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Sample records for lumbar apophyseal ring

  1. A posterior ring apophyseal fracture and disc herniation in a 21-year-old competitive basketball player: a case report

    PubMed Central

    Deleo, Trevor; Merotto, Samuel; Smith, Colyn; D’Angelo, Kevin

    2015-01-01

    Objective: To describe the diagnosis and management of a competitive male basketball player with discogenic low back pain and presence of an old posterior ring apophyseal fracture (PRAF). This case will highlight the importance of early recognition and considerations regarding patient management for this differential of radiating low back pain. Clinical Features: A 21-year-old provincial basketball player presented with recurrent radiating low back pain into the left groin and lower limb. After several weeks of persistent symptoms including pain, muscle weakness, and changes in the Achilles deep tendon reflex, imaging was obtained that revealed a large disc extrusion with an old posterior ring apophyseal fracture. In collaboration with a spine surgeon and family physician, the patient was treated using a conservative, multimodal approach. Treatment consisted of graded mobilizations, spinal manipulative therapy, interferential current, and soft tissue therapy to the lumbar spine. Rehabilitation exercises focused on centralizing symptoms and improving strength, proprioception and function of the lower limb. After a period of 8 weeks, the patient was able to complete all activities of daily living without pain in addition to returning to basketball practice. Summary: PRAF is a unique condition in the immature spine and recent evidence suggests that those involved in sports requiring repetitive motion of the lumbar spine may be at increased risk. The astute clinician must consider this differential in young populations presenting with discogenic low back pain, as a timely diagnosis and necessary referral may allow for effective conservative management to reduce symptoms. Equally as important, one must be aware of the complications from PRAF as a contributing source of low back pain and dysfunction into adulthood. Knowing when to refer for advanced imaging and/or a surgical consult given the variable clinical presentation and prognosis is an essential component to care

  2. Calcaneal apophysitis due to brucellosis.

    PubMed

    Ozgocmen, Salih; Kocakoc, Ercan; Kiris, Adem; Sen, Yasar; Ardicoğlu, Ozge

    2003-02-01

    Brucellosis is still a major health problem in many geographical areas. Osteoarticular complications are important owing to their high prevalence. We report an unusual case of childhood brucellosis presenting with septic apophysitis of the calcaneus and abscess formation in a 12-year-old boy. The patient was successfully treated with a combination of antibiotics. The importance of early recognition of the disease and differential diagnosis is emphasized. Early recognition of infection, prolonged treatment, and long-term follow-up may improve the outcome.

  3. Greater trochanter apophysitis in the adolescent athlete.

    PubMed

    Young, Simon W; Safran, Marc R

    2015-05-01

    Lower limb traction apophysitis is common in young athletes, occurring at sites such as the tibial tubercle (Osgood-Schlatter disease) and distal patella (Sinding-Larsen-Johansson disease). Around the hip, iliac apophysitis is well recognized, but no cases of greater trochanter apophysitis have previously been reported. We describe the case of a 15-year-old male basketball player with a 2-month history of the right hip pain and significant functional limitation. X-rays revealed widening of the greater trochanter apophysis with subchondral sclerosis, consistent with a diagnosis of traction apophysitis. The patient was treated with a period of relative rest and anti-inflammatory medication. He gradually returned to full athletic activity, including basketball, without recurrence of pain or limitation. We describe the first reported case of traction apophysitis of the greater trochanter. The unique muscular anatomy of this apophysis with balanced forces explains the rarity of this condition. If encountered, rest and activity modification is the recommended treatment.

  4. Study of lesions of the lumbar endplate based on the stage of maturation of the lumbar vertebral body: the relationship between skeletal maturity and chronological age.

    PubMed

    Uraoka, Hideyuki; Higashino, Kosaku; Morimoto, Masatoshi; Yamashita, Kazuta; Tezuka, Fumitake; Takata, Yoichiro; Sakai, Toshinori; Nagamachi, Akihiro; Murase, Masaaki; Sairyo, Koichi

    2017-09-16

    The lesion of the lumbar endplate is sometimes identified in the vertebrae of children and adolescents. The purpose of this study is to compare between skeletal maturity and chronological age. The second purpose of this study is to clarify the lesions of the lumbar endplate based on the maturation of the lumbar vertebral body. Six hundred and thirty-two (485 men and 147 women) consecutive patients were included. The mean age at the first medical examination was 13.8 years. Their skeletal maturity was evaluated based on the appearances of the secondary ossification center of L3. The area of the endplate lesions was classified into five types. The apophyseal stage was observed from 10 years old to 18 years old, and the apophyseal stage was shown the peak at 14 years old. The appearance of the apophyseal ring was observed earlier in female patients than in male patients. For the concave type, the lesion at upper level vertebra was more prevalent. The anterior and middle type of the lesion at upper level vertebra was more prevalent. For the posterior type, the lesion of the inferior rim of L4 and the lesion of the rim of L5 were more prevalent. This study emerged after comparing skeletal maturity based on the maturation of the lumbar vertebral body with the chronological age of a large number of patients and examining the lesions of the lumbar endplate based on the stage of maturation of the lumbar vertebral body.

  5. [Bilateral hyperplasia of the coronoid apophyses. A clinical case].

    PubMed

    Parascandolo, S; Rusciano, A; Tamai, M; Morlino, M

    1993-03-01

    The authors report on the case of a young patient affected with bilateral hyperplasia of the coronoid apophyses, who presented a serious reduction of the mandibular excursion. Normal mouth opening was re-established by a bilateral osteotomy with endoral removal of the coronoid apophyses.

  6. Ischial apophyseal fracture in an abused infant.

    PubMed

    Bixby, Sarah D; Wilson, Celeste R; Barber, Ignasi; Kleinman, Paul K

    2014-09-01

    We report a previously healthy 4-month-old who presented to the hospital with leg pain and swelling and no history of trauma. Radiographs demonstrated a comminuted left femur fracture. Given the concern for child abuse, skeletal survey was performed and revealed four vertebral compression deformities. Although abuse was suspected, the possibility of a lytic lesion associated with the femur fracture and multiple spinal abnormalities raised the possibility of an underlying process such as Langerhans cell histiocytosis. Subsequently 18F-NaF positron emission tomographic (PET) scintigraphy revealed increased tracer activity in the ischium, and MRI confirmed an ischial apophyseal fracture. Pelvic fractures, particularly ischial fractures, are extremely rare in the setting of child abuse. This case report describes the multimodality imaging findings of an ischial fracture in an abused infant.

  7. [Macroscopic and functional anatomy of the apophyseal plate].

    PubMed

    Putz, R; Milz, S

    2016-03-01

    Apophyses are growth zones attached to the shaft (corpus) of larger bones. They vary in size and develop their own ossification centres or form as part of an usually fibrocartilaginous tendon or ligament insertion. The structure of the cartilaginous apophyseal plate is very similar to that of an epiphyseal growth plate and like these they are adapted to withstand perpendicular compressive forces without becoming harmed. This is best highlighted by the fact that their mineralized borders always orient themselves perpendicular to the overall resulting force vector. The edges of the apophyseal plates are characteristically bent which allows them to resist moderate shear forces. Like the epiphyseal plates the apophyseal plates exhibit a zonal organization which is not very well adapted to permanently withstand shear forces, especially if they occur under dynamic conditions. In these situations the tendinous insertions with their collagen fibre anchoring system have to provide compensation when balancing the load transmitted across the system.

  8. Age estimation using thoracic and first two lumbar vertebral ring epiphyseal union.

    PubMed

    Albert, Midori; Mulhern, Dawn; Torpey, Melissa A; Boone, Edward

    2010-03-01

    Union of the vertebral centra or "ring" epiphyses occurs during adolescence and early adulthood, providing valuable age at death information. We present a system for estimating age based on the timing and pattern of vertebral ring union. Data from 57 known individuals aged 14-27 years were used to establish age ranges for various patterns of union in females and males. Female age ranges were more well defined with less overlap in patterns of union than male age ranges. The age ranges are accompanied by descriptions of the stages of union observed that aid in applying this method. A test of interobserver error in scoring stages of union demonstrated strong consistency among three observers (r = 0.91-0.97). Estimating age by observing all stages documented resulted in 78%, 88%, and 100% accuracies using vertebral data alone. We encourage the continued use of this method, in conjunction with other age indicators.

  9. [Apophyseal avulsions of the pelvis and proximal femur].

    PubMed

    Jacobsen, S

    1993-07-05

    Avulsion fractures of the pelvic and proximal femoral apophyseal centres are not uncommonly seen in adolescent athletes engaged in vigorous sports. They are the result of strong or uncoordinated muscular traction, and are the equivalents of muscle or tendon pulls in mature athletes. They are particularly seen in athletics, soccer, rugby, ice hockey and break dance. They involve the anterior third of the iliac crest, the anterior iliac spines, the tuber ischiadicum, the symphysis pubis and the trochanter minor. The radiographic and clinical diagnosis, symptoms and signs, treatment and prognosis are well described in the orthopaedic literature and this literature is evaluated here. The fractures are easily and almost exclusively treated conservatively, and will only in a few cases result in a lasting functional disability.

  10. Three-Dimensional Analysis of a Ballet Dancer with Ischial Tuberosity Apophysitis. A Case Study

    PubMed Central

    Pohjola, Hanna; Sayers, Mark; Mellifont, Rebecca; Mellifont, Daniel; Venojärvi, Mika

    2014-01-01

    The purpose of this case study was to describe the three-dimensional biomechanics of common ballet exercises in a ballet dancer with ischial tuberosity apophysitis. This was achieved by comparing kinematics between the symptomatic (i.e. ischial apophyseal symptoms) and contralateral lower limbs, as well as via reported pain. Results suggest consistent differences in movement patterns in this dancer. These differences included: 1) decreased external rotation of contralateral hip, hence a decreased hip contribution to ‘turn out’; 2) increased contralateral knee adduction and internal rotation; 3) an apparent synchronicity in the contralateral lower limb of the decreased hip external rotation and increased knee adduction; and 4) minimal use of ankle plantar/dorsiflexion movement for symptomatic side. Pain related to the left ischial apophysitis was associated with reduced amplitudes especially in fast ballet movements that required large range of motion in flexion and adduction in the left hip joint. These findings suggest that ischial apophysitis may limit dancer’s ballet technique and performance. Key Points The pain related to the left ischial apophysitis was associated with reduced amplitudes especially in fast ballet movements that require large range of motion. This may affect to the lower limbs kinematics, and limit dancer’s technique and performance. Compensatory strategies in the kinetic chain, differences in the joint angles between the lower limbs, traction forces, velocity and amplitude demands should be taken in consideration while training and rehabilitation of the ischial apophyseal injury within classical ballet. PMID:25435780

  11. Three-dimensional analysis of a ballet dancer with ischial tuberosity apophysitis. A case study.

    PubMed

    Pohjola, Hanna; Sayers, Mark; Mellifont, Rebecca; Mellifont, Daniel; Venojärvi, Mika

    2014-12-01

    The purpose of this case study was to describe the three-dimensional biomechanics of common ballet exercises in a ballet dancer with ischial tuberosity apophysitis. This was achieved by comparing kinematics between the symptomatic (i.e. ischial apophyseal symptoms) and contralateral lower limbs, as well as via reported pain. Results suggest consistent differences in movement patterns in this dancer. These differences included: 1) decreased external rotation of contralateral hip, hence a decreased hip contribution to 'turn out'; 2) increased contralateral knee adduction and internal rotation; 3) an apparent synchronicity in the contralateral lower limb of the decreased hip external rotation and increased knee adduction; and 4) minimal use of ankle plantar/dorsiflexion movement for symptomatic side. Pain related to the left ischial apophysitis was associated with reduced amplitudes especially in fast ballet movements that required large range of motion in flexion and adduction in the left hip joint. These findings suggest that ischial apophysitis may limit dancer's ballet technique and performance. Key PointsThe pain related to the left ischial apophysitis was associated with reduced amplitudes especially in fast ballet movements that require large range of motion. This may affect to the lower limbs kinematics, and limit dancer's technique and performance.Compensatory strategies in the kinetic chain, differences in the joint angles between the lower limbs, traction forces, velocity and amplitude demands should be taken in consideration while training and rehabilitation of the ischial apophyseal injury within classical ballet.

  12. McKenzie treatment versus mulligan sustained natural apophyseal glides for chronic mechanical low back pain

    PubMed Central

    Waqqar, Saira; Shakil-ur-Rehman, Syed; Ahmad, Shakeel

    2016-01-01

    Background and Objective: Chronic mechanical low back pain is common among different age groups and genders. Different manual therapy techniques combined with exercise therapy and electrotherapy modalities play an important role in its management. Our objective was to compare the effects of McKenzie extension exercisesprogram (EEP) versus Mulligan Sustained Natural Apophyseal Glides (SNAGs) for chronic mechanical low back pain (CMLBP). Methods: This randomized control trial (RCT) was conducted at Riphah Physical Rehabilitation Centre, Pakistan Railways General Hospital Rawalpindi, from 1st July to 31st December 2014. The inclusion criteria was patients of both gender and age range 30-70 years with minimum 4 weeks history of CMLBP. A total of 37 patients were screened out as per inclusion criteria and randomly placed into two groups. Twenty patients in group A were treated with Mulligan SNAGs and 17 patients in group B with McKenzie EEP for four weeks at two session per week and single session per day. Visual Analogue Scale (VAS), Oswestry Disability Scale (ODI) and lumber Range of Motion (ROM) were used as an assessment tools and were measured at baseline and at the completion 4 weeks intervention. The data was analyzed with SPSS to draw the statistical and clinical significance of both interventions. Results: At the completion of 4 weeks intervention the pre and post statistical analysis revealed that clinically the McKenzie EEP improved pain (mean 9.12 to 1.46) and disability (73.82 to 6.24) slightly more than Mulligan SNAGs (pain: from 8.85 to 2.55, disability 73.75 to 7.05), while the Mulligan SNAGs improved lumbar ROM more effectively than McKenzie EEP in all directions including flexion, extension, side bending and rotation. Statistically there was no significant difference between the effects of two interventions in managing pain and disability, and improving Lumber ROM. Conclusion: McKenzie EEP is clinically slightly more effective in the management of pain

  13. Pubic apophysitis: a previously undescribed clinical entity of groin pain in athletes

    PubMed Central

    Sailly, Matthieu; Whiteley, Rod; Read, John W; Giuffre, Bruno; Johnson, Amanda; Hölmich, Per

    2015-01-01

    Background Sport-related pubalgia is often a diagnostic challenge in elite athletes. While scientific attention has focused on adults, there is little data on adolescents. Cadaveric and imaging studies identify a secondary ossification centre located along the anteromedial corner of pubis beneath the insertions of symphysial joint capsule and adductor longus tendon. Little is known about this apophysis and its response to chronic stress. Aim We report pubic apophysitis as a clinically relevant entity in adolescent athletes. Methods The clinical and imaging findings in 26 highly trained adolescent football players (15.6 years±1.3) who complained of adductor-related groin pain were reviewed. The imaging features (X-ray 26/26, US 9/26, MRI 11/26, CT 7/26) of the pubic apophyses in this symptomatic group were compared against those of a comparison group of 31 male patients (age range 9–30 years) with no known history of groin pain or pelvic trauma, who underwent pelvic CT scans for unrelated medical reasons. Results All symptomatic subjects presented with similar history and physical findings. The CT scans of these patients demonstrated open pubic apophyses with stress-related physeal changes (widening, asymmetry and small rounded cyst-like expansions) that were not observed in the comparison group. No comparison subject demonstrated apophyseal maturity before 21 years of age, and immaturity was seen up to the age of 26 years. Conclusions This retrospective case series identifies pubic apophyseal stress (or ‘apophysitis’) as an important differential consideration in the adolescent athlete who presents with groin pain. PMID:26031648

  14. Health related quality of life of children with calcaneal apophysitis: child & parent perceptions.

    PubMed

    James, Alicia M; Williams, Cylie M; Haines, Terry P

    2016-06-24

    Children with a clinical diagnosis of calcaneal apophysitis reportedly experience impaired physical ability. Patient reported outcome assessments measure the level of conditional specific interference in everyday life. The aim of this study was to assess and compare the child and parent perceptions of health related quality of life (QOL) associated with calcaneal apophysitis. This is a longitudinal repeated measure study nested within a randomized comparative effectiveness trial. Children who had symptoms of calcaneal apophysitis were recruited from local advertising and from the caseload of podiatrists within the health setting (Australia). The Oxford Ankle Foot Questionnaire for Children (OxAFQ-C) was completed at baseline, 1, 2, 6 and 12 month time points by both child and parent. A total of 133 children were recruited and 124 participated in the study with 101 completing the OxAFQ-C at all five time points. The inter-rater reliability between the child and parent for the physical domain ranged between poor (0.06) to good (0.77) agreement, and the footwear domain ranged between poor (0.09) to good (0.66) across the time points. Both the school and emotional domains had moderate (0.46) to good (0.77) agreement. Children with calcaneal apophysitis have differing perceptions of health related QOL impact compared to their parents. Parents initially reported greater impact than their child however there was convergence of agreement over the follow-up period. These findings suggest understanding the impact from both child and parent perspective is imperative during treatment. ACTRN12609000696291.

  15. Effects of cervical sustained natural apophyseal glide on forward head posture and respiratory function.

    PubMed

    Kim, Se-Yoon; Kim, Nan-Soo; Kim, Laurentius Jongsoon

    2015-06-01

    [Purpose] To determine the effects of cervical sustained natural apophyseal glide on forward head posture and respiratory function. [Subjects and Methods] Thirty male and female adults in their 20s with forward head posture were included in the study. The subjects were divided randomly into experimental and control groups (n=15 each). Subjects in the experimental group performed cervical sustained natural apophyseal glide three times/week for four weeks while subjects in the control group did not perform the intervention. The craniovertebral angle, forced vital capacity and forced expiratory volume in the first second, as well as the % predicted value of each measurement were assessed to determine the changes in respiration functions before and after the exercise. [Results] The craniovertebral angle four weeks after the experiment was increased in the experimental group, whereas the control group showed no significant difference compared to baseline. The forced vital capacity, forced expiratory volume in the first second, and the % predicted values thereof were significantly increased in the experimental group four weeks after the experiment, but not in the control group. [Conclusion] Cervical sustained natural apophyseal glide was determined to be effective in improving neck posture and respiratory functions for patients with forward head posture.

  16. Spinous process apophysitis: a cause of low back pain following repetitive hyperextension in an adolescent female dancer.

    PubMed

    Quinlan, Erin; Reinke, Tari; Bogar, William C

    2013-12-01

    We report a case of a 13-year-old female dancer with spinous process apophysitis following repetitive microtrauma during end-range hyperextension movements. Following appropriate rest and limitation of hyperextension, she was able to return to her previous level of training. It is important to recognize that numerous diagnostic possibilities arise when presented with a young dancer with back pain. The intention of this case report is to compare and contrast the pertinent clinical and radiologic findings of spinous process apophysitis and its more common and debilitating mimic, spondylolysis. The correct diagnosis is paramount in cases of this sort due to the variable treatment requirements of each disorder.

  17. Treatment of Calcaneal Apophysitis: Wait and See Versus Orthotic Device Versus Physical Therapy: A Pragmatic Therapeutic Randomized Clinical Trial.

    PubMed

    Wiegerinck, Johannes I; Zwiers, Ruben; Sierevelt, Inger N; van Weert, Henk C P M; van Dijk, C Niek; Struijs, Peter A A

    2016-03-01

    Calcaneal apophysitis is a frequent cause of heel pain in children and is known to have a significant negative effect on the quality of life in affected children. The most effective treatment is currently unknown. The purpose of this study is to evaluate 3 frequently used conventional treatment modalities for calcaneal apophysitis. Three treatment modalities were evaluated and compared in a prospective randomized single-blind setting: a pragmatic wait and see protocol versus a heel raise inlay (ViscoHeel; Bauerfeind) versus an eccentric exercise regime under physiotherapeutic supervision. Treatment duration was 10 weeks. age between 8 and 15 years old, at least 4 weeks of heel pain complaints due to calcaneal apophysitis based, with a minimal Faces Pain Scale-Revised of 3 points. Primary exclusion criteria included other causes of heel pain and previous similar treatment. Primary outcome was Faces Pain Scale-Revised at 3 months. Secondary outcomes included patient satisfaction and Oxford Ankle and Foot Questionnaire (OAFQ). Points of measure were at baseline, 6 weeks, and 3 months. Analysis was performed according to the intention-to-treat principles. A total of 101 subjects were included. Three subjects were lost to follow-up. At 6 weeks, the heel raise subjects were more satisfied compared with both other groups (P<0.01); the heel raise group improved significantly compared with the wait and see group for OAFQ Children (P<0.01); the physical therapy group showed significant improvement compared with the wait and see group for OAFQ Parents (P<0.01). Each treatment modality showed significant improvement of all outcome measures during follow-up (P<0.005). No clinical relevant differences were found between the respective treatment modalities at final follow-up. Treatment with wait and see, a heel raise inlay, or physical therapy each resulted in a clinical relevant and statistical significant reduction of heel pain due to calcaneal apophysitis. No significant

  18. Results of Non-operative and Operative Management Of Apophyseal Avulsion Fractures of the Hip and Pelvis in Adolescent Athletes

    PubMed Central

    Heyworth, Benton E.; Bonner, Bryant; Suppan, Catherine A.; Kocher, Mininder S.; Yen, Yi-Meng; Micheli, Lyle J.

    2014-01-01

    Objectives: Apophyseal avulsion fractures of the hip and pelvis occur almost exclusively in the adolescent population, with greater numbers being seen recently as the popularity and intensity of youth sports increases. Limited evidence exists detailing the demographics or distribution of these fractures by injury site. The goal of the current study was to present a comprehensive perspective on 437 of these fractures, including the indications and clinical course of 25 cases that underwent surgical intervention. Methods: All cases of an apophyseal avulsion fracture of the hip or pelvis between the years of 1981-2012 at a tertiary care pediatric center underwent radiographic and chart review, including operative details for that sub-population. Demographic data was analyzed, along with radiographic displacement, healing times, and return to sports for both groups. Results: 413 patients underwent definitive non-operative treatment, 72% of which were male. The mean age was 14.5 years. The anatomic site of injury was well-distributed: AIIS 29%, ASIS 27%, ischial tuberosity 17%, lesser trochanter 15%, and iliac crest 11%. Half of all injuries occurred during one of three different athletic activities (soccer 26%, track 13%, baseball/softball 11%), with a wide range of sports in the overall cohort. In the 287 nonop cases with adequate follow up data to confirm mean radiographic union and time of return to sports (RTS), healing occurred at 2.7 months and RTS at 2.8 months respectively. The mean age of the cohort of 25 patients who ultimately required operative treatment was 15.7 years, with 72% of cases being initially treated with nonoperative measures. The ischial tuberosity was the most common (64%) anatomic site with others including AIIS 16%, iliac crest 16%, and ASIS 4%. Excision of the apophyseal fragment was the intervention pursued for 48% of cases, with the mean time to union of 4.8 months in 11 cases which underwent fixation and had adequate follow up data

  19. The relationship of calcaneal apophyseal ossification and Sanders hand scores to the timing of peak height velocity in adolescents.

    PubMed

    Nicholson, A D; Sanders, J O; Liu, R W; Cooperman, D R

    2015-12-01

    The accurate assessment of skeletal maturity is essential in the management of orthopaedic conditions in the growing child. In order to identify the time of peak height velocity (PHV) in adolescents, two systems for assessing skeletal maturity have been described recently; the calcaneal apophyseal ossification method and the Sanders hand scores. The purpose of this study was to compare these methods in assessing skeletal maturity relative to PHV. We studied the radiographs of a historical group of 94 healthy children (49 females and 45 males), who had been followed longitudinally between the ages of three and 18 years with serial radiographs and physical examination. Radiographs of the foot and hand were undertaken in these children at least annually between the ages of ten and 15 years. We reviewed 738 radiographs of the foot and 694 radiographs of the hand. PHV was calculated from measurements of height taken at the time of the radiographs. Prior to PHV we observed four of six stages of calcaneal apophyseal ossification and two of eight Sanders stages. Calcaneal stage 3 and Sanders stage 2 was seen to occur about 0.9 years before PHV, while calcaneal stage 4 and Sanders stage 3 occurred approximately 0.5 years after PHV. The stages of the calcaneal and Sanders systems can be used in combination, offering better assessment of skeletal maturity with respect to PHV than either system alone.

  20. Lumbar lordosis.

    PubMed

    Been, Ella; Kalichman, Leonid

    2014-01-01

    Lumbar lordosis is a key postural component that has interested both clinicians and researchers for many years. Despite its wide use in assessing postural abnormalities, there remain many unanswered questions regarding lumbar lordosis measurements. Therefore, in this article we reviewed different factors associated with the lordosis angle based on existing literature and determined normal values of lordosis. We reviewed more than 120 articles that measure and describe the different factors associated with the lumbar lordosis angle. Because of a variety of factors influencing the evaluation of lumbar lordosis such as how to position the patient and the number of vertebrae included in the calculation, we recommend establishing a uniform method of evaluating the lordosis angle. Based on our review, it seems that the optimal position for radiologic measurement of lordosis is standing with arms supported while shoulders are flexed at a 30° angle. There is evidence that many factors, such as age, gender, body mass index, ethnicity, and sport, may affect the lordosis angle, making it difficult to determine uniform normal values. Normal lordosis should be determined based on the specific characteristics of each individual; we therefore presented normal lordosis values for different groups/populations. There is also evidence that the lumbar lordosis angle is positively and significantly associated with spondylolysis and isthmic spondylolisthesis. However, no association has been found with other spinal degenerative features. Inconclusive evidence exists for association between lordosis and low back pain. Additional studies are needed to evaluate these associations. The optimal lordotic range remains unknown and may be related to a variety of individual factors such as weight, activity, muscular strength, and flexibility of the spine and lower extremities. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Heel raises versus prefabricated orthoses in the treatment of posterior heel pain associated with calcaneal apophysitis (Sever's Disease): study protocol for a randomised controlled trial

    PubMed Central

    2010-01-01

    Background Posterior Heel pain can present in children of 8 to 14 years, associated with or clinically diagnosed as Sever's disease, or calcaneal apophysitis. Presently, there are no comparative randomised studies evaluating treatment options for posterior heel pain in children with the clinical diagnosis of calcaneal apophysitis or Sever's disease. This study seeks to compare the clinical efficacy of some currently employed treatment options for the relief of disability and pain associated with posterior heel pain in children. Method Design: Factorial 2 × 2 randomised controlled trial with monthly follow-up for 3 months. Participants: Children with clinically diagnosed posterior heel pain possibly associated with calcaneal apophysitis/Sever's disease (n = 124). Interventions: Treatment factor 1 will be two types of shoe orthoses: a heel raise or prefabricated orthoses. Both of these interventions are widely available, mutually exclusive treatment approaches that are relatively low in cost. Treatment factor 2 will be a footwear prescription/replacement intervention involving a shoe with a firm heel counter, dual density EVA midsole and rear foot control. The alternate condition in this factor is no footwear prescription/replacement, with the participant wearing their current footwear. Outcomes: Oxford Foot and Ankle Questionnaire and the Faces pain scale. Discussion This will be a randomised trial to compare the efficacy of various treatment options for posterior heel pain in children that may be associated with calcaneal apophysitis also known as Sever's disease. Trial Registration Trial Number: ACTRN12609000696291 Ethics Approval Southern Health: HREC Ref: 09271B PMID:20196866

  2. Ischiofemoral impingement and hamstring dysfunction as a potential pain generator after ischial tuberosity apophyseal fracture non-union/malunion.

    PubMed

    Spencer-Gardner, Luke; Bedi, Asheesh; Stuart, Michael J; Larson, Christopher M; Kelly, Bryan T; Krych, Aaron J

    2017-01-01

    The purpose of this study was to describe the occurrence of ischiofemoral impingement (IFI) and hamstring dysfunction following malunion or non-union of ischial tuberosity apophyseal avulsion fractures and report the short-term outcomes of surgical treatment with regard to alleviating symptomatic extra-articular impingement. All patients who underwent surgery for recalcitrant hip and buttock pain in the setting of prior ischial tuberosity avulsion fracture at three tertiary-level hip preservation centres were included for this review. A total of ten patients met our inclusion criteria and underwent sciatic neurolysis, resection of the ischial tuberosity fragment and hamstring reattachment. Clinical outcomes scores were collected post-operatively including the Modified Harris Hip Score (mHHS) and the Hip Outcomes Score (HOS). Ten patients with a mean age of 18 years (range 14-28) underwent surgery for symptomatic ischiofemoral impingement after ischial tuberosity avulsion fracture. At a mean of 2.2-year follow-up (range 1.7-3.5), the median post-operative mHHS was 89.7 (65.7-96.8) and HOS ADL and Sport subscales were 90 % or greater in all cases. Five patients (50 %) rated their hip as normal, and five patients (50 %) rated their hip as near normal. Malunion or non-union following ischial tuberosity apophyseal fracture can lead to IFI and hamstring dysfunction. Clinically, the resultant pain and dysfunction is often chronic, and can be debilitating. In select cases, a reliable surgical technique is presented to improve hamstring function and correct ischiofemoral impingement in this setting with good-to-excellent outcomes in the majority of cases at short-term follow-up. IV.

  3. “Effectiveness of interventions in reducing pain and maintaining physical activity in children and adolescents with calcaneal apophysitis (Sever’s disease): a systematic review”

    PubMed Central

    2013-01-01

    Background Calcaneal apophysitis, also commonly known as sever’s disease, is a condition seen in children usually aged between 8–15 years. Conservative therapies, such as taping, heel lifts and orthotic intervention are accepted management practices for calcaneal apophysitis, though there is very little high quality research examining the efficacy of such treatment modalities. Previous narrative literature reviews and opinion pieces provide some evidence for the use of heel raises or orthoses. The aim of this manuscript was to complete a systemic review on the treatment options for calcaneal apophysitis as measured by pain reduction and maintenance of physical activity. Methods A search strategy completed by two reviewers examined nine databases from inception to May 2012. Search terms included heel pain, children, adolescent, calcaneal apophysitis, sever’s disease, treatment, and management (full text publications, human studies). Systematic reviews, randomised control trials, case series, and case studies were included. The reference lists of the selected articles were also examined. The methodology, quality and risk of bias was examined and assessed using the PEDro scale. Results Nine articles were retrieved including three clinical trials involving randomisation, two case series, two retrospective case reviews, and two case reports. Effect size calculations and a meta analysis were unable to be completed due to the limited data reported within the literature. Numerous treatment options were reported throughout the literature, though few were examined against a control or alternate treatment option in well-designed trials. The limited evidence indicated that orthoses provided greater short-term pain relief than heel raises. Health practitioners should view these results with caution, as there were apparent methodological problems with the employed study design and limited follow-up of participants. Conclusion There is limited evidence to support the use

  4. Apophyseal Ossification of the Iliac Crest in Forensic Age Estimation: Computed Tomography Standards for Modern Australian Subadults.

    PubMed

    Lottering, Nicolene; Alston-Knox, Clair L; MacGregor, Donna M; Izatt, Maree T; Grant, Caroline A; Adam, Clayton J; Gregory, Laura S

    2017-03-01

    This study contrasts the ontogeny of the iliac crest apophysis using conventional radiography and multislice computed tomography (MSCT), providing probabilistic information for age estimation of modern Australian subadults. Retrospective abdominopelvic MSCT data acquired from 524 Australian individuals aged 7-25 and surveillance radiographs of adolescent idiopathic scoliosis patients included in the Paediatric Spine Research Group Progression Study (n = 531) were assessed. Ossification scoring of pseudo-radiographs and three-dimensional (3D) volume-rendered reconstructions using Risser (1958) quantitative descriptors indicate discrepancies in age estimates, stage allocation, and conflicting morphological progression. To mitigate visualization limitations associated with two-dimensional radiographs, we provide and validate a modified 3D-MSCT scoring tier of ossification, demonstrating complete fusion between 17.3-19.2 and 17.1-20.1 years in males and females. Legal demarcation for doli incapax presumption and age of majority (18 years) can be achieved using probability estimates from a fitted cumulative probit model for apophyseal fusion using the recalibrated standards.

  5. Kickboxing power hour: case report of fifth metatarsal apophysitis (Iselin disease) and its magnetic resonance imaging features

    PubMed Central

    Gupta, Nishant; Sharma, Komal; Bansal, Itisha; Kumar, Yogesh

    2017-01-01

    Youth now-a-days are getting more involved in mixed martial arts, with increasing number of cases of lateral foot pain due to various causes. The differential diagnoses of lateral foot pain in the pediatric population include avulsion fracture of the fifth metatarsal base, Jones fracture, diaphyseal stress fracture as well as os vesalianum pedis. We present a case of a 15-year-old athletic boy who presented with left lateral foot pain for a few weeks. The patient was actively involved in Kickboxing as well as active running. Left foot radiographs were normal, including normal radiographic appearance of the fifth metatarsal apophysis. Due to ongoing pain, magnetic resonance imaging of the left foot was performed, which revealed apophysitis of the fifth metatarsal, known as Iselin disease. Iselin disease has been postulated to be caused by traction on the fifth metatarsal apophysis by performing sidekicks or round kicks during the kickboxing practice. Iselin disease should be suspected in young children of 10–15 years age involved in physical activity presenting with lateral foot pain. Magnetic resonance imaging is extremely useful to correctly diagnose this condition and avoid misdiagnosis of a fracture. PMID:28503415

  6. Kickboxing power hour: case report of fifth metatarsal apophysitis (Iselin disease) and its magnetic resonance imaging features.

    PubMed

    Gupta, Nishant; Sharma, Komal; Bansal, Itisha; Kumar, Yogesh; Hayashi, Daichi

    2017-04-01

    Youth now-a-days are getting more involved in mixed martial arts, with increasing number of cases of lateral foot pain due to various causes. The differential diagnoses of lateral foot pain in the pediatric population include avulsion fracture of the fifth metatarsal base, Jones fracture, diaphyseal stress fracture as well as os vesalianum pedis. We present a case of a 15-year-old athletic boy who presented with left lateral foot pain for a few weeks. The patient was actively involved in Kickboxing as well as active running. Left foot radiographs were normal, including normal radiographic appearance of the fifth metatarsal apophysis. Due to ongoing pain, magnetic resonance imaging of the left foot was performed, which revealed apophysitis of the fifth metatarsal, known as Iselin disease. Iselin disease has been postulated to be caused by traction on the fifth metatarsal apophysis by performing sidekicks or round kicks during the kickboxing practice. Iselin disease should be suspected in young children of 10-15 years age involved in physical activity presenting with lateral foot pain. Magnetic resonance imaging is extremely useful to correctly diagnose this condition and avoid misdiagnosis of a fracture.

  7. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry

    2014-03-01

    Preface: a personal view of planetary rings; 1. Introduction: the allure of the ringed planets; 2. Studies of planetary rings 1610-2013; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Uranus' rings and moons; 13. Neptune's partial rings; 14. Jupiter's ring-moon system after Galileo and New Horizons; 15. Ring photometry; 16. Dusty rings; 17. Concluding remarks; Afterword; Glossary; References; Index.

  8. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry W.

    2011-07-01

    Preface; 1. Introduction: the allure of ringed planets; 2. Studies of planetary rings 1610-2004; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-Body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Neptune's partial rings; 13. Jupiter's ring-moon system after Galileo; 14. Ring photometry; 15. Dusty rings; 16. Cassini observations; 17. Summary: the big questions; Glossary; References; Index.

  9. Comparison of mulligan sustained natural apophyseal glides and maitland mobilizations for treatment of cervicogenic dizziness: a randomized controlled trial.

    PubMed

    Reid, Susan A; Rivett, Darren A; Katekar, Michael G; Callister, Robin

    2014-04-01

    There is short-term evidence for treatment of cervicogenic dizziness with Mulligan sustained natural apophyseal glides (SNAGs) but no evidence for treatment with Maitland mobilizations. The purpose of this study was to compare the effectiveness of SNAGs and Maitland mobilizations for cervicogenic dizziness. A double-blind, parallel-arm randomized controlled trial was conducted. The study was conducted at a university in Newcastle, Australia. Eighty-six people with cervicogenic dizziness were the study participants. Included participants were randomly allocated to receive 1 of 3 interventions: Mulligan SNAGs (including self-administered SNAGs), Maitland mobilizations plus range-of-motion exercises, or placebo. The primary outcome measure was intensity of dizziness. Other outcome measures were: frequency of dizziness, the Dizziness Handicap Inventory (DHI), intensity of pain, and global perceived effect (GPE). Both manual therapy groups had reduced dizziness intensity and frequency posttreatment and at 12 weeks compared with baseline. There was no change in the placebo group. Both manual therapy groups had less dizziness intensity posttreatment (SNAGs: mean difference=-20.7, 95% confidence interval [95% CI]=-33.6, -7.7; mobilizations: mean difference=-15.2, 95% CI=-27.9, -2.4) and at 12 weeks (SNAGs: mean difference=-18.4, 95% CI=-31.3, -5.4; mobilizations: mean difference=-14.4, 95% CI=-27.4, -1.5) compared with the placebo group. Compared with the placebo group, both the SNAG and Maitland mobilization groups had less frequency of dizziness at 12 weeks. There were no differences between the 2 manual therapy interventions for these dizziness measures. For DHI and pain, all 3 groups improved posttreatment and at 12 weeks. Both manual therapy groups reported a higher GPE compared with the placebo group. There were no treatment-related adverse effects lasting longer than 24 hours. The therapist performing the interventions was not blind to group allocation. Both SNAGs

  10. Herniated Lumbar Disc

    MedlinePlus

    ... at and just below the waist. A herniated lumbar disc can press on the nerves in the spine and may cause pain, numbness, ... point injections do not help heal a herniated lumbar ... on and irritating the nerves, causing symptoms of pain and weakness. The most ...

  11. Lumbar Spinal Canal Stenosis

    MedlinePlus

    ... time. This narrowing is called “stenosis.” As the lumbar spinal canal narrows, the nerves that go through it are squeezed. This squeezing ... chest). It’s thought that these positions “open” the lumbar canal and take the pressure off the nerves that go to the legs. In severe cases, ...

  12. Failure of the human lumbar motion-segments resulting from anterior shear fatigue loading

    PubMed Central

    SKRZYPIEC, Daniel M.; NAGEL, Katrin; SELLENSCHLOH, Kay; KLEIN, Anke; PÜSCHEL, Klaus; MORLOCK, Michael M.; HUBER, Gerd

    2016-01-01

    An in-vitro experiment was designed to investigate the mode of failure following shear fatigue loading of lumbar motion-segments. Human male lumbar motion-segments (age 32–42 years, n=6) were immersed in Ringer solution at 37°C and repeatedly loaded, using a modified materials testing machine. Fatigue loading consisted of a sinusoidal shear load from 0 N to 1,500 N (750 N±750 N) applied to the upper vertebra of the motion-segment, at a frequency of 5 Hz. During fatigue experiments, several failure events were observed in the dynamic creep curves. Post-test x-ray, CT and dissection revealed that all specimens had delamination of the intervertebral disc. Anterior shear fatigue predominantly resulted in fracture of the apophyseal processes of the upper vertebrae (n=4). Exposure to the anterior shear fatigue loading caused motion-segment instability and resulted in vertebral slip corresponding to grade I and ‘mild’ grade II spondylolisthesis, as observed clinically. PMID:26829975

  13. The effect of sustained natural apophyseal glide (SNAG) combined with neurodynamics in the management of a patient with cervical radiculopathy: a case report.

    PubMed

    Anandkumar, Sudarshan

    2015-02-01

    This case report describes a 47-year-old female who presented with complaints of pain in the right elbow radiating down to the thumb. Physical examination revealed symptom reproduction with Spurling A test, upper limb neurodynamic testing-1 and right cervical rotation along with reduced symptoms with neck distraction. Clinical diagnosis of cervical radiculopathy (CR) was made based on a clinical prediction rule. This case report speculates a potentially first-time description of successful conservative management of CR in a patient utilizing simultaneous combination of sustained natural apophyseal glide and neurodynamic mobilization. Immediate improvements were seen in pain, cervical range of motion and functional abilities. The patient was discharged from physical therapy by the second week after four treatment sessions with complete pain resolution maintained at a four-month follow-up period.

  14. Diagnostic Lumbar Puncture

    PubMed Central

    Doherty, Carolynne M; Forbes, Raeburn B

    2014-01-01

    Diagnostic Lumbar Puncture is one of the most commonly performed invasive tests in clinical medicine. Evaluation of an acute headache and investigation of inflammatory or infectious disease of the nervous system are the most common indications. Serious complications are rare, and correct technique will minimise diagnostic error and maximise patient comfort. We review the technique of diagnostic Lumbar Puncture including anatomy, needle selection, needle insertion, measurement of opening pressure, Cerebrospinal Fluid (CSF) specimen handling and after care. We also make some quality improvement suggestions for those designing services incorporating diagnostic Lumbar Puncture. PMID:25075138

  15. Quantification of lumbar endurance on a backup lumbar extension dynamometer.

    PubMed

    Hager, Staci M; Udermann, Brian E; Reineke, David M; Gibson, Mark H; Mayer, John M; Murray, Steven R

    2006-01-01

    We evaluated the reliability of static and dynamic lumbar muscle endurance measurements on a BackUP lumbar extension dynamometer. Sixteen healthy participants (8 male; 8 female) volunteered for this investigation. Fifty percent of each participant's body weight was calculated to determine the weight load utilized for the static (holding time) and dynamic (repetitions) lumbar extension endurance tests. Four separate tests (2 static, 2 dynamic) were conducted with at least a 24-hour rest period between tests. Test-retest intraclass correlations were shown to be high (static lumbar endurance, ICC = 0.92 (p < 0.0005); dynamic lumbar endurance, ICC = 0.93 (p < 0.0005) for both of the performed tests. Our results demonstrated that static and dynamic lumbar endurance can be assessed reliably on a BackUP lumbar extension dynamometer. Key PointsReliability studies that test lumbar endurance on machines that effectively stabilize the pelvis and isolate the lumbar extensors are limited.This is the first study to report reliability measures of static and dynamic lumbar endurance on a BackUP lumbar extension dynamometer.Static and dynamic lumbar endurance on a BackUP lumbar extension dynamometer, which uses a variety of pelvic stabilization mechanisms, can be reliably assessed in apparently healthy individuals.Future research is necessary to examine the reliability of lumbar extension endurance on the BackUP dynamometer in patient populations and validity in various settings.

  16. Lumbar MRI scan

    MedlinePlus

    ... may need a lumbar MRI if you have: Low back pain that does not get better after treatment Leg ... spine Injury or trauma to the lower spine Low back pain and a history or signs of cancer Multiple ...

  17. Minimally invasive lumbar foraminotomy.

    PubMed

    Deutsch, Harel

    2013-07-01

    Lumbar radiculopathy is a common problem. Nerve root compression can occur at different places along a nerve root's course including in the foramina. Minimal invasive approaches allow easier exposure of the lateral foramina and decompression of the nerve root in the foramina. This video demonstrates a minimally invasive approach to decompress the lumbar nerve root in the foramina with a lateral to medial decompression. The video can be found here: http://youtu.be/jqa61HSpzIA.

  18. [The role of computed tomography and magnetic resonance in assessing degenerative arthropathy of the lumbar articular facets].

    PubMed

    Leone, A; Aulisa, L; Tamburrelli, F; Lupparelli, S; Tartaglione, T

    1994-11-01

    Degenerative arthropathy of the lumbar facet joints remains a debated issue relative to both its etiopathogenesis and its clinical significance. The authors studied 9 autoptic specimens by means of CT and MRI: the diagnostic value of the two methods was assessed taking the histopathologic findings of the relative specimens as the gold standard. The following signs of degenerative arthropathy were investigated in each specimen: cartilaginous wears, hypertrophy of the articular processes, osteophytosis, subchondral sclerosis and geodes and capsular and ligamentous calcifications. CT clearly demonstrated the characteristic signs of arthropathy, although failing to assess the cartilaginous wears in the early degeneration phases. Cartilaginous surface tears were directly depicted by MRI in the specimens showing medium and advanced degeneration. In our opinion, CT represents the examination of choice in the diagnosis of degenerative arthropathy of the lumbar apophyseal joints. Nevertheless, human trials are needed to assess MR capabilities in better detailing subchondral bone structure and in depicting the joint capsule and the synovial membrane and fluid as a major MR potential to diagnose back pain syndromes arising from the posterior arch.

  19. Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Cuzzi, J. N.

    2014-12-01

    The rings are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major ring science progress over the mission to date, and describe new observations planned for Cassini's final three years. Ring Composition and particle sizes: The rings are nearly all water ice with no other ices - so why are they reddish? The C Ring and Cassini Division are "dirtier" than the more massive B and A Rings, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. Ring structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main ring divisions, the C Ring plateau structures, and the B Ring irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A ring. Rubble pile ringmoons just outside the rings may escaped from the rings, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the rings: Comet fragments set the rings to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the Rings: The ring mass and bombardment play key roles. The ring mass is well known everywhere but in the B Ring (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient rings, of which the current ring is just a shadow. During its last three years, the Cassini tour profile will allow entirely new

  20. Herniated lumbar disk (image)

    MedlinePlus

    Herniated lumbar disk is a condition in which part or all of the soft, gelatinous central portion of an intervertebral disk (the nucleus pulposus) is forced through a weakened part of the disk, resulting in back pain and nerve root irritation.

  1. Neptune's rings

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This 591-second exposure of the rings of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera. The two main rings are clearly visible and appear complete over the region imaged. Also visible in this image is the inner faint ring and the faint band which extends smoothly from the ring roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings. The bright glare is due to over-exposure of the crescent on Neptune. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  2. Ring World

    NASA Image and Video Library

    2007-03-01

    Our robotic emissary, flying high above Saturn, captured this view of an alien copper-colored ring world. The overexposed planet has deliberately been removed to show the unlit rings alone, seen from an elevation of 60 degrees

  3. Neptune Rings

    NASA Image and Video Library

    1999-10-29

    This 591-second exposure of the rings of Neptune were taken with the clear filter by NASA Voyager 2 wide-angle camera. The two main rings are clearly visible and appear complete over the region imaged.

  4. Ring Backdrop

    NASA Image and Video Library

    2011-01-03

    Saturn moon Enceladus brightly reflects sunlight before a backdrop of the planet rings and the rings shadows cast onto the planet. NASA Cassini spacecraft captured this snapshot during its flyby of the moon on Nov. 30, 2010.

  5. Lumbar spinal stenosis.

    PubMed Central

    Ciricillo, S F; Weinstein, P R

    1993-01-01

    Lumbar spinal stenosis, the results of congenital and degenerative constriction of the neural canal and foramina leading to lumbosacral nerve root or cauda equina compression, is a common cause of disability in middle-aged and elderly patients. Advanced neuroradiologic imaging techniques have improved our ability to localize the site of nerve root entrapment in patients presenting with neurogenic claudication or painful radiculopathy. Although conservative medical management may be successful initially, surgical decompression by wide laminectomy or an intralaminar approach should be done in patients with serious or progressive pain or neurologic dysfunction. Because the early diagnosis and treatment of lumbar spinal stenosis may prevent intractable pain and the permanent neurologic sequelae of chronic nerve root entrapment, all physicians should be aware of the different neurologic presentations and the treatment options for patients with spinal stenosis. Images PMID:8434469

  6. Postoperative lumbar spine.

    PubMed

    Leone, A; Cerase, A; Lauro, L; Cianfoni, A; Aulisa, L

    2000-01-01

    The differentiation between normal sequelae and complications of any surgical treatment of the lumbar spine is of the utmost importance. Clinical and radiological diagnosis is often difficult. Certainly the introduction of computed tomography (CT) and magnetic resonance imaging (MRI) has improved and refined the diagnostic possibilities, however not all problems have been resolved. For example, the frequent resort in vertebral surgery to metal implants which may limit or even prevent the interpretation of CT or MR images, should be kept in mind. The main types of surgical procedures involving the lumbar spine are briefly reviewed, focusing on CT and MRI appearance of normal sequelae of early or late complications and the recurrence of the lesion that necessitated the first procedure.

  7. LUMBAR DISC HERNIATION

    PubMed Central

    Vialle, Luis Roberto; Vialle, Emiliano Neves; Suárez Henao, Juan Esteban; Giraldo, Gustavo

    2015-01-01

    Lumbar disc herniation is the most common diagnosis among the degenerative abnormalities of the lumbar spine (affecting 2 to 3% of the population), and is the principal cause of spinal surgery among the adult population. The typical clinical picture includes initial lumbalgia, followed by progressive sciatica. The natural history of disc herniation is one of rapid resolution of the symptoms (four to six weeks). The initial treatment should be conservative, managed through medication and physiotherapy, sometimes associated with percutaneous nerve root block. Surgical treatment is indicated if pain control is unsuccessful, if there is a motor deficit greater than grade 3, if there is radicular pain associated with foraminal stenosis, or if cauda equina syndrome is present. The latter represents a medical emergency. A refined surgical technique, with removal of the extruded fragment and preservation of the ligamentum flavum, resolves the sciatic symptoms and reduces the risk of recurrence over the long term. PMID:27019834

  8. Transforaminal lumbar interbody fusion.

    PubMed

    Moskowitz, Alan

    2002-04-01

    Indication and technique of TLIF procedure are described. TLIF provides for anterior column support and posterior tension band. It is a unilateral approach to the spine, and there is no need to expose or manipulate the dura. It provides the benefits of a 360 degrees fusion without performing an anterior approach. It restores the normal anatomy of the motion segment and maintains normal lumbar lordosis. Patients are mobilized quickly and resume activities early.

