loading of the vasti resulted in significantly greater contact pressure at 0 degrees and significantly less contact pressure at 90 degrees of knee flexion. Furthermore, the multi-plane loading condition resulted in greater lateral patellar rotation from 0-75 degrees of knee flexion, and greater lateral glide at 30 degrees of knee flexion. Greater patellar flexion was observed with the axial loading condition. CONCLUSIONS: These findings indicate that axial loading of the extensor mechanism underestimates contact pressure at 0 degrees and overestimates contact pressure at 90 degrees of knee flexion when compared to multi-plane loading. Additionally, loading of the individual vasti appears to have an effect on patellar kinematics. RELEVANCE: The results of this study indicate that anatomically based, multi-plane loading of the

  13. Decreased Knee Joint Loading Associated With Early Knee Osteoarthritis After Anterior Cruciate Ligament Injury

    PubMed Central

    Wellsandt, Elizabeth; Gardinier, Emily S.; Manal, Kurt; Axe, Michael J.; Buchanan, Thomas S.; Snyder-Mackler, Lynn

    2015-01-01

    Background Anterior cruciate ligament (ACL) injury predisposes individuals to early-onset knee joint osteoarthritis (OA). Abnormal joint loading is apparent after ACL injury and reconstruction. The relationship between altered joint biomechanics and the development of knee OA is unknown. Hypothesis Altered knee joint kinetics and medial compartment contact forces initially after injury and reconstruction are associated with radiographic knee OA 5 years after reconstruction. Study Design Case-control study; Level of evidence, 3. Methods Individuals with acute, unilateral ACL injury completed gait analysis before (baseline) and after (posttraining) preoperative rehabilitation and at 6 months, 1 year, and 2 years after reconstruction. Surface electromyographic and knee biomechanical data served as inputs to an electromyographically driven musculoskeletal model to estimate knee joint contact forces. Patients completed radiographic testing 5 years after reconstruction. Differences in knee joint kinetics and contact forces were compared between patients with and those without radiographic knee OA. Results Patients with OA walked with greater frontal plane interlimb differences than those without OA (nonOA) at baseline (peak knee adduction moment difference: 0.00 ± 0.08 N·m/kg·m [nonOA] vs −0.15 ± 0.09 N·m/kg·m [OA], P = .014; peak knee adduction moment impulse difference: −0.001 ± 0.032 N·m·s/kg·m [nonOA] vs −0.048 ± 0.031 N·m·s/kg·m [OA], P = .042). The involved limb knee adduction moment impulse of the group with osteoarthritis was also lower than that of the group without osteoarthritis at baseline (0.087 ± 0.023 N·m·s/kg·m [nonOA] vs 0.049 ± 0.018 N·m·s/kg·m [OA], P = .023). Significant group differences were absent at posttraining but reemerged 6 months after reconstruction (peak knee adduction moment difference: 0.02 ± 0.04 N·m/kg·m [nonOA] vs −0.06 ± 0.11 N·m/kg·m [OA], P = .043). In addition, the OA group walked with lower peak

  14. Assessment of cartilage contact pressure and loading in the hip joint during split posture.

    PubMed

    Assassi, Lazhari; Magnenat-Thalmann, Nadia

    2016-05-01

    Given the crucial role of the mechanical behavior in the degenerative process of the hip joint, analyzing the contact mechanics in the articular layers during physical activities could contribute to understanding the pathology. Indeed, the development process of hip osteoarthritis generally evolves over a long time period, and therefore analyzing the mechanical behavior of the hip joint during extreme repetitive movements will be helpful to analyze degeneration causes. The aim of the study was to investigate the link between the excessive movements and the development of hip osteoarthritis. To individualize the analysis, we used a subject-specific and noninvasive approach based on finite element analysis and magnetic resonance imaging (MRI) data. The contact pressure distribution and loading conditions on the acetabular cartilage were assessed on eleven professional dancer subjects performing a split movement. This movement is frequently practiced (repetitive) by dancers during their daily exercises. Moreover, split postures are mostly characterized by high anatomical angles with subluxation (excessive). To ensure the motion accuracy, MRI data of the subjects were acquired in neutral and split positions performed inside the MRI scanner. Based on the reconstructed bone models from the MRI data, a motion tracking approach was used to compute the transformation between the two poses. To evaluate the contact during the split movement and to quantify the role of the labrum in the hip joint mechanics, additional simulations of two daily activities (walking and stand-up) were performed. Finally, a clinical study based on morphological and radiological analysis of the subjects was performed and validated by orthopedic surgeons and radiological experts to evaluate the proposed approach. The reconstructed split movement was characterized by high anatomical angles with a subluxation on the left hip. Consequently, strong deformations and pressures were observed during the

  15. In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint

    PubMed Central

    Jang, Andrew T.; Lin, Jeremy D.; Seo, Youngho; Etchin, Sergey; Merkle, Arno; Fahey, Kevin; Ho, Sunita P.

    2014-01-01

    This study demonstrates a novel biomechanics testing protocol. The advantage of this protocol includes the use of an in situ loading device coupled to a high resolution X-ray microscope, thus enabling visualization of internal structural elements under simulated physiological loads and wet conditions. Experimental specimens will include intact bone-periodontal ligament (PDL)-tooth fibrous joints. Results will illustrate three important features of the protocol as they can be applied to organ level biomechanics: 1) reactionary force vs. displacement: tooth displacement within the alveolar socket and its reactionary response to loading, 2) three-dimensional (3D) spatial configuration and morphometrics: geometric relationship of the tooth with the alveolar socket, and 3) changes in readouts 1 and 2 due to a change in loading axis, i.e. from concentric to eccentric loads. Efficacy of the proposed protocol will be evaluated by coupling mechanical testing readouts to 3D morphometrics and overall biomechanics of the joint. In addition, this technique will emphasize on the need to equilibrate experimental conditions, specifically reactionary loads prior to acquiring tomograms of fibrous joints. It should be noted that the proposed protocol is limited to testing specimens under ex vivo conditions, and that use of contrast agents to visualize soft tissue mechanical response could lead to erroneous conclusions about tissue and organ-level biomechanics. PMID:24638035

  16. Effects of surgical joint destabilization on load sharing between ligamentous structures in the thoracic spine: a finite element investigation.

    PubMed

    Little, J P; Adam, C J

    2011-11-01

    In vitro investigations have demonstrated the importance of the ribcage in stabilizing the thoracic spine. Surgical alterations of the ribcage may change load-sharing patterns in the thoracic spine. Computer models are used in this study to explore the effect of surgical disruption of the rib-vertebrae connections on ligament load-sharing in the thoracic spine. A finite element model of a T7-8 motion segment, including the T8 rib, was developed using CT-derived spinal anatomy for the Visible Woman. Both the intact motion segment and the motion segment with four successive stages of destabilization (discectomy and removal of right costovertebral joint, right costotransverse joint and left costovertebral joint) were analyzed for a 2000 Nmm moment in flexion/extension, lateral bending and axial rotation. Joint rotational moments were compared with existing in vitro data and a detailed investigation of the load sharing between the posterior ligaments carried out. The simulated motion segment demonstrated acceptable agreement with in vitro data at all stages of destabilization. Under lateral bending and axial rotation, the costovertebral joints were of critical importance in resisting applied moments. In comparison to the intact joint, anterior destabilization increases the total moment contributed by the posterior ligaments. Surgical removal of the costovertebral joints may lead to excessive rotational motion in a spinal joint, increasing the risk of overload and damage to the remaining ligaments. The findings of this study are particularly relevant for surgical procedures involving rib head resection, such as some techniques for scoliosis deformity correction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Evaluation of articular disc loading in the temporomandibular joints after prosthetic and pharmacological treatment in model studies.

    PubMed

    Pihut, Małgorzata E; Margielewicz, Jerzy; Kijak, Edward; Wiśniewska, Grażyna

    2017-01-01

    Temporomandibular joint dysfunction is often related to excessive load in the stomatognathic system. The objective of the model tests, using numeric calculations, was to assess the articular disc loads in the temporomandibular joints after prosthetic and pharmacological treatment of functional disorders of the masticatory organ. The study involved 10 patients, aged 21-48 years, of both sexes, randomly selected from a group of 120 patients treated with relaxation occlusal splints (60 patients, group I) and intramuscular injection of botulinum toxin type A (60 patients, group II), suffering from temporomandibular joint dysfunction with the dominant muscle component. In all subjects, a specialized functional examination was carried out. Treatment groups: occlusal splint therapy (group I) and intramuscular injection of botulinum toxin type A (group II). An assessment of the loads of 4 disc zones of the temporomandibular joints was carried out based on the results of clinical studies (phase I of the study), and numeric model tests (phase II). In the representatives of the study groups (5 patients in each group), measurements of occlusal forces and an evaluation of tension of the masseter and temporalis muscle were performed. The results of the average load values for all evaluated zones of the right and left articular disc differ in a statistically significant way in favor of group II, with the exception of the external mid part of the discs. In the case of the anterior of the right disc, the load was lower in patients belonging to group I than in those obtained in group II. Botulinum toxin type A significantly reduces the loads within the temporomandibular joints, generated by masseter muscle hypertonia.

  18. Seasonal Hydrological Loading in Southern Tibet Detected by Joint Analysis of GPS and GRACE

    PubMed Central

    Zou, Rong; Wang, Qi; Freymueller, Jeffrey T.; Poutanen, Markku; Cao, Xuelian; Zhang, Caihong; Yang, Shaomin; He, Ping

    2015-01-01

    In southern Tibet, ongoing vertical and horizontal motions due to the collision between India and Eurasia are monitored by large numbers of global positioning system (GPS) continuous and campaign sites installed in the past decade. Displacements measured by GPS usually include tectonic deformation as well as non-tectonic, time-dependent signals. To estimate the regional long-term tectonic deformation using GPS more precisely, seasonal elastic deformation signals associated with surface loading must be removed from the observations. In this study, we focus on seasonal variation in vertical and horizontal motions of southern Tibet by performing a joint analysis of GRACE (Gravity Recovery and Climate Experiment) and GPS data, not only using continuous sites but also GPS campaign-mode sites. We found that the GPS-observed and GRACE-modeled seasonal oscillations are in good agreements, and a seasonal displacement model demonstrates that the main reason for seasonal variations in southern Tibet is from the summer monsoon and its precipitation. The biggest loading appears from July to August in the summer season. Vertical deformations observed by GPS and modeled by GRACE are two to three times larger than horizontal oscillations, and the north components demonstrate larger amplitudes than the east components. We corrected the GPS position time series using the GRACE-modeled seasonal variations, which gives significant reductions in the misfit and weighted root-mean-squares (WRMS). Misfit (χ2 divided by degree of freedom) reductions for campaign sites range between 20% and 56% for the vertical component, and are much smaller for the horizontal components. Moreover, time series of continuous GPS (cGPS) sites near the 2015 Nepal earthquakes must be corrected using appropriate models of seasonal loading for analyzing postseismic deformation to avoid biasing estimates of the postseismic relaxation. PMID:26690157

  19. Seasonal Hydrological Loading in Southern Tibet Detected by Joint Analysis of GPS and GRACE.

    PubMed

    Zou, Rong; Wang, Qi; Freymueller, Jeffrey T; Poutanen, Markku; Cao, Xuelian; Zhang, Caihong; Yang, Shaomin; He, Ping

    2015-12-04

    In southern Tibet, ongoing vertical and horizontal motions due to the collision between India and Eurasia are monitored by large numbers of global positioning system (GPS) continuous and campaign sites installed in the past decade. Displacements measured by GPS usually include tectonic deformation as well as non-tectonic, time-dependent signals. To estimate the regional long-term tectonic deformation using GPS more precisely, seasonal elastic deformation signals associated with surface loading must be removed from the observations. In this study, we focus on seasonal variation in vertical and horizontal motions of southern Tibet by performing a joint analysis of GRACE (Gravity Recovery and Climate Experiment) and GPS data, not only using continuous sites but also GPS campaign-mode sites. We found that the GPS-observed and GRACE-modeled seasonal oscillations are in good agreements, and a seasonal displacement model demonstrates that the main reason for seasonal variations in southern Tibet is from the summer monsoon and its precipitation. The biggest loading appears from July to August in the summer season. Vertical deformations observed by GPS and modeled by GRACE are two to three times larger than horizontal oscillations, and the north components demonstrate larger amplitudes than the east components. We corrected the GPS position time series using the GRACE-modeled seasonal variations, which gives significant reductions in the misfit and weighted root-mean-squares (WRMS). Misfit (χ2 divided by degree of freedom) reductions for campaign sites range between 20% and 56% for the vertical component, and are much smaller for the horizontal components. Moreover, time series of continuous GPS (cGPS) sites near the 2015 Nepal earthquakes must be corrected using appropriate models of seasonal loading for analyzing postseismic deformation to avoid biasing estimates of the postseismic relaxation.

  20. Distraction Arthrodesis of the C1-C2 Facet Joint with Preservation of the C2 Root for the Management of Intractable Occipital Neuralgia Caused by C2 Root Compression.

    PubMed

    Yeom, Jin S; Riew, K Daniel; Kang, Sung Shik; Yi, Jemin; Lee, Gun Woo; Yeom, Arim; Chang, Bong-Soon; Lee, Choon-Ki; Kim, Ho-Joong

    2015-10-15

    Prospective observational cohort study. To compare the outcomes of our new technique, distraction arthrodesis of C1-C2 facet joint with C2 root preservation (Study group), to those of conventional C1-C2 fusion with C2 root transection (Control group) for the management of intractable occipital neuralgia caused by C2 root compression. We are not aware of any report concerning C2 root decompression during C1-C2 fusion. Inclusion criteria were visual analogue scale (VAS) score for occipital neuralgia 7 or more; C2 root compression at the collapsed C1-C2 neural foramen; and follow-up 12 months or more. The Study group underwent surgery with our new technique including (1) C1-C2 facet joint distraction and bone block insertion while preserving the C2 root; and (2) use of C1 posterior arch screws instead of conventional lateral mass screws during C1-C2 segmental screw fixation. The Control group underwent C2 root transection with C1-C2 segmental screw fixation and fusion. We compared the prospectively collected outcomes data. There were 15 patients in the Study group and 8 in the Control group. Although there was no significant difference in the VAS score for the occipital neuralgia between the 2 groups preoperatively (8.2 ± 0.9 vs. 7.9 ± 0.6, P = 0.39), it was significantly lower in the Study group at 1, 3, and 6 months postoperatively (P < 0.01, respectively). At 12 months, it was 0.4 ± 0.6 versus 2.5 ± 2.6 (P = 0.01). There was no significant difference in improvement in the VAS score for neck pain and neck disability index and Japanese Orthopedic Association recovery rate, which are minimally influenced by occipital neuralgia. Our novel technique of distraction arthrodesis with C2 root preservation can be an effective option for the management of intractable occipital neuralgia caused by C2 root compression.