  9. Lumbar retrodiscal transforaminal injection.

    PubMed

    Jasper, Joseph F

    2007-05-01

    Spinal injections are commonly used to treat lumbar radiculitis and back pain. Delivery of medication to specific targeted pathology is considered important for a successful therapeutic outcome. A variety of routes of injection have been devised for epidural injection of corticosteroid. The author demonstrates a variation of the transforaminal injection technique. The radiographic spread of contrast is described using a more oblique and ventral caudad approach in the epidural space "retrodiscal." It is suggested that the radiographic findings of this technique for discogenic causes of induced radiculitis and/or back pain may yield more precise targeting of putative pathologic sources of radiculopathy and back pain in selected patients. In patients with disc pathology and radiculitis, the anatomy of the lumbar epidural space is reviewed for its potential effect on the flow of injectate. Contrast spread was documented for lumbar transforaminal injection using a needle placement more oblique and behind the disc rather than in the cranial portion. Comparison is made to a typical contrast spread of an infra-pedicular placed transforaminal injection. Retrodiscal contrast injection results in reliable coverage of the retrodiscal region, the exiting nerve at that foraminal level and the proximal portion of the transiting segmental neural sleeve. The radiographic findings demonstrate a difference between classic infra-pedicular versus retrodiscal transforaminal epidural contrast injection patterns, particularly at relatively low volumes. The clinical advantage of one technique versus the other should be established in randomized prospective studies.

  10. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Tiscareno, Matthew S.

    Planetary rings are the only nearby astrophysical disks and the only disks that have been investigated by spacecraft (especially the Cassini spacecraft orbiting Saturn). Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 10- 7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close range and in real time in planetary rings.We review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We then review planetary rings by type. The A, B, and C rings of Saturn, plus the Cassini Division, comprise our solar system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are found both at Uranus (where they comprise the main rings entirely) and at Saturn (where they are embedded in the broad disk) and are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty rings, likely generated by embedded source bodies, are surprisingly found to sport azimuthally confined arcs at Neptune, Saturn, and Jupiter. Finally, every known ring system includes a substantial component of diffuse dusty rings.Planetary rings have shown themselves to be useful as detectors of planetary processes around them, including the planetary magnetic field and interplanetary impactors as well as the gravity of nearby perturbing moons. Experimental rings science has made great progress in recent decades, especially numerical simulations of self-gravity wakes and other processes but also laboratory investigations of coefficient of restitution and spectroscopic ground truth. The age of self-sustained ring systems is a matter of

  11. Nerve Wrapping of the Sciatic Nerve With Acellular Dermal Matrix in Chronic Complete Proximal Hamstring Ruptures and Ischial Apophyseal Avulsion Fractures.

    PubMed

    Haus, Brian M; Arora, Danny; Upton, Joseph; Micheli, Lyle J

    2016-03-01

    Patients with chronic injuries of the proximal hamstring can develop significant impairment because of weakness of the hamstring muscles, sciatic nerve compression from scar formation, or myositis ossificans. To describe the surgical outcomes of patients with chronic injury of the proximal hamstrings who were treated with hamstring repair and sciatic neurolysis supplemented with nerve wrapping with acellular dermal matrix. Retrospective case series; Level of evidence, 4. Fifteen consecutive patients with a diagnosis of chronic complete proximal hamstring rupture or chronic ischial tuberosity apophyseal avulsion fracture (mean age, 39.67 years; range, 14-69 years) were treated with proximal hamstring repair and sciatic neurolysis supplemented with nerve wrapping with acellular dermal matrix. Nine patients had preoperative sciatica, and 6 did not. Retrospective chart review recorded clinical outcomes measured by the degree of pain relief, the rate of return to activities, and associated postoperative complications. All 15 patients were followed in the postoperative period for an average of 16.6 months. Postoperatively, there were 4 cases of transient sciatic nerve neurapraxia. Four patients (26%) required postoperative betamethasone sodium phosphate (Celestone Soluspan) injectable suspension USP 6 mg/mL. Among the 9 patients with preoperative sciatica, 6 (66%) had a good or excellent outcome and were able to return to their respective activities/sports; 3 (33%) had persistent chronic pain. One of these had persistent sciatic neuropathy that required 2 surgical reexplorations and scar excision after development of recurrent extraneural scar formation. Among the 6 without preoperative sciatica, 100% had a good or excellent outcomes and 83% returned to their respective activities/sports. Better outcomes were observed in younger patients, as the 3 cases of persistent chronic sciatic pain were in patients older than 45 years. This study suggests that when used as an

  12. Vortex rings

    NASA Technical Reports Server (NTRS)

    Shariff, Karim; Leonard, Anthony

    1992-01-01

    The vortex-ring problem in fluid mechanics is examined generally in terms of formation, the steady state, the duration of the rings, and vortex interactions. The formation is studied by examining the generation of laminar and turbulent vortex rings and their resulting structures with attention given to the three stages of laminar ring development. Inviscid dynamics is addressed to show how core dynamics affects overall ring motion, and laminar vortex structures are described in two dimensions. Viscous and inviscid structures are related in terms of 'leapfrogging', head-on collisions, and collisions with a no-slip wall. Linear instability theory is shown to successfully describe observational data, although late stages in the breakdown are not completely understood. This study of vortex rings has important implications for key aerodynamic issues including sound generation, transport and mixing, and vortex interactions.

  13. Translucent Rings

    NASA Image and Video Library

    2014-12-08

    Although solid-looking in many images, Saturn's rings are actually translucent. In this picture, we can glimpse the shadow of the rings on the planet through (and below) the A and C rings themselves, towards the lower right hand corner. For centuries people have studied Saturn's rings, but questions about the structure and composition of the rings lingered. It was only in 1857 when the physicist James Clerk Maxwell demonstrated that the rings must be composed of many small particles and not solid rings around the planet, and not until the 1970s that spectroscopic evidence definitively showed that the rings are composed mostly of water ice. This view looks toward the sunlit side of the rings from about 17 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on Aug. 12, 2014 in near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 1.4 million miles (2.3 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 24 degrees. Image scale is 85 miles (136 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18295

  14. Widening Rings

    NASA Image and Video Library

    2010-03-18

    Saturn rings and its moon Rhea are imaged before a crescent of the planet in this image captured by NASA Cassini spacecraft. The shadows of the rings continue to grow wider after their disappearing act during the planet August 2009 equinox.

  15. Planetary Rings

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  16. Ring Slicer

    NASA Image and Video Library

    2015-07-06

    Saturn's moon Prometheus, seen here looking suspiciously blade-like, is captured near some of its sculpting in the F ring. Prometheus' (53 miles or 86 kilometers across) orbit sometimes takes it into the F ring. When it enters the ring, it leaves a gore where its gravitational influence clears out some of the smaller ring particles. Below Prometheus, the dark lanes interior to the F ring's bright core provide examples of previous ring-moon interactions. This view looks toward the unilluminated side of the rings from about 7 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 15, 2015. The view was obtained at a distance of approximately 286,000 miles (461,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 115 degrees. Image scale is 1.7 miles (2.8 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18324

  17. Planetary Rings

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  18. Upper lumbar disk herniations.

    PubMed

    Cedoz, M E; Larbre, J P; Lequin, C; Fischer, G; Llorca, G

    1996-06-01

    Specific features of upper lumbar disk herniations are reviewed based on data from the literature and from a retrospective study of 24 cases treated surgically between 1982 and 1994 (seven at L1-L2 and 17 at L2-L3). Clinical manifestations are polymorphic, misleading (abdominogenital pain suggestive of a visceral or psychogenic condition, meralgia paresthetica, isolated sciatica; femoral neuralgia is uncommon) and sometimes severe (five cases of cauda equina syndrome in our study group). The diagnostic usefulness of imaging studies (radiography, myelography, computed tomography, magnetic resonance imaging) and results of surgery are discussed. The risk of misdiagnosis and the encouraging results of surgery are emphasized.

  19. Lumbar radicular pain.

    PubMed

    Govind, Jay

    2004-06-01

    Radicular pain is caused by irritation of the sensory root or dorsal root ganglion of a spinal nerve. The irritation causes ectopic nerve impulses perceived as pain in the distribution of the axon. The pathophysiology is more than just mass effect: it is a combination of compression sensitising the nerve root to mechanical stimulation, stretching, and a chemically mediated noncellular inflammatory reaction. This article discusses the clinical features, assessment and management of lumbar radicular pain (LRP). Lumbar radicular pain is sharp, shooting or lancinating, and is typically felt as a narrow band of pain down the length of the leg, both superficially and deep. It may be associated with radiculopathy (objective sensory and/or motor dysfunction as a result of conduction block) and may coexist with spinal or somatic referred pain. In more than 50% of cases, LRP settles with simple analgesics. Significant and lasting pain relief can be achieved with transforaminal epidural steroid injection. Surgery is indicated for those patients with progressive neurological deficits or severe LRP refractory to conservative measures.

  20. Postlaminectomy Bilateral Lumbar Intraspinal Synovial Cysts

    PubMed Central

    Cho, Sung Ik; Lee, Jung Hwan

    2016-01-01

    Lumbar intraspinal synovial cysts are included in the difference diagnosis of lumbar radiculopathy. Developing imaging modalities has result in increased reporting about these lesions. However, the case of bilateral new lumbar intraspinal synovial cysts after laminectomy has been rarely reported. We report of a rare case with bilateral lumbar intraspinal synovial cysts after laminectomy, requiring surgical excision. PMID:27799997

  1. Complications and Rates of Subsequent Lumbar Surgery Following Lumbar Total Disc Arthroplasty and Lumbar Fusion.

    PubMed

    Eliasberg, Claire D; Kelly, Michael P; Ajiboye, Remi M; SooHoo, Nelson F

    2016-01-01

    Retrospective analysis. To examine complications and rates of subsequent surgery following lumbar spinal fusion (LF) and lumbar total disc arthroplasty (TDA) at up to 5-year follow-up. LF is commonly used in the management of degenerative disc disease causing pain refractory to nonoperative management. Lumbar TDA was developed as an alternative to fusion with the theoretical advantage of reducing rates of adjacent segment pathology and reoperation. Most prior reports comparing these 2 interventions have come from industry-sponsored investigational device exemption trials and no large-scale administrative database comparisons exist. The California Office of Statewide Health Planning and Development discharge database was queried for patients aged 18 to 65 years undergoing lumbar TDA and LF for degenerative disc disease from 2004 to 2010. Patient characteristics were collected, and rates of complications and readmission were identified. Rates of repeat lumbar surgery were calculated at 90-day and 1-, 3-, and 5-year follow-up intervals. A total of 52,877 patients met the inclusion criteria (LF = 50,462, TDA = 2415). Wound infections were more common following LF than TDA (1.03% vs. 0.25%, P < 0.001). Rates of subsequent lumbar surgery at 90-day and 1-year follow-up were lower with lumbar TDA than LF (90-day-TDA: 2.94% vs. LF: 4.01%, P = 0.007; 1-yr-TDA: 3.46% vs. LF: 4.78%, P = 0.009). However, there were no differences in rates of subsequent lumbar surgery between the 2 groups at 3-year and 5-year follow-up. Lumbar TDA was associated with fewer early reoperations, though beyond 1 year, rates of reoperation were similar. Lumbar TDA may be associated with fewer acute infections, though this may be approach related and unrelated to the device itself. 3.

  2. Complications and Rates of Subsequent Lumbar Surgery Following Lumbar Total Disc Arthroplasty and Lumbar Fusion

    PubMed Central

    Eliasberg, Claire D.; Kelly, Michael P.; Ajiboye, Remi M.; SooHoo, Nelson F.

    2015-01-01

    Study Design Retrospective analysis. Objectives To examine complications and rates of subsequent surgery following lumbar spinal fusion (LF) and lumbar total disc arthroplasty (TDA) at up to 5 years follow-up. Summary of Background Data LF is commonly used in the management of degenerative disc disease causing pain refractory to nonoperative management. Lumbar TDA was developed as an alternative to fusion with the theoretical advantage of reducing rates of adjacent segment pathology and reoperation. Most prior reports comparing these two interventions have come from industry-sponsored investigational device exemption trials and no large-scale administrative database comparisons exist. Methods The California Office of Statewide Health Planning and Development discharge database was queried for patients aged 18 to 65 years undergoing lumbar TDA and LF for degenerative disc disease from 2004 to 2010. Patient characteristics were collected, and rates of complications and readmission were identified. Rates of repeat lumbar surgery were calculated at 90-day and 1-, 3-, and 5-year follow-up intervals. Results A total of 52,877 patients met the inclusion criteria (LF = 50462, TDA = 2415). Wound infections were more common following LF than TDA (1.03% vs. 0.25%, p<0.001). Rates of subsequent lumbar surgery at 90-day and 1-year follow-up were lower with lumbar TDA than LF (90-day – TDA: 2.94% vs. LF: 4.01%, p=0.007; 1-year – TDA: 3.46% vs. LF: 4.78%, p=0.009). However, there were no differences in rates of subsequent lumbar surgery between the two groups at 3-year and 5-year follow-up. Conclusions Lumbar TDA was associated with fewer early reoperations, though beyond one year, rates of reoperation were similar. Lumbar TDA may be associated with fewer acute infections, though this may be approach-related and unrelated to the device itself. PMID:26751061

  3. Nerve Wrapping of the Sciatic Nerve With Acellular Dermal Matrix in Chronic Complete Proximal Hamstring Ruptures and Ischial Apophyseal Avulsion Fractures

    PubMed Central

    Haus, Brian M.; Arora, Danny; Upton, Joseph; Micheli, Lyle J.

    2016-01-01

    Background: Patients with chronic injuries of the proximal hamstring can develop significant impairment because of weakness of the hamstring muscles, sciatic nerve compression from scar formation, or myositis ossificans. Purpose: To describe the surgical outcomes of patients with chronic injury of the proximal hamstrings who were treated with hamstring repair and sciatic neurolysis supplemented with nerve wrapping with acellular dermal matrix. Study Design: Retrospective case series; Level of evidence, 4. Methods: Fifteen consecutive patients with a diagnosis of chronic complete proximal hamstring rupture or chronic ischial tuberosity apophyseal avulsion fracture (mean age, 39.67 years; range, 14-69 years) were treated with proximal hamstring repair and sciatic neurolysis supplemented with nerve wrapping with acellular dermal matrix. Nine patients had preoperative sciatica, and 6 did not. Retrospective chart review recorded clinical outcomes measured by the degree of pain relief, the rate of return to activities, and associated postoperative complications. Results: All 15 patients were followed in the postoperative period for an average of 16.6 months. Postoperatively, there were 4 cases of transient sciatic nerve neurapraxia. Four patients (26%) required postoperative betamethasone sodium phosphate (Celestone Soluspan) injectable suspension USP 6 mg/mL. Among the 9 patients with preoperative sciatica, 6 (66%) had a good or excellent outcome and were able to return to their respective activities/sports; 3 (33%) had persistent chronic pain. One of these had persistent sciatic neuropathy that required 2 surgical reexplorations and scar excision after development of recurrent extraneural scar formation. Among the 6 without preoperative sciatica, 100% had a good or excellent outcomes and 83% returned to their respective activities/sports. Better outcomes were observed in younger patients, as the 3 cases of persistent chronic sciatic pain were in patients older than 45

  4. Ring King

    NASA Image and Video Library

    2014-08-18

    Saturn reigns supreme, encircled by its retinue of rings. Although all four giant planets have ring systems, Saturn's is by far the most massive and impressive. Scientists are trying to understand why by studying how the rings have formed and how they have evolved over time. Also seen in this image is Saturn's famous north polar vortex and hexagon. This view looks toward the sunlit side of the rings from about 37 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on May 4, 2014 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 2 million miles (3 million kilometers) from Saturn. Image scale is 110 miles (180 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18278

  5. Vascular rings.

    PubMed

    Backer, Carl L; Mongé, Michael C; Popescu, Andrada R; Eltayeb, Osama M; Rastatter, Jeffrey C; Rigsby, Cynthia K

    2016-06-01

    The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Occult lumbar spinal stenosis.

    PubMed Central

    Choudhury, A R; Taylor, J C

    1977-01-01

    Twenty-eight patients presenting with low back pain, associated with sciatic or femoral neuropathy, were found to have lateral recess stenosis occurring as a result of hypertrophy of the facet joints, with preservation within normal limits of the sagittal AP diameter of the lumbar canal. Pathology was believed to be traumatic in origin, and the variable nature of the adhesions suggested recurrent inflammation; the hypertrophy of the facet joints may have been the result of traumatic inflammatory hyperaemia. Radiological investigations were unhelpful. The diagnosis of the condition was made at the time of surgical exploration by the findings of alteration of the facet joints, adhesions and fixity of the nerve roots, normal sagittal AP diameter of the canal, and absence of other significant lesions. Gratifying results were obtained with decompression by wide laminectomy with excision of overhanging facet joints and release of adhesions. PMID:894321

  7. [Intradural lumbar disk hernia].

    PubMed

    Alonso-Bartolomé, P; Canga, A; Vázquez-Barquero, A; García-Valtuille, R; Abascal, F; Cerezal, L

    2001-04-01

    Intradural disc herniation is a rare complication of degenerative disc disease. A correct diagnosis of this process is frequently difficult. If this entity is not preoperatively diagnosed and is omitted at surgery, severe neurologic sequels may be provoked. We report a case of a pathologically proven intradural disc herniation preoperatively diagnosed by MR imaging. Clinically, it was manifested by sudden onset of right leg ciatalgia and progressive right lower extremity weakness. The patient also referred a one-month history of sexual dysfunction. MR imaging revealed interruption of the low signal of the anulus fibrosus and of the posterior longitudinal ligament at L2-L3 level and a voluminous disc fragment migrated in the dural sac that showed rim enhancement with gadolinium.The clinical, neuroradiological, and surgical management of lumbar intradural disc herniation are reviewed.

  8. Outcome of Salvage Lumbar Fusion after Lumbar Arthroplasty

    PubMed Central

    Deutsch, Harel

    2014-01-01

    Study Design Retrospective review. Purpose This study aims to define the role of lumbar fusion for persistent back pains after the lumbar disc replacement. Overview of Literature Little is written about lumbar fusion after optimally placed lumbar arthroplasty in patients with persistent lower back pains. Methods Retrospective review of cases of lumbar artificial disc requiring subsequent fusion because of persistent back pains despite optimally placed artificial discs. Outcomes were evaluated using Oswestry Disability Index (ODI) and visual analogue scale (VAS). Clinical improvements indicated 25% improvement in ODI and VAS values. Results Five patients met the study criteria. The mean baseline ODI for the five patients was 52. The mean baseline VAS scores for back and leg pains were 76 and 26, respectively. All the five patients had optimally placed prosthesis. The indication for surgery was the constant low back pains found in all the patients. Revision surgery involved disc explantation and fusion in two of the patients and posterolateral fusion without removing the prosthesis in three. None of the patients achieved adequate pain control after the revision surgery despite the solid bony fusion documented by postoperative computed tomography. The mean ODI value after the fusion was 55. The mean values for back and leg pains VAS were 72 and 30, respectively. Conclusions Lack of good pain relief after successful lumbar artifical disc replacements may indicate different etiology for the back pains. The spine-treating surgeons should have a high threshold level to perform salvage fusion at that level. PMID:24596600

  9. Saturn Ring

    NASA Image and Video Library

    2007-12-12

    Like Earth, Saturn has an invisible ring of energetic ions trapped in its magnetic field. This feature is known as a "ring current." This ring current has been imaged with a special camera on Cassini sensitive to energetic neutral atoms. This is a false color map of the intensity of the energetic neutral atoms emitted from the ring current through a processed called charged exchange. In this process a trapped energetic ion steals and electron from cold gas atoms and becomes neutral and escapes the magnetic field. The Cassini Magnetospheric Imaging Instrument's ion and neutral camera records the intensity of the escaping particles, which provides a map of the ring current. In this image, the colors represent the intensity of the neutral emission, which is a reflection of the trapped ions. This "ring" is much farther from Saturn (roughly five times farther) than Saturn's famous icy rings. Red in the image represents the higher intensity of the particles, while blue is less intense. Saturn's ring current had not been mapped before on a global scale, only "snippets" or areas were mapped previously but not in this detail. This instrument allows scientists to produce movies (see PIA10083) that show how this ring changes over time. These movies reveal a dynamic system, which is usually not as uniform as depicted in this image. The ring current is doughnut shaped but in some instances it appears as if someone took a bite out of it. This image was obtained on March 19, 2007, at a latitude of about 54.5 degrees and radial distance 1.5 million kilometres (920,000 miles). Saturn is at the center, and the dotted circles represent the orbits of the moon's Rhea and Titan. The Z axis points parallel to Saturn's spin axis, the X axis points roughly sunward in the sun-spin axis plane, and the Y axis completes the system, pointing roughly toward dusk. The ion and neutral camera's field of view is marked by the white line and accounts for the cut-off of the image on the left. The

  10. Luminescent Rings

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This view shows the unlit face of Saturn's rings, visible via scattered and transmitted light. In these views, dark regions represent gaps and areas of higher particle densities, while brighter regions are filled with less dense concentrations of ring particles.

    The dim right side of the image contains nearly the entire C ring. The brighter region in the middle is the inner B ring, while the darkest part represents the dense outer B Ring. The Cassini Division and the innermost part of the A ring are at the upper-left.

    Saturn's shadow carves a dark triangle out of the lower right corner of this image.

    The image was taken in visible light with the Cassini spacecraft wide-angle camera on June 8, 2005, at a distance of approximately 433,000 kilometers (269,000 miles) from Saturn. The image scale is 22 kilometers (14 miles) per pixel.

    The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

    For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

  11. Cave Rings

    DTIC Science & Technology

    2010-10-13

    hypothesis, that cave rings are formed in the same manner as coffee rings[3], that is, due to the enhanced deposition at the edges of sessile drops ...Literature The ‘splash ring’ conjecture is described in [5]. It is claimed that 45◦ is the most probable angle for secondary drops to be ejected at, and that...ring’ is the deposit formed when a sessile drop of a solution containing dissolved particles, such as coffee or salt, dries. This was investigated by

  12. [Lumbar stabilization exercises].

    PubMed

    Vásquez-Ríos, Jorge Rodrigo; Nava-Bringas, Tania Inés

    2014-01-01

    Antecedentes: el ejercicio es la intervención con mayor grado de evidencia de eficacia para el tratamiento del dolor crónico de la espalda baja, con beneficio superior en términos de dolor y funcionalidad, en comparación con cualquiera otra intervención. Existe una amplia variedad de ejercicios diseñados; sin embargo, actualmente los llamados ejercicios de estabilización lumbar adquiririeron una popularidad creciente entre los clínicos que están en contacto con enfermedades de la columna. Sin embargo, existe controversia en cuanto a la prescripción adecuada de los mismos y los múltiples protocolos publicados. Objetivo: analizar la bibliografía científica acerca del uso y prescripción de estos ejercicios para favorecer la mejor toma de decisiones enlos clínicos y diseñar, con base a la evidencia, el programa más adecuado para cada paciente. Conclusión: se encontró que este programa es una herramienta esencial en el tratamiento del dolor de espalda baja, en la etapa terapéutica y en la preventiva.

  13. Lumbar Spinal Stenosis

    PubMed Central

    Genevay, Stephane

    2009-01-01

    Lumbar spinal stenosis (LSS) is most commonly due to degenerative changes in older individuals. LSS is being more commonly diagnosed and may relate to better access to advanced imaging and to an aging population. This review focuses on radicular symptoms related to degenerative central and lateral stenosis and updates knowledge of LSS pathophysiology, diagnosis and management. Since patients with anatomic LSS can range from asymptomatic to severely disabled, the clinical diagnosis focuses on symptoms and examination findings associated with LSS. Imaging findings are helpful for patients with persistent, bothersome symptoms in whom invasive treatments are being considered. There is limited information from high quality studies about the relative benefits and harms of commonly used treatments. Interpreting and comparing results of available research is limited by a lack of consensus about the definition of LSS. Nevertheless, evidence supports decompressive laminectomy for patients with persistent and bothersome symptoms. Recommendations favor a shared decision making approach due to important trade-offs between alternative therapies and differences among patients in their preferences and values. PMID:20227646

  14. Lumbar intrathecal ligaments.

    PubMed

    Kershner, David E; Binhammer, Robert T

    2002-03-01

    A meticulous examination was performed on 56 vertebral columns from cadavers between 64 and 89 years of age. Identification of all contents within the dural sac was completed; however, the main focus was the cauda equina and lumbar region. In addition to scope dissection, radiographs and histological preparations were used to identify structures, tissue types, and any possible pathology. Discrete intrathecal ligamentous bands were observed in all cadavers examined. They were found randomly binding the dorsal nerve roots of the cauda equina to the dura. Occasional binding of the ventral nerve roots to the dorsal roots was observed. Histological examination demonstrated a dense collagen ligament varying between 0.13 and 0.35 microm in thickness and from 3 mm to 3.5 cm in length. The average number of ligaments found per cadaver was 18. These ligaments displayed a broad base attachment to the nerve root or dura of approximately 3 mm. Looping of the nerve roots associated with these ligaments was seen in one cadaver with a burst fracture. Electron microscopic studies of these ligaments demonstrated similarities to denticulate ligaments. It is suggested that the intrathecal ligaments represent remnants from fetal development of the denticulate ligaments.

  15. Lumbar and sacral radiofrequency neurotomy.

    PubMed

    Mazin, David A; Sullivan, Joseph P

    2010-11-01

    Radiofrequency (RF) neurotomy is an interventional procedure used to alleviate certain types of low back pain. RF energy is used to thermally coagulate the specific nerves that transmit pain signals. Recent evidence has shown that this procedure demonstrates significant efficacy in relieving low back pain in lumbar zygapophysial joints, and research is ongoing to determine if pain relief for the sacroiliac joint is also possible. This article provides an evidence-based background for performing RF neurotomy, discusses the relevant anatomy, and highlights the indications and technique for lumbar and sacral RF neurotomy. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Lumbar discography: an update.

    PubMed

    Anderson, Mark W

    2004-01-01

    and then come back to reinject more contrast into the disk in question. As radiologists, we tend to focus on the technical aspects of a procedure and the anatomic/morphologic information it provides. However, it cannot be emphasized enough that when performing lumbar discography, the assessment of the patient's pain response during the injection is the most important component of the procedure, and requires not only technical skills, but an understanding of how best to avoid some of the pitfalls that can lead to inaccurate results.

  17. Ringing wormholes

    SciTech Connect

    Konoplya, R.A.; Molina, C.

    2005-06-15

    We investigate the response of traversable wormholes to external perturbations through finding their characteristic frequencies and time-domain profiles. The considered solution describes traversable wormholes between the branes in the two brane Randall-Sundrum model and was previously found within Einstein gravity with a conformally coupled scalar field. The evolution of perturbations of a wormhole is similar to that of a black hole and represents damped oscillations (ringing) at intermediately late times, which are suppressed by power-law tails (proportional to t{sup -2} for monopole perturbations) at asymptotically late times.

  18. Management of lumbar spinal stenosis.

    PubMed

    Lurie, Jon; Tomkins-Lane, Christy

    2016-01-04

    Lumbar spinal stenosis (LSS) affects more than 200,000 adults in the United States, resulting in substantial pain and disability. It is the most common reason for spinal surgery in patients over 65 years. Lumbar spinal stenosis is a clinical syndrome of pain in the buttocks or lower extremities, with or without back pain. It is associated with reduced space available for the neural and vascular elements of the lumbar spine. The condition is often exacerbated by standing, walking, or lumbar extension and relieved by forward flexion, sitting, or recumbency. Clinical care and research into lumbar spinal stenosis is complicated by the heterogeneity of the condition, the lack of standard criteria for diagnosis and inclusion in studies, and high rates of anatomic stenosis on imaging studies in older people who are completely asymptomatic. The options for non-surgical management include drugs, physiotherapy, spinal injections, lifestyle modification, and multidisciplinary rehabilitation. However, few high quality randomized trials have looked at conservative management. A systematic review concluded that there is insufficient evidence to recommend any specific type of non-surgical treatment. Several different surgical procedures are used to treat patients who do not improve with non-operative therapies. Given that rapid deterioration is rare and that symptoms often wax and wane or gradually improve, surgery is almost always elective and considered only if sufficiently bothersome symptoms persist despite trials of less invasive interventions. Outcomes (leg pain and disability) seem to be better for surgery than for non-operative treatment, but the evidence is heterogeneous and often of limited quality. © BMJ Publishing Group Ltd 2015.

  19. Degenerative lumbar spinal stenosis and lumbar spine configuration

    PubMed Central

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

    2010-01-01

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

  20. Kinetics of ring formation

    NASA Astrophysics Data System (ADS)

    Ben-Naim, E.; Krapivsky, P. L.

    2011-06-01

    We study reversible polymerization of rings. In this stochastic process, two monomers bond and, as a consequence, two disjoint rings may merge into a compound ring or a single ring may split into two fragment rings. This aggregation-fragmentation process exhibits a percolation transition with a finite-ring phase in which all rings have microscopic length and a giant-ring phase where macroscopic rings account for a finite fraction of the entire mass. Interestingly, while the total mass of the giant rings is a deterministic quantity, their total number and their sizes are stochastic quantities. The size distribution of the macroscopic rings is universal, although the span of this distribution increases with time. Moreover, the average number of giant rings scales logarithmically with system size. We introduce a card-shuffling algorithm for efficient simulation of the ring formation process and we present numerical verification of the theoretical predictions.

  1. The human lumbar dorsal rami.

    PubMed Central

    Bogduk, N; Wilson, A S; Tynan, W

    1982-01-01

    The L 1-4 dorsal rami tend to form three branches, medial, lateral, and intermediate, which are distributed, respectively, to multifidus, iliocostalis, and longissimus. The intertransversarii mediales are innervated by a branch of the dorsal ramus near the origin of the medial branch. The L 4 dorsal ramus regularly forms three branches while the L 1-3 levels the lateral and intermediate branches may, alternatively, arise from a short common stem. The L 5 dorsal ramus is much longer than the others and forms only a medial and an intermediate branch. Each lumbar medial branch innervates two adjacent zygapophysial joints and ramifies in multifidus, supplying only those fascicles which arise from the spinous process with the same segmental number as the nerve. The comparative anatomy of the lumbar dorsal rami is discussed and the applied anatomy with respect to 'rhizolysis', 'facet denervation' and diagnostic paraspinal electromyography is described. PMID:7076562

  2. Lumbar lordosis of extinct hominins.

    PubMed

    Been, Ella; Gómez-Olivencia, Asier; Kramer, Patricia A

    2012-01-01

    The lordotic curvature of the lumbar spine (lumbar lordosis) in humans is a critical component in the ability to achieve upright posture and bipedal gait. Only general estimates of the lordotic angle (LA) of extinct hominins are currently available, most of which are based on the wedging of the vertebral bodies. Recently, a new method for calculating the LA in skeletal material has become available. This method is based on the relationship between the lordotic curvature and the orientation of the inferior articular processes relative to vertebral bodies in the lumbar spines of living primates. Using this relationship, we developed new regression models in order to calculate the LAs in hominins. The new models are based on primate group-means and were used to calculate the LAs in the spines of eight extinct hominins. The results were also compared with the LAs of modern humans and modern nonhuman apes. The lordotic angles of australopithecines (41° ± 4), H. erectus (45°) and fossil H. sapiens (54° ± 14) are similar to those of modern humans (51° ± 11). This analysis confirms the assumption that human-like lordotic curvature was a morphological change that took place during the acquisition of erect posture and bipedalism as the habitual form of locomotion. Neandertals have smaller lordotic angles (LA = 29° ± 4) than modern humans, but higher angles than nonhuman apes (22° ± 3). This suggests possible subtle differences in Neandertal posture and locomotion from that of modern humans.

  3. [Regional anesthesia for lumbar microdiscectomy].

    PubMed

    Dagher, Christine; Naccache, Nicole; Narchi, Patrick; Hage, Paul; Antakly, Marie-Claire

    2002-01-01

    Lumbar microdiscectomy surgery is already performed under spinal anesthesia (SA) in many institutions. The aim of this study is to compare the quality of analgesia and recovery after SA when compared to general anesthesia (GA) after lumbar microdiscectomy surgery. Following light sedation, SA is performed with the patient in the left lateral decubitus position, one to two levels above the herniated disc level. Isobaric 0.5% bupivacaine 3-3.5 ml was injected intrathecally followed by wound infiltration with 15 ml of bupivacaine with 1/200 000 epinephrine prior to surgical incision. Despite randomization, we found significantly more females in the GA group. Pain scores at 4 and 8 h postoperatively were lower in SA group as well as total analgesic consumption during the first 24 h. Postoperative recovery including time to drinking, eating and walking were more rapid after SA when compared to GA. During the postoperative period, the incidence of urinary retention was comparable between groups but the occurrence of postoperative nausea and vomiting was significantly higher in the GA group. Moreover, the overall patient's and surgeon's satisfaction were significantly better in the SA group. SA associated to wound infiltration using bupivacaine is an interesting alternative to general anesthesia for outpatient lumbar microdiscectomy surgery.

  4. Assessment of Lumbar Lordosis and Lumbar Core Strength in Information Technology Professionals

    PubMed Central

    Mehta, Roma Satish; Dabadghav, Rachana; Rairikar, Savita; Shayam, Ashok; Sancheti, Parag

    2016-01-01

    Study Design Observational study. Purpose To correlate lumbar lordosis and lumbar core strength in information technology (IT) professionals. Overview of Literature IT professionals have to work for long hours in a sitting position, which can affect lumbar lordosis and lumbar core strength. Methods Flexicurve was used to assess the lumbar lordosis, and pressure biofeedback was used to assess the lumbar core strength in the IT professionals. All subjects, both male and female, with and without complaint of low back pain and working for two or more years were included, and subjects with a history of spinal surgery or spinal deformity were excluded from the study. Analysis was done using Pearson's correlation. Results For the IT workers, no correlation was seen between lumbar lordosis and lumbar core strength (r=–0.04); however, a weak negative correlation was seen in IT people who complained of pain (r=–0.12), while there was no correlation of lumbar lordosis and lumbar core in IT people who had no complains of pain (r=0.007). Conclusions The study shows that there is no correlation of lumbar lordosis and lumbar core strength in IT professionals, but a weak negative correlation was seen in IT people who complained of pain. PMID:27340529

  5. Assessment of Lumbar Lordosis and Lumbar Core Strength in Information Technology Professionals.

    PubMed

    Mehta, Roma Satish; Nagrale, Sanket; Dabadghav, Rachana; Rairikar, Savita; Shayam, Ashok; Sancheti, Parag

    2016-06-01

    Observational study. To correlate lumbar lordosis and lumbar core strength in information technology (IT) professionals. IT professionals have to work for long hours in a sitting position, which can affect lumbar lordosis and lumbar core strength. Flexicurve was used to assess the lumbar lordosis, and pressure biofeedback was used to assess the lumbar core strength in the IT professionals. All subjects, both male and female, with and without complaint of low back pain and working for two or more years were included, and subjects with a history of spinal surgery or spinal deformity were excluded from the study. Analysis was done using Pearson's correlation. For the IT workers, no correlation was seen between lumbar lordosis and lumbar core strength (r=-0.04); however, a weak negative correlation was seen in IT people who complained of pain (r=-0.12), while there was no correlation of lumbar lordosis and lumbar core in IT people who had no complains of pain (r=0.007). The study shows that there is no correlation of lumbar lordosis and lumbar core strength in IT professionals, but a weak negative correlation was seen in IT people who complained of pain.

  6. Ringing phenomenon of the fiber ring resonator.

    PubMed

    Ying, Diqing; Ma, Huilian; Jin, Zhonghe

    2007-08-01

    A resonator fiber-optic gyro (R-FOG) is a high-accuracy inertial rotation sensor based on the Sagnac effect. A fiber ring resonator is the core sensing element in the R-FOG. When the frequency of the fiber ring resonator input laser is swept linearly with time, ringing of the output resonance curve is observed. The output field of the fiber ring resonator is derived from the superposition of the light transmitted through the directional coupler directly and the multiple light components circulated in the fiber ring resonator when the frequency of the laser is swept. The amplitude and phase of the output field are analyzed, and it is found that the difference in time for different light components in the fiber ring resonator to reach a point of destructive interference causes the ringing phenomenon. Finally the ringing phenomenon is observed in experiments, and the experimental results agree with the theoretical analysis well.

  7. Clinical anatomy and 3D virtual reconstruction of the lumbar plexus with respect to lumbar surgery.

    PubMed

    Lu, Sheng; Chang, Shan; Zhang, Yuan-zhi; Ding, Zi-hai; Xu, Xin Ming; Xu, Yong-qing

    2011-04-14

    Exposure of the anterior or lateral lumbar via the retroperitoneal approach easily causes injuries to the lumbar plexus. Lumbar plexus injuries which occur during anterior or transpsoas lumbar spine exposure and placement of instruments have been reported. This study aims is to provide more anatomical data and surgical landmarks in operations concerning the lumbar plexus in order to prevent lumbar plexus injuries and to increase the possibility of safety in anterior approach lumbar surgery. To study the applied anatomy related to the lumbar plexus of fifteen formaldehyde-preserved cadavers, Five sets of Virtual Human (VH) data set were prepared and used in the study. Three-dimensional (3D) computerized reconstructions of the lumbar plexus and their adjacent structures were conducted from the VH female data set. The order of lumbar nerves is regular. From the anterior view, lumbar plexus nerves are arranged from medial at L5 to lateral at L2. From the lateral view, lumbar nerves are arranged from ventral at L2 to dorsal at L5. The angle of each nerve root exiting outward to the corresponding intervertebral foramen increases from L1 to L5. The lumbar plexus nerves are observed to be in close contact with transverse processes (TP). All parts of the lumbar plexus were located by sectional anatomy in the dorsal third of the psoas muscle. Thus, access to the psoas major muscle at the ventral 2/3 region can safely prevent nerve injuries. 3D reconstruction of the lumbar plexus based on VCH data can clearly show the relationships between the lumbar plexus and the blood vessels, vertebral body, kidney, and psoas muscle. The psoas muscle can be considered as a surgical landmark since incision at the ventral 2/3 of the region can prevent lumbar plexus injuries for procedures requiring exposure of the lateral anterior of the lumbar. The transverse process can be considered as a landmark and reference in surgical operations by its relative position to the lumbar plexus. 3D

  8. The Ring Sculptor

    NASA Image and Video Library

    2006-09-08

    Prometheus zooms across the Cassini spacecraft field of view, attended by faint streamers and deep gores in the F ring. This movie sequence of five images shows the F ring shepherd moon shaping the ring inner edge

  9. Beyond Bright Rings

    NASA Image and Video Library

    2009-12-30

    The tiny moon Pandora appears beyond the bright disk of Saturn rings in this image taken by NASA Cassini spacecraft. Pandora orbits outside the F ring and, in this image, is farther from Cassini than the rings are.

  10. Asymmetric dipolar ring

    DOEpatents

    Prosandeev, Sergey A.; Ponomareva, Inna V.; Kornev, Igor A.; Bellaiche, Laurent M.

    2010-11-16

    A device having a dipolar ring surrounding an interior region that is disposed asymmetrically on the ring. The dipolar ring generates a toroidal moment switchable between at least two stable states by a homogeneous field applied to the dipolar ring in the plane of the ring. The ring may be made of ferroelectric or magnetic material. In the former case, the homogeneous field is an electric field and in the latter case, the homogeneous field is a magnetic field.

  11. Saturn's Spectacular Ring System

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Saturn's beautiful rings have fascinated astronomers since they were first observed by Galileo in 1610. The main rings consist of solid particles mostly in the 1 cm - 10 m range, composed primarily of water ice. The ring disk is exceptionally thin - the typical local thickness of the bright rings is tens of meters, whereas the diameter of the main rings is 250,000 km! The main rings exhibit substantial radial variations "ringlets", many of which are actively maintained via gravitational perturbations from Saturn's moons. Exterior to the main rings lie tenuous dust rings, which have little mass but occupy a very large volume of space. This seminar will emphasize the physics of ring-moon interactions, recent advances in our understanding of various aspects of the rings obtained from observations taken during 1995 when the rings appeared edge-on to the Earth and then to the Sun, and observations in subsequent years from HST.

  12. Spontaneous hemorrhage into a lumbar synovial cyst

    PubMed Central

    Alen, Jose F.; Ramos, Ana; Lobato, Ramiro D.; Lagares, Alfonso

    2010-01-01

    Lumbar synovial cysts frequently present with back pain, chronic radiculopathy and/or progressive symptoms of spinal canal compromise. These cysts generally appear in the context of degenerative lumbar spinal disease. Few cases of spontaneous hemorrhage into synovial cysts have been reported in the literature. PMID:20174835

  13. Primary lumbar hernia: A rarely encountered hernia

    PubMed Central

    Sundaramurthy, Sharada; Suresh, H.B.; Anirudh, A.V.; Prakash Rozario, Anthony

    2015-01-01

    Introduction Lumbar hernia is an uncommon abdominal wall hernia, making its diagnosis and management a challenge to the treating surgeon. Presentation may be misleading and diagnosis often missed. An imaging study forms an indispensable aid in the diagnosis and surgery is the only treatment option. Presentation of case A 42 year old male presented with history of pain in lower back of 4 years duration and was being treated symptomatically over 4 years with analgesics and physiotherapy. He had noticed a swelling over the left side of his mid-back and consequently on examination was found to have a primary acquired lumbar hernia arising from the deep superior lumbar triangle of Grynfelt. Diagnosis was confirmed by Computed Tomographic imaging. Discussion A lumbar hernia may be primary or secondary with only about 300 cases of primary lumbar hernia reported in literature. Lumbar hernias manifest through two possible defects in the posterior abdominal wall, the superior being more common. Management remains surgical with various techniques emerging over the years. The patient at our center underwent an open sublay mesh repair with excellent outcome. Conclusion A surgeon may encounter a primary lumbar hernia perhaps once in his lifetime making it an interesting surgical challenge. Sound anatomical knowledge and adequate imaging are indispensable. Inspite of advances in minimally invasive surgery, it cannot be universally applied to patients with lumbar hernia and management requires a more tailored approach. PMID:26812667

  14. Lumbar adhesive arachnoiditis. Etiologic and pathologic aspects.

    PubMed

    Quiles, M; Marchisello, P J; Tsairis, P

    1978-03-01

    The etiologic factors and pathologic findings in 38 patients with lumbar arachnoiditis are presented. Lumbar spine surgery and the injection of contrast materials prior to the diagnosis of this condition are considered the most important factors in its genesis. In this series, there was microscopic evidence of arachnoiditis ossificans in 3 patients and arachnoiditis calcificans in 1 patient.

  15. [Lumbar pain in old age].

    PubMed

    Baumgartner, H

    1996-10-22

    In advanced age, lumbar pain is less frequently caused by occupational stress and psychosomatic factors. Unstable segments and spondylo-arthrotic degeneration can lead to muscular strain whenever insufficient secondary stability and missing muscular equilibrium are involved. In the differential diagnosis one must distinguish between osteoporosis and spinal stenosis, which increases in frequency with age. Pain due to internal or gynecological problems must be excluded. From the therapeutic point of view, patients should be instructed in ergonomics and the simple application of physiotherapeutic procedures, e.g. heat and cold. Analgetics become increasingly important with age, consequently resulting in reduced use of antirheumatics. There exists enough evidence to show that muscular training of the lumbar muscles play an important role in the secondary prevention of lumbar pain in elderly people as well. Essentially, it can be stated that physical age is not directly related to possible ailment. The change of occupational obligations, with possibilities to adapt to personal stress levels, as well as the positive attitude towards everyday life in retirement have a major influence in accepting and handling ability of problems, concerning pain. In the department of Physical Medicine, Rehabilitation and Rheumatology of the Clinic Wilhelm Schulthess it was found that among 7806 patients with lower back pain (1990-1995) 43.3% involved the ages of 40 to 60 and 31.3% the ages of 60 to 80. More distinctly than in younger patients, older aged patients tend to show a marked discrepancy between radiological findings and effective pain. Lower back pains of elderly patients are of a different nature from those found in younger or middle-aged people. Ischialgia due to the protrusion of an intervertebral disk or an acute lumbovertebral syndrome caused by muscular instability are found much less frequently.

  16. Lumbar intraspinal extradural ganglion cysts.

    PubMed

    Cho, Sung Min; Rhee, Woo Tack; Choi, Soo Jung; Eom, Dae Woon

    2009-07-01

    The lumbar intraspinal epidural ganglion cyst has been a rare cause of the low back pain or leg pain. Ganglion cysts and synovial cysts compose the juxtafacet cysts. Extensive studies have been performed about the synovial cysts, however, very little has been known about the ganglion cyst. Current report is about two ganglion cysts associated with implicative findings in young male patients. We discuss about the underlying pathology of the ganglion cyst based on intraoperative evidences, associated disc herniation at the same location or severe degeneration of the ligament flavum that the cyst originated from in young patients.

  17. Lumbar Epidural Varix Mimicking Disc Herniation

    PubMed Central

    Bursalı, Adem; Guvenal, Ahmet Burak; Yaman, Onur

    2016-01-01

    Lumbar radiculopathy is generally caused by such well-recognized entity as lumbar disc herniation in neurosurgical practice; however rare pathologies such as thrombosed epidural varix may mimic them by causing radicular symptoms. In this case report, we present a 26-year-old man with the complaint of back and right leg pain who was operated for right L4–5 disc herniation. The lesion interpreted as an extruded disc herniation preoperatively was found to be a thrombosed epidural varix compressing the nerve root preoperatively. The nerve root was decompressed by shrinking the lesion with bipolar thermocoagulation and excision. The patient's complaints disappeared in the postoperative period. Thrombosed lumbar epidural varices may mimic lumbar disc herniations both radiologically and clinically. Therefore, must be kept in mind in the differential diagnosis of lumbar disc herniations. Microsurgical techniques are mandatory for the treatment of these pathologies and decompression with thermocoagulation and excision is an efficient method. PMID:27446525

  18. Uranus Tenth Ring

    NASA Image and Video Library

    1996-01-29

    On Jan. 23, 1986, NASA Voyager 2 discovered a tenth ring orbiting Uranus. The tenth ring is about midway between the bright, outermost epsilon ring and the next ring down, called delta. http://photojournal.jpl.nasa.gov/catalog/PIA00035

  19. Stirling engine piston ring

    DOEpatents

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  20. Birth Control Ring

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Ring KidsHealth > For Teens > Birth Control Ring Print A A A What's in this ... español Anillo vaginal anticonceptivo What Is It? The birth control ring is a soft, flexible, doughnut-shaped ring ...

  1. New Dust Belts of Uranus: One Ring, Two Ring, Red Ring, Blue Ring

    SciTech Connect

    de Pater, I; Hammel, H B; Gibbard, S G; Showalter, M R

    2006-02-02

    We compare near-infrared observations of the recently discovered outer rings of Uranus with HST results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced via impacts into the embedded moon Mab, which apparently orbits at a location where non-gravitational perturbations favor the survival and spreading of sub-micron sized dust. R/2003 U 2 more closely resembles Saturn's G ring.

  2. Lumbar interspinous bursitis in active polymyalgia rheumatica.

    PubMed

    Salvarani, Carlo; Barozzi, Libero; Boiardi, Luigi; Pipitone, Nicolò; Bajocchi, Gian Luigi; Macchioni, Pier Luigi; Catanoso, Mariagrazia; Pazzola, Giulia; Valentino, Massimo; De Luca, Carlo; Hunder, Gene G

    2013-01-01

    To evaluate the inflammatory involvement of lumbar interspinous bursae in patients with polymyalgia rheumatica (PMR) using magnetic resonance imaging (MRI). Ten consecutive, untreated new patients with PMR and pain in the shoulder and pelvic girdles were investigated. Seven patients with spondyloarthritis (4 with psoriatic spondyloarthrits, one with entheropatic spondyloarthritis, and 2 with ankylosing spondylitis) as well as 2 patients with spinal osteoarthritis and 2 patients with rheumatoid arthritis with lumbar pain served as controls. MRI of lumbar spine was performed in all PMR patients and controls. Nine patients (5 PMR patients and 4 controls) also had MRI of the thoracic spine. MRI evidence of interspinous lumbar bursitis was found in 9/10 patients with PMR and in 5/11 controls. A moderate to marked (grade ≥2 on a semiquantitative 0-3 scale) lumbar bursitis occurred significantly more frequently in patients with PMR than in control patients (60% vs. 9%, p=0.020). In most of the patients and controls lumbar bursitis was found at the L3-L5 interspaces. Only 2 patients had bursitis at a different level (one patient had widespread lumbar bursitis, and one control at L2-L4). No interspinous bursitis was demonstrated by MRI of the thoracic spine in patients and controls. Inflammation of lumbar bursae may be responsible for the low back pain reported by patients with PMR. The prominent inflammatory involvement of bursae including those of the lumbar spine supports the hypothesis that PMR may be a disorder affecting predominantly extra-articular synovial structures.

  3. Lumbar stenosis: clinical case☆☆☆

    PubMed Central

    Sá, Pedro; Marques, Pedro; Alpoim, Bruno; Rodrigues, Elisa; Félix, António; Silva, Luís; Leal, Miguel

    2014-01-01

    Lumbar stenosis is an increasingly common pathological condition that is becoming more frequent with increasing mean life expectancy, with high costs for society. It has many causes, among which degenerative, neoplastic and traumatic causes stand out. Most of the patients respond well to conservative therapy. Surgical treatment is reserved for patients who present symptoms after implementation of conservative measures. Here, a case of severe stenosis of the lumbar spine at several levels, in a female patient with pathological and surgical antecedents in the lumbar spine, is presented. The patient underwent two different decompression techniques within the same operation. PMID:26229836

  4. ISASS Policy Statement – Lumbar Artificial Disc

    PubMed Central

    Garcia, Rolando

    2015-01-01

    Purpose The primary goal of this Policy Statement is to educate patients, physicians, medical providers, reviewers, adjustors, case managers, insurers, and all others involved or affected by insurance coverage decisions regarding lumbar disc replacement surgery. Procedures This Policy Statement was developed by a panel of physicians selected by the Board of Directors of ISASS for their expertise and experience with lumbar TDR. The panel's recommendation was entirely based on the best evidence-based scientific research available regarding the safety and effectiveness of lumbar TDR. PMID:25785243

  5. Jupiter's Main Ring/Ring Halo

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (28.5 miles) per picture element (pixel) along Jupiter's rings. Because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun; the ring was approximately 2.3 million kilometers (1.4 million miles) away. The arc on the far right of the image is produced when sunlight is scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

    Jupiter's ring system is composed of three parts - - a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, outside the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the figure's far left side. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the ring's ansa (top image). A faint mist of particles can be seen above and below the main rings. This vertically extended 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces pushing the smallest grains out of the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. To accentuate faint features in the bottom image of the ring halo, different brightnesses are shown through color. Brightest features are white or yellow and the

  6. Jupiter's Main Ring/Ring Halo

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (28.5 miles) per picture element (pixel) along Jupiter's rings. Because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun; the ring was approximately 2.3 million kilometers (1.4 million miles) away. The arc on the far right of the image is produced when sunlight is scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

    Jupiter's ring system is composed of three parts - - a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, outside the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the figure's far left side. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the ring's ansa (top image). A faint mist of particles can be seen above and below the main rings. This vertically extended 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces pushing the smallest grains out of the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. To accentuate faint features in the bottom image of the ring halo, different brightnesses are shown through color. Brightest features are white or yellow and the

  7. Adhesive arachnoiditis following lumbar myelography.

    PubMed

    Skalpe, I O

    1978-03-01

    Late sequelae (adhesive arachnoiditis) have been reported following myelography with the oily contrast medium (Pantopaque) and with the ionic water-soluble contrast media methiodal sodium (Abrodil, Conturex, Kontrast U) meglumine iothalamate (Conray Meglumine) and meglumine iocarmate (Bis-Conray, Dimer-X). Adhesive arachnoiditis has not yet been reported after the use of the nonionic water-soluble contrast medium metrizamide (Amipaque). Thus, this is considered the contrast medium of choice for lumbar myelography. Using the recommended dose of 10 ml with an iodine concentration of 170 mg/ml for this examination, adhesive arachnoiditis is unlikely to occur. Increased osmolality of spinal fluid after injection of contrast medium is related to increased frequency of arachnoiditis.

  8. Lumbar herniated disc: spontaneous regression

    PubMed Central

    Yüksel, Kasım Zafer

    2017-01-01

    Background Low back pain is a frequent condition that results in substantial disability and causes admission of patients to neurosurgery clinics. To evaluate and present the therapeutic outcomes in lumbar disc hernia (LDH) patients treated by means of a conservative approach, consisting of bed rest and medical therapy. Methods This retrospective cohort was carried out in the neurosurgery departments of hospitals in Kahramanmaraş city and 23 patients diagnosed with LDH at the levels of L3−L4, L4−L5 or L5−S1 were enrolled. Results The average age was 38.4 ± 8.0 and the chief complaint was low back pain and sciatica radiating to one or both lower extremities. Conservative treatment was administered. Neurological examination findings, durations of treatment and intervals until symptomatic recovery were recorded. Laségue tests and neurosensory examination revealed that mild neurological deficits existed in 16 of our patients. Previously, 5 patients had received physiotherapy and 7 patients had been on medical treatment. The number of patients with LDH at the level of L3−L4, L4−L5, and L5−S1 were 1, 13, and 9, respectively. All patients reported that they had benefit from medical treatment and bed rest, and radiologic improvement was observed simultaneously on MRI scans. The average duration until symptomatic recovery and/or regression of LDH symptoms was 13.6 ± 5.4 months (range: 5−22). Conclusions It should be kept in mind that lumbar disc hernias could regress with medical treatment and rest without surgery, and there should be an awareness that these patients could recover radiologically. This condition must be taken into account during decision making for surgical intervention in LDH patients devoid of indications for emergent surgery. PMID:28119770

  9. New dust belts of Uranus: one ring, two ring, red ring, blue ring.

    PubMed

    de Pater, Imke; Hammel, Heidi B; Gibbard, Seran G; Showalter, Mark R

    2006-04-07

    We compared near-infrared observations of the recently discovered outer rings of Uranus with Hubble Space Telescope results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced by impacts into the embedded moon Mab, which apparently orbits at a location where nongravitational perturbations favor the survival and spreading of submicron-sized dust. R/2003 U 2 more closely resembles Saturn's G ring, which is red, a typical color for dusty rings.

  10. Rings Through Atmosphere

    NASA Image and Video Library

    2010-05-26

    NASA Cassini spacecraft looks toward the limb of Saturn and, on the right of this image, views part of the rings through the planet atmosphere. Saturn atmosphere can distort the view of the rings from some angles.

  11. Wavy, Wiggly Ring

    NASA Image and Video Library

    2012-04-23

    The constant change in Saturn wavy, wiggly F ring is on display in this image obtained by NASA Cassini spacecraft. The image shows a view looking directly down onto the ring with the planet removed from the center.

  12. Saturn Rings in Infrared

    NASA Image and Video Library

    2006-10-11

    This mosaic of Saturn rings was acquired by NASA Cassini visual and infrared mapping spectrometer instrument on Sept. 15, 2006, while the spacecraft was in the shadow of the planet looking back towards the rings

  13. The Inner Rings

    NASA Image and Video Library

    2007-02-01

    The Cassini spacecraft looks toward the innermost region of Saturn rings, capturing from right to left the C and B rings. The dark, inner edge of the Cassini Division is just visible in the lower left corner

  14. Lumbar Puncture (Spinal Tap) (For Parents)

    MedlinePlus

    ... treatment while waiting for the results of the culture. Risks A lumbar puncture is considered a safe procedure with minimal risks. Most of the time, there are no complications. In some instances, a ...

  15. Saturn's F-Ring

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This narrow-angle camera image of Saturn's F Ring was taken through the Clear filter while at a distance of 6.9 million km from Saturn on 8 November 1980. The brightness variations of this tightly-constrained ring shown here indicate that the ring is less uniform in makeup than the larger rings. JPL managed the Voyager Project for NASA's Office of Space Science

  16. Saturn's F-Ring

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This narrow-angle camera image of Saturn's F Ring was taken through the Clear filter while at a distance of 6.9 million km from Saturn on 8 November 1980. The brightness variations of this tightly-constrained ring shown here indicate that the ring is less uniform in makeup than the larger rings. JPL managed the Voyager Project for NASA's Office of Space Science

  17. Posteroanterior versus anteroposterior lumbar spine radiology

    SciTech Connect

    Tsuno, M.M.; Shu, G.J. )

    1990-03-01

    The posteroanterior view of the lumbar spine has important features including radiation protection and image quality; these have been studied by various investigators. Investigators have shown that sensitive tissues receive less radiation dosage in the posteroanterior view of the spine for scoliosis screening and intracranial tomography without altering the image quality. This paper emphasizes the importance of the radiation safety aspect of the posteroanterior view and shows the improvement in shape distortion in the lumbar vertebrae.

  18. Factors that influence recurrent lumbar disc herniation.

    PubMed

    Yaman, M E; Kazancı, A; Yaman, N D; Baş, F; Ayberk, G

    2017-06-01

    The most common cause of poor outcome following lumbar disc surgery is recurrent herniation. Recurrence has been noted in 5% to 15% of patients with surgically treated primary lumbar disc herniation. There have been many studies designed to determine the risk factors for recurrent lumbar disc herniation. In this study, we retrospectively analysed the influence of disc degeneration, endplate changes, surgical technique, and patient's clinical characteristics on recurrent lumbar disc herniation. Patients who underwent primary single-level L4-L5 lumbar discectomy and who were reoperated on for recurrent L4-L5 disc herniation were retrospectively reviewed. All these operations were performed between August 2004 and September 2009 at the Neurosurgery Department of Ataturk Education and Research Hospital in Ankara, Turkey. During the study period, 126 patients were reviewed, with 101 patients underwent primary single-level L4-L5 lumbar discectomy and 25 patients were reoperated on for recurrent L4-L5 disc herniation. Preoperative higher intervertebral disc height (P<0.001) and higher body mass index (P=0.042) might be risk factors for recurrence. Modic endplate changes were statistically significantly greater in the recurrent group than in the non-recurrent group (P=0.032). Our study suggests that patients who had recurrent lumbar disc herniation had preoperative higher disc height and higher body mass index. Modic endplate changes had a higher tendency for recurrence of lumbar disc herniation. Well-planned and well-conducted large-scale prospective cohort studies are needed to confirm this and enable convenient treatment modalities to prevent recurrent disc pathology.

  19. Modules over hereditary rings

    SciTech Connect

    Tuganbaev, A A

    1998-04-30

    Let A be a hereditary Noetherian prime ring that is not right primitive. A complete description of {pi}-injective A-modules is obtained. Conditions under which the classical ring of quotients of A is a {pi}-projective A-module are determined. A criterion for a right hereditary right Noetherian prime ring to be serial is obtained.

  20. Rings Around Uranus

    ERIC Educational Resources Information Center

    Maran, Stephen P.

    1977-01-01

    Events leading up to the discovery of the rings of Uranus are described. The methods used and the logic behind the methods are explained. Data collected to prove the existence of the rings are outlined and theories concerning the presence of planetary rings are presented. (AJ)

  1. Rings Around Uranus

    ERIC Educational Resources Information Center

    Maran, Stephen P.

    1977-01-01

    Events leading up to the discovery of the rings of Uranus are described. The methods used and the logic behind the methods are explained. Data collected to prove the existence of the rings are outlined and theories concerning the presence of planetary rings are presented. (AJ)

  2. Eyeing the E Ring

    NASA Image and Video Library

    2009-12-24

    NASA Cassini spacecraft takes a look at Saturn diffuse E ring which is formed from icy material spewing out of the south pole of the moon Enceladus. The E ring is seen nearly edge-on from slightly above the northern side of Saturn ring plane.

  3. The Jumping Ring Experiment

    ERIC Educational Resources Information Center

    Baylie, M.; Ford, P. J.; Mathlin, G. P.; Palmer, C.

    2009-01-01

    The jumping ring experiment has become central to liquid nitrogen shows given as part of the outreach and open day activities carried out within the University of Bath. The basic principles of the experiment are described as well as the effect of changing the geometry of the rings and their metallurgical state. In general, aluminium rings are…

  4. The Jumping Ring Experiment

    ERIC Educational Resources Information Center

    Baylie, M.; Ford, P. J.; Mathlin, G. P.; Palmer, C.

    2009-01-01

    The jumping ring experiment has become central to liquid nitrogen shows given as part of the outreach and open day activities carried out within the University of Bath. The basic principles of the experiment are described as well as the effect of changing the geometry of the rings and their metallurgical state. In general, aluminium rings are…

  5. Dusty D Ring

    NASA Image and Video Library

    2014-02-24

    Saturn D ring is easy to overlook since it trapped between the brighter C ring and the planet itself. In this view from NASA Cassini spacecraft, all that can be seen of the D ring is the faint and narrow arc as it stretches from top right of the ima

  6. On certain Hecke rings

    PubMed Central

    Evens, Sam; Bressler, Paul

    1987-01-01

    We examine rings that embed into the smash product of the group algebra of the Weyl group with the field of meromorphic functions on the Cartan subalgebra and are generated by elements that satisfy braid relations. We prove that every such ring is isomorphic to either the Hecke algebra, the nil Hecke ring, or the group algebra of the Weyl group. PMID:16593804

  7. Soft normed rings.

    PubMed

    Uluçay, Vakkas; Şahin, Mehmet; Olgun, Necati

    2016-01-01

    Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft normed rings by soft set theory. The notions of soft normed rings, soft normed ideals, soft complete normed rings are introduced and also several related properties and examples are given.

  8. Extraforaminal ligament attachments of human lumbar nerves.

    PubMed

    Kraan, G A; Delwel, E J; Hoogland, P V J M; van der Veen, M R; Wuisman, P I J M; Stoeckart, R; Kleinrensink, G J; Snijders, C J

    2005-03-15

    An anatomic study of the extraforaminal attachments of the lumbar spinal nerves was performed using human lumbar spinal columns. To identify and describe the existence of ligamentous structures at each lumbar level that attach lumbar spinal nerves to structures at the level of the extraforaminal region. During the last 120 years, several mechanisms to protect the spinal nerve against traction have been described. All these structures involved are located in the spinal canal, proximal to the intervertebral foramen. Five embalmed human lumbar spines (T12-S1) were used. Bilaterally, the extraforaminal region was dissected to describe and measure anatomic structures and their relationships. Histology was performed with staining on the sites of attachment and along the ligament. The levels T12-L2 show bilaterally 2 ligaments, a superior extraforaminal ligament and an inferior extraforaminal ligament. The superior extraforaminal ligament emerges from the joint capsule of the facet joints and inserts in both, the intervertebral disc and the ventral crista of the intervertebral foramen, passing the spinal nerve laterally. In one specimen on level L2-L3, the superior extraforaminal ligament is not attached to the spinal nerve. The inferior extraforaminal ligament emerges from the intervertebral disc, passing the nerve medially and attaching the spinal nerve. At the levels L2-L5, the inferior extraforaminal ligaments are only attached to the intervertebral disc, not to the joint capsule. Histologically, the ligaments consisted of mainly collagenous structures. Ligamentous connections exist between lumbar extraforaminal spinal nerves and nearby structures.

  9. Scoliosis secondary to lumbar osteoid osteoma

    PubMed Central

    Zhang, Haiping; Niu, Xingbang; Wang, Biao; He, Simin; Hao, Dingjun

    2016-01-01

    Abstract Rationale: Lumbar osteoid osteoma has a low incidence, which could easily lead to scoliosis. Patient concerns: Scoliosis secondary to lumbar osteoid osteoma could be easily misdiagnosed when patients do not complain of obvious symptoms. Diagnoses: We reported a case of a 9-year-old boy with back deformity that was firstly diagnosed with scoliosis at the local hospital. After prescribed with orthosis, the patient experienced aggravating pain that could not be relieved with painkillers. After he admitted to our hospital for further medical advice, he was prescribed to complete radiological examinations. Considering his radiological examination results and his medical history, correct diagnosis of lumbar osteoid osteoma was made. Interventions: Surgical intervention of posterior lesion resection was conducted after diagnosis. Intra-operative frozen pathology indicated features of osteoid osteoma. As the lesion involved inferior articular process of L5, which could cause lumbar instability after lesion resection, internal fixation was conducted at L4-S1 segment, and posterolateral bone fusion was also conducted at L5-S1 segment. Outcomes: Three months after operation, the patient showed marked improvement of scoliosis deformity and great relief of lumbar pain. Lessons subsections: Although spine osteoid osteoma is clinically rare, it shall not be overlooked when young patients present with scoliosis first. Radiological results including computed tomography and magnetic resonance imaging shall be taken carefully as reference when making diagnosis. Surgical intervention of lesion resection could well improve scoliosis and relieve lumbar pain. PMID:27893671

  10. Automatic Lumbar Spondylolisthesis Measurement in CT Images.

    PubMed

    Liao, Shu; Zhan, Yiqiang; Dong, Zhongxing; Yan, Ruyi; Gong, Liyan; Zhou, Xiang Sean; Salganicoff, Marcos; Fei, Jun

    2016-07-01

    Lumbar spondylolisthesis is one of the most common spinal diseases. It is caused by the anterior shift of a lumbar vertebrae relative to subjacent vertebrae. In current clinical practices, staging of spondylolisthesis is often conducted in a qualitative way. Although meyerding grading opens the door to stage spondylolisthesis in a more quantitative way, it relies on the manual measurement, which is time consuming and irreproducible. Thus, an automatic measurement algorithm becomes desirable for spondylolisthesis diagnosis and staging. However, there are two challenges. 1) Accurate detection of the most anterior and posterior points on the superior and inferior surfaces of each lumbar vertebrae. Due to the small size of the vertebrae, slight errors of detection may lead to significant measurement errors, hence, wrong disease stages. 2) Automatic localize and label each lumbar vertebrae is required to provide the semantic meaning of the measurement. It is difficult since different lumbar vertebraes have high similarity of both shape and image appearance. To resolve these challenges, a new auto measurement framework is proposed with two major contributions: First, a learning based spine labeling method that integrates both the image appearance and spine geometry information is designed to detect lumbar vertebrae. Second, a hierarchical method using both the population information from atlases and domain-specific information in the target image is proposed for most anterior and posterior points positioning. Validated on 258 CT spondylolisthesis patients, our method shows very similar results to manual measurements by radiologists and significantly increases the measurement efficiency.

  11. The lumbar sympathetic. Anatomy and surgical implications.

    PubMed

    Simeone, F A

    1977-01-01

    The ganglionated lumbar sympathetic chains lie on the lateral aspects of the bodies of the lumbar vertebrae and not more laterally as in the thorax where the chain lies in relation to the heads and necks of the ribs. Lumbar ganglia vary in number. They are best numbered according to the spinal nerve to which the particular ganglion sends its postganglionic fibers, but, at operation, the surgeon is unable to obtain this kind of information. It is customary to mark the extent of resection by the application of a dura clip to the proximal and distal ends of the trunk. Roentgenographic visualization later can approximate the level of resection in relation to the vertebrae. Anomalies can lead to unsuccessful denervation of the lower extremities. These include extraganglionic connecting sympathetic nerve trunks, intermediate ganglia, and cross-over fibers connecting the right and left lumbar sympathetic trunks usually at the level of the fourth and fifth lumbar segments, but anatomically sometimes as high as the third and second. Specific complications of lumbar sympathectomy include failure of adequate denervation, brief paralytic ileus, hyperidrosis in parts of the body which remain normally innervated, sexual dysfunction, and post-sympathectomy neuralgia.

  12. Rehabilitation after lumbar disc surgery.

    PubMed

    Ostelo, R W; de Vet, H C; Waddell, G; Kerckhoffs, M R; Leffers, P; van Tulder, M W

    2002-01-01

    Although several rehabilitation programs, physical fitness programs or protocols regarding instruction for patients to return to work after lumbar disc surgery have been suggested, little is known about the efficacy and effectiveness of these treatments. There are still persistent fears of causing re-injury, re-herniation, or instability. The objective of this systematic review was to evaluate the effectiveness of active treatments that are used in the rehabilitation after first-time lumbar disc surgery. We searched the MEDLINE, EMBASE and Psyclit databases up to April 2000 and the Cochrane Controlled Trials Register 2001, Issue 3. Both randomized and non-randomized controlled trials on any type of active rehabilitation program after first-time disc surgery were included. Two independent reviewers performed the inclusion of studies and two other reviewers independently performed the methodological quality assessment. A rating system that consists of four levels of scientific evidence summarizes the results. Thirteen studies were included, six of which were of high quality. There is no strong evidence for the effectiveness for any treatment starting immediately post-surgery, mainly because of lack of (good quality) studies. For treatments that start four to six weeks post-surgery there is strong evidence (level 1) that intensive exercise programs are more effective on functional status and faster return to work (short-term follow-up) as compared to mild exercise programs and there is strong evidence (level 1) that on long term follow up there is no difference between intensive exercise programs and mild exercise programs with regard to overall improvement. For all other primary outcome measures for the comparison between intensive and mild exercise programs there is conflicting evidence (level 3) with regard to long-term follow-up. Furthermore, there is no strong evidence for the effectiveness of supervised training as compared to home exercises. There was also no

  13. Saturn's largest ring.

    PubMed

    Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P

    2009-10-22

    Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus.

  14. On the solar dust ring(s)

    NASA Astrophysics Data System (ADS)

    Mukai, T.

    Based on a mechanism to form the solar dust ring, it is proved that the observed peak in infrared F-corona cannot be explained by silicate type grains alone. Preliminary analysis on the recent infrared data of the F-corona by Maihara et al. (1984) has suggested that the ring particles have different physical properties compared with the dust grains, which produce the background F-corona.

  15. Lumbar degenerative kyphosis: radiologic analysis and classifications.

    PubMed

    Jang, Jee-Soo; Lee, Sang-Ho; Min, Jun-Hong; Han, Kyoung-Mi

    2007-11-15

    Retrospective study of a consecutive patient series. To review the radiographic classification of patients with sagittal imbalance due to lumbar degenerative kyphosis (LDK) and to determine correlation between thoracic and lumbar curve. Lumbar degenerative kyphosis is one of the common spinal deformities in Asian countries, especially Korea and Japan. However, there have been few studies regarding the classification and treatment of this disease. Seventy-eight patients with LDK were analyzed and classified according to the standing lateral whole spine findings. Total lumbar lordosis (L1-S1), thoracic kyphosis (T5-T12), sacral slope, thoracolumbar angle (T11-L1), and sagittal vertical axis (SVA) were measured on the lateral view of the whole spine. Spinal curve deformities were classified into 2 groups according to the thoracolumbar (T-L) junction angle: flat or lordotic angle (Group 1; N = 53) and kyphotic angle (Group 2; N = 25). In Group 1, significant correlations between the thoracic and lumbar curves (r = 0.772, P < 0.0001), and between the lumbar curve and sacral slope (r = 0.785, P < 0.0001) were observed. By this result, Group 1 was classified as sagittal thoracic compensated group. In contrast, In Group 2, no correlation was found between the thoracic and lumbar curves in the decompensated group (r = 0.179, P = 0.391), but we found a significant correlation between lordosis and sacral slope (r = 0.442, P = 0.027). By this result, Group 2 was classified as sagittal thoracic decompensated group. There was significant difference in SVA between 2 groups (P = 0.020). The angle of the thoracolumbar junction is an important parameter in determining whether a sagittal thoracic compensatory mechanism exists in LDK. We assumed that existence of a compensatory mechanism in the proximal spine is central to the determination of the fusion levels in the treatment of LDK.

  16. Lumbar posture and muscular activity while sitting during office work.

    PubMed

    Mörl, Falk; Bradl, Ingo

    2013-04-01

    Field study, cross-sectional study to measure the posture and sEMG of the lumbar spine during office work for a better understanding of the lumbar spine within such conditions. There is high incidence of low back pain in office workers. Currently there is little information about lumbar posture and the activity of lumbar muscles during extended office work. Thirteen volunteers were examined for around 2h of their normal office work. Typical tasks were documented and synchronised to a portable long term measuring device for sEMG and posture examination. The correlation of lumbar spine posture and sEMG was tested statistically. The majority of time spent in office work was sedentary (82%). Only 5% of the measured time was undertaken in erect body position (standing or walking). The sEMG of the lumbar muscles under investigation was task dependent. A strong relation to lumbar spine posture was found within each task. The more the lumbar spine was flexed, the less there was activation of lumbar muscles (P < .01). Periods of very low or no activation of lumbar muscles accounted for about 30% of relaxed sitting postures. Because of very low activation of lumbar muscles while sitting, the load is transmitted by passive structures like ligaments and intervertebral discs. Due to the viscoelasticity of passive structures and low activation of lumbar muscles, the lumbar spine may incline into de-conditioning. This may be a reason for low back pain. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Dust and Planetary Rings

    NASA Astrophysics Data System (ADS)

    Siddiqui, Muddassir

    ABSTRACT Space is not empty it has comic radiations (CMBR), dust etc. Cosmic dust is that type of dust which is composed of particles in space which vary from few molecules to 0.1micro metres in size. This type of dust is made up of heavier atoms born in the heart of stars and supernova. Mainly it contains dust grains and when these dust grains starts compacting then it turns to dense clouds, planetary ring dust and circumstellar dust. Dust grains are mainly silicate particles. Dust plays a major role in our solar system, for example in zodiacal light, Saturn's B ring spokes, planetary rings at Jovian planets and comets. Observations and measurements of cosmic dust in different regions of universe provide an important insight into the Universe's recycling processes. Astronomers consider dust in its most recycled state. Cosmic dust have radiative properties by which they can be detected. Cosmic dusts are classified as intergalactic dusts, interstellar dusts and planetary rings. A planetary ring is a ring of cosmic dust and other small particles orbiting around a planet in flat disc shape. All of the Jovian planets in our solar system have rings. But the most notable one is the Saturn's ring which is the brightest one. In March 2008 a report suggested that the Saturn's moon Rhea may have its own tenuous ring system. The ring swirling around Saturn consists of chunks of ice and dust. Most rings were thought to be unstable and to dissipate over course of tens or hundreds of millions of years but it now appears that Saturn's rings might be older than that. The dust particles in the ring collide with each other and are subjected to forces other than gravity of its own planet. Such collisions and extra forces tend to spread out the rings. Pluto is not known to have any ring system but some Astronomers believe that New Horizons probe might find a ring system when it visits in 2015.It is also predicted that Phobos, a moon of Mars will break up and form into a planetary ring

  18. Surge in the Ring

    NASA Image and Video Library

    2016-08-29

    An ethereal, glowing spot appears on Saturn's B ring in this view from NASA's Cassini spacecraft. There is nothing particular about that place in the rings that produces the glowing effect -- instead, it is an example of an "opposition surge" making that area on the rings appear extra bright. An opposition surge occurs when the Sun is directly behind the observer looking toward the rings. The particular geometry of this observation makes the point in the rings appear much, much brighter than would otherwise be expected. This view looks toward the sunlit side of the rings from about 28 degrees above the ring plane. The image was taken in visible light with the Cassini wide-angle camera on June 26, 2016. The view was acquired at a distance of approximately 940,000 miles (1.5 million kilometers) from the rings and at a Sun-ring-spacecraft, or phase, angle of 0 degrees. Image scale on the rings at center is 56 miles (90 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20496

  19. Traceable Ring Signature

    NASA Astrophysics Data System (ADS)

    Fujisaki, Eiichiro; Suzuki, Koutarou

    The ring signature allows a signer to leak secrets anonymously, without the risk of identity escrow. At the same time, the ring signature provides great flexibility: No group manager, no special setup, and the dynamics of group choice. The ring signature is, however, vulnerable to malicious or irresponsible signers in some applications, because of its anonymity. In this paper, we propose a traceable ring signature scheme. A traceable ring scheme is a ring signature except that it can restrict “excessive” anonymity. The traceable ring signature has a tag that consists of a list of ring members and an issue that refers to, for instance, a social affair or an election. A ring member can make any signed but anonymous opinion regarding the issue, but only once (per tag). If the member submits another signed opinion, possibly pretending to be another person who supports the first opinion, the identity of the member is immediately revealed. If the member submits the same opinion, for instance, voting “yes” regarding the same issue twice, everyone can see that these two are linked. The traceable ring signature can suit to many applications, such as an anonymous voting on a BBS. We formalize the security definitions for this primitive and show an efficient and simple construction in the random oracle model.

  20. Minimally invasive procedures on the lumbar spine

    PubMed Central

    Skovrlj, Branko; Gilligan, Jeffrey; Cutler, Holt S; Qureshi, Sheeraz A

    2015-01-01

    Degenerative disease of the lumbar spine is a common and increasingly prevalent condition that is often implicated as the primary reason for chronic low back pain and the leading cause of disability in the western world. Surgical management of lumbar degenerative disease has historically been approached by way of open surgical procedures aimed at decompressing and/or stabilizing the lumbar spine. Advances in technology and surgical instrumentation have led to minimally invasive surgical techniques being developed and increasingly used in the treatment of lumbar degenerative disease. Compared to the traditional open spine surgery, minimally invasive techniques require smaller incisions and decrease approach-related morbidity by avoiding muscle crush injury by self-retaining retractors, preventing the disruption of tendon attachment sites of important muscles at the spinous processes, using known anatomic neurovascular and muscle planes, and minimizing collateral soft-tissue injury by limiting the width of the surgical corridor. The theoretical benefits of minimally invasive surgery over traditional open surgery include reduced blood loss, decreased postoperative pain and narcotics use, shorter hospital length of stay, faster recover and quicker return to work and normal activity. This paper describes the different minimally invasive techniques that are currently available for the treatment of degenerative disease of the lumbar spine. PMID:25610845

  1. Automatic lumbar spine measurement in CT images

    NASA Astrophysics Data System (ADS)

    Mao, Yunxiang; Zheng, Dong; Liao, Shu; Peng, Zhigang; Yan, Ruyi; Liu, Junhua; Dong, Zhongxing; Gong, Liyan; Zhou, Xiang Sean; Zhan, Yiqiang; Fei, Jun

    2017-03-01

    Accurate lumbar spine measurement in CT images provides an essential way for quantitative spinal diseases analysis such as spondylolisthesis and scoliosis. In today's clinical workflow, the measurements are manually performed by radiologists and surgeons, which is time consuming and irreproducible. Therefore, automatic and accurate lumbar spine measurement algorithm becomes highly desirable. In this study, we propose a method to automatically calculate five different lumbar spine measurements in CT images. There are three main stages of the proposed method: First, a learning based spine labeling method, which integrates both the image appearance and spine geometry information, is used to detect lumbar and sacrum vertebrae in CT images. Then, a multiatlases based image segmentation method is used to segment each lumbar vertebra and the sacrum based on the detection result. Finally, measurements are derived from the segmentation result of each vertebra. Our method has been evaluated on 138 spinal CT scans to automatically calculate five widely used clinical spine measurements. Experimental results show that our method can achieve more than 90% success rates across all the measurements. Our method also significantly improves the measurement efficiency compared to manual measurements. Besides benefiting the routine clinical diagnosis of spinal diseases, our method also enables the large scale data analytics for scientific and clinical researches.

  2. Strength gains through lumbar lordosis restoration

    PubMed Central

    Morningstar, Mark W

    2003-01-01

    Abstract Objective To test the hypothesis that restoring the lumbar lordosis will increase a patient's voluntary muscular strength and decrease back pain symptoms. Clinical Features A patient was diagnosed with mechanical low back pain. The initial radiographic study revealed a loss of the lumbar lordosis. The patient determined his maximum bench press prior to the treatment program. The treatment outcome was based upon post-intervention radiographs, a Borg pain scale, and the patient's post-intervention maximum bench press. Intervention and Outcome The treatment program consisted of warm-up exercises, spinal manipulation, rehabilitative exercises, neuromuscular re-education, and prescribed home care. The treatment period consisted of 12 visits in the first 4 weeks, followed by once weekly for another 12 weeks, for a total of 24 visits in 4 months. In the first month, the Borg scale decreased from 5/10 to 0/10, and after 4 months the lumbar lordosis was increased from 2° to 31°. The sacral base angle (Ferguson's angle) increased from 18° to 31°. The patient's maximum bench press also increased from 245 pounds to 305 pounds. Conclusion Restoration of the lumbar lordosis appears to have a positive effect on muscular strength. This study supports the previous premise that a lumbar lordosis provides an inherent mechanical advantage for strength and stability. PMID:19674610

  3. Economic impact of minimally invasive lumbar surgery

    PubMed Central

    Hofstetter, Christoph P; Hofer, Anna S; Wang, Michael Y

    2015-01-01

    Cost effectiveness has been demonstrated for traditional lumbar discectomy, lumbar laminectomy as well as for instrumented and noninstrumented arthrodesis. While emerging evidence suggests that minimally invasive spine surgery reduces morbidity, duration of hospitalization, and accelerates return to activites of daily living, data regarding cost effectiveness of these novel techniques is limited. The current study analyzes all available data on minimally invasive techniques for lumbar discectomy, decompression, short-segment fusion and deformity surgery. In general, minimally invasive spine procedures appear to hold promise in quicker patient recovery times and earlier return to work. Thus, minimally invasive lumbar spine surgery appears to have the potential to be a cost-effective intervention. Moreover, novel less invasive procedures are less destabilizing and may therefore be utilized in certain indications that traditionally required arthrodesis procedures. However, there is a lack of studies analyzing the economic impact of minimally invasive spine surgery. Future studies are necessary to confirm the durability and further define indications for minimally invasive lumbar spine procedures. PMID:25793159

  4. Magnetic Resonance Imaging (MRI): Lumbar Spine (For Parents)

    MedlinePlus

    ... If You Have Questions en español Resonancia magnética: columna lumbar What It Is Magnetic resonance imaging (MRI) ... MORE ON THIS TOPIC Magnetic Resonance Imaging (MRI): Cervical Spine Lumbar Puncture (Spinal Tap) Magnetic Resonance Imaging ( ...

  5. Slowing of Vortex Rings

    NASA Astrophysics Data System (ADS)

    Donnelly, Russell; Bolster, Diogo; Hershberger, Robert

    2008-11-01

    We have investigated the slowing of vortex rings in water which are created with very thin cores. We find that these rings propagate with no measurable change in diameter or core size. The drag appears to be the result of viscous forces on the core. A simple model for this drag describes experimental data in terms of a drag coefficient, which depends only on Reynolds number. Barenghi's group at Newcastle found that the translational velocity of a ring in an inviscid fluid perturbed by Kelvin waves decreases with increasing amplitude of Kelvin waves. This suggests that the velocity of vortex rings in a viscous fluid may well depend on the amplitude of Kelvin waves at the time of formation. Rings with substantial amplitude of Kelvin waves will be expected to move more slowly than rings with little or no Kelvin wave amplitude. We present experimental data confirming this suggestion.

  6. Ring Details on Display

    NASA Image and Video Library

    2016-11-07

    This view from NASA's Cassini spacecraft showcases some of the amazingly detailed structure of Saturn's rings. The rings are made up of many smaller ringlets that blur together when seen from a distance. But when imaged up close, the rings' structures display quite a bit of variation. Ring scientists are debating the nature of these features -- whether they have always appeared this way or if their appearance has evolved over time. This view looks toward the sunlit side of the rings from about 4 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Sept. 24, 2016. The view was acquired at a distance of approximately 283,000 miles (456,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 32 degrees. Image scale is 17 miles (27 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20506

  7. Use of autologous growth factors in lumbar spinal fusion.

    PubMed

    Lowery, G L; Kulkarni, S; Pennisi, A E

    1999-08-01

    The results of spinal fusion, especially posteriorly above the lumbosacral junction, have been mixed. Autologous growth factor concentrate (AGF) prepared by ultraconcentration of platelets contains multiple growth factors having a chemotactic and mitogenic effect on mesenchymal stem cells and osteoblasts and may play a role in initiating bone healing. The purpose of this retrospective study is to review our results with AGF in lumbar spinal fusions. To date, AGF has been used in 39 patients having lumbar spinal fusion. The study group consisted of the first 19 consecutive cases to allow at least 6 months follow-up. The average follow-up was 13 months (range 6 to 18 months). Follow-up compliance was 91%. There were 7 men and 12 women. Average age was 52 years (range 30-72 years). Nine patients had prior back surgery. There were 8 smokers. AGF was used in posterior (n = 15) or anterior intradiscal (n = 4) fusions. AGF was used with autograft and coraline hydroxyapatite in all posterior fusions, and autograft, coral, and intradiscal spacer (carbon fiber spinal fusion cages or Synthes femoral ring) in intradiscal fusions. Posterior stabilization was used in all cases. Eight cases were single-level fusions, 6 were two-level, and 1 was a three-level fusion. Autologous iliac crest bone graft was taken in 14 cases and local autograft used in 5 cases. Posteriorly, a total of 23 levels were fused; of these, nine were at L5-S1, eight at L4-L5, five at L3-L4, and one at L2-L3. No impending pseudoarthroses were noted on plain radiographic examination at last follow-up visit. Solid fusion was confirmed in 3 patients having routine hardware removal, and in 2 patients who had surgery at an adjacent level. There was one posterior wound infection, which was managed without sequelae. When used as an adjunct to autograft, AGF offers theoretical advantages that need to be examined in controlled studies. Further study is necessary to determine whether coralline hydroxyapatite used as a

  8. Effect of Lumbar Progressive Resistance Exercise on Lumbar Muscular Strength and Core Muscular Endurance in Soldiers.

    PubMed

    Mayer, John M; Childs, John D; Neilson, Brett D; Chen, Henian; Koppenhaver, Shane L; Quillen, William S

    2016-11-01

    Low back pain is common, costly, and disabling for active duty military personnel and veterans. The evidence is unclear on which management approaches are most effective. The purpose of this study was to assess the effectiveness of lumbar extensor high-intensity progressive resistance exercise (HIPRE) training versus control on improving lumbar extension muscular strength and core muscular endurance in soldiers. A randomized controlled trial was conducted with active duty U.S. Army Soldiers (n = 582) in combat medic training at Fort Sam Houston, Texas. Soldiers were randomized by platoon to receive the experimental intervention (lumbar extensor HIPRE training, n = 298) or control intervention (core stabilization exercise training, n = 284) at one set, one time per week, for 11 weeks. Lumbar extension muscular strength and core muscular endurance were assessed before and after the intervention period. At 11-week follow-up, lumbar extension muscular strength was 9.7% greater (p = 0.001) for HIPRE compared with control. No improvements in core muscular endurance were observed for HIPRE or control. Lumbar extensor HIPRE training is effective to improve isometric lumbar extension muscular strength in U.S. Army Soldiers. Research is needed to explore the clinical relevance of these gains. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

  9. Saturn's rings - an overview

    NASA Astrophysics Data System (ADS)

    Cuzzi, J. N.

    2005-08-01

    Saturn's rings embody in their diversity the entire spectrum of ring properties seen across the outer solar system, and remain unique in fundamental ways. The Voyager flybys revealed their complexity in 1980-1981, while groundbased and HST observations have provided important new insights since that time. Since July 2004, when it skimmed only tens of thousands of km over the unlit face of the rings - collecting unique remote and in-situ observations as it entered orbit - Cassini has been fulfilling the long-held dream of understanding Saturn's rings in depth. As of this meeting, if all continues as planned, seven orbits designed specifically with ring observations in mind will have been completed - each providing even better geometric opportunities than an entire Voyager flyby (to a spacecraft with far more powerful instruments than Voyager). Even these represent only a fraction of what the complete mission will tell us about the rings. This talk will review the key properties of the rings, highlight the themes and new insights emerging from recent studies, and serve as a context for new results presented at the meeting. The key properties include the relationship of the rings to their close-in and embedded moons; the composition of the rings and its spatial variation; and the complex radial and vertical structure of the rings, as related to local particle sizes and mass density. The main themes are that several evolutionary processes cause all these to vary - we think substantially - with time, and that the rings may be much younger than Saturn. To achieve our goal of understanding the origin of the rings, we must start from an in-depth characterization of their current state, and peer back through their extensive evolution. Cassini observations, and their theoretical analysis, will ultimately make this possible.

  10. Radioactive gold ring dermatitis

    SciTech Connect

    Miller, R.A.; Aldrich, J.E. )

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  11. The lumbar lordosis below Harrington instrumentation for scoliosis.

    PubMed

    Swank, S M; Mauri, T M; Brown, J C

    1990-03-01

    This retrospective study evaluates lumbar lordosis in 43 patients before and after Harrington instrumentation into the lumbar spine. The authors measured overall lumbar lordosis, lordosis of unfused lumbar levels, and sagittal vertical axis. Lordosis decreased progressively in lower levels of fusion. The increase in lordosis below the fusion did not compensate for the overall loss of lordosis. The sagittal vertical axis moved forward, producing a subtle, asymptomatic form of flat back syndrome.

  12. Tiny Mimas, Huge Rings

    NASA Image and Video Library

    2016-11-28

    Saturn's icy moon Mimas is dwarfed by the planet's enormous rings. Because Mimas (near lower left) appears tiny by comparison, it might seem that the rings would be far more massive, but this is not the case. Scientists think the rings are no more than a few times as massive as Mimas, or perhaps just a fraction of Mimas' mass. Cassini is expected to determine the mass of Saturn's rings to within just a few hundredths of Mimas' mass as the mission winds down by tracking radio signals from the spacecraft as it flies close to the rings. The rings, which are made of small, icy particles spread over a vast area, are extremely thin -- generally no thicker than the height of a house. Thus, despite their giant proportions, the rings contain a surprisingly small amount of material. Mimas is 246 miles (396 kilometers) wide. This view looks toward the sunlit side of the rings from about 6 degrees above the ring plane. The image was taken in red light with the Cassini spacecraft wide-angle camera on July 21, 2016. The view was obtained at a distance of approximately 564,000 miles (907,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 31 degrees. Image scale is 34 miles (54 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20509

  13. Faint D Ring

    NASA Image and Video Library

    2015-04-27

    Not all of Saturn's rings are created equal: here the C and D rings appear side-by-side, but the C ring, which occupies the bottom half of this image, clearly outshines its neighbor. The D ring appears fainter than the C ring because it is comprised of less material. However, even rings as thin as the D ring can pose hazards to spacecraft. Given the high speeds at which Cassini travels, impacts with particles just fractions of a millimeter in size have the potential to damage key spacecraft components and instruments. Nonetheless, near the end of Cassini's mission, navigators plan to thread the spacecraft's orbit through the narrow region between the D ring and the top of Saturn's atmosphere. This view looks toward the unilluminated side of the rings from about 12 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 11, 2015. The view was acquired at a distance of approximately 372,000 miles (599,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 133 degrees. Image scale is 2.2 miles (3.6 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/pia18313

  14. Jupiter's Ring Halo

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

    Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow.

    A faint mist of particles can be seen above and below the main rings; this vertically extended, toroidal 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces which can push small grains out of the ring plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest

  15. Jupiter's Ring Halo

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

    Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow.

    A faint mist of particles can be seen above and below the main rings; this vertically extended, toroidal 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces which can push small grains out of the ring plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest

  16. Saturn's E ring revisited

    NASA Astrophysics Data System (ADS)

    Feibelman, W. A.; Klinglesmith, D. A.

    1980-07-01

    Images of the E ring of Saturn obtained by the image processing of photographs of the 1966 edge-on presentation of the planet's ring plane are presented. Two methods of image enhancement were used: scanning with an image quantizer operated in the derivative mode to enhance contrast and computerized subtraction of a circularly symmetric image of the overexposed Saturn disk. Further photographic and CCD observation confirming the existence of the ring extending to twice the diameter of the A ring, which was not detected by the Pioneer 11 imaging photopolarimeter, is indicated.

  17. Jupiter Ring Halo

    NASA Image and Video Library

    1998-03-26

    A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age. Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. A faint mist of particles can be seen above and below the main rings; this vertically extended, toroidal "halo" is unusual in planetary rings, and is probably caused by electromagnetic forces which can push small grains out of the ring plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest being

  18. Viscosity in Saturn's rings

    NASA Technical Reports Server (NTRS)

    Lissauer, J. J.; Shu, F. H.; Cuzzi, J. N.

    1982-01-01

    The technique of estimating the viscosity in Saturn's rings from the damping rate of waves observed to be propagating within the rings is discussed. The wavetrains of attempts using spiral density waves as a diagnostic suffer significant complications that compromise the interpretations. A method that considers the damping of spiral bending waves was used to deduce a kinematic viscosity of 260 (+150, -100) sqcm/sec for the middle of the A ring where bending waves are excited by the 5:3 vertical resonance with Mimas. This value implies upper limits on the particle velocity dispersion and local ring thickness of 0.4 cm/sec and 30 m, respectively.

  19. Imaging of current spinal hardware: lumbar spine.

    PubMed

    Ha, Alice S; Petscavage-Thomas, Jonelle M

    2014-09-01

    The purposes of this article are to review the indications for and the materials and designs of hardware more commonly used in the lumbar spine; to discuss alternatives for each of the types of hardware; to review normal postoperative imaging findings; to describe the appropriateness of different imaging modalities for postoperative evaluation; and to show examples of hardware complications. Stabilization and fusion of the lumbar spine with intervertebral disk replacement, artificial ligaments, spinous process distraction devices, plate-and-rod systems, dynamic posterior fusion devices, and newer types of material incorporation are increasingly more common in contemporary surgical practice. These spinal hardware devices will be seen more often in radiology practice. Successful postoperative radiologic evaluation of this spinal hardware necessitates an understanding of fundamental hardware design, physiologic objectives, normal postoperative imaging appearances, and unique complications. Radiologists may have little training and experience with the new and modified types of hardware used in the lumbar spine.

  20. Cervical Meningomyelitis After Lumbar Epidural Steroid Injection

    PubMed Central

    Kim, Joon-Sung; Kim, Ji Yeon

    2015-01-01

    Epidural steroid injections (ESI) are a common treatment for back pain management. ESI-related complications have increased with the growing number of procedures. We report a case of cervical meningomyelitis followed by multiple lumbar ESI. A 60-year-old male with diabetes mellitus presented to our hospital with severe neck pain. He had a history of multiple lumbar injections from a local pain clinic. After admission, high fever and elevated inflammatory values were detected. L-spine magnetic resonance imaging (MRI) revealed hematoma in the S1 epidural space. Antibiotic treatment began under the diagnosis of a lumbar epidural abscess. Despite the treatment, he started to complain of weakness in both lower extremities. Three days later, the weakness progressed to both upper extremities. C-spine MRI revealed cervical leptomeningeal enhancement in the medulla oblongata and cervical spinal cord. Removal of the epidural abscess was performed, but there was no neurological improvement. PMID:26161360

  1. Biomechanical implications of lumbar spinal ligament transection.

    PubMed

    Von Forell, Gregory A; Bowden, Anton E

    2014-11-01

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

  2. Concomitant cervical and lumbar intradural intramedullary lipoma.

    PubMed

    Muthusubramanian, Vikram; Pande, Anil; Vasudevan, Madhabushi Chakravarthy; Ramamurthi, Ravi

    2008-03-01

    Lipomas of the spinal cord are often a component of spinal dysraphic states. Nondysraphic intramedullary spinal cord lipomas are rare, and concomitant isolated cervical and lumbar intradural intramedullary lipomata are very rare. One patient with concomitant isolated nondysraphic cervical and lumbar spinal cord lipomata has been reported and management options discussed. A young girl presented with insidious-onset diffuse neck pain and early myelopathic signs. Conventional radiographs were normal. Magnetic resonance imaging of the whole neuraxis revealed concomitant cervical and lumbar intradural intramedullary lipoma. Subtotal resection of the lesion was performed at both levels, after which the patient improved symptomatically and was ambulant independently. Concomitant intradural lipomas at 2 different locations unassociated with a dysraphic state is very rare. Magnetic resonance imaging with fat suppression study is the investigation of choice. Adequate decompression with subtotal removal is the treatment of choice.

  3. A Foundation for Systems Anthropometry: Lumbar/Pelvic Kinematics

    DTIC Science & Technology

    1983-02-01

    Roentgenographic Measurement of Lumbar Intervertebral Disc Height ." Spine , 6(2):154:158. Andriacchi, T., Schultz, A... measured , enabling coupled motion (Wite and Panjabi, 1978), for example, in lateral bending of the lumbar spine , to be investigated. Two different...to seated position. They describe measured positions of the lumbar spine , sacrum, and inncminate with anatomical landmarks important to

  4. [Lumbar disc protrusion in childhood. Description of a case].

    PubMed

    Lins, E; Basedow, H

    1976-02-01

    This is a case of lumbar disc protrusion in a 14 year old girl, with typical symptomatology. Special attention should be called to the rarity of this case. The clinical and myelographic diagnosis showed a lumbar herniation L 4/L5. Treatment was performed by lumbar hemilaminectomie. The post operative controll showed remission of the clinical findings.

  5. Modified spiral wound retaining ring

    NASA Technical Reports Server (NTRS)

    Lawson, A. G. (Inventor)

    1980-01-01

    A spiral wound retaining ring with angled ends is described. The ring is crimped at the same angle as the ring ends to maintain a constant thickness dimension. The angling of the ends of the ring and crimp allow the ends to be positioned closer together while maintaining enough clearance to enable insertion and removal of the ring. By reducing the separation distance between the ends a stronger ring results since the double layer area of the ring is maximized.

  6. Lumbar microendoscopic discectomy: surgical technique and nuances.

    PubMed

    Azab, Waleed A; Nasim, Khurram; Najibullah, Mostafa

    2016-04-01

    Lumbar microendoscopic discectomy (MED) is a minimally invasive transmuscular approach that combines standard lumbar microsurgical techniques with endoscopy. MED advantages include reduced tissue trauma, direct visualization of the nerve root and disc disease, and allowing bony decompression in cases with spinal or lateral recess stenosis. Operative charts and videos of patients undergoing MED were retrieved from our database and reviewed. A description of the surgical technique was then formulated. The surgical technique of MED is described and is essentially similar to conventional microdiscectomy. Some modifications are, however, necessary owing to the difference between microscopic and endoscopic views.