  1. Three-dimensional lower extremity joint loading in a carved ski and snowboard turn: a pilot study.

    PubMed

    Klous, Miriam; Müller, Erich; Schwameder, Hermann

    2014-01-01

    A large number of injuries to the lower extremity occur in skiing and snowboarding. Due to the difficulty of collecting 3D kinematic and kinetic data with high accuracy, a possible relationship between injury statistic and joint loading has not been studied. Therefore, the purpose of the current study was to compare ankle and knee joint loading at the steering leg between carved ski and snowboard turns. Kinetic data were collected using mobile force plates mounted under the toe and heel part of the binding on skies or snowboard (KISTLER). Kinematic data were collected with five synchronized, panning, tilting, and zooming cameras. An extended version of the Yeadon model was applied to calculate inertial properties of the segments. Ankle and knee joint forces and moments were calculated using inverse dynamic analysis. Results showed higher forces along the longitudinal axis in skiing and similar forces for skiing and snowboarding in anterior-posterior and mediolateral direction. Joint moments were consistently greater during a snowboard turn, but more fluctuations were observed in skiing. Hence, when comparing joint loading between carved ski and snowboard turns, one should differentiate between forces and moments, including the direction of forces and moments and the turn phase.

  2. Joint mimicking mechanical load activates TGFβ1 in fibrin-poly(ester-urethane) scaffolds seeded with mesenchymal stem cells.

    PubMed

    Gardner, Oliver F W; Fahy, Niamh; Alini, Mauro; Stoddart, Martin J

    2016-07-22

    Transforming growth factor-β1 (TGF-β1) is widely used in an active recombinant form to stimulate the chondrogenic differentiation of mesenchymal stem cells (MSCs). Recently, it has been shown that the application of multiaxial load, that mimics the loading within diarthrodial joints, to MSCs seeded in to fibrin-poly(ester-urethane) scaffolds leads to the endogenous production and secretion of TGF-β1 by the mechanically stimulated cells, which in turn drives the chondrogenic differentiation of the cells within the scaffold. The work presented in this short communication provides further evidence that the application of joint mimicking multiaxial load induces the secretion of TGF-β1 by mechanically stimulated MSCs. The results of this work also show that joint-like multiaxial mechanical load activates latent TGF-β1 in response to loading in the presence or absence of cells; this activation was not seen in non-loaded control scaffolds. Despite the application of mechanical load to scaffolds with different distributions/numbers of cells no significant differences were seen in the percentage of active TGF-β1 quantified in the culture medium of scaffolds from different groups. The similar level of activation in scaffolds containing different numbers of cells, cells at different stages of differentiation or with different distributions of cells suggests that this activation results from the mechanical forces applied to the culture system rather than differences in cellular behaviour. These results are relevant when considering rehabilitation protocols after cell therapy or microfracture, for articular cartilage repair, where increased TGF-β1 activation in response to joint mobilization may improve the quality of developing cartilaginous repair material. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Dynamic simulation of knee-joint loading during gait using force-feedback control and surrogate contact modelling.

    PubMed

    Walter, Jonathan P; Pandy, Marcus G

    2017-10-01

    The aim of this study was to perform multi-body, muscle-driven, forward-dynamics simulations of human gait using a 6-degree-of-freedom (6-DOF) model of the knee in tandem with a surrogate model of articular contact and force control. A forward-dynamics simulation incorporating position, velocity and contact force-feedback control (FFC) was used to track full-body motion capture data recorded for multiple trials of level walking and stair descent performed by two individuals with instrumented knee implants. Tibiofemoral contact force errors for FFC were compared against those obtained from a standard computed muscle control algorithm (CMC) with a 6-DOF knee contact model (CMC6); CMC with a 1-DOF translating hinge-knee model (CMC1); and static optimization with a 1-DOF translating hinge-knee model (SO). Tibiofemoral joint loads predicted by FFC and CMC6 were comparable for level walking, however FFC produced more accurate results for stair descent. SO yielded reasonable predictions of joint contact loading for level walking but significant differences between model and experiment were observed for stair descent. CMC1 produced the least accurate predictions of tibiofemoral contact loads for both tasks. Our findings suggest that reliable estimates of knee-joint loading may be obtained by incorporating position, velocity and force-feedback control with a multi-DOF model of joint contact in a forward-dynamics simulation of gait. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  4. Value of (18) F-FDG PET/MRI for the outcome of CT-guided facet block therapy in cervical facet syndrome: initial results.

    PubMed

    Sawicki, Lino M; Schaarschmidt, Benedikt M; Heusch, Philipp; Buchbender, Christian; Rosenbaum-Krumme, Sandra; Umutlu, Lale; Eicker, Sven O; Bockisch, Andreas; Antoch, Gerald; Floeth, Frank W

    2017-06-01

    The aim of this study was to evaluate the ability of (18) F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging ((18) F-FDG PET/MRI) to detect PET-positive cervical facet arthropathy and identify patients who benefit from facet block therapy. Ten patients with cervical facet syndrome (mean age: 65 ± 12 years) underwent (18) F-FDG PET/MRI of the neck. Focal (18) F-FDG uptake in PET-positive facet joints served as target for computed tomography (CT)-guided facet blocks. In PET-negative patients, the target joint for facet block therapy was selected by current clinical standards considering the level of maximum facet arthrosis and pain. Neck pain was measured on visual analogue scale (VAS) before and after therapy. Bone marrow signal intensity (SI) ratio on turbo inversion recovery magnitude (TIRM) images and maximum standard uptake values (SUVmax) was calculated for each facet joint. Pearson's correlation coefficient (r) was calculated between bone marrow SI ratios on TIRM and SUVmax. (18) F-FDG PET/MRI detected PET-positive facet arthropathy in six patients. Patients with PET-positive facet arthropathy had significantly less pain compared with the pretreatment pain 3 h (P = 0.002), 4 weeks (P = 0.002) and 3 months (P = 0.026) after facet block therapy. Pain did not change significantly in patients with PET-negative facet arthropathy. TIRM SI ratio was higher in PET-positive facet arthropathy than in PET-negative facet arthropathy (P < 0.001). Correlation was strong between bone marrow SI ratio on TIRM images and SUVmax (r = 0.7; P < 0.001). (18) F-FDG PET/MRI can detect PET-positive cervical facet arthropathy and help to identify patients benefitting from facet block therapy. Bone marrow TIRM SI ratio might be a surrogate for PET-positive facet arthropathy. © 2016 The Royal Australian and New Zealand College of Radiologists.

  5. Loading of the knee joint during ergometer cycling: telemetric in vivo data.

    PubMed

    Kutzner, Ines; Heinlein, Bernd; Graichen, Friedmar; Rohlmann, Antonius; Halder, Andreas M; Beier, Alexander; Bergmann, Georg

    2012-12-01

    Within-subject, repeated-measures design. To measure tibiofemoral contact forces during cycling in vivo and to quantify the influences of power, pedaling cadence, and seat height on tibiofemoral contact forces. Cycling is usually classified as a low-demand activity for the knee joint and is therefore recommended for persons with osteoarthritis and rehabilitation programs following knee surgery. However, there are limited data regarding actual joint loading. Instrumented knee implants with telemetric data transmission were used to measure the tibiofemoral contact forces. Data were obtained in 9 subjects, during ergometer cycling and walking, 15 ± 7 months after total knee arthroplasty. Tibiofemoral forces during cycling at power levels between 25 and 120 W, cadences of 40 and 60 rpm, and 2 seat heights were investigated. Within the examined power range, tibiofemoral forces during cycling were smaller than those during walking. At the moderate condition of 60 W and 40 rpm, peak resultant forces of 119% of body weight were measured during the pedal downstroke. Shear forces ranged from 5% to 7% of body weight. Forces increased linearly with cycling power. Higher cadences led to smaller forces. A lower seat height did not increase the resultant force but caused higher posterior shear forces. Due to the relatively small tibiofemoral forces, cycling with moderate power levels is suited for individuals with osteoarthritis and rehabilitation programs following knee surgery, such as cartilage repair or total knee replacement. The lowest forces can be expected while cycling at a low power level, a high cadence, and a high seat height.

  6. 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

  7. Effect of rocker-soled shoes on parameters of knee joint load in knee osteoarthritis.

    PubMed

    Madden, Elizabeth G; Kean, Crystal O; Wrigley, Tim V; Bennell, Kim L; Hinman, Rana S

    2015-01-01

    This study evaluated the immediate effects of rocker-soled shoes on parameters of the knee adduction moment (KAM) and pain in individuals with knee osteoarthritis (OA). Three-dimensional gait analysis was performed on 30 individuals (mean (SD): age, 61 (7) yr; 15 (50%) male) with radiographic and symptomatic knee OA under three walking conditions in a randomized order: i) wearing rocker-soled shoes (Skechers Shape-ups), ii) wearing non-rocker-soled shoes (ASICS walking shoes), and iii) barefoot. Peak KAM and KAM angular impulse were measured as primary indicators of knee load distribution. Secondary measures included the knee flexion moment (KFM) and knee pain during walking. Peak KAM was significantly lower when wearing the rocker-soled shoes compared with that when wearing the non-rocker-soled shoes (mean difference (95% confidence interval), -0.27 (-0.42 to -0.12) N·m/BW × Ht%; P < 0.001). Post hoc tests revealed no significant difference in KAM impulse between rocker-soled and non-rocker-soled shoe conditions (P = 0.13). Both peak KAM and KAM impulse were significantly higher during both shoe conditions compared with those during the barefoot condition (P < 0.001). There were no significant differences in KFM (P = 0.36) or knee pain (P = 0.89) between conditions. Rocker-soled shoes significantly reduced peak KAM when compared with non-rocker-soled shoes, without a concomitant change in KFM, and thus may potentially reduce medial knee joint loading. However, KAM parameters in the rocker-soled shoes remained significantly higher than those during barefoot walking. Wearing rocker-soled shoes did not have a significant immediate effect on walking pain. Further research is required to evaluate whether rocker-soled shoes can influence symptoms and progression of knee OA with prolonged wear.

  8. Delamination Damage Analyses of FRP Composite Spar Wingskin Joints with Modified Elliptical Adhesive Load Coupler Profile

    NASA Astrophysics Data System (ADS)

    Panigrahi, S. K.; Pradhan, B.

    2008-11-01

    Three-dimensional non-linear finite element analyses (FEA) for delamination damage onset and its growth in Graphite Fiber Reinforced Plastic (GFRP) composite Spar Wingskin Joints (SWJ) with modified elliptical adhesive load coupler profile for varied ratios of base width to height of the spar have been presented in this paper. Both in-plane and out-of-plane normal and shear stress variations on the interfacial surface of the wingskin between the spar and the wingskin have been evaluated. Coupled stress failure criterion has been used to predict the locations of initiation of failures due to delamination induced damages. Based on the stress and delamination damage analyses, suitable geometry of the modified elliptical adhesive load coupler profile of the SWJ has been recommended. The delamination damage has been observed to be initiated from the toe-end of the interfacial surface of the spar and the wingskin of the SWJ. Subsequently, the delamination propagations have also been studied by calculating the individual and the total Mode of Strain Energy Release Rate (SERR) along the delamination front using Modified Crack Closure Integral (MCCI) technique based on Linear Elastic Fracture Mechanics (LEFM) approach. It is seen that SERR variations along the delamination front i.e. across the width of the SWJ are not uniform. Therefore, a straight delamination front may grow into a curved delamination front as the delamination propagates. Also, it is found that Mode I SERR ( G I) governs the delamination propagation predominantly for the SWJ. Accordingly, suitable delamination arresting mechanism has been suggested.

  9. High load-bearing multi-material-joints of metal sheets and composites by incremental in-situ forming processes

    NASA Astrophysics Data System (ADS)

    Seidlitz, Holger; Fritzsche, Sebastian; Bambach, Markus; Gerstenberger, Colin

    2016-10-01

    Thermo-mechanically flow-formed joints (FDJ) are an appropriate joining technology to realize high load-bearing multi-material-joints between fiber reinforced thermoplastics and sheet metals, without additional joining components. As in the automotive industry new vehicle and lightweight designs with one-sided accessibility joints are required, the technology which so far requires a two-sided accessibility of the joint, is examined for the ability to be performed with one-sided accessibility. The main part of the paper are therefore experimental studies on the one-sided manufacturing of FDJ-joints without an additional forming tool and their examination with head pull test and tension shear test according to DIN EN ISO 14272 and DIN EN ISO 14273. In this context, a tool and an experimental setup were designed to provide a corresponding joint production of a material combination of continuous glass fiber reinforced polypropylene (Plytron) and an aluminum alloy (EN AW-6082 T6). In the experiment, the novel joints bear maximum forces of 291 N in the head pull test and 708 N in the tension shear test.

  10. Medial knee joint loading increases in those who respond to hyaluronan injection for medial knee osteoarthritis.

    PubMed

    Briem, Kristin; Axe, Michael J; Snyder-Mackler, Lynn

    2009-11-01

    Knee osteoarthritis (OA) is a cause of decline in function and the medial compartment is often affected. Intraarticular injection of hyaluronic acid (HA) is indicated as a symptom modifying treatment with at least 6 months passing between consecutive injection series. The effects of HA injection on gait variables have not been extensively examined. Therefore, our objective was to investigate the effects of HA injection on gait in people with medial knee OA. Twenty-seven subjects were included; each was tested prior to treatment (baseline), no later than 3 weeks following the last injection (post-HA), and again 5 months after treatment ended (follow-up). Responder criteria were defined to identify responders and non-responders. Subjects underwent 3D gait analysis, muscle activity was sampled, and co-contraction indices were calculated. Responders experienced increased peak knee adduction moments post-HA, whereas non-responders did not. Improved self-report scores were associated with increased knee adduction moments and increased medial co-contraction. Pain relief may result in higher loading onto the already vulnerable medial compartment due to changes in lower limb mechanics and muscle activation patterns. Eventually this may result in a more rapid progression of joint deterioration.