  7. DEGENERATIVE STENOSIS OF THE LUMBAR SPINE

    PubMed Central

    Zylbersztejn, Sérgio; Spinelli, Leandro de Freitas; Rodrigues, Nilson Rodinei; Werlang, Pablo Mariotti; Kisaki, Yorito; Rios, Aldemar Roberto Mieres; Bello, Cesar Dall

    2015-01-01

    This paper presents an update on degenerative stenosis of the lumbar spine, which is a common pathological condition among patients over the age of 65 years. The anamnesis and physical examination need to be precise, since radiography often only provides indirect signs. Magnetic resonance imaging is necessary if the symptoms persist. The treatment for lumbar stenosis is a matter of controversy. However, there seems to be some benefit from surgical treatment rather than conservative treatment, such that surgery brings improvements in symptoms and functions for a period of up to two years. PMID:27042635

  8. Lumbar vertebral pedicles: radiologic anatomy and pathology

    SciTech Connect

    Patel, N.P.; Kumar, R.; Kinkhabwala, M.; Wengrover, S.I.

    1988-01-01

    With the advancement of high-resolution computed tomography (CT) scanning the spine has added new knowledge to the various conditions affecting the pedicles. We wish to review the entire spectrum of pedicular lesions: the embryology, normal anatomy, normal variants, pitfalls, congenital anomalies, and pathological conditions are discussed. Different imaging modalities involving CT, isotope bone scanning, and Magnetic Resonance Imaging (MRI) are used to complement plain films of the lumbar spine. This subject review is an excellent source for future reference to lumbar pedicular lesions. 27 references.

  9. Computed tomography of the postoperative lumbar spine

    SciTech Connect

    Teplick, J.G.; Haskin, M.E.

    1983-11-01

    In the postoperative patient ordinary radiographs of the spine generally add very little information, revealing the usual postoperative bone changes and often postoperative narrowing of the intervertebral space. Myelography may sometimes be informative, showing evidence of focal arachnoiditis or a focal defect at the surgical site. However, the latter finding is difficult to interpret. As experience with high-resolution CT scanning of the lumbar spine has been increasing, it is becoming apparent that this noninvasive and easily performed study can give considerably more information about the postoperative spine than any of the other current imaging methods. About 750 patients with previous lumbar laminectomies had CT scanning within a 28 month period.

  10. Mini-open anterior lumbar interbody fusion.

    PubMed

    Gandhoke, Gurpreet S; Ricks, Christian; Tempel, Zachary; Zuckerbraun, Brian; Hamilton, D Kojo; Okonkwo, David O; Kanter, Adam S

    2016-07-01

    In deformity surgery, anterior lumbar interbody fusion provides excellent biomechanical support, creates a broad surface area for arthrodesis, and induces lordosis in the lower lumbar spine. Preoperative MRI, plain radiographs, and, when available, CT scan should be carefully assessed for sacral slope as it relates to pubic symphysis, position of the great vessels (especially at L4/5), disc space height, or contraindication to an anterior approach. This video demonstrates the steps in an anterior surgical procedure with minimal open exposure. The video can be found here: https://youtu.be/r3bC4_vu1hQ .

  11. Iatrogenic lumbar meningocoele: report of three cases

    PubMed Central

    Rinaldi, Italo; Hodges, Thomas O.

    1970-01-01

    We have reported three cases of iatrogenic lumbar meningocoeles after surgery for herniated lumbar intervertebral discs. We reject the term spurious, pseudo, or false as given by earlier writers. We feel that, in reality, these sacs are true meningocoeles, with complete arachnoidal lining and freely communicating with the intraspinal subarachnoid space. We have also given a brief outline of the clinical features, elucidated the mechanisms operative in the production of symptoms, and suggested the cardinal features of radiographic diagnosis. Prevention is, of course, the best way to avoid this complication. If a dural tear does occur, every effort should be made to suture it in a watertight manner. Images PMID:4918460

  12. Comparison of electromyographic activities of lumbar iliocostalis and lumbar multifidus muscles during stabilization exercises in prone, quadruped, and sitting positions

    PubMed Central

    Kelly, Marie; Jacobs, Dee; Wooten, Mary E.; Edeer, Ayse Ozcan

    2016-01-01

    [Purpose] The purposes of this study were: 1) describe a hierarchy of electromyographic activity production, using percentage maximum voluntary contraction of lumbar iliocostalis and lumbar multifidus muscles during prone, quadruped and sitting exercises; and 2) identify optimal recruitment exercises for both lumbar iliocostalis as a global multi-segmental stabilizer and lumbar multifidus as a segmental stabilizer. [Subjects] Twelve healthy volunteers (six male and six female) aged 24 to 45 participated. [Methods] Surface electromyographic activity data were collected bilaterally from lumbar iliocostalis and lumbar multifidus muscles during exercises. [Results] Two-way ANOVA showed that prone extension, and prone alternate arm and leg lifting exercises produce a statistically significant difference in percent maximum voluntary contraction of lumbar iliocostalis and lumbar multifidus bilaterally compared to other exercises. Quadruped alternate arm and leg lifting exercises produce greater activity in lumbar multifidus muscle than sitting exercises [Conclusion] Prone exercises generate the greatest electromyographic activity and may be the most effective exercises for strengthening both lumbar iliocostalis and lumbar multifidus muscles. Quadruped alternate arm and leg lifting produces electromyographic activity at the recommended percent maximum voluntary contraction for training the lumbar multifidus in its role as a segmental stabilizer and is an effective training exercise for this goal. PMID:27821968

  13. Inner B Ring Terminus

    NASA Image and Video Library

    2009-09-21

    This mosaic, part of a larger mosaic of images captured by NASA Cassini Orbiter just hours before exact equinox at Saturn, shows that the spiral corrugation in the planet’s inner rings continues right up to the inner B ring.

  14. Neptune's ring system.

    NASA Astrophysics Data System (ADS)

    Porco, C. C.; Nicholson, P. D.; Cuzzi, J. N.; Lissauer, J. J.; Esposito, L. W.

    The authors review the current state of knowledge regarding the structure, particle properties, kinematics, dynamics, origin, and evolution of the Neptune rings derived from Earth-based and Voyager data. Neptune has a diverse system of five continuous rings - 2 broad (Galle and Lassell) and 3 narrow (Adams, Le Verrier, and Arago) - plus a narrow discontinuous ring sharing the orbit of one of its ring-region satellites, Galatea. The outermost Adams ring contains the only arcs observed so far in Voyager images. The five arcs vary in angular extent from ≡1° to ≡10°, and exhibit internal azimuthal structure with typical spatial scales of ≡0.5°. All five lie within ≡40° of longitude. Dust is present throughout the Neptune system and measureable quantities of it were detected over Neptune's north pole. The Adams ring (including the arcs) and the Le Verrier ring contain a significant fraction of dust. The Neptune ring particles are probably red, and may consist of ice "dirtied" with silicates and/or some carbon-bearing material. A kinematic model for the arcs derived from Voyager data, the arcs' physical characteristics, and their orbital geometry and phasing are all roughly in accord with single-satellite arc shepherding by Galatea, though the presence of small kilometer-sized bodies embedded either within the arcs or placed at their Lagrange points may explain some inconsistencies with this model.

  15. EBT ring physics

    SciTech Connect

    Uckan, N.A.

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers. (MOW)

  16. Uranus Ring System

    NASA Image and Video Library

    1996-01-29

    This image captured by NASA's Voyager 2 in 1986 revealed a continuous distribution of small particles throughout the Uranus ring system. This unique geometry, the highest phase angle at which Voyager imaged the rings, allowed us to see lanes of fine dust. http://photojournal.jpl.nasa.gov/catalog/PIA00142

  17. Smoke Ring Physics

    NASA Astrophysics Data System (ADS)

    Huggins, Elisha

    2011-11-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampère's law in an introductory physics course. We discuss these common features.

  18. Smoke Ring Physics

    ERIC Educational Resources Information Center

    Huggins, Elisha

    2011-01-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)

  19. Steroidal contraceptive vaginal rings.

    PubMed

    Sarkar, N N

    2003-06-01

    The development of steroid-releasing vaginal rings over the past three decades is reviewed to illustrate the role of this device as an effective hormonal contraceptive for women. Vaginal rings are made of polysiloxane rubber or ethylene-vinyl-acetate copolymer with an outer diameter of 54-60 mm and a cross-sectional diameter of 4-9.5 mm and contain progestogen only or a combination of progestogen and oestrogen. The soft flexible combined ring is inserted in the vagina for three weeks and removed for seven days to allow withdrawal bleeding. Progesterone/progestogen-only rings are kept in for varying periods and replaced without a ring-free period. Rings are in various stages of research and development but a few, such as NuvaRing, have reached the market in some countries. Women find this method easy to use, effective, well tolerated and acceptable with no serious side-effects. Though the contraceptive efficacy of these vaginal rings is high, acceptability is yet to be established.

  20. Smoke Ring Physics

    ERIC Educational Resources Information Center

    Huggins, Elisha

    2011-01-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)

  1. The Fermilab recycler ring

    SciTech Connect

    Martin Hu

    2001-07-24

    The Fermilab Recycler is a permanent magnet storage ring for the accumulation of antiprotons from the Antiproton Source, and the recovery and cooling of the antiprotons remaining at the end of a Tevatron store. It is an integral part of the Fermilab III luminosity upgrade. The following paper describes the design features, operational and commissioning status of the Recycler Ring.

  2. Lower esophageal ring (Schatzki)

    MedlinePlus

    ... narrowed area to stretch the ring. Sometimes, a balloon is placed in the area and inflated, to help widen the ring. Outlook (Prognosis) Swallowing problems may return. You may need repeat treatment. When to Contact a Medical Professional Call your health care provider if you ...

  3. Contactless Magnetic Slip Ring

    NASA Technical Reports Server (NTRS)

    Kumagai, Hiroyuki (Inventor); Deardon, Joe D. (Inventor)

    1997-01-01

    A contactless magnetic slip ring is disclosed having a primary coil and a secondary coil. The primary and secondary coils are preferably magnetically coupled together, in a highly reliable efficient manner, by a magnetic layered core. One of the secondary and primary coils is rotatable and the contactless magnetic slip ring provides a substantially constant output.

  4. Rings of Neptune

    NASA Image and Video Library

    1999-07-25

    These two 591-second exposures of the rings of Neptune were taken with the clear filter by the NASA Voyager 2 wide-angle camera on Aug. 26, 1989. The two main rings are clearly visible and appear complete over the region imaged.

  5. Illustration of Saturn's Rings

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This illustration shows a close-up of Saturn's rings. These rings are thought to have formed from material that was unable to form into a Moon because of tidal forces from Saturn, or from a Moon that was broken up by Saturn's tidal forces.

  6. Birth Control Ring

    MedlinePlus

    ... It? The birth control ring is a soft, flexible, doughnut-shaped ring about 2 inches (5 centimeters) in diameter. It is inserted into the vagina, where it slowly releases hormones — the chemicals the body makes to control organ function — through the vaginal wall into the ...

  7. A-ring Propeller

    NASA Image and Video Library

    2010-08-26

    A propeller-shaped structure, created by an unseen moon, can be seen in Saturn A ring and looks like a small, dark line interrupting the bright surrounding ring material in the upper left of this image taken by NASA Cassini spacecraft.

  8. Telemetry carrier ring and support

    NASA Technical Reports Server (NTRS)

    Wakeman, Thomas G. (Inventor)

    1992-01-01

    A telemetry carrier ring for use in a gas turbine engine includes an annular support ring connected to the engine and an annular carrier ring coupled to the support ring, each ring exhibiting different growth characteristics in response to thermal and mechanical loading. The carrier ring is coupled to the support ring by a plurality of circumferentially spaced web members which are relatively thin in an engine radial direction to provide a predetermined degree of radial flexibility. the web members have a circumferential width and straight axial line of action selected to transfer torque and thrust between the support ring and the carrier ring without substantial deflection. The use of the web members with radial flexibility provides compensation between the support ring and the carrier ring since the carrier ring grows at a different rate than the supporting ring.

  9. Jupiter's Gossamer Rings Explained.

    NASA Astrophysics Data System (ADS)

    Hamilton, D. P.

    2003-05-01

    Over the past several years, Galileo measurements and groundbased imaging have drastically improved our knowledge of Jupiter's faint ring system. We now recognize that the ring consists of four components: a main ring 7000km wide, whose inner edge blossoms into a vertically-extended halo, and a pair of more tenuous Gossamer rings, one associated with each of the small moons Thebe and Amalthea. When viewed edge on, the Gossamer rings appear as diaphanous disks whose thicknesses agree with the vertical excursions of the inclined satellites from the equatorial plane. In addition, the brightness of each Gossamer ring drops off sharply outside the satellite orbits. These correlations allowed Burns etal (1999, Science, 284, 1146) to argue convincingly that the satellites act as sources of the dusty ring material. In addition, since most material is seen inside the orbits of the source satellites, an inwardly-acting dissipative force such as Poynting-Robertson drag is implicated. The most serious problem with this simple and elegant picture is that it is unable to explain the existence of a faint swath of material that extends half a jovian radius outward from Thebe. A key constraint is that this material has the same thickness as the rest of the Thebe ring. In this work, we identify the mechanism responsible for the outward extension: it is a shadow resonance, first investigated by Horanyi and Burns (1991, JGR, 96, 19283). When a dust grain enters Jupiter's shadow, photoelectric processes shut down and the grain's electric charge becomes more negative. The electromagnetic forces associated with the varying charge cause periodic oscillations in the orbital eccentricity and semimajor axis as the orbital pericenter precesses. This results in a ring which spreads both inward and outward of its source satellite while preserving its vertical thickness - just as is observed for the Thebe ring. Predictions of the model are: i) gaps of micron-sized material interior to Thebe and

  10. Jupiter's Rings: Sharpest View

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons spacecraft took the best images of Jupiter's charcoal-black rings as it approached and then looked back at Jupiter. The top image was taken on approach, showing three well-defined lanes of gravel- to boulder-sized material composing the bulk of the rings, as well as lesser amounts of material between the rings. New Horizons snapped the lower image after it had passed Jupiter on February 28, 2007, and looked back in a direction toward the sun. The image is sharply focused, though it appears fuzzy due to the cloud of dust-sized particles enveloping the rings. The dust is brightly illuminated in the same way the dust on a dirty windshield lights up when you drive toward a 'low' sun. The narrow rings are confined in their orbits by small 'shepherding' moons.

  11. Jupiter Ring, With Orion

    NASA Image and Video Library

    2017-05-25

    As NASA's Juno spacecraft flew through the narrow gap between Jupiter's radiation belts and the planet during its first science flyby, Perijove 1, on August 27, 2016, the Stellar Reference Unit (SRU-1) star camera collected the first image of Jupiter's ring taken from the inside looking out. The bright bands in the center of the image are the main ring of Jupiter's ring system. While taking the ring image, the SRU was viewing the constellation Orion. The bright star above the main ring is Betelgeuse, and Orion's belt can be seen in the lower right. Juno's Radiation Monitoring Investigation actively retrieves and analyzes the noise signatures from penetrating radiation in the images of the spacecraft's star cameras and science instruments at Jupiter. https://photojournal.jpl.nasa.gov/catalog/PIA21644

  12. STEEL TRUSS TENSION RING SUPPORTING DOME ROOF. TENSION RING COVERED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    STEEL TRUSS TENSION RING SUPPORTING DOME ROOF. TENSION RING COVERED BY ARCHITECTURAL FINISH. TENSION RING ROLLER SUPPORT AT COLUMN OBSCURED BY COLUMN COVERINGS. - Houston Astrodome, 8400 Kirby Drive, Houston, Harris County, TX

  13. Midsagittal anatomy of lumbar lordosis in adult egyptians: MRI study.

    PubMed

    Hegazy, Abdelmonem A; Hegazy, Raafat A

    2014-01-01

    Despite the increasing recognition of the functional and clinical importance of lumbar lordosis, little is known about its description, particularly in Egypt. At the same time, magnetic resonance imaging (MRI) has been introduced as a noninvasive diagnostic technique. The aim of this study was to investigate the anatomy of the lumbar lordosis using midsagittal MRIs. Normal lumbar spine MRIs obtained from 93 individuals (46 males, 47 females; 25-57 years old) were evaluated retrospectively. The lumbar spine curvature and its segments "vertebrae and discs" were described and measured. The lumbar lordosis angle (LLA) was larger in females than in males. Its mean values increased by age. The lumbar height (LH) was longer in males than in females. At the same time, the lumbar breadth (LB) was higher in females than in males. Lumbar index (LI = LB/LH × 100) showed significant gender differences (P < 0.0001). Lordosis was formed by wedging of intervertebral discs and bodies of lower lumbar vertebrae. In conclusion, MRI might clearly reveal the anatomy of the lumbar lordosis. Use of LI in association with LLA could be useful in evaluation of lumbar lordosis.

  14. Current Status of Lumbar Interbody Fusion for Degenerative Spondylolisthesis

    PubMed Central

    TAKAHASHI, Toshiyuki; HANAKITA, Junya; OHTAKE, Yasufumi; FUNAKOSHI, Yusuke; OICHI, Yuki; KAWAOKA, Taigo; WATANABE, Mizuki

    2016-01-01

    Instrumented lumbar fusion can provide immediate stability and assist in satisfactory arthrodesis in patients who have pain or instability of the lumbar spine. Lumbar adjunctive fusion with decompression is often a good procedure for surgical management of degenerative spondylolisthesis (DS). Among various lumbar fusion techniques, lumbar interbody fusion (LIF) has an advantage in that it maintains favorable lumbar alignment and provides successful fusion with the added effect of indirect decompression. This technique has been widely used and represents an advancement in spinal instrumentation, although the rationale and optimal type of LIF for DS remains controversial. We evaluated the current status and role of LIF in DS treatment, mainly as a means to augment instrumentation. We addressed the basic concept of LIF, its indications, and various types including minimally invasive techniques. It also has acceptable biomechanical features, and offers reconstruction with ideal lumbar alignment. Postsurgical adverse events related to each LIF technique are also addressed. PMID:27169496

  15. Fractures of the Thoracic and Lumbar Spine

    MedlinePlus

    ... Surgical treatment. Fracture-dislocations of the thoracic and lumbar spine are caused by very high-energy trauma. They can be extremely unstable injuries that often result in serious spinal cord or nerve damage. These injuries require stabilization through surgery. The ...

  16. Lumbar spine anomalies in a pycnodysostosis case.

    PubMed

    Beguiristain, J L; Arriola, F J; Leyes, M

    1995-01-01

    We report a case of pycnodysostosis in which several clefts in the laminas, interarticular parts, and pedicles of the whole lumbar spine were revealed for the first time on CT. We review similar findings in the literature, and discuss their pathogenesis.

  17. [A case of giant lumbar neurinoma].

    PubMed

    Bocchini, R; Broggi, S; Gandini, G; Nessi, F; Ponzio, F

    1987-11-30

    A rare case of a giant extradural neurinoma of the IV lumbar root with an anterior development and a soft neurological picture is reported. The Authors stress the important role of CT both in the neurinoma diagnosis and in the correct preoperative evaluation of its extension and its relationship with contiguous organs.

  18. Multiple lumbar arachnoid cysts. Case report.

    PubMed

    Pappalardo, S; Cassarino, A; Braidotti, P

    1986-09-01

    Arachnoid cysts are a rare cause of compression of the contents of the lumbar spinal canal; in the literature only about 100 cases are reported. The various methods of diagnosis are discussed in the light of a recent case observed by the authors.

  19. Lumbar Discitis Caused by Clostridium perfringens

    PubMed Central

    Popoff, M. R.; Degand, Nicolas; Lotte, Laurene; Bouvet, Philippe; Baudin, Guillaume; Cua, Eric; Roger, Pierre-Marie; Ruimy, Raymond

    2014-01-01

    We report here a rare case of chronic lumbar discitis caused by Clostridium perfringens in an elderly patient that was treated with a combination of β-lactams and clindamycin. Molecular analysis performed on the strain revealed an unusual toxin gene pattern. PMID:25056327

  20. Lumbar discitis caused by Clostridium perfringens.

    PubMed

    Lotte, Romain; Popoff, M R; Degand, Nicolas; Lotte, Laurene; Bouvet, Philippe; Baudin, Guillaume; Cua, Eric; Roger, Pierre-Marie; Ruimy, Raymond

    2014-10-01

    We report here a rare case of chronic lumbar discitis caused by Clostridium perfringens in an elderly patient that was treated with a combination of β-lactams and clindamycin. Molecular analysis performed on the strain revealed an unusual toxin gene pattern. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  1. [Lumbar pain and bilateral adrenal masses].

    PubMed

    García, Elena; Sánchez, Raquel; Martínez, Guillermo; Bernal, Carmen; Calatayud, M; Partida, M; Hawkins, Federico

    2009-05-01

    Many problems may arise when defining whether adrenal lesions are primary to the adrenal glands or represent other tissue, whether they are benign or malignant and whether they are functioning or nonfunctioning. Adrenal imaging complements the clinical and hormonal evaluation of these patients. We present a patient with lumbar pain and bilateral adrenal masses.

  2. The Enceladus Ring

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] The Enceladus Ring (labeled)

    This excellent view of the faint E ring -- a ring feature now known to be created by Enceladus -- also shows two of Saturn's small moons that orbit within the ring, among a field of stars in the background.

    The E ring extends from three to eight Saturn radii -- about 180,000 kilometers (118,000 miles) to 482,000 kilometers (300,000 miles). Its full extent is not visible in this view.

    Calypso (22 kilometers, or 14 miles across) and Helene (32 kilometers, or 20 miles across) orbit within the E ring's expanse. Helene skirts the outer parts of the E ring, but here it is projected in front of a region deeper within the ring.

    Calypso and Helene are trojan satellites, or moons that orbit 60 degrees in front or behind a larger moon. Calypso is a Tethys trojan and Helene is a trojan of Dione.

    An interesting feature of note in this image is the double-banded appearance of the E-ring, which is created because the ring is somewhat fainter in the ringplane than it is 500-1,000 kilometers (300-600 miles) above and below the ringplane. This appearance implies that the particles in this part of the ring have nonzero inclinations (a similar affect is seen in Jupiter's gossamer ring). An object with a nonzero inclination does not orbit exactly at Saturn's ringplane. Instead, its orbit takes it above and below the ringplane. Scientists are not entirely sure why the particles should have such inclinations, but they are fairly certain that the reason involves Enceladus.

    One possible explanation is that all the E ring particles come from the plume of icy material that is shooting due south out of the moon's pole. This means all of the particles are created with a certain velocity out of the ringplane, and then they orbit above and below that plane.

    Another possible explanation is that Enceladus produces particles with a range of speeds, but the moon gravitationally

  3. The Enceladus Ring

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] The Enceladus Ring (labeled)

    This excellent view of the faint E ring -- a ring feature now known to be created by Enceladus -- also shows two of Saturn's small moons that orbit within the ring, among a field of stars in the background.

    The E ring extends from three to eight Saturn radii -- about 180,000 kilometers (118,000 miles) to 482,000 kilometers (300,000 miles). Its full extent is not visible in this view.

    Calypso (22 kilometers, or 14 miles across) and Helene (32 kilometers, or 20 miles across) orbit within the E ring's expanse. Helene skirts the outer parts of the E ring, but here it is projected in front of a region deeper within the ring.

    Calypso and Helene are trojan satellites, or moons that orbit 60 degrees in front or behind a larger moon. Calypso is a Tethys trojan and Helene is a trojan of Dione.

    An interesting feature of note in this image is the double-banded appearance of the E-ring, which is created because the ring is somewhat fainter in the ringplane than it is 500-1,000 kilometers (300-600 miles) above and below the ringplane. This appearance implies that the particles in this part of the ring have nonzero inclinations (a similar affect is seen in Jupiter's gossamer ring). An object with a nonzero inclination does not orbit exactly at Saturn's ringplane. Instead, its orbit takes it above and below the ringplane. Scientists are not entirely sure why the particles should have such inclinations, but they are fairly certain that the reason involves Enceladus.

    One possible explanation is that all the E ring particles come from the plume of icy material that is shooting due south out of the moon's pole. This means all of the particles are created with a certain velocity out of the ringplane, and then they orbit above and below that plane.

    Another possible explanation is that Enceladus produces particles with a range of speeds, but the moon gravitationally

  4. Lumbar lordosis in female collegiate dancers and gymnasts.

    PubMed

    Ambegaonkar, Jatin P; Caswell, Amanda M; Kenworthy, Kristen L; Cortes, Nelson; Caswell, Shane V

    2014-12-01

    Postural deviations can predispose an individual to increased injury risk. Specifically, lumbar deviations are related to increased low back pain and injury. Dancers and gymnasts are anecdotally suggested to have exaggerated lumbar lordosis and subsequently may be at increased risk of lumbar pathologies. Our objective was to examine lumbar lordosis levels in dancers and gymnasts. We examined lumbar lordosis in 47 healthy collegiate females (17 dancers, 29 gymnasts; mean age 20.2 ± 1.6 yrs) using 2-dimensional sagittal plane photographs and the Watson MacDonncha Posture Analysis instrument. Participants' lordosis levels were cross-tabulated and a Mann-Whitney U-test compared lumbar lordosis between groups (p<0.05). Most participants (89.4%, n=42) exhibited either marked (dancers 50%, n=9; gymnasts 62.1%, n=18; combined 57.4%, n=27) or moderate (dancers 27.8%, n=5; gymnasts 34.5%, n=10; combined 31.9%, n=15) lumbar lordosis deviations. The distribution of lordosis was similar across groups (p=0.22). Most dancers and gymnasts had moderate or marked lumbar lordosis. The extreme ranges of motion required during dancing and gymnastics may contribute to the participants' high lumbar lordosis. Instructors should be aware that there may be links between repetitive hyperextension activities and lumbar lordosis levels in dancers and gymnasts. Thus, they should proactively examine lumbar lordosis in their dancers and gymnasts. How much age of training onset, regimens, survivor bias, or other factors influence lumbar lordosis requires study. Longitudinal studies are also needed to determine if lumbar lordosis levels influence lumbar injury incidence in dancers and gymnasts.

  5. Earth: A Ringed Planet?

    NASA Astrophysics Data System (ADS)

    Hancock, L. O.; Povenmire, H.

    2010-12-01

    Among the most beautiful findings of the Space Age have been the discoveries of planetary rings. Not only Saturn but also Jupiter, Uranus and Neptune have rings; Saturn’s ring system has structures newly discovered; even Saturn's moon Rhea itself has a ring. All these are apparently supplied by material from the planetary moons (Rhea's ring by Rhea itself). The question naturally arises, why should the Earth not have a ring, and on the other hand, if it does, why has it not been observed? No rings have yet been observed in the inner solar system, but after all, rings in the inner solar system might simply tend to be fainter and more transient than those of the outer solar system: the inner solar system is more affected by the solar wind, and the Sun’s perturbing gravitational influence is greater. J.A. O’Keefe first suggested (1980) that Earth might have a ring system of its own. An Earth ring could account for some climate events. O’Keefe remarked that formation or thickening of a ring system in Earth’s equatorial plane could drive glaciation by deepening the chill of the winter hemisphere. (It is very well established that volcanic dust is an effective agent for the extinction of sunlight; this factor can be overwhelmingly apparent in eclipse observations.) O’Keefe died in 2000 and the speculation was not pursued, but the idea of an Earth ring has a prima facie reasonableness that calls for its renewed consideration. The program of this note is to hypothesize that, as O’Keefe proposed: (a) an Earth ring system exists; (b) it affects Earth's weather and climate; (c) the tektite strewn fields comprise filaments of the ring fallen to Earth's surface on various occasions of disturbance by comets or asteroids. On this basis, and drawing on the world's weather records, together with the Twentieth Century Reanalysis by NCEP/CIRES covering the period 1870-2010 and the geology of the tektite strewn fields, we herein propose the hypothesized Earth ring

  6. Hot piston ring tests

    NASA Technical Reports Server (NTRS)

    Allen, David J.; Tomazic, William A.

    1987-01-01

    As part of the DOE/NASA Automotive Stirling Engine Project, tests were made at NASA Lewis Research Center to determine whether appendix gap losses could be reduced and Stirling engine performance increased by installing an additional piston ring near the top of each piston dome. An MTI-designed upgraded Mod I Automotive Stirling Engine was used. Unlike the conventional rings at the bottom of the piston, these hot rings operated in a high temperature environment (700 C). They were made of a high temperature alloy (Stellite 6B) and a high temperature solid lubricant coating (NASA Lewis-developed PS-200) was applied to the cylinder walls. Engine tests were run at 5, 10, and 15 MPa operating pressure over a range of operating speeds. Tests were run both with hot rings and without to provide a baseline for comparison. Minimum data to assess the potential of both the hot rings and high temperature low friction coating was obtained. Results indicated a slight increase in power and efficiency, an increase over and above the friction loss introduced by the hot rings. Seal leakage measurements showed a significant reduction. Wear on both rings and coating was low.

  7. Seal ring installation tool

    NASA Technical Reports Server (NTRS)

    Haselmaier, L. Haynes (Inventor)

    2004-01-01

    A seal ring tool that allows an installer to position a primary seal ring between hub ends of pipe flanges that are being assembled together. The tool includes a pivoting handle member and extension arms attached to the pivoting handle member. The ends of the arms have side indentation type longitudinal grooves angled toward one another for holding the primary seal ring in place between the hubs of respective pipes that are to be attached together. The arms of the tool can also have flat sides that can be used to abut against an optional second larger seal that is supported within a groove in one of the hub ends so that the second hub end can then be moved against the other side of the primary seal ring. Once the seal ring is positioned between the pipe hubs, the pipe hubs can be moved about the seal ring due to the flat sides of the arms of the tool. The tool eliminates the chances of damaging and contaminating seal rings being installed within pipe hubs that are being attached to one another.

  8. Gored of the Rings

    NASA Image and Video Library

    2014-06-09

    Prometheus is caught in the act of creating gores and streamers in the F ring. Scientists believe that Prometheus and its partner-moon Pandora are responsible for much of the structure in the F ring as shown by NASA Cassini spacecraft. The orbit of Prometheus (53 miles, or 86 kilometers across) regularly brings it into the F ring. When this happens, it creates gores, or channels, in the ring where it entered. Prometheus then draws ring material with it as it exits the ring, leaving streamers in its wake. This process creates the pattern of structures seen in this image. This process is described in detail, along with a movie of Prometheus creating one of the streamer/channel features, in PIA08397. This view looks toward the sunlit side of the rings from about 8.6 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 11, 2014. The view was acquired at a distance of approximately 1.3 million miles (2.1 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 147 degrees. Image scale is 8 miles (13 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18270

  9. Dynamics of the Uranian Rings

    NASA Technical Reports Server (NTRS)

    Dermott, S. F.

    1984-01-01

    Some of the problems of the shepherding satellite model of Goldreich ant tremaine are discussed. The following topics are studied: (1) optical depths of the all the observed narrow rings; (2) satellite and ring separation timescales; (3) ring edge sharpness; (4) shock formation in narrow rings; (5) the existence of small satellites near the Uranian rings; and (6) the apse and node alignments of the eccentric and inclined rings.

  10. Dynamics of the Uranian Rings

    NASA Technical Reports Server (NTRS)

    Dermott, S. F.

    1984-01-01

    Some of the problems of the shepherding satellite model of Goldreich ant tremaine are discussed. The following topics are studied: (1) optical depths of the all the observed narrow rings; (2) satellite and ring separation timescales; (3) ring edge sharpness; (4) shock formation in narrow rings; (5) the existence of small satellites near the Uranian rings; and (6) the apse and node alignments of the eccentric and inclined rings.

  11. Reconstruction of the pelvis and lumbar-pelvic junction using 2 vascularized autologous bone grafts after en bloc resection for an iliosacral chondrosarcoma.

    PubMed

    Mendel, Ehud; Mayerson, Joel L; Nathoo, Narendra; Edgar, Rick L; Schmidt, Carl; Miller, Michael J

    2011-08-01

    Primary pelvic sarcomas remain challenging and complex surgical problems with significant potential for postoperative impairment of ambulation, as well as bowel, bladder, and sexual function. En bloc resection with negative tumor margins represents the best chance of control or cure as current adjuvant therapies remain ineffective. Tumor involvement of the sacrum with extension to the greater sciatic notch and ipsilateral ilium requires an external hemipelvectomy and sagittal sacrectomy with sacrifice of the lower extremity to achieve en bloc resection, followed by lumbar-pelvic reconstruction. A patient with an iliosacral chondrosarcoma is presented to illustrate a novel lumbar-pelvic reconstruction technique, in which vascularized soft tissue and 2 vascularized bone grafts were harvested from the amputated lower extremity and transferred to the pelvis as composite flaps to restore pelvic ring integrity, augment lumbar-pelvic fusion, and close the soft-tissue defect. The biomechanical dynamics of this unique construct are discussed.

  12. Dynamics of planetary rings

    NASA Astrophysics Data System (ADS)

    Araki, S.

    1991-02-01

    The modeling of the dynamics of particle collisions within planetary rings is discussed. Particles in the rings collide with one another because they have small random motions in addition to their orbital velocity. The orbital speed is roughly 10 km/s, while the random motions have an average speed of about a tenth of a millimeter per second. As a result, the particle collisions are very gentle. Numerical analysis and simulation of the ring dynamics, performed with the aid of a supercomputer, is outlined.

  13. Theodolite Ring Lights

    NASA Technical Reports Server (NTRS)

    Clark, David

    2006-01-01

    Theodolite ring lights have been invented to ease a difficulty encountered in the well-established optical-metrology practice of using highly reflective spherical tooling balls as position references. A theodolite ring light produces a more easily visible reflection and eliminates the need for an autocollimating device. A theodolite ring light is a very bright light source that is well centered on the optical axis of the instrument. It can be fabricated, easily and inexpensively, for use on a theodolite or telescope of any diameter.

  14. Heavy ion storage rings

    SciTech Connect

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented.

  15. Alternative parallel ring protocols

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.; Foudriat, E. C.; Maly, Kurt J.; Kale, V.

    1990-01-01

    Communication protocols are know to influence the utilization and performance of communication network. The effect of two token ring protocols on a gigabit network with multiple ring structure is investigated. In the first protocol, a mode sends at most one message on receiving a token. In the second protocol, a mode sends all the waiting messages when a token is received. The behavior of these protocols is shown to be highly dependent on the number of rings as well as the load in the network.

  16. Hopkins with SPHERES RINGS

    NASA Image and Video Library

    2013-11-04

    ISS037-E-025870 (4 Nov. 2013) --- In the International Space Station?s Kibo laboratory, NASA astronaut Michael Hopkins, Expedition 37 flight engineer, conducts a session with a pair of bowling-ball-sized free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. Surrounding the two SPHERES mini-satellites is ring-shaped hardware known as the Resonant Inductive Near-field Generation System, or RINGS. SPHERES-RINGS seeks to demonstrate wireless power transfer between satellites at a distance for enhanced operations.

  17. Hopkins with SPHERES RINGS

    NASA Image and Video Library

    2013-11-04

    ISS037-E-025872 (4 Nov. 2013) --- In the International Space Station?s Kibo laboratory, NASA astronaut Michael Hopkins, Expedition 37 flight engineer, conducts a session with a pair of bowling-ball-sized free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. Surrounding the two SPHERES mini-satellites is ring-shaped hardware known as the Resonant Inductive Near-field Generation System, or RINGS. SPHERES-RINGS seeks to demonstrate wireless power transfer between satellites at a distance for enhanced operations.

  18. Hopkins with SPHERES RINGS

    NASA Image and Video Library

    2013-11-04

    ISS037-E-025866 (4 Nov. 2013) --- In the International Space Station?s Kibo laboratory, NASA astronaut Michael Hopkins, Expedition 37 flight engineer, conducts a session with a pair of bowling-ball-sized free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. Surrounding the two SPHERES mini-satellites is ring-shaped hardware known as the Resonant Inductive Near-field Generation System, or RINGS. SPHERES-RINGS seeks to demonstrate wireless power transfer between satellites at a distance for enhanced operations.

  19. Hopkins with SPHERES RINGS

    NASA Image and Video Library

    2013-11-04

    ISS037-E-025868 (4 Nov. 2013) --- In the International Space Station?s Kibo laboratory, NASA astronaut Michael Hopkins, Expedition 37 flight engineer, conducts a session with a pair of bowling-ball-sized free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. Surrounding the two SPHERES mini-satellites is ring-shaped hardware known as the Resonant Inductive Near-field Generation System, or RINGS. SPHERES-RINGS seeks to demonstrate wireless power transfer between satellites at a distance for enhanced operations.

  20. Hopkins with SPHERES RINGS

    NASA Image and Video Library

    2013-11-04

    ISS037-E-025879 (4 Nov. 2013) --- In the International Space Station?s Kibo laboratory, NASA astronaut Michael Hopkins, Expedition 37 flight engineer, conducts a session with a pair of bowling-ball-sized free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. Surrounding the two SPHERES mini-satellites is ring-shaped hardware known as the Resonant Inductive Near-field Generation System, or RINGS. SPHERES-RINGS seeks to demonstrate wireless power transfer between satellites at a distance for enhanced operations.

  1. Clinical usefulness of assessing lumbar somatosensory evoked potentials in lumbar spinal stenosis. Clinical article.

    PubMed

    Liu, Xinyu; Konno, Shunsuke; Miyamoto, Masabumi; Gembun, Yoshikazu; Horiguchi, Gen; Ito, Hiromoto

    2009-07-01

    The aim of this retrospective study was to evaluate the clinical usefulness of assessing lumbar somatosensory evoked potentials (SSEPs) in central lumbar spinal stenosis (LSS). The latencies of lumbar SSEPs were recorded in 40 patients with central LSS, including 16 men and 24 women. The mean age of the patients was 67.3 +/- 7.4 years. The diagnosis was LSS in 23 cases and LSS associated with degenerative spondylolisthesis in 17 cases. The average duration of symptoms was 43.8 +/- 51.2 months. Twenty-two cases had bilateral and 18 cases had unilateral leg symptoms. Thirty-seven cases were associated with neurogenic intermittent claudication and the mean walking distance of patients with this condition was 246.8 +/- 232.7 m. The mean Japanese Orthopedic Association scale score, as well as the visual analog scale (VAS) scores of low-back pain, leg pain, and numbness, were 16.5 +/- 3.5, 6.0 +/- 2.5, 6.9 +/- 2.1, and 7.8 +/- 2.2, respectively. The minimal cross-sectional area of the dural sac on MR imaging was 0.44 +/- 0.21 cm(2). Thirty-nine cases of cervical spondylotic myelopathy without lumbar and peripheral neuropathy were chosen as the control group. The latencies of lumbar SSEPs in patients with LSS and in the control group were 23.0 +/- 2.0 ms and 21.6 +/- 1.9 ms, respectively. There was a statistically significant difference between the LSS and control groups (p < 0.05). The latency of lumbar SSEPs was significant correlated with the VAS score of leg numbness (p < 0.05). The latency of lumbar SSEPs in LSS was clearly delayed when the VAS score of leg numbness was > or = 8 (p < 0.05). Lumbar SSEPs are able to detect neurological deficit in the lumbar area effectively, and they can reflect part of the subjective severity of sensory disturbance (numbness) in LSS. Both lumbar SSEPs and VAS scores of leg numbness may be useful for clinical evaluation in patients with LSS.

  2. Impaired lumbar movement perception in association with postural stability and motor- and somatosensory-evoked potentials in lumbar spinal stenosis.

    PubMed

    Leinonen, Ville; Määttä, Sara; Taimela, Simo; Herno, Arto; Kankaanpää, Markku; Partanen, Juhani; Kansanen, Martti; Hänninen, Osmo; Airaksinen, Olavi

    2002-05-01

    A descriptive study of the associations between different neurophysiologic findings in patients with lumbar spinal stenosis. To evaluate the ability to sense a change in lumbar position and the associations between lumbar movement perception, postural stability, and motor-evoked potentials and somatosensory-evoked potentials. Patients with low back pain have impaired postural control and impaired lumbar proprioception. Altered motor-evoked potentials and somatosensory-evoked potentials have been often observed in lumbar spinal stenosis. The study included 26 patients with clinically and radiologically diagnosed lumbar spinal stenosis. Their ability to sense lumbar rotation was assessed in a previously validated motorized trunk rotation unit in the seated position. The abilities to indicate the movement direction and the movement magnitude were used as indexes of the ability to sense the lumbar rotatory movement. The postural stability was measured with a vertical force platform. The motor-evoked potentials were elicited by transcranial and lumbar stimulation and recorded from anterior tibialis muscles. The somatosensory-evoked potentials were elicited by transcutaneous electrical stimulation of the tibial nerve at the ankle. Twenty patients (76.9%; P = 0.006) reported the wrong movement direction. Furthermore, the patients consistently localized the movement sensation in their shoulders instead of the lumbar region. The altered motor-evoked potentials and somatosensory-evoked potentials were observed in 11 and 16 patients, respectively. Abnormal motor-evoked potentials had inconsistent associations with impaired movement perception and postural stability and abnormal somatosensory-evoked potentials had no associations with other findings. Many patients with lumbar spinal stenosis have difficulties in sensing the lumbar rotational movement, which may indicate impaired proprioceptive abilities. Abnormal motor-evoked potentials and somatosensory-evoked potentials are

  3. Scintillating C Ring

    NASA Image and Video Library

    2007-01-16

    Both luminous and translucent, the C ring sweeps out of the darkness of Saturn's shadow and obscures the planet at lower left. The ring is characterized by broad, isolated bright areas, or "plateaus," surrounded by fainter material. This view looks toward the unlit side of the rings from about 19 degrees above the ringplane. North on Saturn is up. The dark, inner B ring is seen at lower right. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 15, 2006 at a distance of approximately 632,000 kilometers (393,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 56 degrees. Image scale is 34 kilometers (21 miles) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA08855

  4. Ring of Stellar Fire

    NASA Image and Video Library

    2014-10-22

    This image from NASA Spitzer Space Telescope shows where the action is taking place in galaxy NGC 1291. The outer ring, colored red, is filled with new stars that are igniting and heating up dust that glows with infrared light.

  5. Obscured by Rings

    NASA Image and Video Library

    2012-08-29

    Saturn rings obscure part of Titan colorful visage in this image from NASA Cassini spacecraft. The south polar vortex that first appeared in Titan atmosphere in 2012 is visible at the bottom of this view.

  6. Outer B Ring Edge

    NASA Image and Video Library

    2004-12-03

    This image NASA Cassini spacecraft shows subtle, wavelike patterns, hundreds of narrow features resembling a record grooves in Saturn outer B-ring, and a noticeable abrupt change in overall brightness beyond the dark gap near the right.

  7. A-Ring Structures

    NASA Image and Video Library

    2010-09-23

    Several structures in Saturn A ring are exposed near the Encke Gap in this image captured by NASA Cassini spacecraft. A peculiar kink can be seen in one particularly bright ringlet at the bottom right.

  8. Ring Shadows on Janus

    NASA Image and Video Library

    2009-12-23

    Sunlight passing through the Cassini Division between Saturn A and B rings sweeps across and illuminates the surface of the moon Janus in this image captured by NASA Cassini spacecraft. Go to the Photojournal to view the animation.

  9. View of Saturn Rings

    NASA Image and Video Library

    1999-01-18

    This view shows some detail and differences in the complex system of rings. This was one of the first pictures obtained once NASA Voyager 2 resumed returning images Aug. 29, 1979 after its scan platform was commanded to view Saturn.

  10. Rings and Waves

    NASA Image and Video Library

    2013-09-30

    Saturn A ring is decorated with several kinds of waves. NASA Cassini spacecraft has captured a host of density waves, a bending wave, and the edge waves on the edge of the Keeler gap caused by the small moon Daphnis.

  11. Wisps Under the Rings

    NASA Image and Video Library

    2015-12-28

    Dione beautiful wispy terrain is brightly lit alongside Saturn elegant rings in this image captured by NASA Cassini spacecraft. The wisps are relatively young fractures on the trailing hemisphere of Dione icy surface.

  12. Warm core rings

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Gulf stream phenomena have been the focus of numerous studies by U.S. and Canadian oceanographic laboratories. Two years ago, observations of warm core rings associated with the Gulf Stream were reported in The Oceanography Report, (November 2, 1982, p. 834). It was noted then that the structure of warm core rings can undergo rapid transformation. Recently, a multidisciplinary group of physical and biological oceanographic institutions has examined the evolution of warm core rings in detail [Nature, 308, pp. 837-840, 1984]. The study has involved research vessels Endeavor, Atlantis II, and Albatross IV for surface measurements of temperature, salinity, and for measurement surface pigments to assess the concentration of marine plants. The results are that even though warm core rings are often very stable, undergoing only slow changes, it turns out that major alterations in structure can and do occur in short periods of 2-5 days.

  13. Saturn's dynamic D ring

    USGS Publications Warehouse

    Hedman, M.M.; Burns, J.A.; Showalter, M.R.; Porco, C.C.; Nicholson, P.D.; Bosh, A.S.; Tiscareno, M.S.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Clark, R.

    2007-01-01

    The Cassini spacecraft has provided the first clear images of the D ring since the Voyager missions. These observations show that the structure of the D ring has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, <40-km wide ringlet to a much broader and more diffuse 250-km wide feature. In addition, its center of light has shifted inwards by over 200 km relative to other features in the D ring. Cassini also finds that the locations of other narrow features in the D ring and the structure of the diffuse material in the D ring differ from those measured by Voyager. Furthermore, Cassini has detected additional ringlets and structures in the D ring that were not observed by Voyager. These include a sheet of material just interior to the inner edge of the C ring that is only observable at phase angles below about 60??. New photometric and spectroscopic data from the ISS (Imaging Science Subsystem) and VIMS (Visual and Infrared Mapping Spectrometer) instruments onboard Cassini show the D ring contains a variety of different particle populations with typical particle sizes ranging from 1 to 100 microns. High-resolution images reveal fine-scale structures in the D ring that appear to be variable in time and/or longitude. Particularly interesting is a remarkably regular, periodic structure with a wavelength of ??? 30 ?? km extending between orbital radii of 73,200 and 74,000 km. A similar structure was previously observed in 1995 during the occultation of the star GSC5249-01240, at which time it had a wavelength of ??? 60 ?? km. We interpret this structure as a periodic vertical corrugation in the D ring produced by differential nodal regression of an initially inclined ring. We speculate that this structure may have formed in response to an impact with a comet or meteoroid in early 1984. ?? 2006 Elsevier Inc. All rights reserved.

  14. Ultrasonic Newton's rings

    SciTech Connect

    Hsu, D.K. ); Dayal, V. )

    1992-03-09

    Interference fringes due to bondline thickness variation were observed in ultrasonic scans of the reflected echo amplitude from the bondline of adhesively joined aluminum skins. To demonstrate that full-field interference patterns are observable in point-by-point ultrasonic scans, an optical setup for Newton's rings was scanned ultrasonically in a water immersion tank. The ultrasonic scan showed distinct Newton's rings whose radii were in excellent agreement with the prediction.

  15. Bending the Rings

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Saturn's rings appear strangely warped in this view of the rings seen through the upper Saturn atmosphere.

    The atmosphere acts like a lens in refracting (bending) the light reflected from the rings. As the rings pass behind the overexposed limb (edge) of Saturn as seen from Cassini, the ring structure appears to curve downward due to the bending of the light as it passes through the upper atmosphere.

    This image was obtained using a near-infrared filter. The filter samples a wavelength where methane gas does not absorb light, thus making the far-off rings visible through the upper atmosphere.

    By comparing this image to similar ones taken using filters where methane gas does absorb, scientists can estimate the vertical profile of haze and the abundance of methane in Saturn's high atmosphere.

    The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 14, 2005, through a filter sensitive to wavelengths of infrared light centered at 938 nanometers and at a distance of approximately 197,000 kilometers (123,000 miles) from Saturn. The image scale is 820 meters (2,680 feet) per pixel.

  16. Nardo Ring, Italy

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Nardo Ring is a striking visual feature from space, and astronauts have photographed it several times. The Ring is a race car test track; it is 12.5 kilometers long and steeply banked to reduce the amount of active steering needed by drivers. The Nardo Ring lies in a remote area on the heel of Italy's 'boot,' 50 kilometers east of the naval port of Taranto. The Ring encompasses a number of active (green) and fallow (brown to dark brown) agricultural fields. In this zone of intensive agriculture, farmers gain access to their fields through the Ring via a series of underpasses. Winding features within the southern section of the Ring appear to be smaller, unused race tracks.

    The image covers an area of 18.8 x 16.4 km, was acquired on August 17. 2007, and is located at 49.3 degrees north latitude, 17.8 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  17. Barely Bisected Rings

    NASA Image and Video Library

    2016-09-12

    Saturn's shadow stretched beyond the edge of its rings for many years after Cassini first arrived at Saturn, casting an ever-lengthening shadow that reached its maximum extent at the planet's 2009 equinox. This image captured the moment in 2015 when the shrinking shadow just barely reached across the entire main ring system. The shadow will continue to shrink until the planet's northern summer solstice, at which point it will once again start lengthening across the rings, reaching across them in 2019. Like Earth, Saturn is tilted on its axis. And, just as on Earth, as the sun climbs higher in the sky, shadows get shorter. The projection of the planet's shadow onto the rings shrinks and grows over the course of its 29-year-long orbit, as the angle of the sun changes with respect to Saturn's equator. This view looks toward the sunlit side of the rings from about 11 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Jan. 16, 2015. The view was obtained at a distance of approximately 1.6 million miles (2.5 million kilometers) from Saturn. Image scale is about 90 miles (150 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20498

  18. Propellers in Saturn's rings

    NASA Astrophysics Data System (ADS)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2014-04-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings [5, 8]. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~ 100m in size) have been identified in Saturn's A ring through their propeller signature in the images [10, 7, 9, 11]. Furthermore, recent Cassini observations indicate the possible existence of objects embedded even in Saturn's B and C ring [6, 2]. In this paper we present our new results about by now classical A ring propellers and more enigmatic B ring population. Due to the presence of self-gravity wakes the analysis of propeller brightness in ISS images always bears some ambiguity [7, 9] and consequently the exact morphology of propellers is not a settled issue. In 2008 we obtained a fortunate Cassini Ultraviolet Imaging Spectrograph (UVIS) occultation of the largest A ring propeller Bleriot. Utilizing Cassini ISS images we obtain Bleriot orbit and demonstrate that UVIS Persei Rev42 occultation did cut across Bleriot about 100km downstream from the center. The occultation itself shows a prominent partial gap and higher density outer flanking wakes, while their orientation is consistent with a downstream cut. While in the UVIS occultation the partial gap is more prominent than the flanking wakes, the features mostly seen in Bleriot images are actually flanking wakes. One of the most interesting aspects of the A ring propellers are their wanderings, or longitudinal deviations from a pure circular orbit [11]. We numerically investigated the possibility of simple moon

  19. The Effect of an Adjustable Hinged Operating Table on Lumbar Lordosis during Lumbar Surgery.

    PubMed

    Sebastian, Arjun; Ahmed, Amin; Vernon, Brian; Nguyen, Emily C; Aleem, Ilyas; Clarke, Michelle J; Currier, Bradford L; Anderson, Paul; Bydon, Mohamad; Nassr, Ahmad

    2017-07-24

    Prospective observational study OBJECTIVES.: Quantify the amount of lumbar lordosis achieved on a hinged operative table in neutral, flexion, and extension. Hinged operative tables may allow surgeons to adjust lumbar spine positioning intraoperatively. The amount of lumbar lordosis in neutral, flexion, and extension positions has not been quantified prospectively using a hinged table. Thirty patients undergoing elective lumbar surgery were enrolled. Standing x-rays taken in neutral, maximal flexion, and maximal extension were obtained. Following prone positioning on a hinged operative table, x-rays in neutral, maximal flexion, and maximal extension were taken. Total lumbar lordosis was calculated for all 6 images by two physicians. Disc degeneration was graded using Pfirrmann grades. Lumbar lordosis on the operative table was 56.5 ± 2.1, 43.6 ± 2.2, 63.2 ± 2.0 compared to 46.9 ± 3.1, 33.2 ± 2.8, 52.3 ± 3.3 on the standing films in neutral, flexion, and extension respectively. Average flexion (12.9 ± 1.1) and extension (6.7 ± 1.2) were significantly different from neutral on the table (p < .001). Lumbar lordosis was significantly higher on the operative table (p < .001). Total range of motion was 19.6 ± 1.9 on the table and 19.1 ± 2.0 with standing (p = 0.42). Average Pfirrmann disc grade was 2.77 ± 0.10 which did not correlate with range of motion (p = 0.40). In this cohort, the hinged operative table allowed for a physiologic arc of motion of nearly 20 from flexion to extension. A considerable amount of lumbar sagittal motion can be obtained on hinged operative tables without decreasing overall lumbar lordosis below physiologic levels. 3.

  20. Effects of lumbar stabilization exercise on functional disability and lumbar lordosis angle in patients with chronic low back pain

    PubMed Central

    Cho, Igsoo; Jeon, Chunbae; Lee, Sangyong; Lee, Daehee; Hwangbo, Gak

    2015-01-01

    [Purpose] This study examined the effects of lumbar stabilization exercises on the functional disability and lumbar lordosis angles in patients with chronic low back pain. [Subjects] The subjects were 30 patients with chronic low back pain divided into a lumbar stabilization exercise group (n = 15) and a conservative treatment group (n = 15). [Methods] The lumbar stabilization exercise and conservative treatment groups performed an exercise program and conservative physical treatment, respectively. Both programs were performed 3 times a week for 6 weeks. The degree of functional disability was assessed by the Oswestry disability index, and lumbar lordosis angles were measured by plain radiography. [Results] The Oswestry disability index decreased significantly in the both groups; however, it was significantly lower in the lumbar stabilization exercise group. The lumbar lordosis angle increased significantly in the lumbar stabilization exercise group after treatment and was also significantly greater than that in the conservative treatment group. [Conclusion] Lumbar stabilization exercise is more effective than conservative treatment for improving functional disability and lumbar lordosis angles. PMID:26180363

  1. Changes in bending stiffness and lumbar spine range of movement following lumbar mobilization and manipulation.

    PubMed

    Stamos-Papastamos, Nikolaos; Petty, Nicola J; Williams, Jonathan M

    2011-01-01

    The purpose of this study was to investigate the effects of lumbar rotational manipulation and lumbar central posteroanterior mobilization on lumbar bending stiffness and flexion and extension range of motion (ROM). A same-subject, repeated-measures, crossover design was used using 32 asymptomatic subjects (16 female and 16 male; mean [SD] age, 25.5 [4.5] years; weight, 65.7 [11.8] kg; and height, 1.70 [0.08] m). Each subject received mobilization or manipulation on 2 different occasions. Bending stiffness was calculated using a 3-point bending model using an electromagnetic tracking device and a force platform; lumbar flexion and extension ROM was measured using an electromagnetic tracking device. All variables were measured pre- and postintervention. Their effect was compared using paired t tests. Manipulation and mobilization did not significantly alter either bending stiffness or lumbar flexion and extension ROM (mobilization: P = .175, P = .613, and P = .535; manipulation: P = .973, P = .323, and P = .439). Bending stiffness changes were not correlated to changes in ROM (Pearson r for stiffness-flexion = -0.102, P = .586; Pearson r for stiffness-extension = 0.014, P = .941). Manipulation and mobilization had no significant effect on bending stiffness or flexion and extension ROM for this group of subjects. Some individual variations in effect were observed. Copyright © 2011 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  2. Single incision endoscopic surgery for lumbar hernia.

    PubMed

    Kawaguchi, Masahiko; Ishikawa, Norihiko; Shimizu, Satsuki; Shin, Hisato; Matsunoki, Aika; Watanabe, Go

    2011-01-01

    Single Incision Endoscopic Surgery (SIES) has emerged as a less invasive surgery among laparoscopic surgeries, and this approach for incisional hernia was reported recently. This is the first report of SIES for an incisional lumbar hernia. A 66-year-old Japanese woman was referred to our institution because of a left flank hernia that developed after left iliac crest bone harvesting. A 20-mm incision was created on the left side of the umbilicus and all three trocars (12, 5, and 5 mm) were inserted into the incision. The hernial defect was 14 × 9 cm and was repaired with intraperitoneal onlay mesh and a prosthetic graft. The postoperative course was uneventful. SIES for lumbar hernia offers a safe and effective outcome equivalent compared to laparoscopic surgery. In addition, SIES is less invasive and has a cosmetic benefit.

  3. [Polish nomenclature of lumbar disc disease].

    PubMed

    Radło, Paweł; Smetkowski, Andrzej; Tesiorowski, Maciej

    2014-01-01

    Lumbar disc herniation is one of the most common damage of musculoskeletal system. The incidence of pain of lumbosacral spine is estimated approximately on 60-90% in general population, whereas the incidence of disc herniation in patients experiencing low back pain is about 91%. Despite the high incidence and uncomplicated pathogenesis of disc disease there is a problem with the nomenclature. In the vast majority of cases, the naming confusion stems from ignorance of the etiology of low back pain. Different terminologies: morphological, topographical, Radiological and Clinical are used interchangeably. In addition, diagnosis is presented in a variety of languages: Polish, English and Latin. Moreover, the medical and traditional language are used alternately. The authors found in Polish literature more, than 20 terms to describe lumbar disc herniation. All of these terms in the meaning of the authors are used to determine one pathology--mechanical damage to the intervertebral disc and moving the disc material beyond the anatomical area.

  4. Diskography outcomes in patients following lumbar diskectomy.

    PubMed

    Siambanes, David; Kposowa, Augustine J; Michelsen, Steven

    2003-08-01

    The results of lumbar diskography at post-diskectomy and nonoperative disk levels in postoperative patients and patients without prior back surgery were reviewed over 3 years. Other possible predictive factors, including disk degeneration (per the Adam's classification), end-point resistance, gender, and age, also were reviewed. The results revealed that no statistically significant association was noted between the presence of a prior diskectomy and the outcome of diskography. However, disk degeneration classified as ruptured and fissured correlated statistically with positive diskography. Additionally, age between 30 and 39 years and male gender were statistically associated with a positive diskogram. Disk levels displaying a poor end point during diskography injection (not amendable to pressurization) were statistically related to ruptured or fissured disk levels and thus positive diskography. Based on these results, the assumption that disabling low-back pain presenting after lumbar procedure is due to diskogenic disease arising from the surgical level is not supported.

  5. Recognition of lumbar disk herniation with NMR

    SciTech Connect

    Chafetz, N.I.; Genant, H.K.; Moon, K.L.; Helms, C.A.; Morris, J.M.

    1983-12-01

    Fifteen nuclear magnetic resonance (NMR) studies of 14 patients with herniated lumbar intervertebral disks were performed on the UCSF NMR imager. Computed tomographic (CT) scans done on a GE CT/T 8800 or comparable scanner were available at the time of NMR scan interpretation. Of the 16 posterior disk ruptures seen at CT, 12 were recognized on NMR. Diminished nucleus pulposus signal intensity was present in all ruptured disks. In one patient, NMR scans before and after chymopapain injection showed retraction of the protruding part of the disk and loss of signal intensity after chemonucleolysis. Postoperative fibrosis demonstrated by CT in one patient and at surgery in another showed intermediate to high signal intensity on NMR, easily distinguishing it from nearby thecal sac and disk. While CT remains the method of choice for evaluation of the patient with suspected lumbar disk rupture, the results of this study suggest that NMR may play a role in evaluating this common clinical problem.

  6. [Vascular complications associated with lumbar spinal surgery].

    PubMed

    Riedemann-Wistuba, M; Alonso-Pérez, M; Llaneza-Coto, J M

    2016-01-01

    Although there are currently less invasive techniques available for the treatment of spinal injuries, open surgery is still required in many cases. Vascular injuries occurring during lumbar spine surgery, although uncommon, are of great importance due to their potential gravity. Clinical manifestations vary from an acute hemorrhagic shock that needs urgent treatment to save the patient's life, to insidious injuries or an asymptomatic evolution, and should be studied to choose the best therapeutic alternative. Four cases are reported that represent this range of possibilities and emphasize the importance of a careful surgical technique during lumbar spine interventions, and the need for high clinical suspicion, essential for the early diagnosis of these vascular complications. The current therapeutic options are also discussed. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  7. Characteristics of PMHS Lumbar Motion Segments in Lateral Shear.

    PubMed

    Sundararajan, Srini; Prasad, Priya; Rouhana, Stephen W; Demetropoulos, Constantine K; Yang, King H; King, Albert I; Nolte, Lutz P

    2005-11-01

    The purpose of this study was to determine the characteristics of eighteen lumbar spine motion segments subjected to lateral shear forces under quasi-static (0.5 mm/s) and dynamic (500 mm/s) test conditions. The quasi-static test was also performed on the lumbar spine of a side impact anthropomorphic test device, the EuroSID-2 (ES-2). In the quasi-static tests, the maximum force before disc-endplate separation in the PMHS lumbar motion segments was 1850 +/- 612 N, while the average linear stiffness of PMHS lumbar motion segments was 323 +/- 126 N/mm. There was a statistically significant difference between the quasi-static (1850 +/- 612 N) and dynamic (2616 +/- 1151 N) maximum shear forces. The ES-2 lumbar spine (149 N/mm) was more compliant than the PMHS lumbar segments under the quasi-static test condition.

  8. [Serious thromboembolitic incidents during lumbar spine phlebography].

    PubMed

    Gatti, P; Valat, J P; Videgrain, M

    1983-02-01

    From a series of 400 cases of lumbar spine phlebography by selective catheterisation, 4 serious thrombo-embolic episodes were observed, including 2 cases of severe pulmonary embolism which responded favourably to medical treatment. In 3 cases, risk factors were found (prolonged immobilisation in bed, past history of phlebitis). One case developed severe phlebitis of the lower limbs despite prophylactic treatment with low dose calcium heparin. In the other cases, no anti-coagulant therapy was prescribed before or during the examination.

  9. Diagnostic investigations. Part 1. Lumbar puncture.

    PubMed

    Blows, William

    This article, the first in a three-part series on clinical investigations, discusses the technique and uses of lumbar puncture. This diagnostic procedure involves making a puncture into the subarachnoid space of the spinal cord, to remove an excess of fluid; to obtain fluid for examination and analysis, or to inject medication. The article includes an explanation of the relevant anatomy and the composition and role of cerebrospinal fluid, a detailed description of the procedure and the interpretation of results.

  10. Lumbar nerve root: the enigmatic eponyms.

    PubMed

    Dyck, P

    1984-01-01

    Man's quest for recognition has not escaped the physician, whose contributions to medicine perpetuate his name in print. It is a final grasp for professional immortality, which for men like Imhotep and Hippocrates, has prevailed for millennia. This fervor was particularly evident in the latter 19th century, which created a flurry of eponyms, often two or more physicians publishing the same clinical observation. This article reviews the eponym epidemic as it relates to lumbar radiculopathy.

  11. Lumbar discal cyst in an elite athlete.

    PubMed

    Singleton, Alex; Agarwal, Vikas; Casagranda, Bethany; Hughes, Marion A; Rothfus, William E

    2013-01-01

    Our patient, a 22-year-old starting wide receiver for an NCAA Division I football team, presented with low back pain and sciatica. A lumbar-spine MRI without contrast demonstrated findings suspicious for discal cyst. The patient was referred for surgery, and the lesion was resected. The rarity of discal cyst makes it difficult to diagnose because most radiologists are not aware of the entity. An organized approach to diagnosis can facilitate appropriate management.

  12. Congenitally absent lumbar pedicle: a reappraisal

    SciTech Connect

    Wortzman, G.; Steinhardt, M.I.

    1984-09-01

    Three patients who had a diagnosis of congenitally absent lumbar pedicle underwent CT examination. Findings showed that each patient had an aberrant hypoplastic pedicle plus a retroisthmic defect in their ipsilateral lamina rather than an absent pedicle. Axial CT was the diagnostic modality of choice; reformated images were of little value. The differential diagnosis to be considered from the findings of plain film radiography includes pediculate thinning, neoplastic disease, neurofibroma, mesodermal dysplasia associated with neurofibromatosis, and vascular anomalies.

  13. Retrograde ejaculation after anterior lumbar spine surgery.

    PubMed

    Lindley, Emily M; McBeth, Zachary L; Henry, Sarah E; Cooley, Robert; Burger, Evalina L; Cain, Christopher M J; Patel, Vikas V

    2012-09-15

    A retrospective cohort study. To compare the incidence of retrograde ejaculation (RE) after anterior lumbar spine surgery with disc replacement versus fusion with the use of recombinant human bone morphogenetic protein-2 (BMP). Anterior lumbar interbody fusion (ALIF) has become a popular choice for treating a number of pathologies, largely because it preserves the posterior paravertebral muscles and ligaments. Despite these advantages, the anterior approach is also associated with various complications, one of which is RE. A recent study has questioned whether the risk of RE is increased by the use of BMP in ALIF procedures rather than by the approach alone. We conducted a retrospective review of all male patients who received ALIF using BMP or artificial disc replacement (ADR) on at least the L5-S1 level between 2004 and 2011. Medical records were evaluated for the occurrence of RE, and patients were contacted via the phone to obtain current information. The incidence of RE was then compared between the 2 anterior lumbar surgery procedures. Of the 95 cases of anterior surgery including L5-S1, 54 patients underwent ALIF with BMP (56.8%) and 41 patients were treated with ADR (43.2%). Postoperative RE occurred in 4 of the 54 ALIF patients (7.4%) and in 4 of the 41 ADR patients (9.8%). The incidence of RE was not significantly different between groups (P = 0.7226). At latest follow-up, 1 ALIF and 1 ADR patient reported resolution of the RE. This study found that RE occurred at a similar rate in patients treated with ADR and ALIF with BMP. The overall rate of RE after retroperitoneal anterior lumbar surgery was higher than expected, which underscores the importance of counseling patients about this risk and specifically questioning patients about the symptoms of RE at postoperative visits.

  14. Ring correlations in random networks

    NASA Astrophysics Data System (ADS)

    Sadjadi, Mahdi; Thorpe, M. F.

    2016-12-01

    We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.

  15. DC-Powered Jumping Ring

    NASA Astrophysics Data System (ADS)

    Jeffery, Rondo N.; Amiri, Farhang

    2016-02-01

    The classroom jumping ring demonstration is nearly always performed using alternating current (AC), in which the ring jumps or flies off the extended iron core when the switch is closed. The ring jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant differences from the AC case. In particular, the ring does not fly off the core but rises a short distance and then falls back. If the ring jumps high enough, the rising and the falling motion of the ring does not follow simple vertical motion of a projectile. This indicates that there are additional forces on the ring in each part of its motion. Four possible stages of the motion of the ring with DC are identified, which result from the ring current changing directions during the jump in response to a changing magnetic flux through the moving ring.

  16. Thermodynamic black di-rings

    SciTech Connect

    Iguchi, Hideo; Mishima, Takashi

    2010-10-15

    Previously the five dimensional S{sup 1}-rotating black rings have been superposed in a concentric way by some solitonic methods, and regular systems of two S{sup 1}-rotating black rings were constructed by the authors and then Evslin and Krishnan (we called these solutions 'black di-rings'). In this place we show some characteristics of the solutions of five dimensional black di-rings, especially in thermodynamic equilibrium. After the summary of the di-ring expressions and their physical quantities, first we comment on the equivalence of the two different solution sets of the black di-rings. Then the existence of thermodynamic black di-rings is shown, in which both isothermality and isorotation between the inner black ring and the outer black ring are realized. We also give detailed analysis of peculiar properties of the thermodynamic black di-ring including discussion about a certain kind of thermodynamic stability (instability) of the system.

  17. Linear Lumbar Localized Lysis of Elastic Fibers

    PubMed Central

    Tschen, Jaime A.

    2013-01-01

    Background: The absence or loss of elastic fibers in the skin is referred to as dermal elastolysis. Purpose: This paper describes a woman with a distinctive clinical presentation of mid-dermal elastolysis characterized morphologically by multiple horizontal raised bands on the lower back. Methods: A 20-year-old Filipino woman presented with multiple asymptomatic, flesh-colored, raised, firm, linear, cord-like bands on the lumbar area of her back. There were neither similar lesions elsewhere nor a family member with this condition. Results: Microscopic examination of the raised band showed nearly complete absence of elastic fibers in the mid dermis. In contrast, a biopsy of symmetrically located normal-appearing skin showed a uniform distribution of elastic fibers throughout the dermis. Linear lumbar localized elastolysis is a descriptive designation that accurately reflects a correlation of the clinical and pathological changes of this condition. Conclusion: The clinical differential of raised horizontal cord-like bands on the lower back (without a family history of an inherited elastic fiber disorder, a prior history of trauma, or a significant change in weight or exercise habit) includes linear focal elastosis and linear lumbar localized elastolysis. Microscopic evaluation of a Verhoeff-van Gieson stained lesion specimen (which may be accompanied by a biopsy of normal-appearing skin for comparison) will readily differentiate these conditions. The former is usually characterized by increased elastic fibers, whereas the latter, as in this patient, shows a paucity or absence of elastic fibers in the mid dermis. PMID:23882313

  18. Subarachnoid hemorrhage due to retained lumbar drain.

    PubMed

    Guppy, Kern H; Silverthorn, James W; Akins, Paul T

    2011-12-01

    Intrathecal spinal catheters (lumbar drains) are indicated for several medical and surgical conditions. In neurosurgical procedures, they are used to reduce intracranial and intrathecal pressures by diverting CSF. They have also been placed for therapeutic access to administer drugs, and more recently, vascular surgeons have used them to improve spinal cord perfusion during the treatment of thoracic aortic aneurysms. Insertion of these lumbar drains is not without attendant complications. One complication is the shearing of the distal end of the catheter with a resultant retained fragment. The authors report the case of a 65-year-old man who presented with a subarachnoid hemorrhage due to the migration of a retained lumbar drain that sheared off during its removal. To the best of the authors' knowledge, this is the first case of rostral migration of a retained intrathecal catheter causing subarachnoid hemorrhage. The authors review the literature on retained intrathecal spinal catheters, and their findings support either early removal of easily accessible catheters or close monitoring with serial imaging.

  19. Minimally Invasive Laminectomy in Spondylolisthetic Lumbar Stenosis

    PubMed Central

    Caralopoulos, Ilias N.; Bui, Cuong J.

    2014-01-01

    Background Degenerative lumbar stenosis associated with spondylolisthesis is common in elderly patients. The most common symptoms are those of neurogenic claudication with leg pain. Surgery is indicated for those who fail conservative management. The generally accepted recommendation is to perform a laminectomy and a fusion at the involved level. Methods We reviewed our results for minimally invasive single-level decompression without fusion performed by the senior author in patients with symptomatic lumbar stenosis with spondylolisthesis with no dynamic instability from 2008 to 2011 at a single institution. Outcomes were measured using the visual analog scale (VAS), Prolo Economic Functional Rating Scale, and revised Oswestry Disability Index (ODI) at initial presentation and at 3-month, 6-month, and 1-year follow-up time points. Results Records for 28 patients (19 males, 9 females) were reviewed. The success rate, defined as improvement in pain and functional outcome without the need for surgical fusion, was 86%. VAS scores decreased by 6.3 points, Prolo scores increased by 3.5 points, and the ODI decreased by 31% at 1 year. All changes were statistically significant. Conclusion Minimally invasive decompression alone can be a reasonable alternative to decompression and fusion for patients with spondylolisthetic lumbar stenosis and neurogenic claudication with leg pain. Decompression without fusion should be considered for older patients and for patients who are not ideal fusion candidates. PMID:24688331

  20. Design concepts in lumbar total disc arthroplasty

    PubMed Central

    Bellini, Chiara M.; Zweig, Thomas; Ferguson, Stephen; Raimondi, Manuela T.; Lamartina, Claudio; Brayda-Bruno, Marco; Fornari, Maurizio

    2008-01-01

    The implantation of lumbar disc prostheses based on different design concepts is widely accepted. This paper reviews currently available literature studies on the biomechanics of TDA in the lumbar spine, and is targeted at the evaluation of possible relationships between the aims of TDA and the geometrical, mechanical and material properties of the various available disc prostheses. Both theoretical and experimental studies were analyzed, by a PUBMED search (performed in February 2007, revised in January 2008), focusing on single level TDA. Both semi-constrained and unconstrained lumbar discs seem to be able to restore nearly physiological IAR locations and ROM values. However, both increased and decreased ROM was stated in some papers, unrelated to the clinical outcome. Segmental lordosis alterations after TDA were reported in most cases, for both constrained and unconstrained disc prostheses. An increase in the load through the facet joints was documented, for both semi-constrained and unconstrained artificial discs, but with some contrasting results. Semi-constrained devices may be able to share a greater part of the load, thus protecting the surrounding biological structure from overloading and possible early degeneration, but may be more susceptible to wear. The next level of development will be the biomechanical integration of compression across the motion segment. All these findings need to be supported by long-term clinical outcome studies. PMID:18946684

  1. Risk Factors for Recurrent Lumbar Disc Herniations

    PubMed Central

    2014-01-01

    The most common complication after lumbar discectomy is reherniation. As the first step in reducing the rate of recurrence, many studies have been conducted to find out the factors that may increase the reherniation risk. Some reported factors are age, sex, the type of lumbar disc herniation, the amount of fragments removed, smoking, alcohol consumption and the length of restricted activities. In this review, the factors studied thus far are summarized, excepting factors which cannot be chosen or changed, such as age or sex. Apart from the factors shown here, many other risk factors such as diabetes, family history, history of external injury, duration of illness and body mass index are considered. Few are agreed upon by all. The reason for the diverse opinions may be that many clinical and biomechanical variables are involved in the prognosis following operation. For the investigation of risk factors in recurrent lumbar disc herniation, large-scale multicenter prospective studies will be required in the future. PMID:24761206

  2. Effect of Load Carriage on Lumbar Spine Kinematics

    DTIC Science & Technology

    2013-01-01

    markers 14 – 16 , 18 and ground force plates 7 , 18 , 19 to measure body positioning and ground reac- tion forces . These methods approach...data obtained in this setting do not refl ect the state of the lumbar spine in the upright position due to alterations in bone- muscle interactions...lumbar spine might be related to the greater forces acting on inferior levels through the lumbar spine 38 and that IVDs of inferior levels undergo

  3. Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations

    DTIC Science & Technology

    2014-06-01

    AWARD NUMBER: W81XWH-13-2-0043 TITLE: Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations PRINCIPAL...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations 5b. GRANT NUMBER...evaluated the relationship between 3D geometry of the lumbar spine, under different loading conditions and positions, and the pathophysiology of the

  4. Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations

    DTIC Science & Technology

    2015-06-01

    AWARD NUMBER: W81XWH-13-2-0043 TITLE: Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations PRINCIPAL...TITLE AND SUBTITLE Sa. CONTRACT NUMBER Lumbar Spine Musculoske l etal Physiol ogy and Biomechanics Dur i ng s i mul ated Military Operati ons Sb...l ationship between 3D geometry of the lumbar spine, under different l oading conditions and positions , and the pathophysiol ogy of the

  5. Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations

    DTIC Science & Technology

    2016-06-01

    AWARD NUMBER: W81XWH-13-2-0043 TITLE: Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations PRINCIPAL...31May2016 4. TITLE AND SUBTITLE Lumbar Spine Musculoskeletal Physiology and Biomechanics 5a. CONTRACT NUMBER During Simulated Military Operations 5b...ABSTRACT This study evaluated the relationship between 3D geometry of the lumbar spine, under different loading conditions and positions, and the

  6. The Neandertal vertebral column 2: The lumbar spine.

    PubMed

    Gómez-Olivencia, Asier; Arlegi, Mikel; Barash, Alon; Stock, Jay T; Been, Ella

    2017-05-01

    Here we provide the most extensive metric and morphological analysis performed to date on the Neandertal lumbar spine. Neandertal lumbar vertebrae show differences from modern humans in both the vertebral body and in the neural arch, although not all Neandertal lumbar vertebrae differ from modern humans in the same way. Differences in the vertebral foramen are restricted to the lowermost lumbar vertebrae (L4 and L5), differences in the orientation of the upper articular facets appear in the uppermost lumbar vertebrae (probably in L1 and L2-L3), and differences in the horizontal angle of the transverse process appear in L2-L4. Neandertals, when compared to modern humans, show a smaller degree of lumbar lordosis. Based on a still limited fossil sample, early hominins (australopiths and Homo erectus) had a lumbar lordosis that was similar to but below the mean of modern humans. Here, we hypothesize that from this ancestral degree of lumbar lordosis, the Neandertal lineage decreased their lumbar lordosis and Homo sapiens slightly increased theirs. From a postural point of view, the lower degree of lordosis is related to a more vertical position of the sacrum, which is also positioned more ventrally with respect to the dorsal end of the pelvis. This results in a spino-pelvic alignment that, though different from modern humans, maintained an economic postural equilibrium. Some features, such as a lower degree of lumbar lordosis, were already present in the middle Pleistocene populations ancestral to Neandertals. However, these middle Pleistocene populations do not show the full suite of Neandertal lumbar morphologies, which probably means that the characteristic features of the Neandertal lumbar spine did not arise all at once. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Propellers in Saturn's rings

    NASA Astrophysics Data System (ADS)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2013-12-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~<500m in size) have been indirectly identified in Saturn's A ring through their propeller signature in the images. Furthermore, recent Cassini observations indicate the possible existence of objects embedded even in Saturn's B and C ring. In this paper we present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B

  8. Etiology of lumbar lordosis and its pathophysiology: a review of the evolution of lumbar lordosis, and the mechanics and biology of lumbar degeneration.

    PubMed

    Sparrey, Carolyn J; Bailey, Jeannie F; Safaee, Michael; Clark, Aaron J; Lafage, Virginie; Schwab, Frank; Smith, Justin S; Ames, Christopher P

    2014-05-01

    The goal of this review is to discuss the mechanisms of postural degeneration, particularly the loss of lumbar lordosis commonly observed in the elderly in the context of evolution, mechanical, and biological studies of the human spine and to synthesize recent research findings to clinical management of postural malalignment. Lumbar lordosis is unique to the human spine and is necessary to facilitate our upright posture. However, decreased lumbar lordosis and increased thoracic kyphosis are hallmarks of an aging human spinal column. The unique upright posture and lordotic lumbar curvature of the human spine suggest that an understanding of the evolution of the human spinal column, and the unique anatomical features that support lumbar lordosis may provide insight into spine health and degeneration. Considering evolution of the skeleton in isolation from other scientific studies provides a limited picture for clinicians. The evolution and development of human lumbar lordosis highlight the interdependence of pelvic structure and lumbar lordosis. Studies of fossils of human lineage demonstrate a convergence on the degree of lumbar lordosis and the number of lumbar vertebrae in modern Homo sapiens. Evolution and spine mechanics research show that lumbar lordosis is dictated by pelvic incidence, spinal musculature, vertebral wedging, and disc health. The evolution, mechanics, and biology research all point to the importance of spinal posture and flexibility in supporting optimal health. However, surgical management of postural deformity has focused on restoring posture at the expense of flexibility. It is possible that the need for complex and costly spinal fixation can be eliminated by developing tools for early identification of patients at risk for postural deformities through patient history (genetics, mechanics, and environmental exposure) and tracking postural changes over time.

  9. Delayed Retroperitoneal Hemorrhage due to Lumbar Artery Pseudoaneurysm after Lumbar Posterolateral Fusion

    PubMed Central

    Oh, Young Min; Choi, Ha Young

    2013-01-01

    A 55-year-old female patient presented with lower back pain and neurogenic intermittent claudication and underwent L3-L4 posterolateral fusion. To prepare the bone fusion bed, the transverse process of L3 and L4 was decorticated with a drill. On the 9th post-operative day, the patient complained of a sudden onset of severe abdominal pain and distension. Abdominal computed tomography revealed retroperitoneal hematoma in the right psoas muscle and iatrogenic right L3 transverse process fracture. Lumbar spinal angiography showed the delayed hematoma due to rupture of the 2nd lumbar artery pseudoaneurysm and coil embolization was done at the ruptured lumbar artery pseudoaneusyrm. Since then, the patient's postoperative progress proceeded normally with recovery of the hemodynamic parameters. PMID:24294460

  10. Stacked Corrugated Horn Rings

    NASA Technical Reports Server (NTRS)

    Sosnowski, John B.

    2010-01-01

    This Brief describes a method of machining and assembly when the depth of corrugations far exceeds the width and conventional machining is not practical. The horn is divided into easily machined, individual rings with shoulders to control the depth. In this specific instance, each of the corrugations is identical in profile, and only differs in diameter and outer profile. The horn is segmented into rings that are cut with an interference fit (zero clearance with all machining errors biased toward contact). The interference faces can be cut with a reverse taper to increase the holding strength of the joint. The taper is a compromise between the interference fit and the clearance of the two faces during assembly. Each internal ring is dipped in liquid nitrogen, then nested in the previous, larger ring. The ring is rotated in the nest until the temperature of the two parts equalizes and the pieces lock together. The resulting assay is stable, strong, and has an internal finish that cannot be achieved through other methods.

  11. Piston Ring Pressure Distribution

    NASA Technical Reports Server (NTRS)

    Kuhn, M.

    1943-01-01

    The discovery and introduction of the internal combustion engine has resulted in a very rapid development in machines utilizing the action of a piston. Design has been limited by the internal components of the engine, which has been subjected to ever increasing thermal and mechanical stresses, Of these internal engine components, the piston and piston rings are of particular importance and the momentary position of engine development is not seldom dependent upon the development of both of the components, The piston ring is a well-known component and has been used in its present shape in the steam engine of the last century, Corresponding to its importance, the piston ring has been a rich field for creative activity and it is noteworthy that in spite of this the ring has maintained its shape through the many years. From the many and complicated designs which have been suggested as a packing between piston and cylinder wall hardly one suggestion has remained which does not resemble the original design of cast iron rectangular ring.

  12. Two F Ring Views

    NASA Technical Reports Server (NTRS)

    2005-01-01

    These views, taken two hours apart, demonstrate the dramatic variability in the structure of Saturn's intriguing F ring.

    In the image at the left, ringlets in the F ring and Encke Gap display distinctive kinks, and there is a bright patch of material on the F ring's inner edge. Saturn's moon Janus (181 kilometers, or 113 miles across) is shown here, partly illuminated by reflected light from the planet.

    At the right, Prometheus (102 kilometers, or 63 miles across) orbits ahead of the radial striations in the F ring, called 'drapes' by scientists. The drapes appear to be caused by successive passes of Prometheus as it reaches the greatest distance (apoapse) in its orbit of Saturn. Also in this image, the outermost ringlet visible in the Encke Gap displays distinctive bright patches.

    These views were obtained from about three degrees below the ring plane.

    The images were taken in visible light with the Cassini spacecraft narrow-angle camera on June 29, 2005, when Cassini was about 1.5 million kilometers (900,000 miles) from Saturn. The image scale is about 9 kilometers (6 miles) per pixel.

  13. Ring solitons on vortices.

    PubMed

    Kevrekidis, P G; Nistazakis, H E; Frantzeskakis, D J; Malomed, B A; Bishop, A R

    2001-12-01

    Interaction of a ring dark or antidark soliton (RDS and RADS, respectively) with a vortex is considered in the defocusing nonlinear Schrödinger equation with cubic (for RDS) or saturable (for RADS) nonlinearities. By means of direct simulations, it is found that the interaction gives rise to either an almost isotropic or a spiral-like pattern. A transition between them occurs at a critical value of the RDS or RADS amplitude, the spiral pattern appearing if the amplitude exceeds the critical value. An initial ring soliton created on top of the vortex splits into a pair of rings moving inward and outward. In the subcritical case, the inbound ring reverses its polarity, bouncing from the vortex core, without conspicuous effect on the core. In the transcritical case, the bounced ring soliton suffers a spiral deformation, while the vortex changes its position and structure and also loses its axial symmetry. Through a variational-type approach to the system's Hamiltonian, we additionally find that the vortex-RDS and vortex-RADS interactions are, respectively, attractive and repulsive. Simulations with the vortex placed eccentrically with respect to the RDS or RADS reveal the generation of strongly localized multispot dark and/or antidark coherent structures. The occurrence of spiral-like patterns in many numerical experiments prompted an attempt to generate a spiral dark soliton, but the latter is found to suffer a core instability that converts it into a rotating dipole emitting waves in the outward direction.

  14. Evaluation of ABM/P-15 versus autogenous bone in an ovine lumbar interbody fusion model

    PubMed Central

    Sherman, Blake P.; Lindley, Emily M.; Turner, A. Simon; Seim III, Howard B.; Benedict, James; Burger, Evalina L.

    2010-01-01

    A prospective, randomized study was performed in an ovine model to compare the efficacy of an anorganic bovine-derived hydroxyapatite matrix combined with a synthetic 15 amino acid residue (ABM/P-15) in facilitating lumbar interbody fusion when compared with autogenous bone harvested from the iliac crest. P-15 is a biomimetic to the cell-binding site of Type-I collagen for bone-forming cells. When combined with ABM, it creates the necessary scaffold to initiate cell invasion, binding, and subsequent osteogenesis. In this study, six adult ewes underwent anterior-lateral interbody fusion at L3/L4 and L4/L5 using PEEK interbody rings filled with autogenous bone at one level and ABM/P-15 at the other level and no additional instrumentation. Clinical CT scans were obtained at 3 and 6 months; micro-CT scans and histomorphometry analyses were performed after euthanization at 6 months. Clinical CT scan analysis showed that all autograft and ABM/P-15 treated levels had radiographically fused outside of the rings at the 3-month study time point. Although the clinical CT scans of the autograft treatment group showed significantly better fusion within the PEEK rings than ABM/P-15 at 3 months, micro-CT scans, clinical CT scans, and histomorphometric analyses showed there were no statistical differences between the two treatment groups at 6 months. Thus, ABM/P-15 was as successful as autogenous bone graft in producing lumbar spinal fusion in an ovine model, and it should be further evaluated in clinical studies. PMID:20694847

  15. Evaluation of ABM/P-15 versus autogenous bone in an ovine lumbar interbody fusion model.

    PubMed

    Sherman, Blake P; Lindley, Emily M; Turner, A Simon; Seim, Howard B; Benedict, James; Burger, Evalina L; Patel, Vikas V

    2010-12-01

    A prospective, randomized study was performed in an ovine model to compare the efficacy of an anorganic bovine-derived hydroxyapatite matrix combined with a synthetic 15 amino acid residue (ABM/P-15) in facilitating lumbar interbody fusion when compared with autogenous bone harvested from the iliac crest. P-15 is a biomimetic to the cell-binding site of Type-I collagen for bone-forming cells. When combined with ABM, it creates the necessary scaffold to initiate cell invasion, binding, and subsequent osteogenesis. In this study, six adult ewes underwent anterior-lateral interbody fusion at L3/L4 and L4/L5 using PEEK interbody rings filled with autogenous bone at one level and ABM/P-15 at the other level and no additional instrumentation. Clinical CT scans were obtained at 3 and 6 months; micro-CT scans and histomorphometry analyses were performed after euthanization at 6 months. Clinical CT scan analysis showed that all autograft and ABM/P-15 treated levels had radiographically fused outside of the rings at the 3-month study time point. Although the clinical CT scans of the autograft treatment group showed significantly better fusion within the PEEK rings than ABM/P-15 at 3 months, micro-CT scans, clinical CT scans, and histomorphometric analyses showed there were no statistical differences between the two treatment groups at 6 months. Thus, ABM/P-15 was as successful as autogenous bone graft in producing lumbar spinal fusion in an ovine model, and it should be further evaluated in clinical studies.

  16. Kinematic analysis of dynamic lumbar motion in patients with lumbar segmental instability using digital videofluoroscopy

    PubMed Central

    Maroufi, Nader; Behtash, Hamid; Zekavat, Hajar; Parnianpour, Mohamad

    2009-01-01

    The study design is a prospective, case–control. The aim of this study was to develop a reliable measurement technique for the assessment of lumbar spine kinematics using digital video fluoroscopy in a group of patients with low back pain (LBP) and a control group. Lumbar segmental instability (LSI) is one subgroup of nonspecific LBP the diagnosis of which has not been clarified. The diagnosis of LSI has traditionally relied on the use of lateral functional (flexion–extension) radiographs but use of this method has proven unsatisfactory. Fifteen patients with chronic low back pain suspected to have LSI and 15 matched healthy subjects were recruited. Pulsed digital videofluoroscopy was used to investigate kinematics of lumbar motion segments during flexion and extension movements in vivo. Intersegmental linear translation and angular displacement, and pathway of instantaneous center of rotation (PICR) were calculated for each lumbar motion segment. Movement pattern of lumbar spine between two groups and during the full sagittal plane range of motion were analyzed using ANOVA with repeated measures design. Intersegmental linear translation was significantly higher in patients during both flexion and extension movements at L5–S1 segment (p < 0.05). Arc length of PICR was significantly higher in patients for L1–L2 and L5–S1 motion segments during extension movement (p < 0.05). This study determined some kinematic differences between two groups during the full range of lumbar spine. Devices, such as digital videofluoroscopy can assist in identifying better criteria for diagnosis of LSI in otherwise nonspecific low back pain patients in hope of providing more specific treatment. PMID:19727854

  17. Percutaneous endoscopic transforaminal lumbar spinal canal decompression for lumbar spinal stenosis

    PubMed Central

    Wen, Bingtao; Zhang, Xifeng; Zhang, Lin; Huang, Peng; Zheng, Guoquan

    2016-01-01

    Abstract This study aimed to evaluate the safety and curative effect of percutaneous endoscopic transforaminal lumbar spinal canal decompression in the treatment of lumbar spinal stenosis. This retrospective study recruited 64 patients with lumbar spinal stenosis who underwent percutaneous endoscopic lumbar spinal canal decompression via surgical approach of posterolateral intervertebral foramen. The postoperation neurological function and pain status were evaluated by the visual analog scale (VAS) score of pain and the Oswestry disability index (ODI), and the patient satisfaction was evaluated according to the MacNab outcome criteria. The data, including preoperative comorbidities, operation time, the quantity of bleeding, bed rest time, and intraoperative and postoperative complications, were recorded. The mean operation time was 78 min, the mean quantity of bleeding was 20 mL and bed rest time was 6 h to 3 days. All patients were followed-up for 4 months to 5 years. The mean preoperative VAS score was 7.7 ± 1.2, while postoperative 3 months, 6 months, and final follow-up VAS scores were 2.8 ± 0.7, 2.1 ± 0.6, and 0.8 ± 0.6, respectively (P < 0.001). The mean preoperative ODI score was 72.4 ± 1.2, while postoperative 3 months, 6 months, and final follow-up ODI scores were 29.7 ± 4.9, 23.9 ± 4.0, and 12.5 ± 3.9, respectively (P < 0.001). The excellent and good rate reached 73.4% at the final follow-up. The percutaneous endoscopic transforaminal lumbar spinal canal decompression is an easy, safe, and effective minimally invasive surgery for patients with lumbar spinal stenosis. PMID:27977571

  18. Weightlifter Lumbar Physiology Health Influence Factor Analysis of Sports Medicine

    PubMed Central

    Zhang, Xiangyang

    2015-01-01

    Chinese women's weightlifting project has been in the advanced world level, suggests that the Chinese coaches and athletes have many successful experience in the weight lifting training. Little weight lifting belongs to high-risk sports, however, to the lumbar spine injury, some young good athletes often due to lumbar trauma had to retire, and the national investment and athletes toil is regret things. This article from the perspective of sports medicine, weightlifting athletes training situation analysis and put forward Suggestions, aimed at avoiding lumbar injury, guarantee the health of athletes. In this paper, first of all to 50 professional women's weightlifting athletes doing investigation, found that 82% of the athletes suffer from lumbar disease symptoms, the reason is mainly composed of lumbar strain, intensity is too large, motion error caused by three factors. From the Angle of sports medicine and combined with the characteristics of the structure of human body skeleton athletes lumbar structural mechanics analysis, find out the lumbar force's two biggest technical movement, study, and regulate the action standard, so as to minimize lumbar force, for athletes to contribute to the health of the lumbar spine. PMID:26981162

  19. Rings in the solar system

    SciTech Connect

    Pollack, J.B.; Cuzzi, J.N.

    1981-11-01

    Saturn, Jupiter, and Uranus have rings with different structure and composition. The rings consist of tiny masses in independent orbits. Photographs and data obtained by the Voyager project have aided in the understanding of Saturn's rings. Spokes have been found in B ring and boards, knots, and twist in F ring. Particles on the order of a micrometer in size are believed to occur in F, B, and A rings. The dominant component is water ice. The rings of Uranus are narrow and separated by broad empty regions. The technique used to study them has been stellar occulation. Nothing is known of particle size. The dominant component is believed to be silicates rich in compounds that absorb sunlight. Jupiter's rings consist of 3 main parts: a bright ring, a diffuse disk, and a halo. Use of Pioneer 10 data and other techniques have indicated particle sizes on the order of several micrometers and some at least a centimeter in diameter. The architecture of the ring system results from the interplay of a number of forces. These include gravitational forces due to moons outside the rings and moonlets embedded in them, electromagnetic forces due to the planet's rotating magnetic field, and even the gentle forces exerted by the dilute gaseous medium in which the rings rotate. Each of these forces is discussed. Several alternative explanations of how the rings arose are considered. The primary difference in these hypotheses is the account of the relationship between the ring particles of today and the primordial ring material. (SC)

  20. Physics of planetary rings

    NASA Astrophysics Data System (ADS)

    Gorkavyi, N.

    2007-08-01

    It is difficult to enumerate all the surprises presented by the planetary rings. The Saturnian rings are stratified into thousands of ringlets and the Uranian rings are compressed into narrow streams, which for some reason or other differ from circular orbits like the wheel of an old bicycle. The edge of the rings is jagged and the rings themselves are pegged down under the gravitational pressure of the satellites, bending like a ship's wake. There are spiral waves, elliptical rings, strange interlacing of narrow ringlets, and to cap it all one has observed in the Neptunian ring system three dense, bright arcs - like bunches of sausages on a transparent string. For celestial mechanics this is a spectacle as unnatural as a bear's tooth in the necklace of the English queen. In the dynamics of planetary rings the physics of collective interaction was supplemented by taking collisions between particles into account. One was led to study a kinetic equation with a rather complex collision integral - because the collisions are inelastic - which later on made it possible, both by using the Chapman-Enskog method and by using the solution of the kinetic equation for a plasma in a magnetic field, to reduce it to a closed set of (hydrodynamical) moment equations [1]. The hydrodynamical instabilities lead to the growth of short-wavelength waves and large-scale structures of the Saturnian rings [1]. We have shown that the formation of the existing dense Uranian rings is connected with the capture of positively drifting ring particles in inner Lindblad resonances which arrest this drift [1]. After the formation of dense rings at the positions of satellite resonances the collective interaction between resonant particles is amplified and the rings can leave the resonance and drift away from the planet and the parent resonance. We can expect in the C ring an appreciable positive ballistic particle drift caused by the erosion of the B ring by micrometeorites. It is therefore natural

  1. Revision Surgery Following Operations for Lumbar Stenosis

    PubMed Central

    Deyo, Richard A.; Martin, Brook I.; Kreuter, William; Jarvik, Jeffrey G.; Angier, Heather; Mirza, Sohail K.

    2011-01-01

    Background: For carefully selected patients with lumbar stenosis, decompression surgery is more efficacious than nonoperative treatment. However, some patients undergo repeat surgery, often because of complications, the failure to achieve solid fusion following arthrodesis procedures, or persistent symptoms. We assessed the probability of repeat surgery following operations for the treatment of lumbar stenosis and examined its association with patient age, comorbidity, previous surgery, and the type of surgical procedure. Methods: We performed a retrospective cohort analysis of Medicare claims. The index operation was performed in 2004 (n = 31,543), with follow-up obtained through 2008. Operations were grouped by complexity as decompression alone, simple arthrodesis (one or two disc levels and a single surgical approach), or complex arthrodesis (more than two disc levels or combined anterior and posterior approach). Reoperation rates were calculated for each follow-up year, and the time to reoperation was analyzed with proportional hazards models. Results: The probability of repeat surgery fell with increasing patient age or comorbidity. Aside from age, the strongest predictor was previous lumbar surgery: at four years the reoperation rate was 17.2% among patients who had had lumbar surgery prior to the index operation, compared with 10.6% among those with no prior surgery (p < 0.001). At one year, the reoperation rate for patients who had been managed with decompression alone was slightly higher than that for patients who had been managed with simple arthrodesis, but by four years the rates for these two groups were identical (10.7%) and were lower than the rate for patients who had been managed with complex arthrodesis (13.5%) (p < 0.001). This difference persisted after adjusting for demographic and clinical features (hazard ratio for complex arthrodesis versus decompression 1.56, 95% confidence interval, 1.26 to 1.92). A device-related complication was reported

  2. Lumbar discal cyst with spontaneous regression and subsequent occurrence of lumbar disc herniation.

    PubMed

    Takeshima, Yasuhiro; Takahashi, Toshiyuki; Hanakita, Junya; Watanabe, Mizuki; Kitahama, Yoshihiro; Kuraishi, Keita; Uesaka, Toshio; Minami, Manabu; Nakase, Hiroyuki

    2011-01-01

    A 39-year-old man presented with an extremely rare discal cyst at the L3-4 level manifesting as a left L4 radiculopathy. Two months after onset, he suffered right L4 radiculopathy with new lumbar disc protrusion. Five months after medical treatment, the patient's symptoms improved, and the discal cyst showed complete regression on magnetic resonance imaging. Most cases of discal cyst are surgically treated, with only two previous cases of spontaneous regression. The present case suggests clinical and radiological recovery of symptomatic lumbar discal cyst can be obtained by only conservative therapy.