  11. A handheld computer as part of a portable in vivo knee joint load monitoring system

    PubMed Central

    Szivek, JA; Nandakumar, VS; Geffre, CP; Townsend, CP

    2009-01-01

    In vivo measurement of loads and pressures acting on articular cartilage in the knee joint during various activities and rehabilitative therapies following focal defect repair will provide a means of designing activities that encourage faster and more complete healing of focal defects. It was the goal of this study to develop a totally portable monitoring system that could be used during various activities and allow continuous monitoring of forces acting on the knee. In order to make the monitoring system portable, a handheld computer with custom software, a USB powered miniature wireless receiver and a battery-powered coil were developed to replace a currently used computer, AC powered bench top receiver and power supply. A Dell handheld running Windows Mobile operating system(OS) programmed using Labview was used to collect strain measurements. Measurements collected by the handheld based system connected to the miniature wireless receiver were compared with the measurements collected by a hardwired system and a computer based system during bench top testing and in vivo testing. The newly developed handheld based system had a maximum accuracy of 99% when compared to the computer based system. PMID:19789715

  12. Sensate Scaffolds Coupled to Telemetry Can Monitor In Vivo Loading From Within a Joint Over Extended Periods of Time

    PubMed Central

    Geffre, Chris P.; Bliss, Cody L.; Szivek, John A.; DeYoung, Donald W.; Ruth, John T.; Margolis, David S.

    2008-01-01

    Polymer scaffolds have been used as a tool to provide growth and integration of engineered tissue substrates to repair damaged tissues in many organ systems including articular cartilage. Previous work has shown that “sensate” scaffolds, with integrated strain gauges have the potential for use as both a delivery vehicle for engineered cartilage as well as a device that can measure real time, in vivo joint loading. The purpose of this study was to use an implanted subminiature telemetry system to collect in vivo joint loading measurements over an extended period following placement of a “sensate” scaffold. Measurements were collected from seven of nine sensors that were implanted into the stifles of three canines. The limb loading rates and load distribution through gait were dependent on stride time but did not vary with time post op. The peak loads were not dependent on stride time but significantly increased with time post op. This demonstrated that peak loading measured with “sensate” scaffolds can be used to monitor healing. The portability of the “sensate” scaffolds coupled to telemetry systems highlights the potential use of this system in a clinical research setting to gather important information to improve tissue engineering and rehabilitation regimens. PMID:17557310

  13. Multiwalled nanotube faceting unravelled.

    PubMed

    Leven, Itai; Guerra, Roberto; Vanossi, Andrea; Tosatti, Erio; Hod, Oded

    2016-12-01

    Nanotubes show great promise for miniaturizing advanced technologies. Their exceptional physical properties are intimately related to their morphological and crystal structure. Circumferential faceting of multiwalled nanotubes reinforces their mechanical strength and alters their tribological and electronic properties. Here, the nature of this important phenomenon is fully rationalized in terms of interlayer registry patterns. Regardless of the nanotube identity (that is, diameter, chirality, chemical composition), faceting requires the matching of the chiral angles of adjacent layers. Above a critical diameter that corresponds well with experimental results, achiral multiwalled nanotubes display evenly spaced extended axial facets whose number equals the interlayer difference in circumferential unit cells. Elongated helical facets, commonly observed in experiment, appear in nanotubes that exhibit small interlayer chiral angle mismatch. When the wall chiralities are uncorrelated, faceting is suppressed and outer layer corrugation, which is induced by the Moiré superlattice, is obtained in agreement with experiments. Finally, we offer an explanation for the higher incidence of faceting in multiwalled boron nitride nanotubes with respect to their carbon-based counterparts.

  14. Multiwalled nanotube faceting unravelled

    NASA Astrophysics Data System (ADS)

    Leven, Itai; Guerra, Roberto; Vanossi, Andrea; Tosatti, Erio; Hod, Oded

    2016-12-01

    Nanotubes show great promise for miniaturizing advanced technologies. Their exceptional physical properties are intimately related to their morphological and crystal structure. Circumferential faceting of multiwalled nanotubes reinforces their mechanical strength and alters their tribological and electronic properties. Here, the nature of this important phenomenon is fully rationalized in terms of interlayer registry patterns. Regardless of the nanotube identity (that is, diameter, chirality, chemical composition), faceting requires the matching of the chiral angles of adjacent layers. Above a critical diameter that corresponds well with experimental results, achiral multiwalled nanotubes display evenly spaced extended axial facets whose number equals the interlayer difference in circumferential unit cells. Elongated helical facets, commonly observed in experiment, appear in nanotubes that exhibit small interlayer chiral angle mismatch. When the wall chiralities are uncorrelated, faceting is suppressed and outer layer corrugation, which is induced by the Moiré superlattice, is obtained in agreement with experiments. Finally, we offer an explanation for the higher incidence of faceting in multiwalled boron nitride nanotubes with respect to their carbon-based counterparts.

  15. Hip and knee net joint moments that correlate with success in lateral load transfers over a low friction surface.

    PubMed

    Catena, Robert D; Xu, Xu

    2016-12-01

    We previously described two different preferred strategies used to perform a lateral load transfer. The wide stance strategy was not used successfully on a low-friction surface, while the narrow stance strategy was successful. Here, we retrospectively examined lower extremity net joint moments between successful and unsuccessful strategies to determine if there is a kinetic benefit consideration that may go into choosing the preferred strategy. Success vs. failure over a novel slippery surface was used to dichotomise 35 healthy working-age individuals into the two groups (successful and unsuccessful). Participants performed lateral load transfers over three sequential surface conditions: high friction, novel low friction and practised low friction. The unsuccessful strategy required larger start torques, but lower dynamic moments during transfer compared to the successful strategy. These results indicate that the periodically unsuccessful strategy may be preferred because it requires less muscle recruitment and lower stresses on lower extremity soft tissues. Practitioner Summary: The reason for this paper is to retrospectively examine the joint moment in two different load transfer strategies that are used in a lateral load transfer. We found that periodically unsuccessful strategies that we previously reported may be a beneficial toward reduced lower extremity joint stresses.

  16. Changes in knee joint load indices from before to 12 months after arthroscopic partial meniscectomy: a prospective cohort study.

    PubMed

    Thorlund, J B; Holsgaard-Larsen, A; Creaby, M W; Jørgensen, G M; Nissen, N; Englund, M; Lohmander, L S

    2016-07-01

    Patients undergoing arthroscopic partial meniscectomy (APM) are at increased risk of knee osteoarthritis (OA). Meniscal damage and/or surgery may alter knee joint loading to increase OA risk. We investigated changes in knee joint loading following medial APM surgery, compared with the contra-lateral leg. We estimated indices of knee joint loading (external peak knee adduction moment (KAM), KAM impulse and peak knee flexion moment (KFM)) normalized to body size (i.e., body mass (BM) and height (HT)) using 3D gait analysis in 23 patients (17 men, mean (SD) 46.2 (6.4) years, BMI 25.8 (3.4) kg/m(2)) without radiographic knee OA before and 12 months after medial APM. Static alignment was assessed by radiography and self-reported outcomes by Knee injury and Osteoarthritis Outcome Score (KOOS). Peak KAM and KAM impulse increased in the APM leg compared to the contra-lateral leg from before to 12 months after surgery (change difference: 0.38 Nm/BM*HT% 95% CI 0.01 to 0.76 (P = 0.049) and 0.20 Nm*s/BM*HT% 95% CI 0.10 to 0.30 (P < 0.001)). Patients self-reported improvements on all KOOS subscales (KOOS pain improvement: 22.8 95% CI 14.5 to 31.0 (P < 0.01)). A relative increase in indices of medial compartment loading was observed in the leg undergoing APM compared with the contra-lateral leg from before to 12 months after surgery. This increase may contribute to the elevated risk of knee OA in these patients. Randomized trials including a non-surgical control group are needed to determine if changes in joint loading following APM are caused by surgery or by changes in symptoms. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  17. Numerical Investigation of T-joints with 3D Four Directional Braided Composite Fillers Under Tensile Loading

    NASA Astrophysics Data System (ADS)

    Li, Xiao-kang; Liu, Zhen-guo; Hu, Long; Wang, Yi-bo; Lei, Bing; Huang, Xiang

    2017-02-01

    Numerical studied on T-joints with three-dimensional four directional (3D4D) braided composite fillers was presented in this article. Compared with conventional unidirectional prepreg fillers, the 3D braided composite fillers have excellent ability to prevent crack from penetrating trigone fillers, which constantly occurred in the conventional fillers. Meanwhile, the 3D braided composite fillers had higher fiber volume fraction and eliminated the fiber folding problem in unidirectional prepreg fillers. The braiding technology and mechanical performance of 3D4D braided fillers were studied. The numerical model of carbon fiber T-joints with 3D4D braided composite fillers was built by finite element analysis software. The damage formation, extension and failing process of T-joints with 3D4D braided fillers under tensile load were investigated. Further investigation was extended to the effect of 3D4D braided fillers with different braiding angles on mechanical behavior of the T-joints. The study results revealed that the filling area was the weakest part of the T-joints where the damage first appeared and the crack then rapidly spread to the glue film around the filling area and the interface between over-laminate and soleplate. The 3D4D braided fillers were undamaged and the braiding angle change induced a little effect on the bearing capacity of T-joints.

  18. Effect of head contact on the rim of the cup on the offset loading and torque in hip joint replacement.

    PubMed

    Liu, Feng; Williams, Sophie; Jin, Zhongmin; Fisher, John

    2013-11-01

    Head contact on the rim of the cup causes stress concentration and consequently increased wear. The head contact on the rim of the cup may in addition cause an offset load and torque on the cup. The head-rim contact resulting from microseparation or subluxation has been investigated. An analytical model has been developed to calculate the offset loading and resultant torque on the cup as a function of the translational displacement of the head under simplified loading condition of the hip joint at heel strike during a walking cycle. The magnitude of the torque on the cup was found to increase with the increasing translational displacement, larger diameter heads, eccentric cups, and the coefficient of friction of the contact. The effects of cup inclination, cup rim radius, and cup coverage angle on the magnitude of the torque were found to be relatively small with a maximum variation in the torque magnitude being lower than 20%. This study has shown an increased torque due to the head loading on the rim of the cup, and this may contribute to the incidence of cup loosening. Particularly, metal-on-metal hip joints with larger head diameters may produce the highest offset loading torque.

  19. Altered functional loading causes differential effects in the subchondral bone and condylar cartilage in the temporomandibular joint from young mice

    PubMed Central

    Chen, J.; Sorensen, K. P.; Gupta, T.; Kilts, T.; Young, M.; Wadhwa, S.

    2009-01-01

    Summary Objective Altered loading is an important etiological factor for temporomandibular joint (TMJ) disorders. Studies examining altered loading of the TMJ have been done in rats but the response of the TMJ to altered loading in mice is largely unknown. Therefore, due to the potential usefulness of genetically engineered mice, the goal of this study was to develop a mouse TMJ altered functional loading model. Methods One hundred and thirty four, 21-day-old CD-1 female mice were divided into two groups: (1) normal loading (hard pellet diet) for 2–6 weeks and (2) altered functional loading (incisor trimming every other day and soft dough diet) for 2–6 weeks. The mandibular condylar cartilage was evaluated by histology, the subchondral bone was evaluated by microcomputed tomography (micro-CT) analysis and gene expression was evaluated by real time polymerase chain reaction (PCR) analysis. Results Altered functional loading for 2–6 weeks caused significant reduction in the thickness of the condylar cartilage whereas, only at 4 weeks was there a significant decrease in the bone volume fraction and trabecular thickness of the subchondral bone. Gene expression analysis showed that altered functional loading for 4 weeks caused a significant reduction in the expression of SRY-box containing gene 9 (Sox9), Collagen type X (Col X), Indian hedgehog (lhh), Collagen type II (Col II) and Vascular endothelial growth factor (Vegf) and altered loading for 6 weeks caused a significant decrease in the expression of Sox9, Col II, Vegf and Receptor activator of NF-κB ligand (Rankl) compared to the normal loading group. Conclusion Altered functional TMJ loading in mice for 2–6 weeks leads to a loss of the condylar cartilage and a transient loss in the density of the mandibular condylar subchondral bone. PMID:18789726

  20. Realistic loading conditions for upper body bending.

    PubMed

    Rohlmann, A; Zander, T; Rao, M; Bergmann, G

    2009-05-11

    Different modes of load applications are used to simulate flexion and extension of the upper body. It is not clear which loading modes deliver realistic results and allow the comparison of different studies. In a numerical study, a validated finite element model of the lumbar spine, ranging from the vertebra L1 to the disc L5-S1 was employed. Each of six different loading modes was studied for simulating flexion and extension, including pure moments, an eccentric axial force, using a wedged fixture, and applying upper body weight plus follower load plus muscle forces. Intersegmental rotations, intradiscal pressures and facet joint contact forces were calculated. Where possible, results were compared to data measured in vivo. The results of the loading modes studied show a large variance for some values. Outcome measures such as flexion angle and intradiscal pressure differed at a segment by up to 44% and 88%, respectively, related to their maximum values. Intradiscal pressure is mainly determined by the magnitude of the applied compressive force. For flexion maximum contact forces between 0 and 69 N are predicted in each facet joint for different loading modes. For both flexion and extension, applying upper body weight plus follower load plus muscle forces as well as a follower load together with a bending moment delivers results which agreed well with in vivo data from the literature. Choosing an adequate loading mode is important in spine biomechanics when realistic results are required for intersegmental rotations, intradiscal pressure and facet joint contact forces. Only then will results of different studies be comparable.

  1. FDG uptake in cervical facet subchondral cysts demonstrated by PET/CT.

    PubMed

    Lin, Eugene; Sicuro, Paul

    2008-04-01

    F-18 fluorodeoxyglucose (FDG) uptake in facet joints related to degenerative disease has been previously described. However, FDG uptake in subchondral cysts is the subject of this report. We describe 2 cases of intense focal FDG uptake in subchondral cysts in the cervical facets seen on positron emission tomography/computed tomography (PET/CT) exams. The location of these cysts immediately adjacent to the facet joints and the presence of associated facet joint degenerative changes are helpful in distinguishing this uptake from metastatic disease or other bone lesions.