  3. Characterization of lumbar spinous process morphology: a cadaveric study of 2,955 human lumbar vertebrae.

    PubMed

    Shaw, Jeremy D; Shaw, Daniel L; Cooperman, Daniel R; Eubanks, Jason D; Li, Ling; Kim, David H

    2015-07-01

    Despite the interest in lumbar spinous process (SP)-based surgical innovation, there are no large published studies that have characterized the morphometry of lumbar SPs. To provide accurate level-specific morphometric data with respect to human lumbar SPs using a human cadaveric lumbar spine model and to describe the morphometric variation of lumbar SPs with respect to gender, race, and age. An anatomic observational study. This study used 2,955 cadaveric lumbar vertebrae from 591 adult spines at the Hamann-Todd Human Osteological Collection. Specimens were aged 20 to 79 years. Each vertebra was photographed in standardized positions and measured using ImageJ software. Direct measurements were made for the SP length, width, height, slope, and caudal morphology. Gender, race, and age were recorded and analyzed. Spinous process length was 24.8±4.6 mm (L5) to 33.9±3.9 mm (L3). Effective length varied from 19.5±2.6 mm (L1) to 24.6±3.3 mm (L4). Height was shortest at L5 (18.2±2.7 mm). Caudal width was greater than the cranial width. Slope, caudal morphology, and radius measures showed large interspecimen variation. Slope at L5 was steeper than other levels (23.7°±10.5°, p<.0001). Most specimens demonstrated convex caudal morphology. L4 had the highest proportion of convexity (80.7%). L1 was the only level with predominantly concave morphology. Measurements for female SPs were smaller, but the slope was steeper. Anatomic and effective SP lengths were longer for specimens from white individuals. Specimens from black individuals had larger width and height, as well as steeper slope. Black specimens had more convex morphology at L4 and L5. With increasing age, the SP length, effective length, and width increased. Height increased with age only at L4 and L5. Slope and caudal radius of curvature decreased with age, and increasingly convex morphology was noted at most levels. This large cadaveric study provides level-specific morphometric data regarding the osseous

  4. Pelvic incidence-lumbar lordosis mismatch predisposes to adjacent segment disease after lumbar spinal fusion.

    PubMed

    Rothenfluh, Dominique A; Mueller, Daniel A; Rothenfluh, Esin; Min, Kan

    2015-06-01

    Several risk factors and causes of adjacent segment disease have been debated; however, no quantitative relationship to spino-pelvic parameters has been established so far. A retrospective case-control study was carried out to investigate spino-pelvic alignment in patients with adjacent segment disease compared to a control group. 45 patients (ASDis) were identified that underwent revision surgery for adjacent segment disease after on average 49 months (7-125), 39 patients were selected as control group (CTRL) similar in the distribution of the matching variables, such as age, gender, preoperative degenerative changes, and numbers of segments fused with a mean follow-up of 84 months (61-142) (total n = 84). Several radiographic parameters were measured on pre- and postoperative radiographs, including lumbar lordosis measured (LL), sacral slope, pelvic incidence (PI), and tilt. Significant differences between ASDis and CTRL groups on preoperative radiographs were seen for PI (60.9 ± 10.0° vs. 51.7 ± 10.4°, p = 0.001) and LL (48.1 ± 12.5° vs. 53.8 ± 10.8°, p = 0.012). Pelvic incidence was put into relation to lumbar lordosis by calculating the difference between pelvic incidence and lumbar lordosis (∆PILL = PI-LL, ASDis 12.5 ± 16.7° vs. CTRL 3.4 ± 12.1°, p = 0.001). A cutoff value of 9.8° was determined by logistic regression and ROC analysis and patients classified into a type A (∆PILL <10°) and a type B (∆PILL ≥10°) alignment according to pelvic incidence-lumbar lordosis mismatch. In type A spino-pelvic alignment, 25.5 % of patients underwent revision surgery for adjacent segment disease, whereas 78.3 % of patients classified as type B alignment had revision surgery. Classification of patients into type A and B alignments yields a sensitivity for predicting adjacent segment disease of 71 %, a specificity of 81 % and an odds ratio of 10.6. In degenerative disease of the lumbar spine a high pelvic incidence with diminished lumbar lordosis seems

  5. Stuck on the Rings

    NASA Image and Video Library

    2014-10-13

    Like a drop of dew hanging on a leaf, Tethys appears to be stuck to the A and F rings from this perspective. Tethys (660 miles, or 1,062 kilometers across), like the ring particles, is composed primarily of ice. The gap in the A ring through which Tethys is visible is the Keeler gap, which is kept clear by the small moon Daphnis (not visible here). This view looks toward the Saturn-facing hemisphere of Tethys. North on Tethys is up and rotated 43 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2014. The view was acquired at a distance of approximately 1.1 million miles (1.8 million kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 22 degrees. Image scale is 7 miles (11 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18284

  6. Ring-Bow

    NASA Image and Video Library

    2017-07-24

    Although the rings lack the many colors of the rainbow, they arc across the sky of Saturn. From equatorial locations on the planet, they'd appear very thin since they would be seen edge-on. Closer to the poles, the rings would appear much wider; in some locations (for parts of the Saturn's year), they would even block the sun for part of each day. This view looks toward the sunlit side of the rings from about 19 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on April 10, 2017. The view was obtained at a distance of approximately 680,000 miles (1.1 million kilometers) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 128 degrees. Image scale is 43 miles (69 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21339

  7. Deployable Fresnel Rings

    NASA Technical Reports Server (NTRS)

    Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.; Lin, Gregory Y.

    2014-01-01

    Deployable Fresnel rings (DFRs) significantly enhance the realizable gain of an antenna. This innovation is intended to be used in combination with another antenna element, as the DFR itself acts as a focusing or microwave lens element for a primary antenna. This method is completely passive, and is also completely wireless in that it requires neither a cable, nor a connector from the antenna port of the primary antenna to the DFR. The technology improves upon the previous NASA technology called a Tri-Sector Deployable Array Antenna in at least three critical aspects. In contrast to the previous technology, this innovation requires no connector, cable, or other physical interface to the primary communication radio or sensor device. The achievable improvement in terms of antenna gain is significantly higher than has been achieved with the previous technology. Also, where previous embodiments of the Tri-Sector antenna have been constructed with combinations of conventional (e.g., printed circuit board) and conductive fabric materials, this innovation is realized using only conductive and non-conductive fabric (i.e., "e-textile") materials, with the possible exception of a spring-like deployment ring. Conceptually, a DFR operates by canceling the out-of-phase radiation at a plane by insertion of a conducting ring or rings of a specific size and distance from the source antenna, defined by Fresnel zones. Design of DFRs follow similar procedures to those outlined for conventional Fresnel zone rings. Gain enhancement using a single ring is verified experimentally and through computational simulation. The experimental test setup involves a microstrip patch antenna that is directly behind a single-ring DFR and is radiating towards a second microstrip patch antenna. The first patch antenna and DFR are shown. At 2.42 GHz, the DFR improves the transmit antenna gain by 8.6 dB, as shown in Figure 2, relative to the wireless link without the DFR. A figure illustrates the

  8. Rings dominate western Gulf

    NASA Astrophysics Data System (ADS)

    Vidal L., Francisco V.; Vidal L., Victor M. V.; Molero, José María Pérez

    Surface and deep circulation of the central and western Gulf of Mexico is controlled by interactions of rings of water pinched from the gulf's Loop Current. The discovery was made by Mexican oceanographers who are preparing a full-color, 8-volume oceanographic atlas of the gulf.Anticyclonic warm-core rings pinch off the Loop Current at a rate of about one to two per year, the scientists of the Grupo de Estudios Oceanográficos of the Instituto de Investigaciones Eléctricas (GEO-IIE) found. The rings migrate west until they collide with the continental shelf break of the western gulf, almost always between 22° and 23°N latitude. On their westward travel they transfer angular momentum and vorticity to the surrounding water, generating cyclonic circulations and vortex pairs that completely dominate the entire surface and deep circulation of the central and western gulf.

  9. The Effects of Stretching with Lumbar Traction on VAS and Oswestry Scales of Patients with Lumbar 4–5 Herniated Intervertebral Disc

    PubMed Central

    Yang, Hae-sun; Yoo, Won-gyu

    2014-01-01

    [Purpose] This study investigated the effect of stretching with lumbar traction on VAS and Oswestry scale scores of lumbar 4–5 herniated intervertebral disc (HIVD) patients. [Subjects] We recruited 20 lumbar 4–5 HIVD patients. [Methods] We performed stretching with lumbar traction for lumbar 4–5 HIVD patients during 4 weeks. The VAS and Oswestry scales were measured before and 4 weeks after the intervention. [Results] The results showed a significant decrease in VAS scale scores for stretching with lumbar traction in lumbar 4–5 HIVD patients, from 18±1.29 to 2.1±1.35. The Oswestry scale scores also decreased significantly, from 20.35±2.01 to 3.5±2.84, after stretching with lumbar traction. [Conclusion] Thus, we suggest stretching with lumbar traction for lumbar 4–5 HIVD patients. PMID:25140094

  10. Saturn's rings - high resolution

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Voyager 2 obtained this high-resolution picture of Saturn's rings Aug. 22, when the spacecraft was 4 million kilometers (2.5 million miles) away. Evident here are the numerous 'spoke' features, in the B-ring; their very sharp, narrow appearance suggests short formation times. Scientists think electromagnetic forces are responsible in some way for these features, but no detailed theory has been worked out. Pictures such as this and analyses of Voyager 2's spoke movies may reveal more clues about the origins of these complex structures. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

  11. Unidirectional ring lasers

    DOEpatents

    Hohimer, J.P.; Craft, D.C.

    1994-09-20

    Unidirectional ring lasers formed by integrating nonreciprocal optical elements into the resonant ring cavity is disclosed. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction. 21 figs.

  12. Unidirectional ring lasers

    DOEpatents

    Hohimer, John P.; Craft, David C.

    1994-01-01

    Unidirectional ring lasers formed by integrating nonreciprocal optical elements into the resonant ring cavity. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction.

  13. GUARD RING SEMICONDUCTOR JUNCTION

    DOEpatents

    Goulding, F.S.; Hansen, W.L.

    1963-12-01

    A semiconductor diode having a very low noise characteristic when used under reverse bias is described. Surface leakage currents, which in conventional diodes greatly contribute to noise, are prevented from mixing with the desired signal currents. A p-n junction is formed with a thin layer of heavily doped semiconductor material disposed on a lightly doped, physically thick base material. An annular groove cuts through the thin layer and into the base for a short distance, dividing the thin layer into a peripheral guard ring that encircles the central region. Noise signal currents are shunted through the guard ring, leaving the central region free from such currents. (AEC)

  14. Satellite Rings Movie

    NASA Image and Video Library

    2000-12-30

    This brief movie clip (of which the release image is a still frame), taken by NASA's Cassini spacecraft as it approached Jupiter, shows the motions, over a 16 hour-period, of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies. The movie was made from images taken during a 40-hour sequence of the Jovian ring on December 11, 2000. http://photojournal.jpl.nasa.gov/catalog/PIA02872

  15. Ring laser gyroscope anode

    SciTech Connect

    Ljung, B.H.

    1981-03-17

    An anode for a ring laser gyroscope which provides improved current stability in the glow discharge path is disclosed. The anode of this invention permits operation at lower currents thereby allowing a reduction of heat dissipation in the ring laser gyroscope. The anode of one embodiment of this invention is characterized by a thumbtack appearance with a spherical end where the normal sharp end of the thumbtack would be located. The stem of the anode extends from the outside of the gyroscope structure to the interior of the structure such that the spherical end is substantially adjacent to the laser beam.

  16. Single ring vs multiple ring determination of Super Kamiokande

    NASA Astrophysics Data System (ADS)

    O'Malley, Patrick; Messier, Mark

    2004-10-01

    Super Kamiokande houses the world's largest Cherenkov detector and whose primary goal is to detect and study neutrino interactions. My purpose in the project was to write a program to enhance the accuracy the ring counting. Currently, ring counting is the largest single source of systematic uncertainty in the single ring event rate, contributing an uncertainty of 5-8This article presents an algorithm the single ring selection efficiency based on a statistical test of azimuthal symmetry of the event topology. With the aid of my advisor, Dr. Mark Messier, I was able to write a program that enhanced the decision between single-ring and multiple ring events by 35

  17. Saturn's Rings, the Yarkovsky Effects, and the Ring of Fire

    NASA Technical Reports Server (NTRS)

    Rubincam, David Parry

    2004-01-01

    The dimensions of Saturn's A and B rings may be determined by the seasonal Yarkovsky effect and the Yarkovsky-Schach effect; the two effects confine the rings between approximately 1.68 and approximately 2.23 Saturn radii, in reasonable agreement with the observed values of 1.525 and 2.267. The C ring may be sparsely populated because its particles are transients on their way to Saturn; the infall may create a luminous Ring of Fire around Saturn's equator. The ring system may be young: in the past heat flow from Saturn's interior much above its present value would not permit rings to exist.

  18. The elusive rings of Neptune

    NASA Astrophysics Data System (ADS)

    Porco, C. C.

    1992-04-01

    An overview of investigations of Neptune's rings is presented in which the recent data and findings from the Voyager 2 mission are emphasized. The evolving interpretation of the ring arcs is outlined, and the concept of resonance in the rings is described. Illustrations of the rings, the moons of Neptune, and the interactions between the two are given, and attention is given to the development of the rings by means of the catastrophic breakup of a planetary satellite. The very large crater on the Mimas satellite is given as evidence of potentially catastrophic impacts, and the implications of further breakup are discussed. A total of four rings are identified which include 3 pronounced rings and one ring that is more diaphanous. Clumps in the arcs are discussed in terms of the possible existence of large objects within the rings, and interparticle collisions are theorized to account for the large arc dust content.

  19. Functional aspects of strepsirrhine lumbar vertebral bodies and spinous processes.

    PubMed

    Shapiro, Liza J; Simons, Cornelia V M

    2002-06-01

    The relationship between form and function in the lumbar vertebral column has been well documented among platyrrhines and especially catarrhines, while functional studies of postcranial morphology among strepsirrhines have concentrated predominantly on the limbs. This morphometric study investigates biomechanically relevant attributes of the lumbar vertebral morphology of 20 species of extant strepsirrhines. With this extensive sample, our goal is to address the influence of positional behavior on lumbar vertebral form while also assessing the effects of body size and phylogenetic history. The results reveal distinctions in lumbar vertebral morphology among strepsirrhines in functional association with their habitual postures and primary locomotor behaviors. In general, strepsirrhines that emphasize pronograde posture and quadrupedal locomotion combined with leaping (from a pronograde position) have the relatively longest lumbar regions and lumbar vertebral bodies, features promoting sagittal spinal flexibility. Indrids and galagonids that rely primarily on vertical clinging and leaping with orthograde posture share a relatively short (i.e., stable and resistant to bending) lumbar region, although the length of individual lumbar vertebral bodies varies phylogenetically and possibly allometrically. The other two vertical clingers and leapers, Hapalemur and Lepilemur, more closely resemble the pronograde, quadrupedal taxa. The specialized, suspensory lorids have relatively short lumbar regions as well, but the lengths of their lumbar regions are influenced by body size, and Arctocebus has dramatically longer vertebral bodies than do the other lorids. Lumbar morphology among galagonids appears to reflect a strong phylogenetic signal superimposed on a functional one. In general, relative length of the spinous processes follows a positively allometric trend, although lorids (especially the larger-bodied forms) have relatively short spinous processes for their body size

  20. Making Molecular Borromean Rings

    ERIC Educational Resources Information Center

    Pentecost, Cari D.; Tangchaivang, Nichol; Cantrill, Stuart J.; Chichak, Kelly S.; Peters, Andrea J.; Stoddart, Fraser J.

    2007-01-01

    A procedure that requires seven 4-hour blocks of time to allow undergraduate students to prepare the molecular Borromean rings (BRs) on a gram-scale in 90% yield is described. The experiment would serve as a nice capstone project to culminate any comprehensive organic laboratory course and expose students to fundamental concepts, symmetry point…

  1. Exotic damping ring lattices

    SciTech Connect

    Palmer, R.B.

    1987-05-01

    This paper looks at, and compares three types of damping ring lattices: conventional, wiggler lattice with finite ..cap alpha.., wiggler lattice with ..cap alpha.. = 0, and observes the attainable equilibrium emittances for the three cases assuming a constraint on the attainable longitudinal impedance of 0.2 ohms. The emittance obtained are roughly in the ratio 4:2:1 for these cases.

  2. Reading, Writing, and Rings!

    ERIC Educational Resources Information Center

    Aschbacher, Pamela; Li, Erika; Hammon, Art

    2008-01-01

    "Reading, Writing, and Rings!" was created by a team of elementary teachers, literacy experts, and scientists in order to integrate science and literacy. These free units bring students inside NASA's Cassini-Huygens mission to Saturn. The authors--a science teacher and education outreach specialist and two evaluators of educational programs--have…

  3. Reading, Writing, and Rings!

    ERIC Educational Resources Information Center

    Aschbacher, Pamela; Li, Erika; Hammon, Art

    2008-01-01

    "Reading, Writing, and Rings!" was created by a team of elementary teachers, literacy experts, and scientists in order to integrate science and literacy. These free units bring students inside NASA's Cassini-Huygens mission to Saturn. The authors--a science teacher and education outreach specialist and two evaluators of educational programs--have…

  4. Making Molecular Borromean Rings

    ERIC Educational Resources Information Center

    Pentecost, Cari D.; Tangchaivang, Nichol; Cantrill, Stuart J.; Chichak, Kelly S.; Peters, Andrea J.; Stoddart, Fraser J.

    2007-01-01

    A procedure that requires seven 4-hour blocks of time to allow undergraduate students to prepare the molecular Borromean rings (BRs) on a gram-scale in 90% yield is described. The experiment would serve as a nice capstone project to culminate any comprehensive organic laboratory course and expose students to fundamental concepts, symmetry point…

  5. Ring of Stellar Death

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This false-color image from NASA's Spitzer Space Telescope shows a dying star (center) surrounded by a cloud of glowing gas and dust. Thanks to Spitzer's dust-piercing infrared eyes, the new image also highlights a never-before-seen feature -- a giant ring of material (red) slightly offset from the cloud's core. This clumpy ring consists of material that was expelled from the aging star.

    The star and its cloud halo constitute a 'planetary nebula' called NGC 246. When a star like our own Sun begins to run out of fuel, its core shrinks and heats up, boiling off the star's outer layers. Leftover material shoots outward, expanding in shells around the star. This ejected material is then bombarded with ultraviolet light from the central star's fiery surface, producing huge, glowing clouds -- planetary nebulas -- that look like giant jellyfish in space.

    In this image, the expelled gases appear green, and the ring of expelled material appears red. Astronomers believe the ring is likely made of hydrogen molecules that were ejected from the star in the form of atoms, then cooled to make hydrogen pairs. The new data will help explain how planetary nebulas take shape, and how they nourish future generations of stars.

    This image composite was taken on Dec. 6, 2003, by Spitzer's infrared array camera, and is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

  6. Ring of Stellar Death

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This false-color image from NASA's Spitzer Space Telescope shows a dying star (center) surrounded by a cloud of glowing gas and dust. Thanks to Spitzer's dust-piercing infrared eyes, the new image also highlights a never-before-seen feature -- a giant ring of material (red) slightly offset from the cloud's core. This clumpy ring consists of material that was expelled from the aging star.

    The star and its cloud halo constitute a 'planetary nebula' called NGC 246. When a star like our own Sun begins to run out of fuel, its core shrinks and heats up, boiling off the star's outer layers. Leftover material shoots outward, expanding in shells around the star. This ejected material is then bombarded with ultraviolet light from the central star's fiery surface, producing huge, glowing clouds -- planetary nebulas -- that look like giant jellyfish in space.

    In this image, the expelled gases appear green, and the ring of expelled material appears red. Astronomers believe the ring is likely made of hydrogen molecules that were ejected from the star in the form of atoms, then cooled to make hydrogen pairs. The new data will help explain how planetary nebulas take shape, and how they nourish future generations of stars.

    This image composite was taken on Dec. 6, 2003, by Spitzer's infrared array camera, and is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

  7. Crescent Moon with Rings

    NASA Image and Video Library

    2006-04-14

    This poetic scene shows the giant, smog-enshrouded moon Titan behind Saturn nearly edge-on rings. Much smaller Epimetheus 116 kilometers, or 72 miles across is just visible to the left of Titan 5,150 kilometers, or 3,200 miles across

  8. Epimetheus Above the Rings

    NASA Image and Video Library

    2015-11-09

    Although Epimetheus appears to be lurking above the rings here, it's actually just an illusion resulting from the viewing angle. In reality, Epimetheus and the rings both orbit in Saturn's equatorial plane. Inner moons and rings orbit very near the equatorial plane of each of the four giant planets in our solar system, but more distant moons can have orbits wildly out of the equatorial plane. It has been theorized that the highly inclined orbits of the outer, distant moons are remnants of the random directions from which they approached the planets they orbit. This view looks toward the unilluminated side of the rings from about -0.3 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 26, 2015. The view was obtained at a distance of approximately 500,000 miles (800,000 kilometers) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 62 degrees. Image scale is 3 miles (5 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18342

  9. Rings In Between

    NASA Image and Video Library

    2011-12-05

    Saturn rings lie between a pair of moons in this view from NASA Cassini spacecraft that features Mimas and Prometheus. Mimas is the more noticeable of the two moons at top left, Prometheus is near the center of image and closest to Cassini.

  10. Ring laser scatterometer

    DOEpatents

    Ackermann, Mark; Diels, Jean-Claude

    2005-06-28

    A scatterometer utilizes the dead zone resulting from lockup caused by scatter from a sample located in the optical path of a ring laser at a location where counter-rotating pulses cross. The frequency of one pulse relative to the other is varied across the lockup dead zone.

  11. Ring Bubbles of Dolphins

    NASA Technical Reports Server (NTRS)

    Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)

    1996-01-01

    The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex ring bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex ring in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex ring travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex ring. Often, the dolphin would knock-off a smaller ring bubble from the larger ring (this also involves vortex reconnection) and steer the smaller ring around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex ring, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a ring when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since

  12. Rings from Close Encounters

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-09-01

    Weve recently discovered narrow sets of rings around two minor planets orbiting in our solar system. How did these rings form? A new study shows that they could be a result of close encounters between the minor planets and giants like Jupiter or Neptune.Unexpected Ring SystemsPositions of the centaurs in our solar system (green). Giant planets (red), Jupiter trojans (grey), scattered disk objects (tan) and Kuiper belt objects (blue) are also shown. [WilyD]Centaurs are minor planets in our solar system that orbit between Jupiter and Neptune. These bodies of which there are roughly 44,000 with diameters larger than 1 km have dynamically unstable orbits that cross paths with those of one or more giant planets.Recent occultation observations of two centaurs, 10199 Chariklo and 2060 Chiron, revealed that these bodies both host narrow ring systems. Besides our four giant planets, Chariklo and Chiron are the only other bodies in the solar system known to have rings. But how did these rings form?Scientists have proposed several models, implicating collisions, disruption of a primordial satellite, or dusty outgassing. But a team of scientists led by Ryuki Hyodo (Paris Institute of Earth Physics, Kobe University) has recently proposed an alternative scenario: what if the rings were formed from partial disruption of the centaur itself, after it crossed just a little too close to a giant planet?Tidal Forces from a GiantHyodo and collaborators first used past studies of centaur orbits to estimate that roughly 10% of centaurs experience close encounters (passing within a distance of ~2x the planetary radius) with a giant planet during their million-year lifetime. The team then performed a series of simulations of close encounters between a giant planet and a differentiated centaur a body in which the rocky material has sunk to form a dense silicate core, surrounded by an icy mantle.Some snapshots of simulation outcomes (click for a closer look!) for different initial states of

  13. Ring Bubbles of Dolphins

    NASA Technical Reports Server (NTRS)

    Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)

    1996-01-01

    The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex ring bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex ring in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex ring travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex ring. Often, the dolphin would knock-off a smaller ring bubble from the larger ring (this also involves vortex reconnection) and steer the smaller ring around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex ring, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a ring when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since

  14. The relation between the lumbar vertebrae and the spinal nerves for far lateral lumbar spinal approaches.

    PubMed

    Güvençer, Mustafa; Naderi, Sait; Kiray, Amaç; Yilmaz, Hakan Sinan; Tetik, Süleyman

    2008-02-01

    The far lateral approaches to the lumbar spine require accurate knowledge of regional anatomy. The aim of this study is to evaluate the course of the lumbar nerve roots and their relation to important bony landmarks. Seven adult male cadavers fixed with formaldehyde were used. Morphometric parameters, including the lumbar nerve root diameters, the angle between the nerve roots and the midline, the transverse process length, the inter-transverse process height and width, and the relation between the nerve roots and the transverse processes of the caudal vertebrae were measured. It was observed that the diameter of the nerve roots, and the angle between the nerve roots and the midline, and the distance between the nerve roots and the lateral edge of the superior articular process increased gradually from L1 to L5. The diameter of the nerve root was 4.9+/-0.5mm for L1 and 7.5+/-1.0mm for L5. The midline nerve root angle was 36.1+/-1.6 degrees mm for L1 and 40.4+/-1.4 degrees mm for L5. The distance between the nerve root and the lateral edge of the superior articular process was 6.5+/-1.0mm for L1 and 11.4+/-1.6mm for L5. The nerve roots crossed the transverse processes of the caudal lumbar vertebrae. The nerve roots of L1 and L2 crossed the transverse processes in their first two quarters, the L3 nerve root crossed the transverse process in its second, third or fourth quarters, and the L4 nerve roots crossed the L5 transverse process in its third and fourth quarter or even external to it. Descending toward the lower lumbar vertebrae, the diameter of the lumbar nerve root increases and the nerve roots exit the intervertebral foramen with a larger angle. The special relation between the nerve roots and the caudal vertebra transverse process should be remembered during far lateral lumbar spine approaches.

  15. The gravitational interaction between inclined, elliptical rings. [Uranus rings

    NASA Technical Reports Server (NTRS)

    Yoder, C. F.

    1982-01-01

    An expression for the potential for two elliptical, inclined rings is derived from a model in which the gravitational torque between two wide rings or within a ring of finite width can prevent differential precession caused by planetary oblateness. The model was proposed to explain the observed eccentricity and width variations of the Uranian epsilon ring. The stationary solutions and stability of this system are examined.

  16. Relief of Lumbar Symptoms After Cervical Decompression in Patients with Tandem Spinal Stenosis Presenting with Primarily Lumbar Pain

    PubMed Central

    Felbaum, Daniel R; Stewart, Jeffrey J; Sandhu, Faheem A

    2016-01-01

    Objective: Tandem cervical and lumbar spinal stenosis (TSS) is classically described as intermittent claudication, gait disturbance, and clinical findings of mixed myelopathy and polyradiculopathy. Rarely, patients can present with TSS manifesting in isolated lumbar pain. Several reports have demonstrated improved lumbar back pain and radiculopathy after decompressive cervical spine procedures. We present six patients with dramatic resolution of lumbar spine related symptoms after decompression of the cervical spinal cord despite presenting solely with lower back complaints. Methods: Clinical records of the senior author (F.A.S.) gathered from April 2006 to March 2013 were retrospectively reviewed identifying six patients presenting solely with lumbar symptoms and diagnosed with TSS based on history and physical examination. Results: Six patients with a mean age of 55 (range 39 to 60) presented with solely lower back symptoms and clinical findings suspicious for TSS. Mean follow-up time for all patients was 12 months (range three to 27 months, median 11.5 months). Three patients underwent a cervical procedure as the principal operation, while the remainder had the lumbar spine decompressed initially. All patients that underwent a cervical procedure initially experienced a dramatic decrease or complete resolution of their preoperative lower back pain and radiculopathy (mean preoperative VAS of 6.7 vs. 3.7 postoperative). The remainder of patients with persistent lumbar symptoms resolved after a subsequent cervical operation. Conclusion: Patients presenting with lumbar symptoms out of proportion to imaging require further investigation. We highlight the resolution of lumbar symptoms after a cervical procedure in a select group of patients presenting with lone lower back complaints. In patients presenting with symptoms disproportionate to lumbar imaging, treatment of cervical pathology may provide robust long-term relief of the initial lumbar-related presentation

  17. Simple prediction method of lumbar lordosis for planning of lumbar corrective surgery: radiological analysis in a Korean population.

    PubMed

    Lee, Chong Suh; Chung, Sung Soo; Park, Se Jun; Kim, Dong Min; Shin, Seong Kee

    2014-01-01

    This study aimed at deriving a lordosis predictive equation using the pelvic incidence and to establish a simple prediction method of lumbar lordosis for planning lumbar corrective surgery in Asians. Eighty-six asymptomatic volunteers were enrolled in the study. The maximal lumbar lordosis (MLL), lower lumbar lordosis (LLL), pelvic incidence (PI), and sacral slope (SS) were measured. The correlations between the parameters were analyzed using Pearson correlation analysis. Predictive equations of lumbar lordosis through simple regression analysis of the parameters and simple predictive values of lumbar lordosis using PI were derived. The PI strongly correlated with the SS (r = 0.78), and a strong correlation was found between the SS and LLL (r = 0.89), and between the SS and MLL (r = 0.83). Based on these correlations, the predictive equations of lumbar lordosis were found (SS = 0.80 + 0.74 PI (r = 0.78, R (2) = 0.61), LLL = 5.20 + 0.87 SS (r = 0.89, R (2) = 0.80), MLL = 17.41 + 0.96 SS (r = 0.83, R (2) = 0.68). When PI was between 30° to 35°, 40° to 50° and 55° to 60°, the equations predicted that MLL would be PI + 10°, PI + 5° and PI, and LLL would be PI - 5°, PI - 10° and PI - 15°, respectively. This simple calculation method can provide a more appropriate and simpler prediction of lumbar lordosis for Asian populations. The prediction of lumbar lordosis should be used as a reference for surgeons planning to restore the lumbar lordosis in lumbar corrective surgery.

  18. The lumbar spine in Neanderthals shows natural kyphosis

    PubMed Central

    Pusch, Carsten Matthias

    2008-01-01

    Nowadays, lumbar spondylosis is one of the most frequent causes of lower back pain. In order to improve our understanding of the lumbar spine anatomy and functionality over time, we compared the lumbar vertebrae of Neanderthals with those of anatomically modern humans. The fossil record reports on only two Neanderthal skeletons (i.e., Kebara 2 and Shanidar 3, both predating the appearance of modern humans) with full preservation of the entire lumbar spine. Examination of these early hominids showed that they display natural lumbar kyphosis, with only mild degenerative changes of the lumbar spine (ages at death: 30–35 years, Kebara 2; and 35–50 years, Shanidar 3). This finding is highly unexpected since Neanderthals are known to have had extraordinary physical activity due to demanding living conditions. The adult lumbar spines discussed here therefore show no correlation between high physical activity and degenerative spine disease as known from recent times. We speculate that both the kyphosis itself and the massive and heavily muscled skeleton of Neanderthals are causative for the minimal bone degeneration. We conclude that a kyphotic lumbar spine is the natural anatomy in these two Neanderthal individuals. Future research will reveal if this holds true for the entire Neanderthal species. PMID:18301930

  19. Lumbar-pelvic coordination in the sitting position.

    PubMed

    Kasahara, Satoshi; Miyamoto, Kenji; Takahashi, Mitsuhiko; Yamanaka, Masanori; Takeda, Naoki

    2008-08-01

    This study assessed the relationship of each movement direction on the lumbar spine and on the pelvis in regards to lumbar-pelvic coordination in the sitting position. Lumbar and pelvic motions were recorded using a flexible electrogoniometer in 12 healthy subjects during two different tasks in the sitting position. The coordination of the lumbar spine and pelvis was evaluated using the ratio of lumbar and pelvic angles (L/P ratio hereafter) in three motion phases. There were significant differences in the L/P ratio values between during the "forward bending" and "rising from a forward flexed position" phases (P<0.01). The L/P ratio value ( approximately -0.7) was consistent during the movement from an erect to a slumped sitting position as the lumbar spine and pelvis moved in opposing directions. This study shows that lumbar-pelvic coordination occurs in the sitting position. Lumbar-pelvic coordination is confirmed even if the movement tasks are different in the sitting position, and these findings show that aspects of a particular movement are dependent on the given movement task. These findings may provide greater insight into the kinematic changes involved in lumber-pelvic coordination, and help clinicians implement sitting exercises conducive to the independence of the patient.

  20. 49 CFR 572.115 - Lumbar spine and pelvis.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Lumbar spine and pelvis. 572.115 Section 572.115... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Side Impact Hybrid Dummy 50th Percentile Male § 572.115 Lumbar spine and pelvis. The specifications and test procedure for...

  1. Cervical and lumbar paraspinal calcinosis in systemic sclerosis.

    PubMed

    Tan, C K; Suresh, E

    2016-12-31

    Calcinosis is a well-recognized manifestation of systemic sclerosis. Paraspinal or intraspinal calcinosis is rare, with reports of calcinosis involving the cervical, thoracic and lumbar separately, but not together. We now report a case of limited cutaneous scleroderma with extensive paraspinal calcinosis of the cervical and lumbar spine.

  2. Lumbar discal cyst as a cause of radiculopathy: case report.

    PubMed

    Cho, Newton; Keith, Julia; Pirouzmand, Fahard

    2016-12-01

    Lumbar discal cysts are rare entities causing radicular pain with unknown etiologies. We report a case of a 42-year-old man who developed radiculopathy secondary to a lumbar discal cyst. Our case sheds some light on anatomy, possible etiological association and clinical course which can help management.

  3. 49 CFR 572.85 - Lumbar spine flexure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Lumbar spine flexure. (a) When subjected to continuously applied force in accordance with paragraph (b... degrees at a force level of not less than 18 pounds and not more than 22 pounds, and straighten upon removal of the force to within 5 degrees of its initial position. (b) Test procedure. (1) The lumbar...

  4. 49 CFR 572.43 - Lumbar spine and pelvis.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Lumbar spine and pelvis. 572.43 Section 572.43 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Side Impact Dummy 50th Percentile Male § 572.43 Lumbar spine...

  5. 49 CFR 572.43 - Lumbar spine and pelvis.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Lumbar spine and pelvis. 572.43 Section 572.43 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Side Impact Dummy 50th Percentile Male § 572.43 Lumbar spine...

  6. [Research progress of stress fracture of lumbar pedicle].

    PubMed

    Liu, Yong; Yin, Qudong; Gu, Sanjun; Sun, Zhenzhong; Rui, Yongjun; Shou, Kuishui

    2013-02-01

    To review the research progress of stress fracture of the lumbar pedicle. The literature about the stress fracture of the lumbar pedicle was reviewed extensively and summarized. There are two types of stress fracture: fatigue and structure insufficient. Stress fracture of lumbar pedicle occurred mainly in the crowd with repetitive and large activities of spine, contralateral spondylolysis, or previous surgery of lumbar vertebra. The main stresses causing stress fracture of the lumbar pedicle are shear stress and twisting stress, followed by sudden hyperflexion or hyperextension of the spine. Stress fracture of lumbar pedicle was easily missed by conventional X-ray examination, usually XCT, MRI, or bone scan was needed to confirm the diagnosis. It is divided into 4 types or 4 periods according to MRI findings: stress reaction, incomplete fracture, complete fracture, and pseudarthrosis. For patients with incomplete, complete, and juvenile stress fractures of the lumbar pedicle without nerve root irritation, the majority of claims preferred conservative treatment and the healing rate of fracture was high; for patients with bilateral pseudarthrosis and with nerve root irritation as well as patients who failed to the conservative treatment, surgical management was advocated and the operation result is good. Stress fracture of the lumbar pedicle as one of the causes of low back pain is extremely rare, and is easily missed clinically. Surgery or conservative management should be selected based on type of fracture and specific condition of the patient, the treatment results are satisfactory.

  7. Iohexol versus metrizamide for lumbar myelography: double-blind trial

    SciTech Connect

    Gabrielsen, T.O.; Gebarski, S.S.; Knake, J.E.; Latack, J.T.; Yang, P.J.; Hoff, J.T.

    1984-05-01

    Lumbar myelography was performed in 50 patients; 25 received iohexol and 25 received metrizamide. The two media produced radiographs of equal quality. However, iohexol is stable in solution, while metrizamide is not. Further, markedly less morbidity resulted from iohexol. These features indicate that iohexol may be superior to metrizamide as a contrast agent for lumbar myelography.

  8. Lumbar lordosis in osteoporosis and in osteoarthritis

    PubMed Central

    Papadokostakis, Georgios; Stergiopoulos, Konstantinos; Kampanis, Nikos; Katonis, Pavlos

    2008-01-01

    The curvature of the lumbar spine and the risk of developing either osteoporosis (OP) or osteoarthritis (OA) are influenced by many common factors. The aim of this study is to determine whether lumbar lordosis is different between patients with either disease and healthy persons. A cross-sectional, blinded, controlled design was implemented. One hundred and twelve postmenopausal women were evaluated for bone mineral density as well as undergoing spinal radiography. Lordosis measurement was performed with Cobb’s method. The sample was divided in four groups: patients with OP (n = 34, L1–L5 = 40.7°, L1–S1 = 54.1°), patients with OA (n = 29, L1–L5 = 38°, L1–S1 = 52.3°), patients with both diseases (n = 20, L1–L5 = 41.8°, L1–S1 = 52.3°) and controls (n = 29, L1–L5 = 38.6°, L1–S1 = 51.8°). For all participants age, height, weight, body mass index, physical activity level and basal metabolic rate were measured and recorded. The results revealed that although the four groups have significant constitutional differences, lumbar lordosis was comparable between them. The reasons for the lack of association are discussed. PMID:19089464

  9. Correlation between severity of lumbar spinal stenosis and lumbar epidural steroid injection.

    PubMed

    Park, Chan-Hong; Lee, Sang-Ho

    2014-04-01

    Lumbar spinal stenosis (LSS) is a narrowing of the spinal canal that causes mechanical compression of the spinal nerve roots. The compression of these nerve roots can cause leg pain, as well as neurogenic claudication. Lumbar epidural steroid injections have commonly been used in patients with LSS. The aim of our study was to determine the relationship between the severity of LSS using a grading system (grade 1 = mild stenosis with separation of all cauda equina; grade 2 = moderate stenosis with some cauda equina aggregated; grade 3 = severe stenosis with none of the cauda equina separated) and the subject's response to computed tomography-guided lumbar epidural steroid injection (CTG-LESI) and to evaluate the short-term effectiveness. Forty-seven consecutive patients with degenerative LSS were enrolled in this prospective study. All subjects underwent lumbar spine magnetic resonance imaging. Two radiologists independently graded lumbar central canal stenosis based on T2-weighted axial images. All CTG-LESI were performed in the procedure room. Outcome measures were obtained using the 5-point patient's satisfaction scale at 2 and 8 weeks post-treatment. To evaluate the outcome, we divided the patients into two groups according to their response to the treatment. Improvement (including reports of slightly improved, much improved, and no pain) was observed in 37 patients (78.7%) at 2 weeks and 36 patients (77.6%) at 8 weeks after the procedure. There was no statistically significant correlation between pain relief and age. The grade of LSS appears to have no effect on the degree of pain relief associated with CTG-LESI. However, CTG-LESI seems to provide effective short-term pain relief due to LSS. Wiley Periodicals, Inc.

  10. Radiographic Results of Minimally Invasive (MIS) Lumbar Interbody Fusion (LIF) Compared with Conventional Lumbar Interbody Fusion.

    PubMed

    Lim, Jae Kwan; Kim, Sung Min

    2013-06-01

    To evaluate the radiographic results of minimally invasive (MIS) anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF). Twelve and nineteen patients who underwent MIS-ALIF, MIS-TLIF, respectively, from 2006 to 2008 were analyzed with a minimum 24-months' follow-up. Additionally, 18 patients treated with single level open TLIF surgery in 2007 were evaluated as a comparative group. X-rays and CT images were evaluated preoperatively, postoperatively, and at the final follow-up. Fusion and subsidence rates were determined, and radiographic parameters, including lumbar lordosis angle (LLA), fused segment angle (FSA), sacral slope angle (SSA), disc height (DH), and foraminal height (FH), were analyzed. These parameters were also compared between the open and MIS-TLIF groups. In the MIS interbody fusion group, statistically significant increases were observed in LLA, FSA, and DH and FH between preoperative and final values. The changes in LLA, FSA, and DH were significantly increased in the MIS-ALIF group compared with the MIS-TLIF group, but SSA and FH were not significantly different. No significant differences were seen between open and MIS-TLIF except for DH. The interbody subsidence and fusion rates of the MIS groups were 12.0±4% and 96%, respectively. Radiographic results of MIS interbody fusion surgery are as favorable as those with conventional surgery regarding fusion, restoration of disc height, foraminal height, and lumbar lordosis. MIS-ALIF is more effective than MIS-TLIF for intervertebral disc height restoration and lumbar lordosis.

  11. Radiographic Results of Minimally Invasive (MIS) Lumbar Interbody Fusion (LIF) Compared with Conventional Lumbar Interbody Fusion

    PubMed Central

    Lim, Jae Kwan

    2013-01-01

    Objective To evaluate the radiographic results of minimally invasive (MIS) anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF). Methods Twelve and nineteen patients who underwent MIS-ALIF, MIS-TLIF, respectively, from 2006 to 2008 were analyzed with a minimum 24-months' follow-up. Additionally, 18 patients treated with single level open TLIF surgery in 2007 were evaluated as a comparative group. X-rays and CT images were evaluated preoperatively, postoperatively, and at the final follow-up. Fusion and subsidence rates were determined, and radiographic parameters, including lumbar lordosis angle (LLA), fused segment angle (FSA), sacral slope angle (SSA), disc height (DH), and foraminal height (FH), were analyzed. These parameters were also compared between the open and MIS-TLIF groups. Results In the MIS interbody fusion group, statistically significant increases were observed in LLA, FSA, and DH and FH between preoperative and final values. The changes in LLA, FSA, and DH were significantly increased in the MIS-ALIF group compared with the MIS-TLIF group, but SSA and FH were not significantly different. No significant differences were seen between open and MIS-TLIF except for DH. The interbody subsidence and fusion rates of the MIS groups were 12.0±4% and 96%, respectively. Conclusion Radiographic results of MIS interbody fusion surgery are as favorable as those with conventional surgery regarding fusion, restoration of disc height, foraminal height, and lumbar lordosis. MIS-ALIF is more effective than MIS-TLIF for intervertebral disc height restoration and lumbar lordosis. PMID:24757461

  12. [Severe Raynaud's syndrome treated by lumbar sympathectomy].

    PubMed

    Thomsen, Thomas Laden; Roeder, Ole

    2016-03-28

    Avoiding exposure of extremities to cold combined with pharmacologic treatment usually suffice in the attempt to suppress the related symptoms of Raynaud's syndrome. This case report describes a severe case of Raynaud's syndrome affecting the lower extremities of a 16-year-old female. She was referred to a centre of vascular surgery with severe vasospasms of the feet. After failed attempts of pharmacologic treatment, a laparoscopic lumbar sympathectomy was performed with no complications and a slight reduction of symptoms three years post-surgically.

  13. Radiology of the stenotic lumbar canal.

    PubMed

    Monti, C; Malaguti, C; Mavilla, L; Bettini, N; Ruini, G

    1992-01-01

    The main objective of imaging diagnostics in the study of the stenotic lumbar canal is that of revealing the presence of any contents/container conflict, of determining its site, extent, extension and, when possible, its etiopathogenesis. At present, CT and MRI constitute the most sensitive and specific methods, available necessarily preceded by a conventional radiological examination. Clinical assessment influences the choice of the method to use, whether alone or in association with others, as well as the method used to carry out the investigation; if we add all of this to correct technical execution, the radiological examination will provide a considerable amount of data.

  14. Symptomatic lumbar spinal arachnoiditis: fact or fallacy?

    PubMed

    Petty, P G; Hudgson, P; Hare, W S

    2000-09-01

    It is generally accepted that chronic adhesive lumbar arachnoiditis is a cause of symptoms, notably back pain and/or pain (of almost any type, not necessarily 'anatomical') in the lower limbs, although there is no clearly defined clinical pattern which is clearly associated with this syndrome. There is no doubt that arachnoiditis occurs as a pathological and radiological entity due to a number of causes. In the view of the present authors, the nexus between the pathology and radiology on the one hand, and the patients' symptoms on the other hand, has not been demonstrated with any degree of scientific rigor.

  15. Aneurysmal bone cyst of the lumbar spine.

    PubMed

    Cugati, Goutham; Pande, Anil; Jain, Pradeep K; Symss, Nigel Peter; Ramamurthi, Ravi; Vasudevan, Chakravarthy M

    2015-01-01

    An aneurysmal bone cyst (ABC) is a benign, locally proliferative vascular disorder of non-neoplastic osseous lesions in children and young adults. Seventy-five percent of ABCs occur before the age of 20 years. They comprise 1.4% of all primary bone tumors, and commonly occur in the long bones. Spinal ABCs are much rarer. We present to you one such rare case of ABC involving the lumbar spine which was successfully treated with surgery. The clinical pathological and radiological features are described. The treatment options available are discussed.

  16. Surgical anatomy of the minimally invasive lateral lumbar approach.

    PubMed

    Bina, Robert W; Zoccali, Carmine; Skoch, Jesse; Baaj, Ali A

    2015-03-01

    The lateral lumbar interbody fusion approach (LLIF), which encompasses the extreme lateral interbody fusion or direct lateral interbody fusion techniques, has gained popularity as an alternative to traditional posterior approaches. With rapidly expanding applications, this minimally invasive surgery (MIS) approach is now utilized in basic degenerative pathologies as well as complex lumbar degenerative deformities and tumors. Given the intimate relationship of the psoas muscle, and hence the lumbar plexus, to this MIS approach, several authors have examined the surgical anatomy of this approach. Understanding this regional neural anatomy is imperative given the potential for serious injuries to both the motor and sensory nerves of the lumbar plexus. In this review, we critically and comprehensively discuss all published studies detailing the surgical anatomy of the lateral lumbar approach with respect to the MIS LLIF techniques. This is a timely review given the rapidly growing number of surgeons utilizing this technique. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Oscillations at B Ring Edge

    NASA Image and Video Library

    2010-11-01

    This image obtained by NASA Cassini spacecraft of the outer edge of Saturn?s B ring, reveals the combined effects of a tugging moon and oscillations that can naturally occur in disks like Saturn rings and spiral galaxies.

  18. Inorganic glass ceramic slip rings

    NASA Technical Reports Server (NTRS)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  19. Ring autosomes: some unexpected findings.

    PubMed

    Caba, L; Rusu, C; Plăiaşu; Gug, G; Grămescu, M; Bujoran, C; Ochiană, D; Voloşciuc, M; Popescu, R; Braha, E; Pânzaru, M; Butnariu, L; Sireteanu, A; Covic, M; Gorduza, Ev

    2012-12-01

    Ring chromosomes are rare entities, usually associated with phenotypic abnormalities in correlation with the loss of genetic material. There are various breakpoints and sometimes there is a dynamic mosaicism that is reflected in clinical features. Most of the ring chromosomes are de novo occurrences. Our study reflects the experience of three Romanian cytogenetic laboratories in the field of ring chromosomes. We present six cases with ring chromosomes involving chromosomes 5, 13, 18, and 21. All ring chromosomes were identified after birth in children with plurimalformative syndromes. The ring chromosome was present in mosaic form in three cases, and this feature reflects the ring's instability. In case of ring chromosome 5, we report a possible association with oculo-auriculo-vertebral spectrum.

  20. Planetary rings: Structure and history

    NASA Astrophysics Data System (ADS)

    Esposito, L.

    The composition and structure of planetary rings provide the key evidence to understand their origin and evolution. Before the first space observations, we were able to maintain an idealized view of the rings around Saturn, the only known ring system at that time. Rings were then discovered around Jupiter, Uranus and Neptune. Saturn's F ring was discovered by Pioneer 11. Our ideal view of circular, planar, symmetric and unchanging rings was shattered by observations of inclined, eccentric rings, waves and wavy edges, and numerous processes acting at rates that give timescales much younger than the solar system. Moons within and near the rings sculpt them and are the likely progenitors of future rings. The moonlet lifetimes are much less than Saturn's age. The old idea of ancient rings gave rise to youthful rings, that are recently created by erosion and destruction of small nearby moons. Although this explanation may work well for most rings, Saturn's massive ring system provides a problem. It is extremely improbable that Saturn's rings were recently created by the destruction of a moon as large as Mimas, or even by the breakup of a large comet that passed too close to Saturn. The history of Saturn's rings has been a difficult problem, now made even more challenging by the close-up Cassini measurements. Cassini observations show unexpected ring variability in time and space. Time variations are seen in ring edges, in the thinner D and F rings, and in the neutral oxygen cloud, which outweighs the E ring in the same region around Saturn. The rings are inhomogeneous, with structures on all scales, sharp gradients and edges. Compositional gradients are sharper than expected, but nonetheless cross structural boundaries. This is evidence for ballistic transport that has not gone to completion. The autocovariance maximizes in the middle of the A ring, with smaller structure near the main rings' outer edge. Density wave locations have a fresher ice composition. The

  1. Chemoembolization for Hepatocellular Carcinoma Supplied by a Lumbar Artery

    SciTech Connect

    Kim, Han Myun; Kim, Hyo-Cheol Woo, Sungmin; Son, Kyu Ri; Cho, Seong Whi; Chung, Jin Wook

    2015-02-15

    PurposeTo describe the radiologic findings and imaging response of hepatocellular carcinoma (HCC) supplied by the lumbar artery.MethodsBetween April 2004 and December 2012, we encountered HCC supplied by a lumbar artery in 21 patients. Two investigators retrospectively reviewed clinical and radiological findings of HCC supplied by the lumbar artery using computed tomography (CT) scans and digital subtraction angiograms.ResultsPatients had received 1–27 sessions of previous chemoembolization procedures (mean 7.7 sessions, median 4 sessions). Mean tumor size was 5.3 cm. The locations of HCC supplied by lumbar artery were the bare area (n = 14, 67 %) and segment VI (n = 7, 33 %). Tumor-feeding arteries arose from the main lumbar artery (n = 7), proximal anterior division (n = 4), and distal anterior division (n = 14). In 20 patients, selective chemoembolization through the tumor-feeding arteries of the lumbar artery was achieved. In 1 patient, nonselective embolization at the main lumbar artery was performed. There was no complication such as skin necrosis or paralysis. On the first follow-up enhanced CT scan, target tumors fed by the lumbar artery showed complete response (n = 6), partial response (n = 4), stable disease (n = 3), and progressive disease (n = 8), but overall tumor response was partial response (n = 1) and progressive disease (n = 20).ConclusionWhen HCC is located in the inferior tip or bare area of the liver, a lumbar artery may supply the tumor. Although selective chemoembolization via the tumor-feeding vessel of the lumbar artery can be achieved in most cases, overall tumor response is commonly unfavorable.