  2. Improved dynamic model of the human knee joint and its response to impact loading on the lower leg.

    PubMed

    Engin, A E; Tümer, S T

    1993-05-01

    Almost a decade ago, three-dimensional formulation for the dynamic modeling of an articulating human joint was introduced. Two-dimensional version of this formulation was subsequently applied to the knee joint. However, because of the iterative nature of the solution technique, this model cannot handle impact conditions. In this paper, alternative solution methods are introduced which enable investigation of the response of the human knee to impact loading on the lower leg via an anatomically based model. In addition, the classical impact theory is applied to the same model and a closed-form solution is obtained. The shortcomings of the classical impact theory as applied to the impact problem of the knee joint are delineated.

  3. Effects of loading methods on microstructure of diffusion welded joint of AZ31B/Cu with Ni interlayer

    NASA Astrophysics Data System (ADS)

    Du, S. M.; Zhang, Y. Q.; Du, C.; Hu, J.

    2017-02-01

    Diffusion brazing was carried out to weld AZ31B magnesium alloy and copper with Ni foil interlayer under different loading methods that are divided into intermittent gradient pressure, gradient pressure and constant pressure. The microstructure and element diffusion of welded joint were analyzed by SEM and EDS. The results show that the AZ31B/Cu can achieve good bonded joint composed of brazing seam zone and magnesium substrate grain boundary penetration zone at 500 °C for 20 min. The loading methods have great influence on the thickness of brazing seam zone, microstructure and α-Mg grain size of the welded joint. At intermittent gradient pressure, the brazing seam zone reaches the biggest width of 0.18 mm, and the microstructure of brazing seam zone is composed of Cu11Mg10Ni9, (α-Mg+Mg2Cu+Mg2Ni)eutectic structure and α-Mg. Under gradient pressure, the width of brazing seam zone reduces, and the microstructure of brazing seam zone is mainly dominated by (α-Mg+Mg2Cu+Mg2Ni)eutectic structure and Cu11Mg10Ni9 compounds closed magnesium matrix. When using constant pressure, the microstructure of joint is similar to that under intermittent gradient pressure, the brazing seam zone reaches the smallest width of 0.11 mm, and the size of α-Mg grains reduces.

  4. Moderate loading of the human osteoarthritic knee joint leads to lowering of intraarticular cartilage oligomeric matrix protein.

    PubMed

    Helmark, Ida C; Petersen, Marie C H; Christensen, Helle E; Kjaer, Michael; Langberg, Henning

    2012-04-01

    The non-pharmacological treatment of osteoarthritis (OA) includes exercise therapy; however, little is known about the specific effect of exercise on the joint per se. The purpose of the present study was to investigate the direct effects of a load-bearing exercise upon cartilage in a single, human osteoarthritic joint determined by biochemical markers of cartilage turnover and inflammation in the synovial fluid (SF), serum and urine. Eleven subjects with OA of the knee(s), but with no other joint- or inflammatory disorders, volunteered for the study and had samples of blood, urine and synovial fluid drawn both at baseline and following 30-min one-legged knee-extension exercise. Workload: 60% of 1 RM (Repetition Maximum). Determination of cartilage oligomeric matrix protein (COMP), aggrecan, C-terminal collagen II peptide (CTX-II) and interleukin (IL)-6 were performed in synovial fluid (SF), serum and urine. A significant decrease was found in SF concentration of COMP following exercise, whereas aggrecan, CTX-II and IL-6 remained unchanged. No differences in any of the tested markers were found in serum and urine between baseline and post-exercise. Thirty minutes of mechanical loading of a single knee joint in human subjects with knee OA resulted in a reduced COMP concentration in SF.

  5. Determination of hip-joint loading patterns of living and extinct mammals using an inverse Wolff's law approach.

    PubMed

    Christen, Patrik; Ito, Keita; Galis, Frietson; van Rietbergen, Bert

    2015-04-01

    It is well known that bone adapts its microstructure in response to loading. Based on this form-follows-function relationship, we previously developed a reverse approach to derive joint loads from bone microstructure as acquired with micro-computed tomography. Here, we challenge this approach by calculating hip-joint loading patterns for human and dog, two species exhibiting different locomotion, and comparing them to in vivo measurements. As a proof of concept to use the approach also for extinct taxa, we applied it to a cave lion fossil bone. Calculations were in close agreement with in vivo measurements during walking for extant species, showing distinguished patterns for bipedalism and quadrupedalism. The cave lion calculations clearly revealed its quadrupedal locomotion and suggested a more diverse behaviour compared to the dog, which is in agreement with extant felids. This indicates that our novel approach is potentially useful for making inferences about locomotion in living as well as extinct mammals and to study evolutionary joint development.

  6. Evidence of mechanical load redistribution at the knee joint in the elderly when ascending stairs and ramps.

    PubMed

    Karamanidis, Kiros; Arampatzis, Adamantios

    2009-03-01

    This study examined the external joint moments at the lower extremity in all three directions in a group of older and younger adults when ascending stairs and ramps. Twenty-eight older and 16 younger adults ascended a purpose-built staircase and ramp. A motion capture system and a force plate were used to determine the subjects' 3D kinematics and ground reaction forces. Calculation of the leg kinematics and kinetics was done by means of a rigid, three-segment, 3D leg model. Older had lower dorsiflexion and knee flexion moments but higher hip flexion moments than the younger adults, independent of locomotion condition. Concerning the other two planes, older adults showed higher adduction moments at the knee and hip joint, and higher knee internal rotation moments. Furthermore, the elderly showed a more external position of the shank in relation to the thigh at the initiation of the stance phase for the two conditions examined. The higher adduction and internal rotation moments at the knee when combined with the kinematic changes in the transverse plane for the elderly give evidence that older adults redistribute the mechanical load within the load bearing regions of the knee. We concluded that the redistribution in knee joint loading may increase the risk factors for developing knee osteoarthritis in the elderly.

  7. Analysis of bolt-loaded elliptical holes in laminated composite joints

    NASA Astrophysics Data System (ADS)

    Wang, J. T.; Lotts, C. G.; Davis, D. D., Jr.

    1993-02-01

    The feasibility of changing the bolt shape from circular to elliptical in order to increase the joint strength was investigated. An analytical method using a cosine series to represent the bearing stress was derived, and a boundary collocation method was used to determine the unknown coefficients of this cosine series. Stresses at the hole edge predicted by the analytical method agreed very well with finite element solutions. Failure analyses of joints in two different laminates were performed, and each laminate exhibited a different joint failure mode. Results demonstrate that the joint strength of both laminates can be improved substantially by changing the bolt shape to elliptical. The joint that failed in a bearing mode showed a greater strength increase compared to the joint that failed in a shearing mode.

  8. Analysis of bolt-loaded elliptical holes in laminated composite joints

    NASA Technical Reports Server (NTRS)

    Wang, J. T.; Lotts, C. G.; Davis, D. D., Jr.

    1993-01-01

    The feasibility of changing the bolt shape from circular to elliptical in order to increase the joint strength was investigated. An analytical method using a cosine series to represent the bearing stress was derived, and a boundary collocation method was used to determine the unknown coefficients of this cosine series. Stresses at the hole edge predicted by the analytical method agreed very well with finite element solutions. Failure analyses of joints in two different laminates were performed, and each laminate exhibited a different joint failure mode. Results demonstrate that the joint strength of both laminates can be improved substantially by changing the bolt shape to elliptical. The joint that failed in a bearing mode showed a greater strength increase compared to the joint that failed in a shearing mode.

  9. Wnt signalling controls the response to mechanical loading during zebrafish joint development

    PubMed Central

    Brunt, Lucy H.; Begg, Katie; Kague, Erika; Cross, Stephen

    2017-01-01

    Joint morphogenesis requires mechanical activity during development. Loss of mechanical strain causes abnormal joint development, which can impact long-term joint health. Although cell orientation and proliferation are known to shape the joint, dynamic imaging of developing joints in vivo has not been possible in other species. Using genetic labelling techniques in zebrafish we were able, for the first time, to dynamically track cell behaviours in intact moving joints. We identify that proliferation and migration, which contribute to joint morphogenesis, are mechanically controlled and are significantly reduced in immobilised larvae. By comparison with strain maps of the developing skeleton, we identify canonical Wnt signalling as a candidate for transducing mechanical forces into joint cell behaviours. We show that, in the jaw, Wnt signalling is reduced specifically in regions of high strain in response to loss of muscle activity. By pharmacological manipulation of canonical Wnt signalling, we demonstrate that Wnt acts downstream of mechanical activity and is required for joint patterning and chondrocyte maturation. Wnt16, which is also downstream of muscle activity, controls proliferation and migration, but plays no role in chondrocyte intercalation. PMID:28684625

  10. SLAC All Access: FACET

    ScienceCinema

    Hogan, Mark

    2016-07-12

    SLAC's Facility for Advanced Accelerator Experimental Tests, or FACET, is a test-bed where researchers are developing the technologies required for particle accelerators of the future. Scientists from all over the world come to explore ways of improving the power and efficiency of the particle accelerators used in basic research, medicine, industry and other areas important to society. In this video, Mark Hogan, head of SLAC's Advanced Accelerator Research Department, offers a glimpse into FACET, which uses part of SLAC's historic two-mile-long linear accelerator.

  11. Shear Performance of Horizontal Joints in Short Precast Concrete Columns with Sleeve Grouted Connections under Cyclic Loading.

    PubMed

    Feng, Bo; Xiong, Feng; Liu, Bingyu; Chen, Jiang; Zhang, Yiping

    2016-01-01

    In this study, two short precast concrete columns and two cast-in-situ concrete columns were tested under cyclic loads. It was shown that the sleeve grouted connection was equivalent to the cast-in-situ connections for short columns when the axial compression ratio was 0.6. In order to determine the influence of the axial compression ratio and the shear-span ratio on the shear capacity of the horizontal joint, a FE model was established and verified. The analysis showed that the axial compression ratio is advantageous to the joint and the shear capacity of the horizontal joint increases with increase of the shear-span ratio. Based on the results, the methods used to estimate the shear capacity of horizontal joints in the Chinese Specification and the Japanese Guidelines are discussed and it was found that both overestimated the shear capacity of the horizontal joint. In addition, the Chinese Specification failed to consider the influence of the shear-span ratio.

  12. Shear Performance of Horizontal Joints in Short Precast Concrete Columns with Sleeve Grouted Connections under Cyclic Loading

    PubMed Central

    Liu, Bingyu; Chen, Jiang; Zhang, Yiping

    2016-01-01

    In this study, two short precast concrete columns and two cast-in-situ concrete columns were tested under cyclic loads. It was shown that the sleeve grouted connection was equivalent to the cast-in-situ connections for short columns when the axial compression ratio was 0.6. In order to determine the influence of the axial compression ratio and the shear-span ratio on the shear capacity of the horizontal joint, a FE model was established and verified. The analysis showed that the axial compression ratio is advantageous to the joint and the shear capacity of the horizontal joint increases with increase of the shear-span ratio. Based on the results, the methods used to estimate the shear capacity of horizontal joints in the Chinese Specification and the Japanese Guidelines are discussed and it was found that both overestimated the shear capacity of the horizontal joint. In addition, the Chinese Specification failed to consider the influence of the shear-span ratio. PMID:27861493

  13. The Effect of Backpack Load Carriage on the Kinetics and Kinematics of Ankle and Knee Joints During Uphill Walking.

    PubMed

    Lee, Jinkyu; Yoon, Yong-Jin; Shin, Choongsoo S

    2017-05-22

    The purpose of this study was to investigate the effect of load carriage on the kinematics and kinetics of the ankle and knee joints during uphill walking, including joint work, range of motion (ROM), and stance time. Fourteen males walked at a self-selected speed on an uphill (15°) slope wearing military boots and carrying a rifle in hand without a backpack (control condition) and with a backpack. The results showed that the stance time significantly decreased with backpack carriage (p<.05). The mediolateral impulse significantly increased with backpack carriage (p<.05). In the ankle joints, the inversion-eversion, and dorsi-plantar flexion ROM in the ankle joints increased with backpack carriage (p<.05). The greater dorsi-plantar flexion ROM with backpack carriage suggested one strategy for obtaining high plantar flexor power during uphill walking. The result of the increased mediolateral impulse and inversion-eversion ROM in the ankle joints indicated an increase in body instability caused by an elevated center of mass with backpack carriage during uphill walking. The decreased stance time indicated that an increase in walking speed could be a compensatory mechanism for reducing the instability of the body during uphill walking while carrying a heavy backpack.

  14. Are the Kinematics of the Knee Joint Altered during the Loading Response Phase of Gait in Individuals with Concurrent Knee Osteoarthritis and Complaints of Joint Instability? A Dynamic Stereo X-ray Study

    PubMed Central

    Farrokhi, Shawn; Tashman, Scott; Gil, Alexandra B.; Klatt, Brian A.; Fitzgerald, G. Kelley

    2011-01-01

    Background Joint instability has been suggested as a risk factor for knee osteoarthritis and a cause of significant functional declines in those with symptomatic disease. However, the relationship between altered knee joint mechanics and self-reports of instability in individuals with knee osteoarthritis remains unclear. Methods Fourteen subjects with knee osteoarthritis and complaints of joint instability and 12 control volunteers with no history of knee disease were recruited for this study. Dynamic stereo X-ray technology was used to assess the three-dimensional kinematics of the knee joint during the loading response phase of gait. Findings Individuals with concurrent knee osteoarthritis and joint instability demonstrated significantly reduced flexion and internal/external rotation knee motion excursions during the loading response phase of gait (P < 0.01), while the total abduction/adduction range of motion was increased (P < 0.05). In addition, the coronal and transverse plane alignment of the knee joint at initial contact was significantly different (P < 0.05) for individuals with concurrent knee osteoarthritis and joint instability. However, the anteroposterior and mediolateral tibiofemoral joint positions at initial contact and the corresponding total joint translations were similar between groups during the loading phase of gait. Interpretations The rotational patterns of tibiofemoral joint motion and joint alignments reported for individuals with concurrent knee osteoarthritis and joint instability are consistent with those previously established for individuals with knee osteoarthritis. Furthermore, the findings of similar translatory tibiofemoral motion between groups suggest that self-reports of episodic joint instability in individuals with knee osteoarthritis may not necessarily be associated with adaptive alterations in joint arthrokinematics. PMID:22071429

  15. Faceted solar energy collectors

    NASA Technical Reports Server (NTRS)

    Segna, D. R.

    1976-01-01

    Two concepts enhance efficiency and flexibility of solar collectors: faceting collector surface and adding coloring agent to working fluid. Collector can be placed on existing structures and oriented to take advantage of position of sun. By adding coloring agent to working fluid, total absorbance can be increased and altered if required.