  2. Postural Cueing to Increase Lumbar Lordosis Increases Lumbar Multifidus Activation During Trunk Stabilization Exercises: Electromyographic Assessment Using Intramuscular Electrodes.

    PubMed

    Beneck, George J; Story, John W; Donald, Shelby

    2016-04-01

    Controlled laboratory study, repeated-measures design. Diminished multifidus activation and cross-sectional area are frequent findings in persons with low back pain. Increasing lumbar lordosis has been shown to increase activation of the multifidus with a minimal increase in activation of the long global extensors during unsupported sitting. To examine the influence of postural cueing to increase lumbar lordosis on lumbar extensor activation during trunk stabilization exercises. Thirteen asymptomatic participants (9 male, 4 female) were instructed to perform 6 trunk stabilization exercises using a neutral position and increasing lumbar lordosis. Electrical activity of the deep multifidus and longissimus thoracis was recorded using fine-wire intramuscular electrodes. The mean root-mean-square of the electromyography (EMG) signal obtained during each exercise was normalized to a maximum voluntary isometric contraction (MVIC). A 2-way, repeated-measures analysis of variance (posture by exercise) was performed for each muscle. When averaged across the 6 exercises, postural cueing to increase lumbar lordosis resulted in greater multifidus EMG activity compared to performing the exercises in a neutral posture (35.3% ± 15.1% versus 29.5% ± 11.2% MVIC). No significant increase in longissimus thoracis EMG activity was observed when exercising with cueing to increase lumbar lordosis. This study suggests that postural cueing to increase lumbar lordosis during trunk stabilization exercises may better promote multifidus activation than traditional stabilization exercises alone. Future studies are needed to determine whether increasing lumbar lordosis improves multifidus activation in persons with low back pain.

  3. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    SciTech Connect

    Pugliese, D.; Stuchlík, Z. E-mail: zdenek.stuchlik@physics.cz

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  4. Uranus Rings and Two Moons

    NASA Image and Video Library

    1999-06-19

    Voyager 2 has discovered two hepherd satellites associated with the rings of Uranus. The two moons, designated 1986U7 and 1986U8, are seen here on either side of the bright epsilon ring; all nine of the known Uranian rings are visible.

  5. Uranus: the rings are black.

    PubMed

    Sinton, W M

    1977-11-04

    An upper limit of 0.05 is established for the geometric albedo of the newly discovered rings of Uranus. In view of this very low albedo, the particles of the rings cannot be ice-covered as are those of rings A and B of Saturn.

  6. Ring closure in actin polymers

    NASA Astrophysics Data System (ADS)

    Sinha, Supurna; Chattopadhyay, Sebanti

    2017-03-01

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers.

  7. DC-Powered Jumping Ring

    ERIC Educational Resources Information Center

    Jeffery, Rondo N.; Farhang, Amiri

    2016-01-01

    The classroom jumping ring demonstration is nearly always performed using alternating current (AC), in which the ring jumps or flies off the extended iron core when the switch is closed. The ring jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant…

  8. DC-Powered Jumping Ring

    ERIC Educational Resources Information Center

    Jeffery, Rondo N.; Farhang, Amiri

    2016-01-01

    The classroom jumping ring demonstration is nearly always performed using alternating current (AC), in which the ring jumps or flies off the extended iron core when the switch is closed. The ring jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant…

  9. Investigations of planetary ring phenomena

    NASA Technical Reports Server (NTRS)

    Burns, Joseph A.

    1987-01-01

    Faint planetary rings, their dynamical behavior and physical properties, were the main focus of the research efforts. The motion of weakly-charged dust through the gravitational and magnetic fields of Jupiter were examined. Several topics concerning features of Saturn's rings were addressed. The origin and fate of the Uranian ring dust is presently being studied.

  10. Mimas Against the Rings

    NASA Image and Video Library

    2005-08-05

    During its close flyby of Saturn's moon Mimas on Aug. 2, 2005, Cassini caught a glimpse of Mimas against the broad expanse of Saturn's rings. The Keeler Gap in the outer A ring, in which Cassini spied a never-before-seen small moon (see PIA06237), is at the upper right. The ancient, almost asteroid-like surface of Mimas is evident in its crater-upon-crater appearance. Even the material which has slumped down into the bottom of some of its craters bears the marks of later impacts. This image was taken through the clear filter of the Cassini spacecraft narrow-angle camera at a distance of 68,000 kilometers (42,500 miles) from Mimas and very near closest approach. The smallest features seen on the moon are about 400 meters wide (440 yards); the Sun-Mimas-Cassini angle is 44 degrees. http://photojournal.jpl.nasa.gov/catalog/PIA06412

  11. Saturn Ring Observer

    NASA Technical Reports Server (NTRS)

    Spilker, T. R.

    2001-01-01

    Answering fundamental questions about ring particle characteristics, and individual and group behavior, appears to require close-proximity (a few km) observations. Saturn's magnificent example of a ring system offers a full range of particle sizes, densities, and behaviors for study, so it is a natural choice for such detailed investigation. Missions implementing these observations require post-approach Delta(V) of approximately 10 km/s or more, so past mission concepts called upon Nuclear Electric Propulsion. The concept described here reduces the propulsive Delta(V) requirement to as little as 3.5 km/s, difficult but not impossible for high-performance chemical propulsion systems. Additional information is contained in the original extended abstract.

  12. Satellite Rings Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This brief movie clip (of which the release image is a still frame), taken by NASA's Cassini spacecraft as it approached Jupiter, shows the motions, over a 16 hour-period, of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies.

    The movie was made from images taken during a 40-hour sequence of the Jovian ring on December 11, 2000.

    Cassini is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages Cassini for NASA's Office of Space Science, Washington, D.C.

  13. Satellite Rings Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This brief movie clip (of which the release image is a still frame), taken by NASA's Cassini spacecraft as it approached Jupiter, shows the motions, over a 16 hour-period, of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies.

    The movie was made from images taken during a 40-hour sequence of the Jovian ring on December 11, 2000.

    Cassini is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages Cassini for NASA's Office of Space Science, Washington, D.C.

  14. [Surgical treatment of degenerative lumbar scoliosis with multi-segment lumbar spinal stenosis].

    PubMed

    Lan, Jiaping; Tang, Xun; Xu, Yongqing; Zhou, Tianhua; Shi, Jian; Cui, Yi; Xiang, Qili; Cai, Zhijun; Zhao, Qingkai; Yang, Xiaoyong; Zhao, Caihua

    2014-08-01

    To explore the surgical indications, decompression and fusion method, and fusion level selection of degenerative lumbar scoliosis (DLS) and multi-segment lumbar spinal stenosis. Between April 2000 and November 2011, 46 cases of DLS and multi-segment lumbar spinal stenosis were treated with multi-level decompression by fenestration and crept enlargement plus internal fixation by interbody and posterior-lateral bone graft fusion (5 segments or above). Of 46 cases, 25 were male and 21 were female, with a mean age of 70.2 years (range, 65-81 years) and with a mean disease duration of 6.4 years (range, 4 years and 6 months to 13 years). X-ray films showed that the lumbar Cobb angle was (26.7 ± 10.0) degrees, and the lumbar lordotic angle was (20.3 ± 8.8)degrees. The lumbar CT and MRI images showed three-segment stenosis in 24 cases, four-segment stenosis in 17 cases, and five-segment stenosis in 5 cases. A total of 165 stenosed segments included 12 L1,2, 34 L2,3, 43 L3,4, 45 L4,5, and 31 L5 and S1. Visual analogue scale (VAS) score, Oswestry disability index (ODI), and Japanese Orthopedic Association (JOA) score (29 points) were employed to evaluate effectiveness. Thirteen patients had leakage of cerebrospinal fluid during operation, and no infection was found after corresponding treatment; pulmonary infection and urinary system infection occurred in 4 and 2 patients respectively, who relieved after received antibiotic therapy; 8 patients with poor wound healing received dressing change, adequate drainage, debridement and suture. No death, paralysis, central nervous system infection, or other complication was observed in these patients. Forty-six cases were followed up 12-72 months (mean, 36.2 months). Lumbago and backache and intermittent claudication of lower extremity were obviously improved. During follow-up, no screw incising, loosening and broken screws, or pseudarthrosis was noted under X-ray film and CT scanning. At last follow-up, the lumbar Cobb angle was

  15. A Change in Lumbar Sagittal Alignment After Single-level Anterior Lumbar Interbody Fusion for Lumbar Degenerative Spondylolisthesis With Normal Sagittal Balance.

    PubMed

    Kim, Chi Heon; Chung, Chun Kee; Park, Sung Bae; Yang, Seung Heon; Kim, Jung-Hee

    2017-08-01

    Retrospective analysis. The object is to assess the correlation between whole lumbar lordosis (LL) and the segmental angle (SA) after single-level anterior lumbar interbody fusion for degenerative lumbar spondylolisthesis. The restoration of the SA at lower lumbar spine is meaningful, considering it contributes approximately 60% of LL, and revision surgery due to flat back or adjacent segment pathology was necessary decades after the initial surgery. However, little is known about the change of whole lumbar curvature after single-level lower lumbar fusion surgery, especially for balanced spine. We included 41 consecutive patients (M:F=9:32; mean age, 59.8±9.3 y) with a single-level anterior lumbar interbody fusion surgery for low-grade degenerative spinal spondylolisthesis, with C7 plumb line of <5 cm and ≥2-year follow-up period. The operated levels were L4-L5 in 34 patients and L5-S1 in 7 patients. Whole LL, SA, pelvic tilt, and sacral slope were compared. According to the Macnab criteria, a favorable outcome (excellent, 21; good, 15) was achieved in 36/41 (88%; excellent, 21; good, 15) patients. LL and SA were significantly changed from -50.8±9.9 to -54.6±11.1 degrees and -15.6±6.1 to -18.7±5.1 degrees (P<0.01), and a positive correlation (r=0.43, P=0.01) was observed between LL and SA at postoperative month 24. The changes to the pelvic tilt and sacral slope were not significant. Whole lumbar sagittal alignment was influenced by single SA. Therefore, obtaining adequate segmental lordosis is desirable considering the effect on the whole spine for a long time.

  16. Strained Ring Energetic Binders

    DTIC Science & Technology

    1993-08-27

    polyhomobenzvalene ( PHBV ). PHBV was not found to have the mechanical instability problems of PBV, but was still thermally unstable (Tonset - 660C, Tmax - 1090C...DISCUSSION 4 Polybenzvalene (PBV) 4 Polyhomobenzvalene ( PHBV ) 6 Chain-Transfer Studies 11 CONCLUSIONS 15 EXPERIMENTAL PROCEDURES 16 .F 4E 19 APPENDICES A...strained ring polymers similar to PBV are known. The investigation of one of these polymers, polyhomobenzvalene ( PHBV ), is also described in this report

  17. [Mechanical studies of lumbar interbody fusion implants].

    PubMed

    Bader, R J; Steinhauser, E; Rechl, H; Mittelmeier, W; Bertagnoli, R; Gradinger, R

    2002-05-01

    In addition to autogenous or allogeneic bone grafts, fusion cages composed of metal or plastic are being used increasingly as spacers for interbody fusion of spinal segments. The goal of this study was the mechanical testing of carbon fiber reinforced plastic (CFRP) fusion cages used for anterior lumbar interbody fusion. With a special testing device according to American Society for Testing and Materials (ASTM) standards, the mechanical properties of the implants were determined under four different loading conditions. The implants (UNION cages, Medtronic Sofamor Danek) provide sufficient axial compression, shear, and torsional strength of the implant body. Ultimate axial compression load of the fins is less than the physiological compression loads at the lumbar spine. Therefore by means of an appropriate surgical technique parallel grooves have to be reamed into the endplates of the vertebral bodies according to the fin geometry. Thereby axial compression forces affect the implants body and the fins are protected from damaging loading. Using a supplementary anterior or posterior instrumentation, in vivo failure of the fins as a result of physiological shear and torsional spinal loads is unlikely. Due to specific complications related to autogenous or allogeneic bone grafts, fusion cages made of metal or carbon fiber reinforced plastic are an important alternative implant in interbody fusion.

  18. Evaluation of the postoperative lumbar spine.

    PubMed

    Herrera Herrera, I; Moreno de la Presa, R; González Gutiérrez, R; Bárcena Ruiz, E; García Benassi, J M

    2013-01-01

    Given the prevalence of low back pain, surgical interventions on the lumbar spine are becoming more common. Among the many surgical procedures available for these interventions, the most common are laminectomy and discectomy. In 10 to 40% of patients who undergo surgical interventions on the lumbar spine, low back pain is not completely alleviated or it recurs, and these cases fall into the category of « failed back surgery syndrome ». This syndrome can have many different causes and multiple factors are often involved. It is important not to confuse the normal postoperative findings with those specific to failed back surgery syndrome. Deciding which imaging technique to use will depend on the type of surgical intervention, whether metallic orthopedic material was used, and the clinical suspicion. It is essential to know the advantages and limitations of the available imaging techniques to ensure the optimal evaluation of these patients, especially after interventions carried out with instrumentation to minimize the artifacts due to these materials. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  19. [Lumbar hypermobility: where swimming becomes hydrotherapy].

    PubMed

    Mergeay, D; De Neve, M

    1990-01-01

    In this paper the authors discuss the clinical problem of lumbar hypermobility. The therapeutical possibilities are resumed briefly. The philosophy of medical training therapy ("Heilgymnastik") is described. More extensive the extra-advantages of hydrotherapy (methodical back-stroke swimming) are searched for in a theoretical deductive way. The authors found that: 1. swimming is a low-impact sport so far as the articulations are concerned, 2. back-stroke is done mainly in a lumbar kyphosis, 3. swimming is also an excellent cardiopulmonary training, 4. when swimming the muscles of the shoulder girdle and pelvic girdle are trained in a nearly isokinetic way (power-endurance), 5. the short transverso-spinal muscles are indirectly trained in their tonic more than phasic stretch reflex (posture function), 6. the muscles of the trunk are trained in a nearly isometric way in the appropriate angles (erect position), 7. the position of the head in the water facilitates the abdominal muscles (tonic neck reflex), 8. the cool temperature of the water generates training-enhancing stress-responses, 9. endurance-training is ideal for the postural function of the lower back muscles (especially the deeper layers near the spine) which are anatomical and physiological suited for this purpose, 10. warming-up and cooling-down procedures prepare the neuromuscular, the cardiovascular and metabolic functions before the workout-session (a cold shower afterwards acts to tonicize the skin and muscles).

  20. Operative Management of Lumbar Degenerative Disc Disease.

    PubMed

    Lee, Yu Chao; Zotti, Mario Giuseppe Tedesco; Osti, Orso Lorenzo

    2016-08-01

    Lumbar degenerative disc disease is extremely common. Current evidence supports surgery in carefully selected patients who have failed non-operative treatment and do not exhibit any substantial psychosocial overlay. Fusion surgery employing the correct grafting and stabilization techniques has long-term results demonstrating successful clinical outcomes. However, the best approach for fusion remains debatable. There is some evidence supporting the more complex, technically demanding and higher risk interbody fusion techniques for the younger, active patients or patients with a higher risk of non-union. Lumbar disc arthroplasty and hybrid techniques are still relatively novel procedures despite promising short-term and mid-term outcomes. Long-term studies demonstrating superiority over fusion are required before these techniques may be recommended to replace fusion as the gold standard. Novel stem cell approaches combined with tissue engineering therapies continue to be developed in expectation of improving clinical outcomes. Results with appropriate follow-up are not yet available to indicate if such techniques are safe, cost-effective and reliable in the long-term.

  1. Management of symptomatic lumbar degenerative disk disease.

    PubMed

    Madigan, Luke; Vaccaro, Alexander R; Spector, Leo R; Milam, R Alden

    2009-02-01

    Symptomatic lumbar degenerative disk disease, or discogenic back pain, is difficult to treat. Patients often report transverse low back pain that radiates into the sacroiliac joints. Radicular or claudicatory symptoms are generally absent unless there is concomitant nerve compression. Physical examination findings are often unremarkable. Radiographic examination may reveal disk space narrowing, end-plate sclerosis, or vacuum phenomenon in the disk; magnetic resonance imaging is useful for revealing hydration of the disk, annular bulging, or lumbar spine end-plate (Modic) changes in the adjacent vertebral bodies. The use of diskography as a confirmatory study remains controversial. Recent prospective, randomized trials and meta-analyses of the literature have helped expand what is known about degenerative disk disease. In most patients with low back pain, symptoms resolve without surgical intervention; physical therapy and nonsteroidal anti-inflammatory drugs are the cornerstones of nonsurgical treatment. Intradiskal electrothermal treatment has not been shown to be effective, and arthrodesis remains controversial for the treatment of discogenic back pain. Nucleus replacement and motion-sparing technology are too new to have demonstrated long-term data regarding their efficacy.

  2. Operative Management of Lumbar Degenerative Disc Disease

    PubMed Central

    Lee, Yu Chao; Osti, Orso Lorenzo

    2016-01-01

    Lumbar degenerative disc disease is extremely common. Current evidence supports surgery in carefully selected patients who have failed non-operative treatment and do not exhibit any substantial psychosocial overlay. Fusion surgery employing the correct grafting and stabilization techniques has long-term results demonstrating successful clinical outcomes. However, the best approach for fusion remains debatable. There is some evidence supporting the more complex, technically demanding and higher risk interbody fusion techniques for the younger, active patients or patients with a higher risk of non-union. Lumbar disc arthroplasty and hybrid techniques are still relatively novel procedures despite promising short-term and mid-term outcomes. Long-term studies demonstrating superiority over fusion are required before these techniques may be recommended to replace fusion as the gold standard. Novel stem cell approaches combined with tissue engineering therapies continue to be developed in expectation of improving clinical outcomes. Results with appropriate follow-up are not yet available to indicate if such techniques are safe, cost-effective and reliable in the long-term. PMID:27559465

  3. Which Ringed Planet...!?

    NASA Astrophysics Data System (ADS)

    2002-12-01

    Don't worry - you are not the only one who thought this was a nice amateur photo of planet Saturn, Lord of the Rings in our Solar System! But then the relative brightness and positions of the moons may appear somewhat unfamiliar... and the ring system does look unusually bright when compared to the planetary disk...?? Well, it is not Saturn, but Uranus , the next giant planet further out, located at a distance of about 3,000 million km, or 20 times the distance between the Sun and the Earth. The photo shows Uranus surrounded by its rings and some of the moons, as they appear on a near-infrared image that was obtained in the K s -band (at wavelength 2.2 µm) with the ISAAC multi-mode instrument on the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory (Chile) . The exposure was made on November 19, 2002 (03:00 hrs UT) during a planetary research programme. The observing conditions were excellent (seeing 0.5 arcsec) and the exposure lasted 5 min. The angular diameter of Uranus is about 3.5 arcsec. The observers at ISAAC were Emmanuel Lellouch and Thérése Encrenaz of the Observatoire de Paris (France) and Jean-Gabriel Cuby and Andreas Jaunsen (both ESO-Chile). The rings The rings of Uranus were discovered in 1977, from observations during a stellar occultation event by astronomer teams at the Kuiper Airborne Observatory (KAO) and the Perth Observatory (Australia). Just before and after the planet moved in front of the (occulted) star, the surrounding rings caused the starlight to dim for short intervals of time. Photos obtained from the Voyager-2 spacecraft in 1986 showed a multitude of very tenuous rings. These rings are almost undetectable from the Earth in visible light. However, on the present VLT near-infrared picture, the contrast between the rings and the planet is strongly enhanced. At the particular wavelength at which this observation was made, the infalling sunlight is almost completely absorbed by gaseous methane present in the planetary atmosphere

  4. Precooler Ring Vacuum System

    SciTech Connect

    Moenich, J.

    1980-10-02

    The precooler vacuum system, as proposed by FNAL, is based on a suitable modification of the existing Electron Cooling Ring System. Because of the magnetic cycle of the bending magnets, distributed ion pumping, as exists in the Electron Cooling Ring, is not applicable. Instead, the proposed pumping will be done with commercial appendage ion pumps mounted approximately every two meters around the circumference of the ring. The loss of effective pumping speed and non-uniformity of system pressure with appendage pumps may not be major considerations but the large number required does effect experimental and analytical equipment placement considerations. There is a distributed pumping technique available which: (1) is not affected by the magnetic cycle of the bending magnets; (2) will provide a minimum of four times the hydrogen pumping speed of the proposed appendage ion pumps; (3) will require no power during pumping after the strip is activated; (4) will provide the heat source for bakeout; (5) is easily replaceable; and (6) can be purchased, installed, and operated at a generous economic advantage over the presently proposed ion pumped system. The pumping technique referred to is non-evaporable gettering with ST101 Zr/Al pumping strip. A technical description of this pumping strip is given on Data Sheet 1 and 2 attached to this report.

  5. Swarming rings of bacteria.

    NASA Astrophysics Data System (ADS)

    Brenner, M. P.; Levitov, L. S.

    1996-03-01

    The behavior of bacterii controlled by chemotaxis can lead to a complicated spatial organization, producing swarming rings, and steady or moving aggregates( E. O. Budrene, and H. C. Berg, Complex patterns formed by motile cells of Escherichia coli. Nature 349, 630-633 (1991). ). We present a simple theory that explains the experimentally observed structures, by solving analytically two coupled differential equations, for the densities of bacterii and of chemoattractant. The equations have an interesting relation to the exactly solvable Burgers equation, and admit soliton-like solutions, that can be steady or moving. In addition, we find that there are singular solutions to the equations in which the bacterial density diverges. The theory agrees very well with the experiment: the solitons correspond to the observed travelling rings, the singularities describe formation of aggregates. In particular, the theory explains why the velocity of swarming rings decreases with the increase of the food concentration, the fact apparently not accounted by other existing approaches( L. Tsimring et. al., Phys. Rev. Lett., 75, 1859 (1995); Woodward, et al, Biophysical Journal, 68, 2181-2189 (1995). ).

  6. Characteristics of thoracic and lumbar movements during gait in lumbar spinal stenosis patients before and after decompression surgery.

    PubMed

    Kuwahara, Wataru; Deie, Masataka; Fujita, Naoto; Tanaka, Nobuhiro; Nakanishi, Kazuyoshi; Sunagawa, Toru; Asaeda, Makoto; Nakamura, Haruka; Kono, Yoshifumi; Ochi, Mitsuo

    2016-12-01

    Although gait analysis has been previously conducted for lumbar spinal stenosis patients, the vertebral segmental movements, such as of the thoracic and lumbar regions, and whether the spinal movement during gait changes after decompression surgery remain unclear. Ten patients with lumbar spinal stenosis and 10 healthy controls participated. Clinical outcomes were assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and Visual Analogue Scale. Spinal kinematic data of the participants during gait were acquired using a three-dimensional motion analysis system. The trunk (whole spine), thoracic, and lumbar flexion and pelvic tilting values were calculated. Spinal kinematic data and clinical outcomes were collected preoperatively and 1month postoperatively for the patients. Compared to that observed preoperatively, the clinical outcomes significantly improved at 1month postoperatively. In the standing position, the preoperative lumbar extension of the patients was significantly smaller than that of the controls. Moreover, during gait, the lumbar flexion relative to the standing position of the patients was smaller than that of the controls preoperatively, and increased at 1month postoperatively. The sum of the thoracic and lumbar flexion values during gait negatively correlated with the score for leg pain. The epidural pressure of lumbar spinal stenosis patients is known to be higher than that of normal subjects during gait, and to decrease during walking with lumbar flexion. Preoperatively, smaller thoracic and lumbar flexion movements during gait relative to the standing position cannot decrease epidural pressure; as a result, severe leg pain might be induced. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Lumbar kinematic variability during gait in chronic low back pain and associations with pain, disability and isolated lumbar extension strength.

    PubMed

    Steele, James; Bruce-Low, Stewart; Smith, Dave; Jessop, David; Osborne, Neil

    2014-12-01

    Chronic low back pain is a multifactorial condition with many dysfunctions including gait variability. The lumbar spine and its musculature are involved during gait and in chronic low back pain the lumbar extensors are often deconditioned. It was therefore of interest to examine relationships between lumbar kinematic variability during gait, with pain, disability and isolated lumbar extension strength in participants with chronic low back pain. Twenty four participants with chronic low back pain were assessed for lumbar kinematics during gait, isolated lumbar extension strength, pain, and disability. Angular displacement and kinematic waveform pattern and offset variability were examined. Angular displacement and kinematic waveform pattern and offset variability differed across movement planes; displacement was highest and similar in frontal and transverse planes, and pattern variability and offset variability higher in the sagittal plane compared to frontal and transverse planes which were similar. Spearman's correlations showed significant correlations between transverse plane pattern variability and isolated lumbar extension strength (r=-.411) and disability (r=.401). However, pain was not correlated with pattern variability in any plane. The r(2) values suggested 80.5% to 86.3% of variance was accounted for by other variables. Considering the lumbar extensors role in gait, the relationship between both isolated lumbar extension strength and disability with transverse plane pattern variability suggests that gait variability may result in consequence of lumbar extensor deconditioning or disability accompanying chronic low back pain. However, further study should examine the temporality of these relationships and other variables might account for the unexplained variance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Saturn's ``Gossamer'' Ring: The F Ring's Inner Sheet

    NASA Astrophysics Data System (ADS)

    Showalter, M. R.; Burns, J. A.; Hamilton, D. P.

    1998-09-01

    Recent Galileo and Earth-based images have revealed for the first time that Jupiter's ``gossamer'' ring is actually composed of two rings, one bounded at the outer edge by Amalthea and the other bounded by Thebe. Dynamical models suggest that these rings are composed of dust grains ejected off the surfaces of the two moons, which then evolve inward under Poynting-Robertson drag. A very faint sheet of material filling the region between Saturn's A and F Rings reported by Burns et al. (BAAS 15, 1013--1014, 1983) may be a dynamically analogous system, in which dust escapes from the F Ring and evolves inward to the A Ring. Unlike Jupiter's gossamer rings, however, the inner sheet of Saturn's F Ring has been well observed from a large range of phase angles and visual wavelengths by Voyager. Voyager images reveal that this faint ring shows a tenfold increase in brightness between phase angles of 125(deg) and 165(deg) , indicating that it is composed of fine dust microns in size. Preliminary estimates of the normal optical depth fall in the range 1--2*E(-4) , depending on the dust size distribution assumed. Initial spectrophotometry reveals that the ring is neutral in color. The ring is uniform in brightness over the entire region between the two rings, with no evidence for internal structure associated with Prometheus and Atlas, suggesting that neither of these embedded moons acts as either a source or a sink. We will refine the aforementioned measurements and develop photometric models to better constrain the properties of the dust in this ring. This will enable us to relate the dust population to that in the F Ring proper, and to better explore the dynamical processes at work.

  9. A Biomechanical Stability Study of Extraforaminal Lumbar Interbody Fusion on the Cadaveric Lumbar Spine Specimens

    PubMed Central

    Guo, Song; Yan, Meijun; Han, Yingchao; Xia, Dongdong; Sun, Guixin; Li, Lijun; Tan, Jun

    2016-01-01

    Background Transforaminal lumbar interbody fusion (TLIF) is an effective surgery for lumbar degenerative disease. However, this fusion technique requires resection of inferior facet joint to provide access for superior facet joint resection, which results in reduced lumbar spinal stability and unnecessary trauma. We have previously developed extraforaminal lumbar interbody fusion (ELIF) that can avoid back muscle injury with direct nerve root decompression. This study aims to show that ELIF enhances lumbar spinal stability in comparison to TLIF by comparing lumbar spinal stability of L4–L5 range of motion (ROM) on 12 cadaveric spine specimens after performing TLIF or ELIF. Methods 12 cadaveric spine specimens were randomly divided and treated in accordance with the different internal fixations, including ELIF with a unilateral pedicle screw (ELIF+UPS), TLIF with a unilateral pedicle screw (TLIF+UPS), TLIF with a bilateral pedicle screw (TLIF+BPS), ELIF with a unilateral pedicle screw and translaminar facet screw (ELIF+UPS+TLFS) and ELIF with a bilateral pedicle screw (ELIF+BPS). The treatment groups were exposed to a 400-N load and 6 N·m movement force to calculate the angular displacement of L4-L5 during anterior flexion, posterior extension, lateral flexion and rotation operation conditions. Results The ROM in ELIF+UPS group was smaller than that of TLIF+UPS group under all operating conditions, with the significant differences in left lateral flexion and right rotation by 36.15% and 25.97% respectively. The ROM in ELIF+UPS group was higher than that in TLIF+BPS group. The ROM in the ELIF+UPS+TLFS group was much smaller than that in the ELIF+UPS group, but was not significantly different than that in the TLIF+BPS group. Conclusions Despite that TLIF+BPS has great stability, which can be comparable by that of ELIF+UPS. Additionally, ELIF stability can be further improved by using translaminar facet screws without causing more tissue damage to patient. PMID

  10. Biportal Endoscopic Lumbar Decompression for Lumbar Disk Herniation and Spinal Canal Stenosis: A Technical Note.

    PubMed

    Eun, Sang Soo; Eum, Jin Hwa; Lee, Sang Ho; Sabal, Luigi Andrew

    2017-07-01

    Background and Study Aims Endoscopic lumbar diskectomy through the interlaminar window is gaining recognition. Most of the literature describes these endoscopic procedures using specialized uniportal multichannel endoscopes. However, a single portal limits the motion of the instruments and obscures visualization of the operating field. To overcome this limitation, we propose a new technique that utilizes two portals to access the spinal canal. The biportal endoscopic lumbar decompression (BELD) technique uses two portals to treat difficult lumbar disk herniations and also lumbar spinal stenoses. Patients and Methods Seventeen patients were treated with BELD for 11 lumbar disk herniations and 6 lumbar spinal stenoses. Preoperative back and leg visual analog scale (VAS-B and VAS-L, respectively) scores and the Oswestry Disability Index (ODI) were recorded and compared with corresponding values on final follow-up. Results There was an average follow-up of 14 months. For the disk herniation group, preoperative VAS-L (7.8750 ± 1.24) and ODI (51.73 ± 18.57) was significantly different from follow-up postoperative VAS-L (0.87 ± 0.64, p = 0.000) and ODI (9.37 ± 4.83, p = 0.001). For the stenosis group, preoperative VAS-B (6.17 ± 1.94), VAS-L(7.83 ± 1.47), and ODI (63.27 ± 7.67) were significantly different from follow-up postoperative values (2.5 ± 1.04, p = 0.022; 2.00 ± 1.67, p = 0.001; 24.00 ± 6.45, p = 0.000, respectively). One patient underwent revision microdiskectomy for incomplete decompression. Conclusions BELD can achieve a similar decompression effect as microdiskectomy and unilateral laminotomy for bilateral decompression with a smaller incision than tubular diskectomy. Georg Thieme Verlag KG Stuttgart · New York.

  11. Helmet latching and attaching ring

    NASA Technical Reports Server (NTRS)

    Chase, E. W.; Viikinsalo, S. J. (Inventor)

    1970-01-01

    A neck ring releasably secured to a pressurized garment carries an open-ended ring normally in the engagement position fitted into an annular groove and adapted to fit into a complementary annular groove formed in a helmet. Camming means formed on the inner surface at the end of the helmet engages the open-ended ring to retract the same and allow for one motion donning even when the garment is pressurized. A projection on the end of the split ring is engageable to physically retract the split ring.

  12. Planetary ring dynamics and morphology

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.; Durisen, Richard H.; Shu, Frank H.

    1987-01-01

    Evidence for a moonlet belt in the region between Saturn's close-in moonrings Pandora and Prometheus is discussed. It is argued that little-known observations of magnetospheric electron density by Pioneer 11 imply substantial, ongoing injections of mass into the 2000 km region which surrounds the F ring. A hypothesis is presented that these events result naturally from interparticle collisions between the smaller members of an optically thin belt of moonlets. Also discussed is work on Uranus ring structure and photometry, image processing and analysis of the Jonian ring strucure, photometric and structural studies of the A ring of Saturn, and improvements to an image processing system for ring studies.

  13. Ring Autosomes: Some Unexpected Findings

    PubMed Central

    Caba, L; Rusu, C; Plăiaşu; Gug, G; Grămescu, M; Bujoran, C; Ochiană, D; Voloşciuc, M; Popescu, R; Braha, E; Pânzaru, M; Butnariu, L; Sireteanu, A; Covic, M; Gorduza, EV

    2012-01-01

    Ring chromosomes are rare entities, usually associated with phenotypic abnormalities in correlation with the loss of genetic material. There are various breakpoints and sometimes there is a dynamic mosaicism that is reflected in clinical features. Most of the ring chromosomes are de novo occurrences. Our study reflects the experience of three Romanian cytogenetic laboratories in the field of ring chromosomes. We present six cases with ring chromosomes involving chromosomes 5, 13, 18, and 21. All ring chromosomes were identified after birth in children with plurimalformative syndromes. The ring chromosome was present in mosaic form in three cases, and this feature reflects the ring’s instability. In case of ring chromosome 5, we report a possible association with oculo-auriculo-vertebral spectrum. PMID:24052730

  14. Mass of Saturn's A ring

    NASA Technical Reports Server (NTRS)

    Horn, L. J.; Russell, C. T.

    1993-01-01

    The mass of Saturn's A ring is reestimated using the behavior of spiral density waves embedded in the ring. The Voyager photopolarimeter (PPS) observed the star delta-Scorpii as it was occulted by Saturn's rings during the Voyager 2 flyby of Saturn in 1981 producing a radial profile of the rings. We examined forty spiral density waves in the Voyager PPS data of the A ring including 10 weaker waves that have not been previously analyzed by means of an autoregressive power spectral technique called Burg. The strengths of this new method for ring studies are that weaker, less extended waves are easily detected and characterized. This method is also the first one which does not require precise knowledge of the resonance location and phase of the wave in order to calculate the surface mass density. Uncertainties of up to 3 km are present in the currently available radial scales for Saturn's rings.

  15. Morphological structure and variations of lumbar plexus in human fetuses.

    PubMed

    Yasar, Soner; Kaya, Serdar; Temiz, Cağlar; Tehli, Ozkan; Kural, Cahit; Izci, Yusuf

    2014-04-01

    The objective of this study is to study the anatomy of lumbar plexus on human fetuses and to establish its morphometric characteristics and differences compared with adults. Twenty lumbar plexus of 10 human fetal cadavers in different gestational ages and genders were dissected. Lumbar spinal nerves, ganglions, and peripheral nerves were exposed. Normal anatomical structure and variations of lumbar plexus were investigated and morphometric analyses were performed. The diameters of lumbar spinal nerves increased from L1 to L4. The thickest nerve forming the plexus was femoral nerve, the thinnest was ilioinguinal nerve, the longest nerve through posterior abdominal wall was iliohypogastric nerve, and the shortest nerve was femoral nerve. Each plexus had a single furcal nerve and this arose from L4 nerve in all fetuses. No prefix or postfix plexus variation was observed. In two plexuses, L1 nerve was in the form of a single branch. Also, in two plexuses, genitofemoral nerve arose only from L2 nerve. Accessory obturator nerve was observed in four plexuses. According to these findings, the morphological pattern of the lumbar plexus in the fetus was found to be very similar to the lumbar plexus in adults. Copyright © 2012 Wiley Periodicals, Inc.

  16. Ureter Injury as a Complication of Oblique Lumbar Interbody Fusion.

    PubMed

    Lee, Hyeong-Jin; Kim, Jin-Sung; Ryu, Kyeong-Sik; Park, Choon Keun

    2017-06-01

    Oblique lumbar interbody fusion is a commonly used surgical method of achieving lumbar interbody fusion. There have been some reports about complications of oblique lumbar interbody fusion at the L2-L3 level. However, to our knowledge, there have been no reports about ureter injury during oblique lumbar interbody fusion. We report a case of ureter injury during oblique lumbar interbody fusion to share our experience. A 78-year-old male patient presented with a history of lower back pain and neurogenic intermittent claudication. He was diagnosed with spinal stenosis at L2-L3, L4-L5 level and spondylolisthesis at L4-L5 level. Symptoms were not improved after several months of medical treatments. Then, oblique lumbar interbody fusion was performed at L2-L3, L4-L5 level. During the surgery, anesthesiologist noticed hematuria. A retrourethrogram was performed immediately by urologist, and ureter injury was found. Ureteroureterostomy and double-J catheter insertion were performed. The patient was discharged 2 weeks after surgery without urologic or neurologic complications. At 2 months after surgery, an intravenous pyelogram was performed, which showed an intact ureter. Our study shows that a low threshold of suspicion of ureter injury and careful manipulation of retroperitoneal fat can be helpful to prevent ureter injury during oblique lumbar interbody fusion at the upper level. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Instrumented Posterior Lumbar Interbody Fusion in Adult Spondylolisthesis

    PubMed Central

    Yu, Ching-Hsiao; Wang, Chen-Ti

    2008-01-01

    It is unclear whether using artificial cages increases fusion rates compared with use of bone chips alone in posterior lumbar interbody fusion for patients with lumbar spondylolisthesis. We hypothesized artificial cages for posterior lumbar interbody fusion would provide better clinical and radiographic outcomes than bone chips alone. We assumed solid fusion would provide good clinical outcomes. We clinically and radiographically followed 34 patients with spondylolisthesis having posterior lumbar interbody fusion with mixed autogenous and allogeneic bone chips alone and 42 patients having posterior lumbar interbody fusion with implantation of artificial cages packed with morselized bone graft. Patients with the artificial cage had better functional improvement in the Oswestry disability index than those with bone chips alone, whereas pain score, patient satisfaction, and fusion rate were similar in the two groups. Postoperative disc height ratio, slip ratio, and segmental lordosis all decreased at final followup in the patients with bone chips alone but remained unchanged in the artificial cage group. The functional outcome correlated with radiographic fusion status. We conclude artificial cages provide better functional outcomes and radiographic improvement than bone chips alone in posterior lumbar interbody fusion for lumbar spondylolisthesis, although both techniques achieved comparable fusion rates. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18846411

  18. [Intermittent priapism as a clinical feature of lumbar spinal stenosis].

    PubMed

    Rojas, J I; Zurrú-Ganen, M C; Romano, M; Patrucco, L; Cristiano, E

    Lumbar spinal stenosis is defined as a narrowing of the neural canal and foramina that result in compression of the lumbosacral nerve roots or cauda equina. Patients with lumbar spinal stenosis may present a variety of signs and symptoms. One such syndrome is neurogenic intermittent claudication, characterized by radicular symptoms exacerbated by walking or standing and relieved by rest. Infrequently, lumbar spinal stenosis produces a cauda equina compression, characterized by intermittent urinary or fecal incontinence, impotence and in rare cases priapism. A 50 year-aged male, presented with spontaneous intermittent priapism and few months later weakness, numbness and pain of his legs provoked by bipedestation or physical exertion that completely disappeared by sitting or lying down. A computed tomographic scan showed a lumbar canal narrowing of L4 through L5. A diagnosis of neurogenic intermittent claudication with dysfunction of the cauda equina roots secondary to the presence of lumbar spinal stenosis was carried out. The symptoms completely resolved after descompressive lumbar laminectomy of L4 and L5. Causal interpretation of neurogenic intermittent claudication still remains obscure. An inadequate blood supply provoked by increased intra-raquid pressure among the roots may act as a dynamic factor. This mechanism could cause stagnant anoxia during the exercise resulting in clinical symptoms. Lumbar spinal stenosis should be kept in mind when autonomic features appear.

  19. Postoperative seizure following transforaminal percutaneous endoscopic lumbar discectomy

    PubMed Central

    Kertmen, Hayri; Gürer, Bora; Yilmaz, Erdal Resit; Sekerci, Zeki

    2016-01-01

    Endoscopic surgery for lumbar disc herniation has been available for more than 30 years. Transforaminal percutaneous endoscopic lumbar discectomy is a well-known, safe, and effective method used for the treatment of the lumbar disc herniation. The published complications of the transforaminal percutaneous endoscopic lumbar discectomy consist of infections, thrombophlebitis, dysesthesia, dural tear, vascular injury, and death. Seizure after transforaminal percutaneous endoscopic lumbar discectomy is an extremely rare complication. A 20-year-old patient applied at our department who had undergone transforaminal percutaneous endoscopic lumbar. During the procedure, while performing the discography, non-ionic contrast media was administered into the thecal sac inadvertently. Two hours after surgery, the patient developed generalized tonic-clonic seizure of 5-min duration. Diagnosis of iohexol-induced seizure was made and the patient was treated supportively without anti-epileptics. Here we present the first case of seizure after transforaminal percutaneous endoscopic lumbar discectomy, which was caused by inadvertent administration of the contrast media into the thecal sac. PMID:27695562

  20. A season in Saturn's rings: Cycling, recycling and ring history

    NASA Astrophysics Data System (ADS)

    Esposito, L. W.; Meinke, B. K.; Albers, N.; Sremcevic, M.

    2012-04-01

    Cassini experiments have watched Saturn's ring system evolve before our eyes. Images and occultations show changes and transient events. The rings are a dynamic and complex geophysical system, incompletely modeled as a single-phase fluid. Key Cassini observations: High resolution images show straw, propellers, embedded moonlets, and F ring objects. Multiple UVIS, RSS and VIMS occutlations indicate multimodal ringlet and edge structure, including free and forced modes along with stochastic perturbations that are most likely caused by nearby mass concentrations. Vertical excursions are evident at ring edges and in other perturbed regions. The rings are occasionally hit by meteorites that leave a signature that may last centuries; meteoritic dust pollutes the rings. Temperature, reflectance and transmission spectra are influenced by the dynamical state of the ring particles. Saturn's Equinox 2009: Oblique lighting exposed vertical structure and embedded objects. The rings were the coldest ever. Images inspired new occultation and spectral analysis that show abundant structure in the perturbed regions. The rings are more variable and complex than we had expected prior to this seasonal viewing geometry. Sub-kilometer structure in power spectral analysis: Wavelet analysis shows features in the strongest density waves and at the shepherded outer edge of the B ring. Edges are variable as shown by multiple occultations and occultations of double stars. F ring kittens: 25 features seen in the first 102 occultations show a weak correlation with Prometheus location. We interpret these features as temporary aggregations. Simulation results indicate that accretion must be enhanced to match the kittens' size distribution. Images show that Prometheus triggers the formation of transient objects. Propellers and ghosts: Occulations and images provide evidence for small moonlets in the A, B and C rings. These indicate accretion occurs inside the classical Roche limit. Implications

  1. Adverse Event Recording and Reporting in Clinical Trials Comparing Lumbar Disk Replacement with Lumbar Fusion: A Systematic Review.

    PubMed

    Hiratzka, Jayme; Rastegar, Farbod; Contag, Alec G; Norvell, Daniel C; Anderson, Paul A; Hart, Robert A

    2015-12-01

    Study Design Systematic review. Objectives (1) To compare the quality of adverse event (AE) methodology and reporting among randomized trials comparing lumbar fusion with lumbar total disk replacement (TDR) using established AE reporting systems; (2) to compare the AEs and reoperations of lumbar spinal fusion with those from lumbar TDR; (3) to make recommendations on how to report AEs in randomized controlled trials (RCTs) so that surgeons and patients have more-detailed and comprehensive information when making treatment decisions. Methods A systematic search of PubMed, the Cochrane collaboration database, and the National Guideline Clearinghouse through May 2015 was conducted. Randomized controlled trials with at least 2 years of follow-up comparing lumbar artificial disk replacement with lumbar fusion were included. Patients were required to have axial or mechanical low back pain of ≥3 months' duration due to degenerative joint disease defined as degenerative disk disease, facet joint disease, or spondylosis. Outcomes included the quality of AE acquisition methodology and results reporting, and AEs were defined as those secondary to the procedure and reoperations. Individual and pooled relative risks and their 95% confidence intervals comparing lumbar TDR with fusion were calculated. Results RCTs demonstrated a generally poor description of methods for assessing AEs. There was a consistent lack of clear definition or grading for these events. Furthermore, there was a high degree of variation in reporting of surgery-related AEs. Most studies lacked adequate reporting of the timing of AEs, and there were no clear distinctions between acute or chronic AEs. Meta-analysis of the pooled data demonstrated a twofold increased risk of AEs in patients having lumbar fusion compared with patients having lumbar TDR at 2-year follow-up, and this relative risk was maintained at 5 years. Furthermore, the pooled data demonstrated a 1.7 times greater relative risk of

  2. Lumbar vertebrae fracture injury risk in finite element reconstruction of CIREN and NASS frontal motor vehicle crashes.

    PubMed

    Jones, Derek A; Gaewsky, James P; Kelley, Mireille E; Weaver, Ashley A; Miller, Anna N; Stitzel, Joel D

    2016-09-01

    The objective of this study was to reconstruct 4 real-world motor vehicle crashes (MVCs), 2 with lumbar vertebral fractures and 2 without vertebral fractures in order to elucidate the MVC and/or restraint variables that increase this injury risk. A finite element (FE) simplified vehicle model (SVM) was used in conjunction with a previously developed semi-automated tuning method to arrive at 4 SVMs that were tuned to mimic frontal crash responses of a 2006 Chevrolet Cobalt, 2012 Ford Escape, 2007 Hummer H3, and 2002 Chevrolet Cavalier. Real-world crashes in the first 2 vehicles resulted in lumbar vertebrae fractures, whereas the latter 2 did not. Once each SVM was tuned to its corresponding vehicle, the Total HUman Model for Safety (THUMS) v4.01 was positioned in 120 precrash configurations in each SVM by varying 5 parameters using a Latin hypercube design (LHD) of experiments: seat track position, seatback angle, steering column angle, steering column telescoping position, and d-ring height. For each case, the event data recorder (EDR) crash pulse was used to apply kinematic boundary conditions to the model. By analyzing cross-sectional vertebral loads, vertebral bending moments, and maximum principal strain and stress in both cortical and trabecular bone, injury metric response as a function of posture and restraint parameters was computed. Tuning the SVM to specific vehicle models produced close matches between the simulated and experimental crash test responses for head, T6, and pelvis resultant acceleration; left and right femur loads; and shoulder and lap belt loads. Though vertebral load in the THUMS simulations was highly similar between injury cases and noninjury cases, the amount of bending moment was much higher for the injury cases. Seatback angle had a large effect on the maximum compressive load and bending moment in the lumbar spine, indicating the upward tilt of the seat pan in conjunction with precrash positioning may increase the likelihood of

  3. [Enlargement in managment of lumbar spinal stenosis].

    PubMed

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

    1996-05-01

    Lumbar stenosis has been well discussed recently, especially at the 64th French Orthopaedic Society (SOFCOT: July 1989). The results of different surgical treatments were considered as good, but the indications for surgical treatment were not clear cut. Laminectomy is not the only treatment of spinal stenosis. Laminectomy is an approach with its own rate of complications (dural tear, fibrosis, instability... ).Eight years ago, J. Sénégas described what he called the "recalibrage" (enlargement). His feeling was that, in the spinal canal, we can find two different AP diameters. The first one is a fixed constitutional AP diameter (FCAPD) at the cephalic part of the lamina. The second one is a mobile constitutional AP diameter (MCAPD) marked by the disc and the ligamentum flavum. This diameter is maximal in flexion, minimal in extension. The nerve root proceeds through the lateral part of the canal: first above, between the disc and the superior articular process, then below, in the lateral recess bordered by the pedicle, the vertebral body and the posterior articulation. With the degenerative change the disc space becomes shorter, the superior articular process is worn out with osteophytes. These degenerative events are complicated by inter vertebral instability increasing the stenosis. The idea of the "recalibrage" is to remove only the upper part of the lamina with the ligamentum flavum and to cut the hypertrophied anterior part of the articular process from inside. If needed the disc and other osteophytes are removed. The surgery is finished with a ligamentoplasty reducing the flexion and preventing the extension by a posterior wedge.Our experience in spine surgery especially in scoliosis surgery, showed us that it was possible to cure a radicular compression without opening the canal. The compression is then lifted by the 3D reduction and restoration of an anatomy as normal as possible. Lumbar stenosis is the consequence of a degenerative process. Indeed, hip

  4. New Views of Jupiter's Rings

    NASA Astrophysics Data System (ADS)

    Burns, J. A.