  16. Facets of Subjectification

    ERIC Educational Resources Information Center

    Visconti, Jacqueline

    2013-01-01

    Subjectification, as the diachronic facet of subjectivity, has raised in the last two decades a number of interesting questions in grammaticalization and semantic change theory. In this paper I shall reflect on the nature and construal of subjectification, focusing on the question, formulated by Traugott (2010a, p. 58), "whether it is possible to…

  17. Facets of Subjectification

    ERIC Educational Resources Information Center

    Visconti, Jacqueline

    2013-01-01

    Subjectification, as the diachronic facet of subjectivity, has raised in the last two decades a number of interesting questions in grammaticalization and semantic change theory. In this paper I shall reflect on the nature and construal of subjectification, focusing on the question, formulated by Traugott (2010a, p. 58), "whether it is possible to…

  18. Beam Diagnostics for FACET

    SciTech Connect

    Li, S.Z.; Hogan, M.J.; /SLAC

    2011-08-19

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to about 20 {micro}m long and focussed to about 10 {micro}m wide. Characterization of the beam-plasma interaction requires complete knowledge of the incoming beam parameters on a pulse-to-pulse basis. FACET diagnostics include Beam Position Monitors, Toroidal current monitors, X-ray and Cerenkov based energy spectrometers, optical transition radiation (OTR) profile monitors and coherent transition radiation (CTR) bunch length measurement systems. The compliment of beam diagnostics and their expected performance are reviewed. Beam diagnostic measurements not only provide valuable insights to the running and tuning of the accelerator but also are crucial for the PWFA experiments in particular. Beam diagnostic devices are being set up at FACET and will be ready for beam commissioning in summer 2011.

  19. Three-dimensional dynamic analysis of knee joint during gait in medial knee osteoarthritis using loading axis of knee.

    PubMed

    Nishino, Katsutoshi; Omori, Go; Koga, Yoshio; Kobayashi, Koichi; Sakamoto, Makoto; Tanabe, Yuji; Tanaka, Masaei; Arakawa, Masaaki

    2015-07-01

    We recently developed a new method for three-dimensional evaluation of mechanical factors affecting knee joint in order to help identify factors that contribute to the progression of knee osteoarthritis (KOA). This study aimed to verify the clinical validity of our method by evaluating knee joint dynamics during gait. Subjects were 41 individuals (14 normal knees; 8 mild KOAs; 19 severe KOAs). The positions of skin markers attached to the body were captured during gait, and bi-planar X-ray images of the lower extremities were obtained in standing position. The positional relationship between the markers and femorotibial bones was determined from the X-ray images. Combining this relationship with gait capture allowed for the estimation of relative movement between femorotibial bones. We also calculated the point of intersection of loading axis of knee on the tibial proximal surface (LAK point) to analyze knee joint dynamics. Knee flexion range in subjects with severe KOA during gait was significantly smaller than that in those with normal knees (p=0.011), and knee adduction in those with severe KOA was significantly larger than in those with mild KOA (p<0.000). LAK point was locally loaded on the medial compartment of the tibial surface as KOA progressed, with LAK point of subjects with severe KOA rapidly shifting medially during loading response. Local loading and medial shear force were applied to the tibial surface during stance phase as medial KOA progressed. Our findings suggest that our method is useful for the quantitative evaluation of mechanical factors that affect KOA progression.

  20. The effect of external ankle support on knee and ankle joint movement and loading in netball players.

    PubMed

    Vanwanseele, Benedicte; Stuelcken, Max; Greene, Andrew; Smith, Richard

    2014-09-01

    External ankle support has been successfully used to prevent ankle sprains. However, some recent studies have indicated that reducing ankle range of motion can place larger loads on the knee. The aim of this study was to investigate the effect of external ankle support (braces and high-top shoes) on the ankle and knee joint loading during a netball specific landing task. A repeated measure design. High performance netball players with no previously diagnosed severe ankle or knee injury (n=11) were recruited from NSW Institute of Sport netball programme. The kinematic and kinetic data were collected simultaneously using a 3-D Motion Analysis System and one Kistler force plate to measure ground reaction forces. Players performed a single leg landing whilst receiving a pass while wearing a standard netball shoe, the same shoe with a lace-up brace and a high-top shoe. Only the brace condition significantly reduced the ankle range of motion in the frontal plane (in/eversion) by 3.95 ± 3.74 degrees compared to the standard condition. No changes were found for the knee joint loading in the brace condition. The high-top shoes acted to increase the peak knee internal rotation moment by 15%. Both the brace and high-top conditions brought about increases in the peak ankle plantar flexion moment during the landing phase. Lace-up braces can be used by netball players to restrict ankle range of motion during a single leg landing while receiving a pass without increasing the load on the knee joint. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Individuals with Isolated Patellofemoral Joint Osteoarthritis Exhibit Higher Mechanical Loading at the Knee during the Second Half of the Gait Cycle

    PubMed Central

    Teng, Hsiang-Ling; MacLeod, Toran D.; Kumar, Deepak; Link, Thomas M; Majumdar, Sharmila; Souza, Richard B

    2015-01-01

    Background Patellofemoral joint osteoarthritis is a highly prevalent condition and an important source of pain and disability. Nonetheless, biomechanical risk factors associated with patellofemoral joint osteoarthritis remain unclear. The purpose of this study was to compare biomechanical factors that are associated with patellofemoral joint loading during walking between individuals with isolated patellofemoral joint osteoarthritis and no osteoarthritis. Methods MR images of the knee were obtained using a 3D fast-spin echo sequence to identify patellofemoral joint cartilage lesions (patellofemoral joint osteoarthritis group). Thirty-five subjects with isolated patellofemoral joint osteoarthritis (29 females) and 35 control subjects (21 females) walked at a self-selected speed and as fast as possible. Peak knee flexion moment, flexion moment impulse and peak patellofemoral joint stress during the first and second halves of the stance phase were compared between groups. Findings When compared to the controls, individuals with patellofemoral joint osteoarthritis demonstrated significantly higher peak knee flexion moment (P =.03, Eta2 =.07), higher knee flexion moment impulse (P =.03, Eta2 =.07) and higher peak patellofemoral joint stress (P =.01, Eta2 =.10) during the second half of the stance phase. No significant group difference was observed during the first half of the stance phase. Interpretation Findings of this study suggest that increased mechanical loading (i.e. knee flexion moment, impulse and patellofemoral joint stress) during the second half of the stance phase is associated with patellofemoral joint osteoarthritis. Prevention and rehabilitation programs for patellofemoral joint osteoarthritis may focus on reducing the loading on the patellofemoral joint, specifically during late stance. PMID:25726158

  2. Long-term repetitive mechanical loading of the knee joint by in vivo muscle stimulation accelerates cartilage degeneration and increases chondrocyte death in a rabbit model.

    PubMed

    Horisberger, Monika; Fortuna, Rafael; Valderrabano, Victor; Herzog, Walter

    2013-06-01

    Excessive chronic loading is thought to be one factor responsible for the onset of osteoarthritis. For example, studies using treadmill running have shown an increased risk for osteoarthritis, thereby suggesting that muscle-induced joint loading may play a role in osteoarthritis onset and progression. However, in these studies, muscle-induced loading was not carefully quantified. Here, we present a model of controlled muscular loading which allows for the accurate quantification of joint loading. The aim of this study was to evaluate the effects of long-term, cyclic, isometric and dynamic, muscle-induced joint loading of physiologic magnitude but excessive intensity on cartilage integrity and cell viability in the rabbit knee. 24 rabbits were divided into an (i) eccentric, (ii) concentric, or (iii) isometric knee extensor contraction group (50 min of cyclic, submaximal stimulation 3 times/week for four weeks=19,500 cycles) controlled by the stimulation of a femoral nerve cuff electrode on the right hind limb. The contralateral knee was used as a non-loaded control. The knee articular cartilages were analysed by confocal microscopy for chondrocyte death, and histologically for Mankin Score, cartilage thickness and cell density. All loaded knees had significantly increased cell death rates and Mankin Scores compared to the non-loaded joints. Cartilage thicknesses did not systematically differ between loaded and control joints. Chondrocyte death and Mankin Scores were significantly increased in the loaded joints, thereby linking muscular exercise of physiologic magnitude but excessive intensity to cartilage degeneration and cell death in the rabbit knee. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. [Modelling of the knee joint loading conditions in the view of mechanics].

    PubMed

    Pustovoĭt, K B; Karpins'kyĭ, M Iu

    2013-02-01

    The results of mathematic modelling of work of femoropatellar joint in normal conditions and in the presence of dysplastic deformity were adduced. There was established, that a knee joint (KJ) by its external appearance and function constitutes a classic cam mechanism. Biomechanical scheme of interaction between the femoral bone processus and patella was elaborated. In accordance to scheme of cam mechanism its experimental roentgenometric investigations were performed. According to statistical analysis performed, in conditions of dysplasia in femoropatellar joint the changes in the KJ occur, which may cause its blockade; the patella position in the KJ depends on peculiarities of anatomical structure of the femoral bone processuses.

  4. Experimental and numerical investigation of energy dissipation in elastomeric rotational joint under harmonic loading

    NASA Astrophysics Data System (ADS)

    Jrad, Hanen; Dion, Jean Luc; Renaud, Franck; Tawfiq, Imad; Haddar, Mohamed

    2017-05-01

    This paper focuses on energy losses caused by inner damping and friction in an elastomeric rotational joint. A description of the design of a new experimental device intended to characterize dynamic stiffness in rotational elastomeric joint is presented. An original method based on Lagrange's equations, which allows accurately measuring forces and torques only with accelerometers, is proposed in order to identify dissipated energy in the rotational elastomeric joint. A rheological model developed taking into account dependence of the torque and the angular displacement (rotation). Experimental results and simulations used to quantify the dissipated energy in order to evaluate the damping ratio are presented and discussed.

  5. Experimental and numerical investigation of energy dissipation in elastomeric rotational joint under harmonic loading

    NASA Astrophysics Data System (ADS)

    Jrad, Hanen; Dion, Jean Luc; Renaud, Franck; Tawfiq, Imad; Haddar, Mohamed

    2016-10-01

    This paper focuses on energy losses caused by inner damping and friction in an elastomeric rotational joint. A description of the design of a new experimental device intended to characterize dynamic stiffness in rotational elastomeric joint is presented. An original method based on Lagrange's equations, which allows accurately measuring forces and torques only with accelerometers, is proposed in order to identify dissipated energy in the rotational elastomeric joint. A rheological model developed taking into account dependence of the torque and the angular displacement (rotation). Experimental results and simulations used to quantify the dissipated energy in order to evaluate the damping ratio are presented and discussed.

  6. Craniovertebral Junction Instability: A Review of Facts about Facets

    PubMed Central

    2015-01-01

    Craniovertebral junction surgery involves an appropriate philosophical, biomechanical and anatomical understanding apart from high degree of technical skill and ability of controlling venous and arterial bleeding. The author presents his 30-year experience with treating complex craniovertebral junction instability related surgical issues. The facets of atlas and axis form the primary site of movements at the craniovertebral junction. All craniovertebral junction instability is essentially localized to the atlantoaxial facet joint. Direct manipulation and fixation of the facets forms the basis of treatment for instability. PMID:26240728

  7. Facet-selective photodeposition of gold nanoparticles on faceted ZnO crystals for visible light photocatalysis.

    PubMed

    Wang, Xuewen; Wang, Wuyou; Miao, Yuanquan; Feng, Gang; Zhang, Rongbin

    2016-08-01

    Hexagonal prism-like ZnO crystals dominated with polar facets were synthesized using a hydrothermal method. The Gold (Au) nanoparticles were selectively photodeposited on the polar surfaces of faceted ZnO crystals as a result of anisotropic photocatalytic activities of the polar and nonpolar facets. The size of Au nanoparticles uniformly dispersed on the polar facets increased with increasing Au-loading amount. These Au-loaded ZnO crystals showed an additional visible light absorption band from 400nm to 800nm. The 0.1wt% Au-loaded ZnO crystals with visible light absorption peak at approximately 690nm exhibited the highest photocatalytic activity under visible light irradiation.

  8. Comparison of joint space versus task force load distribution optimization for a multiarm manipulator system

    NASA Technical Reports Server (NTRS)

    Soloway, Donald I.; Alberts, Thomas E.

    1989-01-01

    It is often proposed that the redundancy in choosing a force distribution for multiple arms grasping a single object should be handled by minimizing a quadratic performance index. The performance index may be formulated in terms of joint torques or in terms of the Cartesian space force/torque applied to the body by the grippers. The former seeks to minimize power consumption while the latter minimizes body stresses. Because the cost functions are related to each other by a joint angle dependent transformation on the weight matrix, it might be argued that either method tends to reduce power consumption, but clearly the joint space minimization is optimal. A comparison of these two options is presented with consideration given to computational cost and power consumption. Simulation results using a two arm robot system are presented to show the savings realized by employing the joint space optimization. These savings are offset by additional complexity, computation time and in some cases processor power consumption.

  9. Efficacy of a trunk orthosis with joints providing resistive force on low back load during level walking in elderly persons

    PubMed Central

    Katsuhira, Junji; Matsudaira, Ko; Oka, Hiroyuki; Iijima, Shinno; Ito, Akihiro; Yasui, Tadashi; Yozu, Arito

    2016-01-01

    Purpose The effects of lumbosacral and spinal orthoses on low back pain and gait are not exactly clear. We previously developed a trunk orthosis with joints providing resistive force on low back load to decrease such load, and confirmed its positive effects during level walking in healthy young adults. Therefore, we aimed to determine the efficacy of this trunk orthosis during level walking in healthy elderly subjects. Methods Fifteen community-dwelling elderly subjects performed level walking at a self-selected speed without an orthosis, with our orthosis, and with a lumbosacral orthosis. Kinematic and kinetic data were recorded using a three-dimensional motion analysis system, and erector spinae activity was recorded by electromyography. Results When comparing the three conditions, our orthosis showed the following effects: it decreased the peak extension moment, increased the peak flexion moment, decreased the lateral bending angle, increased the peak thoracic extension angle, and had significantly lower erector spinae activity and significantly larger peak pelvic forward tilt angles. Conclusion Our orthosis with joints providing resistive force decreased low back load and modified trunk and pelvis alignments during level walking in healthy elderly people. PMID:27877028

  10. Increased delivery stride length places greater loads on the ankle joint in elite male cricket fast bowlers.

    PubMed

    Spratford, Wayne; Hicks, Amy

    2014-01-01

    The purpose of this study was to investigate the effect stride length has on ankle biomechanics of the leading leg with reference to the potential risk of injury in cricket fast bowlers. Ankle joint kinematic and kinetic data were collected from 51 male fast bowlers during the stance phase of the final delivery stride. The bowling cohort comprised national under-19, first class and international-level athletes. Bowlers were placed into either Short, Average or Long groups based on final stride length, allowing statistical differences to be measured. A multivariate analysis of variance with a Bonferroni post-hoc correction (α = 0.05) revealed significant differences between peak plantarflexion angles (Short-Long P = 0.005, Average and Long P = 0.04) and negative joint work (Average-Long P = 0.026). This study highlighted that during fast bowling the ankle joint of the leading leg experiences high forces under wide ranges of movement. As stride length increases, greater amounts of negative work and plantarflexion are experienced. These increases place greater loads on the ankle joint and move the foot into positions that make it more susceptible to injuries such as posterior impingement syndrome.

  11. Influence of Interface Gap on the Stress Behaviour of Smart Single Lap Joints Under Time Harmonic Load

    NASA Astrophysics Data System (ADS)

    Ivanova, Jordanka; Valeva, Varbinka

    2017-06-01

    Adhesive joints are frequently used in different composite structures due to their improved mechanical performance and better understanding of the failure mechanics. The application of such structures can be seen in aerospace and high technology components. The authors developed and applied modified shear lag analysis to investigate the hygrothermalpiezoelectric response of a smart single lap joint at environmental conditions (with/without an interface gap along the overlap zone) and under dynamic time harmonic mechanical and electric loads. The main key is the study of the appearance of possible delamination along the interface. As illustrative examples, the analytical closed form solution of the structure shear and the axial stresses response, as well as the interface debond length, including influence of mechanical, piezoelectric, thermal characteristics and frequencies is performed and discussed. All results are presented in figures. The comparison of the shear stress and electric fields for both cases of overlap zone (continuous or with a gap) is also shown in figures and discussed.

  12. A hip joint simulator study using simplified loading and motion cycles generating physiological wear paths and rates.

    PubMed

    Barbour, P S; Stone, M H; Fisher, J

    1999-01-01

    In some designs of hip joint simulator the cost of building a highly complex machine has been offset with the requirement for a large number of test stations. The application of the wear results generated by these machines depends on their ability to reproduce physiological wear rates and processes. In this study a hip joint simulator has been shown to reproduce physiological wear using only one load vector and two degrees of motion with simplified input cycles. The actual path of points on the femoral head relative to the acetabular cup were calculated and compared for physiological and simplified input cycles. The in vitro wear rates were found to be highly dependent on the shape of these paths and similarities could be drawn between the shape of the physiological paths and the simplified elliptical paths.

  13. Bearing-bypass loading in composite joints - Testing and stress analysis

    NASA Technical Reports Server (NTRS)

    Crews, John H., Jr.; Naik, Rajiv A.

    1989-01-01

    A combined experimental and analytical study of bearing and bypass loading on single-fastener specimens of a 16-ply, quasi-isotropic T300/5208 graphite/epoxy laminate with a centrally located hole is reported. The specimens were loaded in either tension or compression, and onset damage, ultimate strengths, and corresponding failure modes were determined. The tension data showed the expected linear interaction for combined bearing-bypass loading with damage developing in the net-section tension mode. However, the bearing-onset strengths showed an unexpected interaction of the bearing and compressive bypass loads in which the latter reduced the bearing-onset strength. A linear finite element analysis showed that bearing-bypass loading had a marked influence on the bolt-hole contact which in turn had a significant effect on local stresses.

  14. Bearing-bypass loading in composite joints - Testing and stress analysis

    NASA Technical Reports Server (NTRS)

    Crews, John H., Jr.; Naik, Rajiv A.

    1989-01-01

    A combined experimental and analytical study of bearing and bypass loading on single-fastener specimens of a 16-ply, quasi-isotropic T300/5208 graphite/epoxy laminate with a centrally located hole is reported. The specimens were loaded in either tension or compression, and onset damage, ultimate strengths, and corresponding failure modes were determined. The tension data showed the expected linear interaction for combined bearing-bypass loading with damage developing in the net-section tension mode. However, the bearing-onset strengths showed an unexpected interaction of the bearing and compressive bypass loads in which the latter reduced the bearing-onset strength. A linear finite element analysis showed that bearing-bypass loading had a marked influence on the bolt-hole contact which in turn had a significant effect on local stresses.

  15. Stress-Strain Analysis of Single-Lap Tensile Loaded Adhesive Joints

    SciTech Connect

    Raos, Pero; Kozak, Drazan; Lucic, Mirjana

    2007-05-17

    Both, experimental investigation and finite element analysis of single-lap adhesive joints subjected to tension have been done to find out an optimal overlap length. As the adherend material aluminum was considered with the two component high-strength engineering adhesive for the bonding of the layers. The thickness of the sheet metal layer was 1,95 mm, while adhesive was 0,15 mm thick. The width of all thin plates was 30 mm, but the overlap length varied as 15, 20, 30, 40 and 60 mm. Real mechanical properties of all materials in the joint have been determined experimentally. Obtained results proved that the overlap length affects directly the joint tensile strength, where an optimum value of overlap length can be defined. Finite element analysis of stress and strain fields could help to determine the moment when the crack initiates at the joint overlap end. In such a manner, complex mechanisms of failure of adhesive joints could be better understood.

  16. Comparison of computed tomography and magnetic resonance imaging in the evaluation of facet tropism and facet arthrosis in degenerative cervical spondylolisthesis.

    PubMed

    Xu, C; Ding, Z H; Xu, Y K

    2014-05-30

    The aim of this study was to determine the reliability of magnetic resonance imaging (MRI) in the assessment of facet tropism and facet arthrosis of spondylolisthesis levels in degenerative cervical spondylolisthesis as compared to computed tomography (CT). The discrepancies in the interpretation of CT and MRI data in the evaluation of facet tropism and arthrosis have given rise to questions regarding the reliability of comparisons of the two techniques. Using a 4-point scale, 3 blinded readers independently graded the severity of facet tropism and facet arthrosis of 79 cervical facet joints on axial T2-weighted and sagittal T1 and T2-weighted turbo spin echo images as well as the corresponding axial CT scans. All results were subjected to the kappa coefficient statistic for strength of agreement. In the assessment of the severity of facet arthrosis, intermethod agreement (weighted κ) between CT scanning with a moderate inter-rater reliability (range κ = 0.43-0.57) and MRI with fair inter-rater reliability (range κ = 0.23-0.38) was 0.76 and 0.43 for the severity of facet tropism and facet arthrosis, respectively. Intra-rater reliability for the severity of facet arthrosis was moderate to substantial for CT and was moderate for MRI scans. Intra-rater reliability for the severity of facet tropism was substantial to very good for CT and substantial for MRI scans. MRI can reliably determine the presence or degree of facet tropism but not facet arthrosis. Therefore, for a comprehensive assessment of cervical facet joint degeneration, both a CT and an MRI scan should be performed.

  17. Knee Joint Loading during Gait in Healthy Controls and Individuals with Knee Osteoarthritis

    PubMed Central

    Kumar, Deepak; Manal, Kurt T.; Rudolph, Katherine S.

    2013-01-01

    Objective People with knee osteoarthritis (OA) are thought to walk with high loads at the knee which are yet to be quantfied using modeling techniques that account for subject specific EMG patterns, kinematics and kinetics. The objective was to estimate medial and lateral loading for people with knee OA and controls using an approach that is sensitive to subject specific muscle activation patterns. Methods 16 OA and 12 control (C) subjects walked while kinematic, kinetic and EMG data were collected. Muscle forces were calculated using an EMG-Driven model and loading was calculated by balancing the external moments with internal muscle and contact forces Results OA subjects walked slower and had greater laxity, static and dynamic varus alignment, less flexion and greater knee adduction moment (KAM). Loading (normalized to body weight) was no different between the groups but OA subjects had greater absolute medial load than controls and maintained a greater %total load on the medial compartment. These patterns were associated with body mass, sagittal and frontal plane moments, static alignment and close to signficance for dynamic alignment. Lateral compartment unloading during mid-late stance was observed in 50% of OA subjects. Conclusions Loading for control subjects was similar to data from instrumented prostheses. Knee OA subjects had high medial contact loads in early stance and half of the OA cohort demonstared lateral compartment lift-off. Results suggest that interventions aimed at reducing body weight and dynamic malalignment might be effective in reducing medial compartment loading and establishing normal medio-lateral load sharing patterns. PMID:23182814

  18. The Evolution of Male-Biased Dispersal under the Joint Selective Forces of Inbreeding Load and Demographic and Environmental Stochasticity.

    PubMed

    Henry, Roslyn C; Coulon, Aurélie; Travis, Justin M J

    2016-10-01

    Sex-biased natal dispersal is widespread, and its significance remains a central question in evolutionary biology. However, theory so far fails to predict some of the most common patterns found in nature. To address this, we present novel results from an individual-based model investigating the joint roles of inbreeding load, demographic stochasticity, environmental stochasticity, and dispersal costs for the evolution of sex-biased dispersal. Most strikingly, we found that male-biased natal dispersal evolved in polygynous systems as a result of the interplay between inbreeding avoidance and stochasticity, whereas previous theory, in contrast to empirical observations, predicted male philopatry and female-biased natal dispersal under inbreeding load alone. Furthermore, the direction of the bias varied according to the nature of stochasticity. Our results therefore provide a unification of previous theory, yielding a much better qualitative match with empirical observations of male-biased dispersal in mate defense mating systems.

  19. Investigation of impact loading rate effects on the ligamentous cervical spinal load-partitioning using finite element model of functional spinal unit C2-C3.

    PubMed

    Mustafy, Tanvir; El-Rich, Marwan; Mesfar, Wissal; Moglo, Kodjo

    2014-09-22

    The cervical spine functions as a complex mechanism that responds to sudden loading in a unique manner, due to intricate structural features and kinematics. The spinal load-sharing under pure compression and sagittal flexion/extension at two different impact rates were compared using a bio-fidelic finite element (FE) model of the ligamentous cervical functional spinal unit (FSU) C2-C3. This model was developed using a comprehensive and realistic geometry of spinal components and material laws that include strain rate dependency, bone fracture, and ligament failure. The range of motion, contact pressure in facet joints, failure forces in ligaments were compared to experimental findings. The model demonstrated that resistance of spinal components to impact load is dependent on loading rate and direction. For the loads applied, stress increased with loading rate in all spinal components, and was concentrated in the outer intervertebral disc (IVD), regions of ligaments to bone attachment, and in the cancellous bone of the facet joints. The highest stress in ligaments was found in capsular ligament (CL) in all cases. Intradiscal pressure (IDP) in the nucleus was affected by loading rate change. It increased under compression/flexion but decreased under extension. Contact pressure in the facet joints showed less variation under compression, but increased significantly under flexion/extension particularly under extension. Cancellous bone of the facet joints region was the only component fractured and fracture occurred under extension at both rates. The cervical ligaments were the primary load-bearing component followed by the IVD, endplates and cancellous bone; however, the latter was the most vulnerable to extension as it fractured at low energy impact.

  20. Load transfer in the stiffener-to-skin joints of a pressurized fuselage

    NASA Technical Reports Server (NTRS)

    Johnson, Eric R.; Rastogi, Naveen

    1995-01-01

    Structural analyses are developed to determine the linear elastic and the geometrically nonlinear elastic response of an internally pressurized, orthogonally stiffened, composite material cylindrical shell. The configuration is a long circular cylindrical shell stiffened on the inside by a regular arrangement of identical stringers and identical rings. Periodicity permits the analysis of a unit cell model consisting of a portion of the shell wall centered over one stringer-ring joint. The stringer-ring-shell joint is modeled in an idealized manner; the stiffeners are mathematically permitted to pass through one another without contact, but do interact indirectly through their mutual contact with the shell at the joint. Discrete beams models of the stiffeners include a stringer with a symmetrical cross section and a ring with either a symmetrical or an asymmetrical open section. Mathematical formulations presented for the linear response include the effect of transverse shear deformations and the effect of warping of the ring's cross section due to torsion. These effects are important when the ring has an asymmetrical cross section because the loss of symmetry in the problem results in torsion and out-of-plane bending of the ring, and a concomitant rotation of the joint at the stiffener intersection about the circumferential axis. Data from a composite material crown panel typical of a large transport fuselage structure are used for two numerical examples. Although the inclusion of geometric nonlinearity reduces the 'pillowing' of the shell, it is found that bending is localized to a narrow region near the stiffener. Including warping deformation of the ring into the analysis changes the sense of the joint rotation. Transverse shear deformation models result in increased joint flexibility.

  1. Joint loading and proximal tibia subchondral trabecular bone microarchitecture differ with walking gait patterns in end-stage knee osteoarthritis.

    PubMed

    Roberts, B C; Solomon, L B; Mercer, G; Reynolds, K J; Thewlis, D; Perilli, E

    2017-06-20

    To (1) stratify patient subgroups according to their distinct walking gait patterns in end-stage knee osteoarthritis (OA); (2) compare measures of joint loading and proximal tibia subchondral trabecular bone (STB) microarchitecture among these gait subgroups. Twenty-five knee OA patients undergoing total knee arthroplasty (TKA) had pre-operative gait analysis. Following surgery, excised tibial plateaus were micro-CT-scanned and STB microarchitecture analysed in four tibial condylar regions of interest. Peak knee moments were input to k-means cluster analysis, to identify subgroups with homogeneous gait patterns. Joint loading and STB microarchitecture parameters were compared among gait subgroups (Kruskal-Wallis, Bonferroni-corrected Mann-Whitney U tests). Three gait subgroups were revealed: biphasics (n = 7), flexors (n = 9), counter-rotators (n = 9). Peak knee adduction moment (KAM) and KAM impulse were significantly higher (P < 0.05) in biphasics than in flexors and counter-rotators (KAM = -0.65, -0.40 and -0.21 Nm/kg, respectively), suggesting a higher medial-to-lateral tibiofemoral load ratio in biphasics. Interestingly, STB medial-to-lateral bone volume fraction (BV/TV) ratio was also significantly higher (more than double) in biphasics and flexors than in counter-rotators (2.24, 2.00 and 1.00, respectively), whereas in biphasics it was only 10% higher than in flexors and not significantly so. Within the confines of the limited sample size, data suggests that different mechanisms between the biphasic and flexor gait subroups may generate comparable loads upon the tibial plateau and corresponding bony responses, despite significantly lower KAM indices in flexors. Hence, in flexor gait OA patients, conservative treatments designed to reduce KAM, may not be appropriate. Understanding joint loading among walking gait patterns and relationships to bone microarchitecture may aid at identifying/improving management of persons at risk for developing knee

  2. Effects of Microstructure and Loading on Fracture of Sn-3.8Ag-0.7Cu Joints on Cu Substrates with ENIG Surface Finish

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Kumar, P.; Dutta, I.; Sidhu, R.; Renavikar, M.; Mahajan, R.

    2014-12-01

    When dropped, electronic packages often undergo failure by propagation of an interfacial crack in solder joints under a combination of tensile and shear loading. Hence, it is crucial to understand and predict the fracture behavior of solder joints under mixed-mode high-rate loading conditions. In this work, the effects of the loading conditions (strain rate and loading angle) and microstructure [interfacial intermetallic compound (IMC) morphology and solder yield strength] on the mixed-mode fracture toughness of Sn-3.8 wt.%Ag-0.7 wt.%Cu solder joints sandwiched between two Cu substrates with electroless nickel immersion gold (ENIG) metallization have been studied, and compared with the fracture behavior of joints attached to bare Cu. Irrespective of the surface finish, the fracture toughness of the solder joints decreased monotonically with strain rate and mode-mixity, both resulting in increased fracture proportion through the interfacial IMC layer. Furthermore, the proportion of crack propagation through the interfacial IMC layer increased with increase in the thickness and the roughness of the interfacial IMC layer and the yield strength of the solder, resulting in a decrease in the fracture toughness of the joint. However, under most conditions, solder joints with ENIG finish showed higher resistance to fracture than joints attached directly to Cu substrates without ENIG metallization. Based on the experimental observations, a fracture mechanism map is constructed correlating the yield strength of the solder, the morphology and thickness of the interfacial IMC, and the fracture mechanisms as well as the fracture toughness values for different solder joints under mode I loading.

  3. Antibacterial activity of joint fluid in cemented total-knee arthroplasty: an in vivo comparative study of polymethylmethacrylate with and without antibiotic loading.

    PubMed

    Ueng, Steve W N; Hsieh, Pang-Hsin; Shih, Hsin-Nung; Chan, Yi-Shan; Lee, Mel S; Chang, Yuhan

    2012-11-01

    The objective of this study was to evaluate the antibacterial activities of joint fluids of patients undergoing total-knee arthroplasty (TKA). Thirty patients who were scheduled for primary cemented TKA were enrolled in the study. The patients were grouped on the basis of whether the cement was without antibiotic loading (control group) or loaded with oxacillin (oxacillin group) or vancomycin (vancomycin group). Cefazolin was administered to every patient as the perioperative prophylactic antibiotic. Samples of joint fluids were collected from the knee joints at 8, 16, 24, 32, 40, and 48 h after prosthesis implantation. We assessed the bioactivities of the joint fluids against methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The antibiotic contents of the joint fluid samples were further evaluated by using high-performance liquid chromatography. Against MSSA, all joint fluid samples exhibited at least 24 h of bacterial inhibition activity. The oxacillin (43.2 h ± 2 h) and vancomycin (40.8 h ± 1.8 h) groups exhibited significantly longer durations of antibacterial activities than the control group (28 h ± 1.3 h; P < 0.05). However, antibacterial activity against MRSA was observed only in the vancomycin group. In conclusion, cefazolin, which was administered as a prophylactic antibiotic in TKA, exhibited good ability for knee joint penetration and was sufficient to inhibit MSSA during its administration. The use of antibiotic-loaded cement can prolong the antibacterial activity of joint fluid in TKA. Further, vancomycin-loaded cement had antibacterial activity against MRSA superior to that of cement loaded with oxacillin or without antibiotic loading.

  4. Changes in the Structure and Properties of Welded Joints of Low-Alloy Steels, Subjected to Cyclic Loads

    NASA Astrophysics Data System (ADS)

    Kuskov, V. N.; Kovenskiy, I. M.; Kuskov, K. V.

    2016-04-01

    Time-varying loads negatively affect the properties and structure of materials. Structural failures typically occur at loads below the yield point. In this work, fatigue tests of welded joints of low-alloy steels were carried out in an asymmetric cycle at loads of 60 and 80% of the yield strength. The stress ratio was 0.8-0.9. On the basis of the results of the tests, equations linking the number of cycles to failure with test parameters were obtained. Such equations can be used for estimating the residual life of elements both under construction and in operation. It has been found that the failure is not instantaneous. Specimens of steels continue to resist variable loads for 4000 - 26000 cycles to failure, depending on steel grade and the parameters of the test. Under operating conditions, it gives an opportunity to discover the onset of failure and dispose of the defective part or to replace the entire structure. A standard technique was used to measure the microhardness on the fractured specimens. The distance between the nearest indentations was 0.2 mm. The results of the measurements were plotted in graphs of ahardness change characteristic for all steels under study. A microhardness “step” has been discovered in areas with high dislocation density, as evidenced by x-ray diffraction and transmission electron microscopy. An intermediate stage of the investigation is the development of recommendations for determining the moment of failure of welded constructions with a probability of 95%.

  5. The pizzicato knee-joint energy harvester: characterization with biomechanical data and the effect of backpack load

    NASA Astrophysics Data System (ADS)

    Pozzi, Michele; Aung, Min S. H.; Zhu, Meiling; Jones, Richard K.; Goulermas, John Y.

    2012-07-01

    The reduced power requirements of miniaturized electronics offer the opportunity to create devices which rely on energy harvesters for their power supply. In the case of wearable devices, human-based piezoelectric energy harvesting is particularly difficult due to the mismatch between the low frequency of human activities and the high-frequency requirements of piezoelectric transducers. We propose a piezoelectric energy harvester, to be worn on the knee-joint, that relies on the plucking technique to achieve frequency up-conversion. During a plucking action, a piezoelectric bimorph is deflected by a plectrum; when released due to loss of contact, the bimorph is free to vibrate at its resonant frequency, generating electrical energy with the highest efficiency. A prototype, featuring four PZT-5H bimorphs, was built and is here studied in a knee simulator which reproduces the gait of a human subject. Biomechanical data were collected with a marker-based motion capture system while the subject was carrying a selection of backpack loads. The paper focuses on the energy generation of the harvester and how this is affected by the backpack load. By altering the gait, the backpack load has a measurable effect on performance: at the highest load of 24 kg, a minor reduction in energy generation (7%) was observed and the output power is reduced by 10%. Both are so moderate to be practically unimportant. The average power output of the prototype is 2.06 ± 0.3 mW, which can increase significantly with further optimization.

  6. Winching up heavy loads with a compliant arm: a new local joint controller.

    PubMed

    Schneider, Axel; Cruse, Holk; Schmitz, Josef

    2008-05-01

    A closed kinematic chain, like an arm that operates a crank, has a constrained movement space. A meaningful movement of the chain's endpoint is only possible along the free movement directions which are given implicitly by the contour of the object that confines the movement of the chain. Many technical solutions for such a movement task, in particular those used in robotics, use central controllers and force-torque sensors in the arm's wrist or a leg's ankle to construct a coordinate system (task frame formalism) at the local point of contact the axes of which coincide with the free and constrained movement directions. Motivated by examples from biology, we introduce a new control system that solves a constrained movement task. The control system is inspired by the control architecture that is found in stick insects like Carausius morosus. It consists of decentral joint controllers that work on elastic joints (compliant manipulator). The decentral controllers are based on local positive velocity feedback (LPVF). It has been shown earlier that LPVF enables contour following of a limb in a compliant motion task without a central controller. In this paper we extend LPVF in such a way that it is even able to follow a contour if a considerable counter force drags the limb away along the contour in a direction opposite to the desired. The controller extension is based on the measurement of the local mechanical power generated in the elastic joint and is called power-controlled relaxation LPVF. The new control approach has the following advantages. First, it still uses local joint controllers without knowledge of the kinematics. Second, it does not need a force or torque measurement at the end of the limb. In this paper we test power-controlled relaxation LPVF on a crank turning task in which a weight has to be winched up by a two-joint compliant manipulator.

  7. The truss structure of cancellous bone. Morphological basis of the function of load transmission of the synovial joint.

    PubMed

    Wang, Y; Bi, W

    1995-01-01

    The structure of cancellous bone of synovial joints was studied under the scanning electron microscope in 4 young cadavers. It was discovered that in all specimens, the cancellous bone beneath the whole coverage of the articular cartilage had a honeycomb pattern in appearance formed by many arched trabeculae running in different directions, and that the major orientation of the arched trabeculae was toward the articular surface. The arms of one arched trabecula extended in different directions, forming the tops of other arched trabeculae; the direction of the collagen fibers conformed circumferentially with that of the arch, but the collagen fibers at the intermediate part of the common arm of the adjacent arched trabeculae crossed in a woven pattern, passing from one trabecula to another. It enables the whole end of the articular bone to have the capacity of integral deformation. That is the foundation of the character of compliance which is essential to the contact of the articular surfaces changing from incongrouity to total congrouity during normal load transmission. This special type of construction is just like the truss structure in the architectural engineering, and therefore the authors suggest to name it the "Truss Structure" of the cancellous bone. The relationship between integral deformation and the following two factors, compliance and incongrouity of the articular surface provides an explanation that the truss structure of the cancellous bone is the morphological basis of high load-bearing capacity and character of compliance of the synovial joint.

  8. A biologically-inspired multi-joint soft exosuit that can reduce the energy cost of loaded walking.

    PubMed

    Panizzolo, Fausto A; Galiana, Ignacio; Asbeck, Alan T; Siviy, Christopher; Schmidt, Kai; Holt, Kenneth G; Walsh, Conor J

    2016-05-12

    Carrying load alters normal walking, imposes additional stress to the musculoskeletal system, and results in an increase in energy consumption and a consequent earlier onset of fatigue. This phenomenon is largely due to increased work requirements in lower extremity joints, in turn requiring higher muscle activation. The aim of this work was to assess the biomechanical and physiological effects of a multi-joint soft exosuit that applies assistive torques to the biological hip and ankle joints during loaded walking. The exosuit was evaluated under three conditions: powered (EXO_ON), unpowered (EXO_OFF) and unpowered removing the equivalent mass of the device (EXO_OFF_EMR). Seven participants walked on an instrumented split-belt treadmill and carried a load equivalent to 30 % their body mass. We assessed their metabolic cost of walking, kinetics, kinematics, and lower limb muscle activation using a portable gas analysis system, motion capture system, and surface electromyography. Our results showed that the exosuit could deliver controlled forces to a wearer. Net metabolic power in the EXO_ON condition (7.5 ± 0.6 W kg(-1)) was 7.3 ± 5.0 % and 14.2 ± 6.1 % lower than in the EXO_OFF_EMR condition (7.9 ± 0.8 W kg(-1); p = 0.027) and in the EXO_OFF condition (8.5 ± 0.9 W kg(-1); p = 0.005), respectively. The exosuit also reduced the total joint positive biological work (sum of hip, knee and ankle) when comparing the EXO_ON condition (1.06 ± 0.16 J kg(-1)) with respect to the EXO_OFF condition (1.28 ± 0.26 J kg(-1); p = 0.020) and to the EXO_OFF_EMR condition (1.22 ± 0.21 J kg(-1); p = 0.007). The results of the present work demonstrate for the first time that a soft wearable robot can improve walking economy. These findings pave the way for future assistive devices that may enhance or restore gait in other applications.

  9. Posterior Tibial Slope Angle Correlates With Peak Sagittal and Frontal Plane Knee Joint Loading During Robotic Simulations of Athletic Tasks.

    PubMed

    Bates, Nathaniel A; Nesbitt, Rebecca J; Shearn, Jason T; Myer, Gregory D; Hewett, Timothy E

    2016-07-01

    Tibial slope angle is a nonmodifiable risk factor for anterior cruciate ligament (ACL) injury. However, the mechanical role of varying tibial slopes during athletic tasks has yet to be clinically quantified. To examine the influence of posterior tibial slope on knee joint loading during controlled, in vitro simulation of the knee joint articulations during athletic tasks. Descriptive laboratory study. A 6 degree of freedom robotic manipulator positionally maneuvered cadaveric knee joints from 12 unique specimens with varying tibial slopes (range, -7.7° to 7.7°) through drop vertical jump and sidestep cutting tasks that were derived from 3-dimensional in vivo motion recordings. Internal knee joint torques and forces were recorded throughout simulation and were linearly correlated with tibial slope. The mean (±SD) posterior tibial slope angle was 2.2° ± 4.3° in the lateral compartment and 2.3° ± 3.3° in the medial compartment. For simulated drop vertical jumps, lateral compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee adduction (r = 0.60-0.65), flexion (r = 0.64-0.66), lateral (r = 0.57-0.69), and external rotation torques (r = 0.47-0.72) as well as inverse correlations with peak abduction (r = -0.42 to -0.61) and internal rotation torques (r = -0.39 to -0.79). Only frontal plane torques were correlated during sidestep cutting simulations. For simulated drop vertical jumps, medial compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee flexion torque (r = 0.64-0.69) and lateral knee force (r = 0.55-0.74) as well as inverse correlations with peak external torque (r = -0.34 to -0.67) and medial knee force (r = -0.58 to -0.59). These moderate correlations were also present during simulated sidestep cutting. The investigation supported the theory that increased posterior tibial slope would lead to greater magnitude knee joint moments, specifically

  10. Posterior Tibial Slope Angle Correlates With Peak Sagittal and Frontal Plane Knee Joint Loading During Robotic Simulations of Athletic Tasks

    PubMed Central

    Bates, Nathaniel A.; Nesbitt, Rebecca J.; Shearn, Jason T.; Myer, Gregory D.; Hewett, Timothy E.

    2017-01-01

    Background Tibial slope angle is a nonmodifiable risk factor for anterior cruciate ligament (ACL) injury. However, the mechanical role of varying tibial slopes during athletic tasks has yet to be clinically quantified. Purpose To examine the influence of posterior tibial slope on knee joint loading during controlled, in vitro simulation of the knee joint articulations during athletic tasks. Study Design Descriptive laboratory study. Methods A 6 degree of freedom robotic manipulator positionally maneuvered cadaveric knee joints from 12 unique specimens with varying tibial slopes (range, −7.7° to 7.7°) through drop vertical jump and sidestep cutting tasks that were derived from 3-dimensional in vivo motion recordings. Internal knee joint torques and forces were recorded throughout simulation and were linearly correlated with tibial slope. Results The mean (6SD) posterior tibial slope angle was 2.2° ± 4.3° in the lateral compartment and 2.3° ± 3.3° in the medial compartment. For simulated drop vertical jumps, lateral compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee adduction (r = 0.60–0.65), flexion (r = 0.64–0.66), lateral (r = 0.57–0.69), and external rotation torques (r = 0.47–0.72) as well as inverse correlations with peak abduction (r = −0.42 to −0.61) and internal rotation torques (r = −0.39 to −0.79). Only frontal plane torques were correlated during sidestep cutting simulations. For simulated drop vertical jumps, medial compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee flexion torque (r = 0.64–0.69) and lateral knee force (r = 0.55–0.74) as well as inverse correlations with peak external torque (r = −0.34 to 20.67) and medial knee force (r = −0.58 to −0.59). These moderate correlations were also present during simulated sidestep cutting. Conclusion The investigation supported the theory that increased posterior

  11. Less hip joint loading only during running rather than walking in elderly compared to young adults.

    PubMed

    Giarmatzis, Georgios; Jonkers, Ilse; Baggen, Remco; Verschueren, Sabine

    2017-03-01

    Walking and running have been found to increase hip bone mass in postmenopausal women. However, the optimal speed to trigger osteogenesis is still under debate because the exact loading during different speeds is poorly characterized. Moreover, age related differences in gait kinematics/kinetics can potentially result in differences in peak hip loading, making extrapolation of results based on young populations to the elderly misleading. Using integrated 3D motion capture and musculoskeletal modeling, peak hip contact forces (HCFs) were calculated during walking and running from 3 to 9km/h in 14 female young (21.4±1.6years old) and elderly (69.8±3.4years old) participants. Peak HCFs were similar during walking in both groups, whereas elderly loaded their hip less than young during running, through reducing their stride length and hip adduction angle at peak loading. Moreover, hip adduction moment was found to best predict peak HCF during impact in walking and running whereas hip extension and external rotation moment can predict the second peak HCF during walking in the elderly and young group respectively. Comparison between same speeds in walking and running revealed that in contrast to young no additional hip loading is imposed during running in elderly. The present study offers an insight into the differences in hip loading profile in postmenopausal women during walking and running at different speeds. Such information is crucial to medical experts that target site-specific bone loading through exercise in elderly populations in order to prevent hip bone loss.

  12. "In vivo" determination of hip joint separation and the forces generated due to impact loading conditions.

    PubMed

    Dennis, D A; Komistek, R D; Northcut, E J; Ochoa, J A; Ritchie, A

    2001-05-01

    Numerous supporting structures assist in the retention of the femoral head within the acetabulum of the normal hip joint including the capsule, labrum, and ligament of the femoral head (LHF). During total hip arthroplasty (THA), the LHF is often disrupted or degenerative and is surgically removed. In addition, a portion of the remaining supporting structures is transected or resected to facilitate surgical exposure. The present study analyzes the effects of LHF absence and surgical dissection in THA patients. Twenty subjects (5 normal hip joints, 10 nonconstrained THA, and 5 constrained THA) were evaluated using fluoroscopy while performing active hip abduction. All THA subjects were considered clinically successful. Fluoroscopic videos of the normal hips were analyzed using digitization, while those with THA were assessed using a computerized interactive model-fitting technique. The distance between the femoral head and acetabulum was measured to determine if femoral head separation occurred. Error analysis revealed measurements to be accurate within 0.75mm. No separation was observed in normal hips or those subjects implanted with constrained THA, while all 10 (100%) with unconstrained THA demonstrated femoral head separation, averaging 3.3mm (range 1.9-5.2mm). This study has shown that separation of the prosthetic femoral head from the acetabular component can occur. The normal hip joint has surrounding capsuloligamentous structures and a ligament attaching the femoral head to the acetabulum. We hypothesize that these soft tissue supports create a passive, resistant force at the hip, preventing femoral head separation. The absence of these supporting structures after THA may allow increased hip joint forces, which may play a role in premature polyethylene wear or prosthetic loosening.

  13. Experimental Investigation into the Fatigue Life of Hybrid Joints Under Fully Reversed Flexure Loading

    DTIC Science & Technology

    2008-06-01

    between the bolted and clamped tests when operating in force control is that the displacement in the upward direction is significantly increased for...in the tests fell in the range as expected from currently available data. The case of steel failure fell near the curve of the joint detail presented...forming abilities, and low electromagnetic signature characteristics can be exceedingly advantageous in such areas. The U.S. Navy currently has an

  14. Stress analysis method for clearance-fit joints with bearing-bypass loads

    NASA Technical Reports Server (NTRS)

    Naik, R. A.; Crews, J. H., Jr.

    1989-01-01

    A simple direct stress analysis method is proposed for a laminate with a clearance-fit fastener subjected to combined bearing and bypass loads in tension or compression, including bearing and bypass loads on bolt-hole contact and local stresses. The approach uses a linear-elastic finite element analysis with an inverse formulation; conditions along the bolt-hole interface are specified by constraint equations that limit nodal displacements to a circular arc corresponding to the bolt diameter. The application of the method to the analysis of the effects of bearing-bypass loading on bolt-hole contact angles and local stresses, with the plate material properties representing a quasi-isotropic T300/5208 graphite/epoxy laminate, is discussed.

  15. Validation of net joint loads calculated by inverse dynamics in case of complex movements: application to balance recovery movements.

    PubMed

    Robert, T; Chèze, L; Dumas, R; Verriest, J-P

    2007-01-01

    The joint forces and moments driving the motion of a human subject are classically computed by an inverse dynamic calculation. However, even if this process is theoretically simple, many sources of errors may lead to huge inaccuracies in the results. Moreover, a direct comparison with in vivo measured loads or with "gold standard" values from literature is only possible for very specific studies. Therefore, assessing the inaccuracy of inverse dynamic results is not a trivial problem and a simple method is still required. This paper presents a simple method to evaluate both: (1) the consistency of the results obtained by inverse dynamics; (2) the influence of possible modifications in the inverse dynamic hypotheses. This technique concerns recursive calculation performed on full kinematic chains, and consists in evaluating the loads obtained by two different recursive strategies. It has been applied to complex 3D whole body movements of balance recovery. A recursive Newton-Euler procedure was used to compute the net joint loads. Two models were used to represent the subject bodies, considering or not the upper body as a unique rigid segment. The inertial parameters of the body segments were estimated from two different sets of scaling equations [De Leva, P., 1996. Adjustments to Zatsiorsky-Suleyanov's segment inertia parameters. Journal of Biomechanics 29, 1223-1230; Dumas, R., Chèze, L., Verriest, J.-P., 2006b. Adjustments to McConville et al. and Young et al. Body Segment Inertial Parameters. Journal of Biomechanics, in press]. Using this comparison technique, it has been shown that, for the balance recovery motions investigated: (1) the use of the scaling equations proposed by Dumas et al., instead of those proposed by De Leva, improves the consistency of the results (average relative influence up to 30% for the transversal moment); (2) the arm motions dynamically influence the recovery motion in a non negligible way (average relative influence up to 15% and 30

  16. Two-Dimensional Strain Fields on the Cross-Section of the Human Patellofemoral Joint under Physiological Loading

    PubMed Central

    Guterl, Clare Canal; Gardner, Thomas R.; Rajan, Vikram; Ahmad, Christopher S.; Hung, Clark T.; Ateshian, Gerard A.

    2009-01-01

    The objective of this study was to provide a detailed experimental assessment of the two-dimensional cartilage strain distribution on the cross-section of the human patellofemoral joint (PFJ) subjected to physiological load magnitudes and rates. The medial side of six human PFJs sectioned along their mid-sagittal plane was loaded up to the equivalent of two body weights on a whole joint, and strain measurements obtained from digital image correlation are reported at 0.5s. Normal strains tangential to the articular surface and shear strains in the plane of the cross-section showed consistent patterns among all specimens, whereas normal strains perpendicular to the articular surface exhibited some variability that may be attributed to subject-specific variations in material properties through the depth of the articular layers. Elevated tensile and compressive principal normal strains were observed near the articular surface, around the center of the contact region, with additional locations of elevated compressive strains occurring at the bone-cartilage interface. Under an average contact stress of ∼3.3 MPa, the peak compressive principal normal strains for the patella and femur averaged -0.158 ± 0.072 and -0.118 ± 0.051 respectively, magnitudes that are significantly greater than the relative changes in cartilage thickness, -0.090 ± 0.030 and -0.072 ± 0.038 (p < 0.005). These experimental results provide a detailed description of the manner by which human PFJ articular layers deform in situ under physiological load conditions. PMID:19433326

  17. Calculation of muscle loading and joint contact forces during the rock step in Irish dance.

    PubMed

    Shippen, James M; May, Barbara

    2010-01-01

    A biomechanical model for the analysis of dancers and their movements is described. The model consisted of 31 segments, 35 joints, and 539 muscles, and was animated using movement data obtained from a three-dimensional optical tracking system that recorded the motion of dancers. The model was used to calculate forces within the muscles and contact forces at the joints of the dancers in this study. Ground reaction forces were measured using force plates mounted in a sprung floor. The analysis procedure is generic and can be applied to any dance form. As an exemplar of the application process an Irish dance step, the rock, was analyzed. The maximum ground reaction force found was 4.5 times the dancer's body weight. The muscles connected to the Achilles tendon experienced a maximum force comparable to their maximal isometric strength. The contact force at the ankle joint was 14 times body weight, of which the majority of the force was due to muscle contraction. It is suggested that as the rock step produces high forces, and therefore the potential to cause injury, its use should be carefully monitored.

  18. Knee joint kinetics in relation to commonly prescribed squat loads and depths.

    PubMed

    Cotter, Joshua A; Chaudhari, Ajit M; Jamison, Steve T; Devor, Steven T

    2013-07-01

    Controversy exists regarding the safety and performance benefits of performing the squat exercise to depths beyond 90° of knee flexion. Our aim was to compare the net peak external knee flexion moments (pEKFM) experienced over typical ranges of squat loads and depths. Sixteen recreationally trained men (n = 16; age, 22.7 ± 1.1 years; body mass, 85.4 ± 2.1 kg; height, 177.6 ± 0.96 cm; mean ± SEM) with no previous lower-limb surgeries or other orthopedic issues and at least 1 year of consistent resistance training experience while using the squat exercise performed single-repetition squat trials in a random order at squat depths of above parallel, parallel, and below parallel. Less than 1 week before testing, 1RM values were found for each squat depth. Subsequent testing required the subjects to perform squats at the 3 depths with 3 different loads: unloaded, 50% 1RM, and 85% 1RM (9 total trials). Force platform and kinematic data were collected to calculate pEKFM. To assess the differences among loads and depths, a 2-factor (load and depth) repeated measures analysis of variance with significance set at the p < 0.05 level was used. Squat 1RM significantly decreased 13.6% from the above-parallel to the parallel squat and another 3.6% from the parallel to the below-parallel squat (p < 0.05). Net peak external knee flexion moments significantly increased as both squat depth and load were increased (p ≤ 0.02). Slopes of pEKFM were greater from unloaded to 50% 1RM than when progressing from 50% to 85% 1RM (p < 0.001). The results suggest that typical decreases in squat loads used with increasing depths are not enough to offset increases in pEKFM.

  19. Knee Joint Kinetics in Relation to Commonly Prescribed Squat Loads and Depths

    PubMed Central

    Cotter, Joshua A.; Chaudhari, Ait M.; Jamison, Steve T.; Devor, Steven T.

    2014-01-01

    Controversy exists regarding the safety and performance benefits of performing the squat exercise to depths beyond 90° of knee flexion. Our aim was to compare the net peak external knee flexion moments (pEKFM) experienced over typical ranges of squat loads and depths. Sixteen recreationally trained males (n = 16; 22.7 ± 1.1 yrs; 85.4 ± 2.1 kg; 177.6 ± 0.96 cm; mean ± SEM) with no previous lower limb surgeries or other orthopedic issues and at least one year of consistent resistance training experience while utilizing the squat exercise performed single repetition squat trials in a random order at squat depths of above parallel, parallel, and below parallel. Less than one week before testing, one repetition maximum (1RM) values were found for each squat depth. Subsequent testing required subjects to perform squats at the three depths with three different loads: unloaded, 50% 1RM, and 85% 1RM (nine total trials). Force platform and kinematic data were collected to calculate pEKFM. To assess differences among loads and depths, a two-factor (load and depth) repeated-measures ANOVA with significance set at the P < 0.05 level was used. Squat 1RM significantly decreased 13.6% from the above parallel to parallel squat and another 3.6% from the parallel to the below parallel squat (P < 0.05). Net peak external knee flexion moments significantly increased as both squat depth and load were increased (P ≤ 0.02). Slopes of pEKFM were greater from unloaded to 50% 1RM than when progressing from 50% to 85% 1RM (P < 0.001). The results suggest that that typical decreases in squat loads used with increasing depths are not enough to offset increases in pEKFM. PMID:23085977

  20. Exploring third metacarpal capitate facet shape in early hominins.

    PubMed

    Rein, Thomas R; Harvati, Katerina

    2013-02-01

    The joint between the capitate and third metacarpal plays an important role in stabilizing the manus during hand use in great apes and humans. Researchers have examined the morphology of this region in humans, our fossil relatives, and other extant primates to try to understand the importance of this joint in human evolution. The first goal of our research was to explore shape variation of the third metacarpal capitate facet across extant anthropoids, including hominoids, cercopithecoids, and platyrrhines. This analysis allowed us to examine the range of variation in the capitate facet and the degree to which locomotor behavior, phylogeny, and size explained shape variation. We also examined capitate facet shape in the early hominin fossil record in order to explore how the shape of this articular surface has changed during early hominin evolution. We captured six landmark coordinates on the edge of the capitate facet in extant anthropoids and fossil specimens to quantify and visualize shape variation in this region. We used principal components analysis, Procrustes distances, and multivariate regression analysis to investigate different possible influences on shape variation. We found that shape variation corresponded to function, phylogeny, and size. With the exception of brachiation, shape variation did not clearly correspond with any specific locomotor behavior. However, we identified a shift in the relative mediolateral breadth of the capitate facet during early hominin evolution, which is most likely one of several adaptations for a more stable joint surface. Copyright © 2012 Wiley Periodicals, Inc.