    1998-09-01

    Jupiter's rings are the archetype of ethereal planetary rings (very-low optical-depth bands containing micron-sized "dust"). As a result of much improved observations by Galileo (Ockert-Bell* -- most citations are et al. and Icarus in press* or this meeting) and Keck (de Pater*), we now understand the nature of such rings. The ring has three components: a 104 km-thick toroidal halo (1.4-1.7 RJ; normal optical depth t = 10-6), a thin main ring (1.7-1.8 RJ; t = 10-6), and a pair of exterior gossamer rings (1.8-3.5RJ; t = 10-7). The main ring has patchy ( 20-30 percent) brightness. The ring is reddish and its particles satisfy a -2.5 differential power-law size distribution. Because particle lifetimes are brief, the rings must be continually regenerated, by collisions into parent bodies, which may be unseen or may be the known small ring-moons (Thomas*, Simonelli). The gossamer ring seems to be collisional ejecta derived from the ring-moons Amalthea and Thebe, and evolving inward by Poynting-Robertson drag (Burns). The particles drift through many electromagnetic resonances, clustering around synchronous orbit, which produce jumps in the particles' inclinations (Hamilton). The main ring is probably debris from Adrastea and Metis, which orbit in the equatorial plane. The halo particles are driven vertically by electromagnetic forces, which may be resonant (Schaffer & Burns) or not (Horanyi & Cravens). When halo orbits become highly distorted, particles are lost into Jupiter. Similar faint rings may be attendant to all small, close-in satellites (Showalter).

  5. Ligaments associated with lumbar intervertebral foramina. 2. The fifth lumbar level.

    PubMed Central

    Amonoo-Kuofi, H S; el-Badawi, M G; Fatani, J A; Butt, M M

    1988-01-01

    The lumbosacral spines of two fetal and twelve adult cadavers have been studied by dissection. Evidence shows that the fifth lumbar intervertebral foramen is crossed on its external aspect by a strong, cord-like corporotransverse ligament passing obliquely downwards, forwards and medially from the inferior aspect of the accessory process of the fifth lumbar vertebra to the lateral surface of the intervertebral disc and the adjacent parts of the bodies of the fifth and first sacral vertebrae. Superficially, the ligament is related to another flat band--the lumbosacral hood. Together these ligaments separate and provide openings for the sympathetic ramus, the ventral ramus and blood vessels related to the intervertebral foramen. On the dorsal aspect, a tripartite ligament, the mamillo-transverso-accessory ligament, bears important relationships to the subdivisions of the dorsal ramus and also the zygapophyseal joint. The significance of these findings is discussed. Images Fig. 2 Fig. 3 Fig. 4 Fig. 1 Fig. 5 PMID:3248957

  6. Derecruitment of the lumbar musculature with fatiguing trunk extension exercise.

    PubMed

    Clark, Brian C; Manini, Todd M; Ploutz-Snyder, Lori L

    2003-02-01

    This was a descriptive study involving 20 healthy individuals. To evaluate the neuromuscular activation patterns of the lumbar paraspinal and hip extensor muscles during isotonic trunk extension exercise. Few studies have evaluated the effect of muscle fatigue on the lumbar musculature during isotonic exercise. Electromyographic activity was recorded continuously from the lumbar paraspinal, gluteus maximus, and biceps femoris muscles during isotonic trunk extension exercise performed to muscular failure. Root mean squared electromyography was determined over the concentric portion of each repetition, and polynomial regression analysis was used to describe the association between fatigue and the recruitment patterns. The lumbar paraspinals demonstrated an increase in the electromyogram signal up to 57.9% of maximal fatigue, at which point decrements in electromyography were observed (lumbar [quadratic curve] R2 = 0.0807, SEE = 0.228; beta2 = -8.245(-5)) (P < 0.000). Associated with fatigue, the gluteus maximus demonstrated an increase in electromyography, with an exponential breakpoint occurring at 35.9% of maximal fatigue (gluteus maximus [quadratic curve]: R2 = 0.5059, SEE = 0.865; beta2 = 0.00017) (P = 0.014). The biceps femoris demonstrated a linear increase in electromyography with fatigue (R2 = 0.4667, SEE = 0.284; beta2 = 0.0091) (P < 0.000). To further investigate the derecruitment of the lumbar extensors associated with fatigue, study participants were analyzed individually with regression analyses. Results revealed that the majority of study participants (68.5%) demonstrated a significant decrease (quadratic bend) in lumbar electromyography, with decrements in muscle activity beginning at 53% of maximum. During fatiguing trunk extension exercise, an increase in the lumbar paraspinal electromyogram signal occurs up to approximately 55% of maximum fatigue, at which point a decrease in electromyography is observed. Associated with this derecruitment is a

  7. The top 100 classic papers in lumbar spine surgery.

    PubMed

    Steinberger, Jeremy; Skovrlj, Branko; Caridi, John M; Cho, Samuel K

    2015-05-15

    Bibliometric review of the literature. To analyze and quantify the most frequently cited papers in lumbar spine surgery and to measure their impact on the entire lumbar spine literature. Lumbar spine surgery is a dynamic and complex field. Basic science and clinical research remain paramount in understanding and advancing the field. While new literature is published at increasing rates, few studies make long-lasting impacts. The Thomson Reuters Web of Knowledge was searched for citations of all papers relevant to lumbar spine surgery. The number of citations, authorship, year of publication, journal of publication, country of publication, and institution were recorded for each paper. The most cited paper was found to be the classic paper from 1990 by Boden et al that described magnetic resonance imaging findings in individuals without back pain, sciatica, and neurogenic claudication showing that spinal stenosis and herniated discs can be incidentally found when scanning patients. The second most cited study similarly showed that asymptomatic patients who underwent lumbar spine magnetic resonance imaging frequently had lumbar pathology. The third most cited paper was the 2000 publication of Fairbank and Pynsent reviewing the Oswestry Disability Index, the outcome-measure questionnaire most commonly used to evaluate low back pain. The majority of the papers originate in the United States (n=58), and most were published in Spine (n=63). Most papers were published in the 1990s (n=49), and the 3 most common topics were low back pain, biomechanics, and disc degeneration. This report identifies the top 100 papers in lumbar spine surgery and acknowledges those individuals who have contributed the most to the advancement of the study of the lumbar spine and the body of knowledge used to guide evidence-based clinical decision making in lumbar spine surgery today. 3.

  8. Randomized clinical trial comparing lumbar percutaneous hydrodiscectomy with lumbar open microdiscectomy for the treatment of lumbar disc protrusions and herniations

    PubMed Central

    Cristante, Alexandre Fogaça; Rocha, Ivan Diasda; Marcon, Raphael Martus; de Barros Filho, Tarcísio Eloy Pessoa

    2016-01-01

    OBJECTIVES: Hydrodiscectomy is a new technique used for percutaneous spinal discectomy that employs a high-intensity stream of water for herniated disc ablation and tissue aspiration. No previous clinical study has examined the effects of percutaneous hydrodiscectomy. The aim of this study is to evaluate the outcomes of hydrodiscectomy compared to open microdiscectomy regarding pain, function, satisfaction, complications and recurrence rates. METHODS: In this randomized clinical trial, patients referred to our tertiary hospital for lumbar back pain were recruited and included in the study if they had disc protrusion or small herniation in only one level, without neurological deficits and with no resolution after six weeks of conservative treatment. One group underwent open microdiscectomy, and the other group underwent percutaneous microdiscectomy via hydrosurgery. Function was evaluated using the Oswestry Disability Index and pain was assessed using a visual analog scale. Evaluations were performed preoperatively, and then during the first week and at one, three, six and twelve months postoperatively. Personal satisfaction was verified. Clinicaltrials.gov: NCT01367860. RESULTS: During the study period, 20 patients were included in each arm and 39 completed one-year of follow-up (one patient died of unrelated causes). Both groups exhibited equal improvement on the visual analog scale and Oswestry evaluations after treatment, without any significant differences. The improvement in the lumbar visual analog scale score was not significant in the hydrodiscectomy group (p=0.138). The rates of infection, pain, recurrence and satisfaction were similar between the two groups. CONCLUSION: Percutaneous hydrodiscectomy was demonstrated to be as effective as open microdiscectomy for reducing pain. The rates of complications and recurrence of herniation were similar between groups. Patient satisfaction with the treatment was also similar between groups. PMID:27276397

  9. Lumbar lordosis and sacral slope in lumbar spinal stenosis: standard values and measurement accuracy.

    PubMed

    Bredow, J; Oppermann, J; Scheyerer, M J; Gundlfinger, K; Neiss, W F; Budde, S; Floerkemeier, T; Eysel, P; Beyer, F

    2015-05-01

    Radiological study. To asses standard values, intra- and interobserver reliability and reproducibility of sacral slope (SS) and lumbar lordosis (LL) and the correlation of these parameters in patients with lumbar spinal stenosis (LSS). Anteroposterior and lateral X-rays of the lumbar spine of 102 patients with LSS were included in this retrospective, radiologic study. Measurements of SS and LL were carried out by five examiners. Intraobserver correlation and correlation between LL and SS were calculated with Pearson's r linear correlation coefficient and intraclass correlation coefficients (ICC) were calculated for inter- and intraobserver reliability. In addition, patients were examined in subgroups with respect to previous surgery and the current therapy. Lumbar lordosis averaged 45.6° (range 2.5°-74.9°; SD 14.2°), intraobserver correlation was between Pearson r = 0.93 and 0.98. The measurement of SS averaged 35.3° (range 13.8°-66.9°; SD 9.6°), intraobserver correlation was between Pearson r = 0.89 and 0.96. Intraobserver reliability ranged from 0.966 to 0.992 ICC in LL measurements and 0.944-0.983 ICC in SS measurements. There was an interobserver reliability ICC of 0.944 in LL and 0.990 in SS. Correlation between LL and SS averaged r = 0.79. No statistically significant differences were observed between the analyzed subgroups. Manual measurement of LL and SS in patients with LSS on lateral radiographs is easily performed with excellent intra- and interobserver reliability. Correlation between LL and SS is very high. Differences between patients with and without previous decompression were not statistically significant.

  10. Comparison of the Dynesys Dynamic Stabilization System and Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease

    PubMed Central

    Zhang, Yang; Shan, Jian-Lin; Liu, Xiu-Mei; Li, Fang; Guan, Kai; Sun, Tian-Sheng

    2016-01-01

    Background There have been few studies comparing the clinical and radiographic outcomes between the Dynesys dynamic stabilization system and posterior lumbar interbody fusion (PLIF). The objective of this study is to compare the clinical and radiographic outcomes of Dynesys and PLIF for lumbar degenerative disease. Methods Of 96 patients with lumbar degenerative disease included in this retrospectively analysis, 46 were treated with the Dynesys system and 50 underwent PLIF from July 2008 to March 2011. Clinical and radiographic outcomes were evaluated. We also evaluated the occurrence of radiographic and symptomatic adjacent segment degeneration (ASD). Results The mean follow-up time in the Dynesys group was 53.6 ± 5.3 months, while that in the PLIF group was 55.2 ± 6.8 months. At the final follow-up, the Oswestry disability index and visual analogue scale score were significantly improved in both groups. The range of motion (ROM) of stabilized segments in Dynesys group decreased from 7.1 ± 2.2° to 4.9 ± 2.2° (P < 0.05), while that of in PLIF group decreased from 7.3 ± 2.3° to 0° (P < 0.05). The ROM of the upper segments increased significantly in both groups at the final follow-up, the ROM was higher in the PLIF group. There were significantly more radiographic ASDs in the PLIF group than in the Dynesys group. The incidence of complications was comparable between groups. Conclusions Both Dynesys and PLIF can improve the clinical outcomes for lumbar degenerative disease. Compared to PLIF, Dynesys stabilization partially preserves the ROM of the stabilized segments, limits hypermobility in the upper adjacent segment, and may prevent the occurrence of ASD. PMID:26824851

  11. Benchmarking Lumbar Puncture Fluoroscopy Time during Fellowship Training.

    PubMed

    Yang, H; Schaffer, K; Liu, L; Mahesh, M; Yousem, D M

    2017-03-01

    We sought to establish a guide for identifying fellowship competency in performing fluoroscopically guided lumbar punctures. With a linear mixed-effects model, we compared the fluoroscopy time between the first and last 3 months of neuroradiology training. During 7 years, 55 fellows performed 1142 and 861 lumbar punctures in the first and last quarters of training. A target fluoroscopy time of 0.26 minutes, the upper 95% confidence interval, can serve as a fellowship benchmark for successfully achieving competence in fluoroscopically guided lumbar punctures.

  12. Vascular Complications in Lumbar Spinal Surgery: Percutaneous Endovascular Treatment

    SciTech Connect

    Lee, Kyoung Ho; Park, Jae Hyung; Chung, Jin Wook; Han, Joon Koo; Shin, Sang Joon; Kang, Heung Sik

    2000-01-15

    Four patients underwent endovascular treatment of vascular injuries complicating lumbar spinal surgery. In two patients with massive retroperitoneal hemorrhage, the extravasating lumbar arteries were successfully embolized with microcoils. Two patients with large iliac arteriovenous fistula (AVF) were treated, one with embolization using a detachable balloon and coils, which failed, and the other with placement of a stent graft after embolization of distal runoff vessels, which occluded the fistula.We conclude that acute arterial laceration or delayed AVF complicating lumbar spinal surgery can be managed effectively with selective embolization or stent-graft placement, respectively.

  13. Contraindications to lumbar puncture as defined by computed cranial tomography.

    PubMed Central

    Gower, D J; Baker, A L; Bell, W O; Ball, M R

    1987-01-01

    Papilloedema is not always an adequate predictor of potential complications from lumbar puncture, and many clinicians are using computed tomography (CT) before lumbar puncture in an effort to identify more accurately the "at risk" patient. This paper identifies the following anatomical criteria defined by CT scanning that correlate with unequal pressures between intracranial compartments and predispose a patient to herniation following decompression of the spinal compartment: lateral shift of midline structures, loss of the suprachiasmatic and basilar cisterns, obliteration of the fourth ventricle, or obliteration of the superior cerebellar and quadrigeminal plate cisterns with sparing of the ambient cisterns. These criteria should be considered to be contraindications to lumbar puncture. Images PMID:3655817

  14. Influence Of Lumbar Spine Kinematics On Feet Pressure Distribution

    NASA Astrophysics Data System (ADS)

    Săftescu-Jescu, C.; Bereteu, L.

    2012-12-01

    Determining the center of pressure trajectories, as an indicator of postural stability or lumbar pathology, has been a challenging issue for researchers during the last decades. The paper advances an investigational method in order to determine a correlation between lumbar spine movements and feet center of pressure distribution. Five young healthy volunteers were simultaneously tested using an ultrasound based motion analyzing system and a force platform, while performing imposed tasks. Results showed specific patterns described by the center of pressure trajectories and a good coordination of angular amplitudes during lumbar spine movement.

  15. Tree Rings: Timekeepers of the Past.

    ERIC Educational Resources Information Center

    Phipps, R. L.; McGowan, J.

    One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

  16. Suprapedicular Foraminal Endoscopic Approach to Lumbar Lateral Recess Decompression Surgery to Treat Degenerative Lumbar Spinal Stenosis.

    PubMed

    Wang, Ya-Peng; Zhang, Wei; Li, Bao-Li; Sun, Ya-Peng; Ding, Wen-Yuan; Shen, Yong

    2016-11-28

    BACKGROUND To discuss the strategy of suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression and evaluate the safety and effectiveness of this strategy. MATERIAL AND METHODS Complete clinical information of 52 cases of lumbar lateral recess decompression with therapy of suprapedicular foraminal endoscopic approach were analyzed during the period from February 2010 to April 2014 in the Third Hospital of Hebei. All patients were followed up for 24 months, and VAS, JOA, ODI, and LRD were compared between preoperative and postoperative therapy and changes of FA. Intraoperative and postoperative complications were recorded and the safety of the surgery was evaluated. The surgical "excellent" and "good" rates were evaluated using MacNab score. RESULTS VAS scores for lumbago and leg pain at 3, 6, 12, and 24 months after surgery were significantly lower than before surgery (p<0.05). JOA scores at 12 and 24 months after surgery were significantly higher than before surgery (p<0.05). ODI at 12 and 24 months after surgery were significantly lower than before surgery (p<0.05). LRD after surgery was higher (p<0.05), and FA was lower than before surgery. CONCLUSIONS Use of the suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression is safe and effective, and this minimally invasive treatment can achieve satisfactory results, especially for elderly patients with complicated underlying diseases.

  17. Traumatic lumbar artery rupture after lumbar spinal fracture dislocation causing hypovolemic shock: An endovascular treatment.

    PubMed

    Eun, Jong-Pil; Oh, Young-Min

    2015-01-01

    Recently, we observed a case of lumbar artery injury after trauma, which was treated by endovascular embolization. A 67-year-old woman who was injured in a traffic accident was brought to the emergency room. She was conscious and her hemodynamic condition was stable, but she had paraplegia below L1 dermatome. Contrast-enhanced computed tomography scan of abdomen and pelvis revealed fracture dislocation of L3/4 along with retroperitoneal hematomas. However, there was no evidence of traumatic injury in both thoracic and abdominal cavity. At that time, her blood pressure suddenly decreased to 60/40 mmHg and her mental status deteriorated. Also, her hemoglobin level was 5.4 g/dl. While her hemodynamic condition stabilized with massive fluid resuscitation including blood transfusion, an angiography was immediately performed to look for and embolize site of retroperitoneal hemorrhage. On the angiographic images, there was an active extravasation from ruptured left 3rd lumbar artery, and we performed complete embolization with GELFOAM and coil. Lumbar artery injury after trauma is rare and endovascular treatment is useful in case of hemodynamic instability.

  18. Suprapedicular Foraminal Endoscopic Approach to Lumbar Lateral Recess Decompression Surgery to Treat Degenerative Lumbar Spinal Stenosis

    PubMed Central

    Wang, Ya-peng; Zhang, Wei; Li, Bao-li; Sun, Ya-peng; Ding, Wen-yuan; Shen, Yong

    2016-01-01

    Background To discuss the strategy of suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression and evaluate the safety and effectiveness of this strategy. Material/Methods Complete clinical information of 52 cases of lumbar lateral recess decompression with therapy of suprapedicular foraminal endoscopic approach were analyzed during the period from February 2010 to April 2014 in the Third Hospital of Hebei. All patients were followed up for 24 months, and VAS, JOA, ODI, and LRD were compared between preoperative and postoperative therapy and changes of FA. Intraoperative and postoperative complications were recorded and the safety of the surgery was evaluated. The surgical “excellent” and “good” rates were evaluated using MacNab score. Results VAS scores for lumbago and leg pain at 3, 6, 12, and 24 months after surgery were significantly lower than before surgery (p<0.05). JOA scores at 12 and 24 months after surgery were significantly higher than before surgery (p<0.05). ODI at 12 and 24 months after surgery were significantly lower than before surgery (p<0.05). LRD after surgery was higher (p<0.05), and FA was lower than before surgery. Conclusions Use of the suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression is safe and effective, and this minimally invasive treatment can achieve satisfactory results, especially for elderly patients with complicated underlying diseases. PMID:27890911

  19. Ring currents in azulene

    NASA Astrophysics Data System (ADS)

    Paxton, A. T.; Todorov, T. N.; Elena, A. M.

    2009-11-01

    We propose a self consistent polarisable ion tight binding theory for the study of push-pull processes in aromatic molecules. We find that the method quantitatively reproduces ab initio calculations of dipole moments and polarisability. We apply the scheme in a simulation which solves the time dependent Schrödinger equation to follow the relaxation of azulene from the second excited to the ground states. We observe rather spectacular oscillating ring currents which we explain in terms of interference between the HOMO and LUMO states.

  20. Wave structure in planetary rings

    NASA Astrophysics Data System (ADS)

    Horn, Linda Joyce

    1992-01-01

    Planetary rings contain a wealth of wavelike structure that is driven by gravitational resonance interactions with nearby satellites. Wave behavior is a powerful tool for estimating physical ring parameters that are key to our understanding of ring origin and evolution. A new technique, utilizing the Burg autoregressive power spectral algorithm, was developed for probing the physical characteristics of rings and for detecting waves that are not otherwise visible. Data from the Voyager photopolarimeter (PPS) stellar occultations by the rings of Saturn, Uranus, and Neptune and the Voyager radio science (RSS) occultation by Saturn's rings were used. Local surface mass density estimates are obtained from the dispersion of 40 spiral density waves in Saturn's A ring, including 10 weaker waves not previously analyzed. Surface mass densities vary from 20 to 60 gm sq cm. Increasing optical depth is not correlated with increasing surface mass density, especially after the Keeler gap, suggesting that ring particle size and composition are not uniform throughout the A ring. Saturn's A ring mass is reestimated using the surface mass densities and is 5.2 +/- 1.3 x 1021 gm. The wakes of Saturn's satellite Pan are not short timescale phenomena because the effects of Pan's gravitational perturbations persist for more than one Pan encounter. Four additional Pan wakes were discovered at longitudes greater than 360 deg. Collective effects such as collisions modify the wake dispersion more extensively at greater longitudes. Pan is the dominant mass in the Encke gap. A spiral density wave was detected inside the Uranian delta ring. Upper and lower bounds were estimated for the surface mass density of the delta ring 5 less than or equal to sigma less than or equal to 10 gm/sq cm, the viscosity 10 less than or equal to nu less than or equal to 40 sq cm/sec, and the local ring height 7 less than or equal to h less than or equal to 20 m. These values are comparable to the corresponding

  1. Orbits of nine Uranian rings

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.; French, R. G.; Frogel, J. A.; Elias, J. H.; Mink, D. J.; Liller, W.

    1981-01-01

    Observations of a stellar occultation by Uranus and its nine rings are presented and used to examine the structures and kinematics of the rings. The observations of the occultation of the K giant star KM 12 were obtained in the K band with the 4-m CTIO telescope at a signal-to-noise ratio higher than any previously obtained. Ring occultation profiles reveal the alpha ring to possibly have a double structure and less abrupt boundaries than the gamma ring, which exhibits diffraction fringes, while the eta ring is a broad ring with an unresolved narrow component at its inner edge. The present timing data, as well as previous occultation timings, are fit to a kinematic model in which all nine rings are treated as coplanar eclipses of zero inclination, precessing due to the zonal harmonics of the Uranian gravitational potential to obtain solutions for the ring orbits. Analysis of the residuals from the fitted orbits reveals that the proposed model is a good representation of ring kinematics. The reference system defined by the orbit solutions has also been used to obtain a value of 0.022 + or - 0.003 for the ellipticity of Uranus and a Uranian rotation period of 15.5 h.

  2. Roentgenographic measurement of lumbar intervertebral disc height.

    PubMed

    Andersson, G B; Schultz, A; Nathan, A; Irstam, L

    1981-01-01

    The influences of differences in both intervertebral motion segment orientations and in reader judgments on measurements of the apparent intervertebral disc heights in lateral roentgenographs of the lumbar spine were examined. Forty-nine roentgenographs were obtained of nine discs that were titled laterally up to +/- 10 degrees, and rotated longitudinally up to +/- 20 degrees. Three orthopaedic surgeons and three radiologists measured disc heights from five of these roentgenographs, all using the same measurement method. The differences in apparent height that resulted from the orientation changes and differences in judgments among the six readers were considerable, usually of the order of one half of the nominal disc height. The results show that, while roentgenographic measurements can be used to estimate disc height, accurate measurements cannot readily be made from routine roentgenographs, and the interpretation should always be cautious.

  3. Traumatic subdural hematoma in the lumbar spine.

    PubMed

    Song, Jenn-Yeu; Chen, Yu-Hao; Hung, Kuang-Chen; Chang, Ti-Sheng

    2011-10-01

    Traumatic spinal subdural hematoma is rare and its mechanism remains unclear. This intervention describes a patient with mental retardation who was suffering from back pain and progressive weakness of the lower limbs following a traffic accident. Magnetic resonance imaging of the spine revealed a lumbar subdural lesion. Hematoma was identified in the spinal subdural space during an operation. The muscle power of both lower limbs recovered to normal after surgery. The isolated traumatic spinal subdural hematoma was not associated with intracranial subdural hemorrhage. A spinal subdural hematoma should be considered in the differential diagnosis of spinal cord compression, especially for patients who have sustained spinal trauma. Emergency surgical decompression is usually the optimal treatment for a spinal subdural hematoma with acute deterioration and severe neurological deficits.

  4. Conservative treatments for lumbar radicular pain.

    PubMed

    Fleury, Gregory; Nissen, Michael J; Genevay, Stéphane

    2014-10-01

    Lumbar radicular pain is a frequent medical pathology and represents a significant burden on society. The diagnosis of sciatica is largely clinical, in the setting of a combination of radicular pain and neurologic deficits (motor, reflexes, and/or sensation) or a positive straight leg raise test. Imaging is generally not necessary for sciatica, except in the presence of warning signs or in the setting of persisting or worsening pain. The recommended first-line treatment has not yet been clearly established. The choice of a conservative treatment approach combined with simple analgesics in the initial stages seems to be reasonable. A detailed discussion with the patient is important to explain the fact that surgery may only be necessary in the event of pain persisting in excess of 3 months or because of the development or worsening of a neurologic deficit. More high quality studies are clearly required to assist the medical practitioner in knowing how best to treat this group of patients.

  5. Electrophysiological effects of lumbar dorsal root stimulation.

    PubMed

    Myklebust, J B; Maiman, D J; Larson, S J; Sances, A

    1984-06-01

    Electrical stimulation was applied to the L-5 and L-6 dorsal root ganglia of 14 monkeys with concurrent monitoring of cortical and intralaminar thalamic evoked potentials. Both responses were decreased by root stimulation, although cortical suppression required current levels 50 to 100% higher. The evoked potentials remained suppressed for periods of up to 60 minutes after 10- to 15-minute stimulation of the lumbar root electrodes. There was no increase in the duration of transmission block with longer stimulation periods. These results and available clinical data suggest that a local conduction block may be responsible for the pain relief produced by peripheral electrical stimulation. Further studies to identify more precisely the neural systems affected are required.

  6. Methodologic evaluation of the lumbar disc syndrome.

    PubMed Central

    Robinson, J. S.

    1981-01-01

    Though the lumbar disc syndrome is a costly and ubiquitous affliction, effective evaluation of the disease process has been confounded by major unaddressed methodological short falls. Prominent difficulties include: inattention to the clinical boundaries of the syndrome, neglected co-morbid disease processes, comparison of unequal treatment groups and premature clinical data extrapolation, inadequate diagnostic validation, variability in surgical observation, and reliance upon follow-up techniques faulted by unaddressed distorting factors. Proposals for improvement include: formulation of suitable stratification subgroups emphasizing age and sign-symptom intensity and duration, techniques for improved diagnostic return from surgical exploration, suggestions toward improved quantitation of clinical testing procedures, and implantation of a quality of life scale. PMID:6454306

  7. Sciatica caused by lumbar epidural gas.

    PubMed

    Belfquih, Hatim; El Mostarchid, Brahim; Akhaddar, Ali; gazzaz, Miloudi; Boucetta, Mohammed

    2014-01-01

    Gas production as a part of disc degeneration can occur but rarely causes nerve compression syndromes. The clinical features are similar to those of common sciatica. CT is very useful in the detection of epidural gas accumulation and nerve root compression. We report a case of symptomatic epidural gas accumulation originating from vacuum phenomenon in the intervertebral disc, causing lumbo-sacral radiculopathy. A 45-year-old woman suffered from sciatica for 9 months. The condition worsened in recent days. Computed tomography (CT) demonstrated intradiscal vacuum phenomenon, and accumulation of gas in the lumbar epidural space compressing the dural sac and S1 nerve root. After evacuation of the gas, her pain resolved without recurrence.

  8. Microscopic lysis of lumbar adhesive arachnoiditis.

    PubMed

    Johnston, J D; Matheny, J B

    1978-03-01

    The results of a long-term study of 28 patients operated on for adhesive lumbar arachnoiditis are presented. The technique involved was microscopic lysis of adhesions. The first case of surgery was performed in 1966 and the last, in 1970, with followup through 1976. Numerous observations are made regarding the clinical picture and the appearance of arachnoiditis at the time of surgery. Some conclusions are drawn regarding the causes of this condition with some emphasis on the role of Pantopaque, multiple surgeries, and other trauma. The conclusion is that surgical attack on arachnoiditis is a straightforward surgical exercise that, when carried out with appropriate caution, produces no further neurologic deficits and some short-term improvement. However, the authors feel that this procedure should not be performed at the present time because there does not appear to be a method for preventing the reaccumulation of the scar tissue and subsequent recurrence of the symptoms.

  9. Methods of evaluating lumbar and cervical fusion.

    PubMed

    Gruskay, Jordan A; Webb, Matthew L; Grauer, Jonathan N

    2014-03-01

    Introduced in 1911, spinal fusion is now widely used to stabilize the cervical, thoracic, and lumbar spine. Despite advancements in surgical techniques, including the use of instrumentation and optimizing bone graft options, pseudarthrosis remains one of the most significant causes of clinical failure following attempted fusion. Diagnosis of this common complication is based on a focused clinical assessment and imaging studies. Pseudarthrosis classically presents with the onset of or return of axial or radicular symptoms during the first postoperative year. However, this diagnosis is complicated because other diagnoses can mimic these symptoms (such as infection or adjacent segment degeneration) and because many cases of pseudarthrosis are asymptomatic. Computed tomography and assessment of motion on flexion/extension radiographs are the two preferred imaging modalities for establishing the diagnosis of pseudarthrosis. The purpose of this article was to review the current status of imaging and clinical practices for assessing fusion following spinal arthrodesis.

  10. Lumbar osteosarcoma in a chinchilla (Chinchilla laniger).

    PubMed

    Simova-Curd, S; Nitzl, D; Pospischil, A; Hatt, J-M

    2008-09-01

    An 11-year-old male chinchilla was presented for investigation of progressive weight loss, apathy, anorexia, changes in faecal quality and alopecia on the tip of the tail. On clinical examination, a stiffness of the back legs was noted. Abdominal palpation revealed a hard immobile, irregular structure in the region of the last lumbar vertebrae. Subsequent radiography and ultrasonography suggested the presence of neoplasia. The following day the chinchilla was showing hindlimb paralysis, and there was severe self-trauma to the distal 5 cm of the tail. In view of the rapid clinical deterioration, the chinchilla was euthanased with the owner's consent. Macroscopic examination supported the clinical suspicion of neoplasia. Histopathological examination revealed a reactive osteoblastic osteosarcoma. To the author's knowledge, this is the first report of osteosarcoma in chinchillas.

  11. The Charging of Planetary Rings

    NASA Astrophysics Data System (ADS)

    Graps, Amara L.; Horanyi, M.; Havnes, O.; Gruen, E.

    2008-09-01

    Planetary rings have an undeniable aesthetic appeal, resulting in media icons of ringed planets as descriptive of the planetary sciences field as a whole. Such far-reaching symbolism might not be misplaced, however, because planetary rings represent a fundamental class of planetary structure that invites interdisciplinary investigations from specialists in dust, gravitational, plasma, collisional, and radiative transfer physics, due to: its sub-micron to meters-sized particles, its immersion in the planet's magnetic field, its embedded moonlets and its close proximity to the ringed planet's ionosphere and innermost moons. As such, planetary rings are a metaphoric bridge through a wide range of planetary physical processes. Processes to charge ring particles have different relative dynamical effects, dependent upon the rings' particle sizes, and the ring's plasma, magnetic and gravitational environments. This presentation will review what is known about the charging parameters and processes of planetary rings, in particular the sum of the individual currents from the time-varying charge dQ/dt, of the planetary ring particle. The individual currents depend on the environmental plasma conditions: number density, flow speed, temperature, and mass for the currents: electron and ion capture from the plasma, ion currents to a moving grain, photoelectron emission, secondary electron emission, thermionic effects, with stochastic charging influencing all of the above. Since rings are an ensemble of particles, ("cloud" Ring), we will define an ensemble, and consider the above currents, including those for the smallest ring particles, the dust particles, to arrive at a table giving charge potential and other relevant parameters.

  12. The effects of gluteus muscle strengthening exercise and lumbar stabilization exercise on lumbar muscle strength and balance in chronic low back pain patients

    PubMed Central

    Jeong, Ui-Cheol; Sim, Jae-Heon; Kim, Cheol-Yong; Hwang-Bo, Gak; Nam, Chan-Woo

    2015-01-01

    [Purpose] The aim of this study was to examine the effects of exercise to strengthen the muscles of the hip together with lumbar segmental stabilization exercise on the lumbar disability index, lumbar muscle strength, and balance. [Subjects and Methods] This study randomly and equally assigned 40 participants who provided written consent to participate in this study to a lumbar segmental stabilization exercise plus exercise to strengthen the muscles of the gluteus group (SMG + LES group) and a lumbar segmental stabilization exercise group. [Results] Each evaluation item showed a statistically significant effect. [Conclusion] Clinical application of exercise in this study showed that lumbar segmental stabilization exercise plus exercise to strengthen the muscles of the gluteus resulted in a greater decrease in low back pain disability index and increase in lumbar muscle strength and balance ability than lumbar segmental stabilization exercise in chronic low back pain patients receiving the exercise treatments during the same period. PMID:26834359

  13. Surgical options for lumbar spinal stenosis.

    PubMed

    Machado, Gustavo C; Ferreira, Paulo H; Yoo, Rafael Ij; Harris, Ian A; Pinheiro, Marina B; Koes, Bart W; van Tulder, Maurits W; Rzewuska, Magdalena; Maher, Christopher G; Ferreira, Manuela L

    2016-11-01

    Hospital charges for lumbar spinal stenosis have increased significantly worldwide in recent times, with great variation in the costs and rates of different surgical procedures. There have also been significant increases in the rate of complex fusion and the use of spinal spacer implants compared to that of traditional decompression surgery, even though the former is known to incur costs up to three times higher. Moreover, the superiority of these new surgical procedures over traditional decompression surgery is still unclear. To determine the efficacy of surgery in the management of patients with symptomatic lumbar spinal stenosis and the comparative effectiveness between commonly performed surgical techniques to treat this condition on patient-related outcomes. We also aimed to investigate the safety of these surgical interventions by including perioperative surgical data and reoperation rates. Review authors performed electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, AMED, Web of Science, LILACS and three trials registries from their inception to 16 June 2016. Authors also conducted citation tracking on the reference lists of included trials and relevant systematic reviews. This review included only randomised controlled trials that investigated the efficacy and safety of surgery compared with no treatment, placebo or sham surgery, or with another surgical technique in patients with lumbar spinal stenosis. Two reviewers independently assessed the studies for inclusion and performed the 'Risk of bias' assessment, using the Cochrane Back and Neck Review Group criteria. Reviewers also extracted demographics, surgery details, and types of outcomes to describe the characteristics of included studies. Primary outcomes were pain intensity, physical function or disability status, quality of life, and recovery. The secondary outcomes included measurements related to surgery, such as perioperative blood loss

  14. Mechanical supporting ring structure

    NASA Astrophysics Data System (ADS)

    Tserodze, Sh.; Medzmariashvili, E.; Tusishvili, O.; Tsignadze, N.; Santiago-Prowald, J.; ‘t Klooster, C. G. M.; Medzmariashvili, N.

    2013-12-01

    Large deployable antenna reflectors are commonly employed for space missions. Scientific, telecommunications and earth observation applications are enabled due to the antenna gain provided by the large apertures (8-25 m). The most relevant requirements that drive the design are the size of the stowed package diameter (0.4-1.50 m), the mass (18-160 kg), the control of the deployment process, the accuracy and stability of the surface and the RF performance requirements. In this paper a new architecture of conical ring reflector is described, with the objective of providing a response to the mentioned requirements. The projected aperture range of 8-25 m is addressed, enabling to create offset reflectors of elliptical rim. The configuration is based on a double pantograph conical ring. It is an architecture suitable for reflector-based radar in LEO missions from P to C band, although the expected stiffness and stability can be seen as an asset for higher operational frequencies. The configuration of the structure is new and has been preliminarily discussed in the paper. Further investigations might well be of interest.

  15. Storage ring injection

    SciTech Connect

    Burke, R.J.

    1980-01-01

    Some basic issues involved in injecting the beam into storage rings with the principal parameters of those studied at the workshop have been considered. The main conclusion is that straightforward adjustments of the storage ring parameters makes injection easy. The largest number of injected turns is fourteen, and the phase space dilution allowance seems adequate to ensure very small beam loss during injection. The adjustments also result in lower bending magnet fields, and high field superconducting magnets (e.g., 5 Tesla) are not necessary. The design changes do not necessarily affect the Keil-Schnell criterion for stability of the longitudinal microwave instability, although that criterion appears to be irrelevant. Because the beams are expected to be unstable, but with slow growth rates, the vacuum chamber impedances required to give equal risetimes for the various designs are compared for systems posing various degrees of difficulty for injection. Finally, the impact of the parameters on cost is noted, and a system is considered that cuts the length of the linac in half by using doubly charged ions.

  16. Vortex and Rings

    NASA Image and Video Library

    2014-07-07

    NASA Cassini spacecraft captures three magnificent sights at once: Saturn north polar vortex and hexagon along with its expansive rings. The hexagon, which is wider than two Earths, owes its appearance to the jet stream that forms its perimeter. The jet stream forms a six-lobed, stationary wave which wraps around the north polar regions at a latitude of roughly 77 degrees North. This view looks toward the sunlit side of the rings from about 37 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on April 2, 2014 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 1.4 million miles (2.2 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 43 degrees. Image scale is 81 miles (131 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18274

  17. Buoyant Norbury's vortex rings

    NASA Astrophysics Data System (ADS)

    Blyth, Mark; Rodriguez-Rodriguez, Javier; Salman, Hayder

    2014-11-01

    Norbury's vortices are a one-parameter family of axisymmetric vortex rings that are exact solutions to the Euler equations. Due to their relative simplicity, they are extensively used to model the behavior of real vortex rings found in experiments and in Nature. In this work, we extend the original formulation of the problem to include buoyancy effects for the case where the fluid that lies within the vortex has a different density to that of the ambient. In this modified formulation, buoyancy effects enter the problem through the baroclinic term of the vorticity equation. This permits an efficient numerical solution of the governing equation of motion in terms of a vortex contour method that tracks the evolution of the boundary of the vortex. Finally, we compare our numerical results with the theoretical analysis of the short-time evolution of a buoyant vortex. Funded by the Spanish Ministry of Economy and Competitiveness through grant DPI2011-28356-C03-02 and by the London Mathematical Society.

  18. Ring Image Analyzer

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry V.

    2012-01-01

    Ring Image Analyzer software analyzes images to recognize elliptical patterns. It determines the ellipse parameters (axes ratio, centroid coordinate, tilt angle). The program attempts to recognize elliptical fringes (e.g., Newton Rings) on a photograph and determine their centroid position, the short-to-long-axis ratio, and the angle of rotation of the long axis relative to the horizontal direction on the photograph. These capabilities are important in interferometric imaging and control of surfaces. In particular, this program has been developed and applied for determining the rim shape of precision-machined optical whispering gallery mode resonators. The program relies on a unique image recognition algorithm aimed at recognizing elliptical shapes, but can be easily adapted to other geometric shapes. It is robust against non-elliptical details of the image and against noise. Interferometric analysis of precision-machined surfaces remains an important technological instrument in hardware development and quality analysis. This software automates and increases the accuracy of this technique. The software has been developed for the needs of an R&TD-funded project and has become an important asset for the future research proposal to NASA as well as other agencies.

  19. Minimally Invasive Transforaminal Lumbar Interbody Fusion and Unilateral Fixation for Degenerative Lumbar Disease.

    PubMed

    Wang, Hui-Wang; Hu, Yong-Cheng; Wu, Zhan-Yong; Wu, Hua-Rong; Wu, Chun-Fu; Zhang, Lian-Suo; Xu, Wei-Kun; Fan, Hui-Long; Cai, Jin-Sheng; Ma, Jian-Qing

    2017-08-01

    To evaluate the clinical effect of the minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation using a tubular retractor in the management of degenerative lumbar disease. A retrospective analysis was conducted to analyze the clinical outcome of 58 degenerative lumbar disease patients who were treated with minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation during December 2012 to January 2015. The spine was unilaterally approached through a 3.0-cm skin incision centered on the disc space, located 2.5 cm lateral to the midline, and the multifidus muscles and longissimus dorsi were stripped off. After transforaminal lumbar interbody fusion and posterolateral fusion the unilateral pedicle screw fixation was performed. The visual analogue scale (VAS) for back and leg pain, the Oswestry disability index (ODI), and the MacNab score were applied to evaluate clinical effects. The operation time, peri-operative bleeding, postoperative time in bed, hospitalization costs, and the change in the intervertebral height were analyzed. Radiological fusion based on the Bridwell grading system was also assessed at the last follow-up. The quality of life of the patients before and after the operation was assessed using the short form-36 scale (SF-36). Fifty-eight operations were successfully performed, and no nerve root injury or dural tear occurred. The average operation time was 138 ± 33 min, intraoperative blood loss was 126 ± 50 mL, the duration from surgery to getting out of bed was 46 ± 8 h, and hospitalization cost was 1.6 ± 0.2 ten thousand yuan. All of the 58 patients were followed up for 7-31 months, with an average of 14.6 months. The postoperative VAS scores and ODI score were significantly improved compared with preoperative data (P < 0.05). The evaluation of the MacNab score was excellent in 41 patients, good

  20. Comprehensive comparing percutaneous endoscopic lumbar discectomy with posterior lumbar internal fixation for treatment of adjacent segment lumbar disc prolapse with stable retrolisthesis: A retrospective case-control study.

    PubMed

    Sun, Yapeng; Zhang, Wei; Qie, Suhui; Zhang, Nan; Ding, Wenyuan; Shen, Yong

    2017-07-01

    The study was to comprehensively compare the postoperative outcome and imaging parameter characters in a short/middle period between the percutaneous endoscopic lumbar discectomy (PELD) and the internal fixation of bone graft fusion (the most common form is posterior lumbar interbody fusion [PLIF]) for the treatment of adjacent segment lumbar disc prolapse with stable retrolisthesis after a previous lumbar internal fixation surgery.In this retrospective case-control study, we collected the medical records from 11 patients who received PELD operation (defined as PELD group) for and from 13 patients who received the internal fixation of bone graft fusion of lumbar posterior vertebral lamina decompression (defined as control group) for the treatment of the lumbar disc prolapse combined with stable retrolisthesis at Department of Spine Surgery, the Third Hospital of Hebei Medical University (Shijiazhuang, China) from May 2010 to December 2015. The operation time, the bleeding volume of perioperation, and the rehabilitation days of postoperation were compared between 2 groups. Before and after surgery at different time points, ODI, VAS index, and imaging parameters (including Taillard index, inter-vertebral height, sagittal dislocation, and forward bending angle of lumbar vertebrae) were compared.The average operation time, the blooding volume, and the rehabilitation days of postoperation were significantly less in PELD than in control group. The ODI and VAS index in PELD group showed a significantly immediate improving on the same day after the surgery. However, Taillard index, intervertebral height, sagittal dislocation in control group showed an immediate improving after surgery, but no changes in PELD group till 12-month after surgery. The forward bending angle of lumbar vertebrae was significantly increased and decreased in PELD and in control group, respectively.PELD operation was superior in terms of operation time, bleeding volume, recovery period, and financial

  1. Lumbar puncture in patients using anticoagulants and antiplatelet agents.

    PubMed

    Domingues, Renan; Bruniera, Gustavo; Brunale, Fernando; Mangueira, Cristóvão; Senne, Carlos

    2016-08-01

    The use of anticoagulants and antiplatelet agents has largely increased. Diagnostic lumbar puncture in patients taking these drugs represents a challenge considering the opposing risks of bleeding and thrombotic complications. To date there are no controlled trials, specific guidelines, nor clear recommendations in this area. In the present review we make some recommendations about lumbar puncture in patients using these drugs. Our recommendations take into consideration the pharmacology of these drugs, the thrombotic risk according to the underlying disease, and the urgency in cerebrospinal fluid analysis. Evaluating such information and a rigorous monitoring of neurological symptoms after lumbar puncture are crucial to minimize the risk of hemorrhage associated neurological deficits. An individualized patient decision-making and an effective communication between the assistant physician and the responsible for conducting the lumbar puncture are essential to minimize potential risks.

  2. Concomitant Lumbar Stenosis and Aortic Pseudoaneurysm: A Case Report

    PubMed Central

    Fuchs, Christoph; Niemeier, Thomas E; Neway, William E

    2016-01-01

    Aortic pseudoaneurysm can create a constellation of symptoms that can mimic lumbar back pain. There are rare but well-documented reports of aortic pathology (aneurysms, pseudoaneurysms, and chronic contained aneurysm ruptures) eroding into the vertebral column causing neural compression. We report a case of a rapidly progressive aortic pseudoaneurysm in a patient with pre-existing lumbar spine pathology which had the potential for catastrophic intraoperative bleeding during a minimally invasive surgery (MIS) using the transforaminal lumbar interbody fusion (TLIF) technique. Postoperatively, the patient’s radicular pain resolved but her back pain remained. Further workup identified the pseudoaneurysm and the patient subsequently underwent open vascular repair. In this report, we highlight a lesser known mimicker of lumbar back pain. PMID:27882269

  3. Diagnosis of Lumbar Foraminal Stenosis using Diffusion Tensor Imaging

    PubMed Central

    Ohtori, Seiji; Suzuki, Munetaka; Oikawa, Yasuhiro; Yamanaka, Hajime; Tamai, Hiroshi; Kobayashi, Tatsuya; Orita, Sumihisa; Yamauchi, Kazuyo; Suzuki, Miyako; Aoki, Yasuchika; Watanabe, Atsuya; Kanamoto, Hirohito; Takahashi, Kazuhisa

    2016-01-01

    Diagnosis of lumbar foraminal stenosis remains difficult. Here, we report on a case in which bilateral lumbar foraminal stenosis was difficult to diagnose, and in which diffusion tensor imaging (DTI) was useful. The patient was a 52-year-old woman with low back pain and pain in both legs that was dominant on the right. Right lumbosacral nerve compression due to a massive uterine myoma was apparent, but the leg pain continued after a myomectomy was performed. No abnormalities were observed during nerve conduction studies. Computed tomography and magnetic resonance imaging indicated bilateral L5 lumbar foraminal stenosis. DTI imaging was done. The extraforaminal values were decreased and tractography was interrupted in the foraminal region. Bilateral L5 vertebral foraminal stenosis was treated by transforaminal lumbar interbody fusion and the pain in both legs disappeared. The case indicates the value of DTI for diagnosing vertebral foraminal stenosis. PMID:26949473

  4. Surgical results of lumbar interbody fusion using calcium phosphate cement.

    PubMed

    Hirasawa, Motohiro; Mure, Hideo; Toi, Hiroyuki; Nagahiro, Shinji

    2014-01-01

    Clinical and radiological outcomes of lumbar interbody fusion using artificial fusion cages filled with calcium phosphate cements (CPCs) were retrospectively reviewed. Between 2002 and 2011, 25 patients underwent lumbar interbody fusion at Tokushima University Hospital, and 22 patients were enrolled in this study. Of these, 5 patients received autologous local bone grafts and 17 received CPC. Japan Orthopedic Association (JOA) score was used for clinical outcome assessments. Lumbar radiography and computed tomography (CT) were performed at 12, 24 months and last follow-up period to assess bony fusion. The mean JOA score of all patients improved from 9.3 before surgery to 21.0 at 24 months after surgery. Fusion had occurred in 5 of 5 patients in the local bone graft group and in 16 of 17 patients in CPC group at 24 months postoperatively. No surgically related complication was occurred in both groups. CPC is a useful and safe graft material for lumbar interbody fusion.

  5. Paraplegia with lumbar artery compression by the diaphragmatic crus.

    PubMed

    Batt, Michel; Rogopoulos, André; Benchimol, Daniel; Chapot, René; Jean-Baptiste, Elixène; Baque, Patrick

    2008-10-01

    The authors report three cases of transient and recurrent paraplegia due to compression of the second right lumbar artery by the diaphragmatic crus. Circumstances of appearance are suggestive when paraplegia occurs in dorsolumbar hyperlordosis and low cardiac output is an associated hemodynamic risk factor. Selective medullary arteriography is indispensable for diagnosis and can demonstrate three signs: an anterior spinal dorsolumbar artery (artery of Adamkiewicz) that does not descend to the conus medullaris; posterior spinal arteries arising from the second lumbar arteries that vascularize the conus medullaris; existence of a tight stenosis on the second right lumbar artery that is aggravated during dynamic maneuvers. Section of the right diaphragmatic crus and release of the second right lumbar artery from the aorta to the fibrous arcade of the psoas permits definitive cure of symptoms.

  6. Sacroiliac joint pain after lumbar/lumbosacral fusion: current knowledge.

    PubMed

    Yoshihara, Hiroyuki

    2012-09-01

    Recently, the sacroiliac joint (SIJ) has gained increased attention as a source of persistent or new pain after lumbar/lumbosacral fusion. The underlying pathophysiology of SIJ pain may be increased mechanical load, iliac crest bone grafting, or a misdiagnosis of SIJ syndrome. Imaging studies show more frequent degeneration of the SIJ in patients with lumbar/lumbosacral fusion than in patients without such fusion. Using injection tests, it has been shown that SIJ pain is the cause of persistent symptoms in a considerable number of patients after fusion surgery. Recent articles reporting on surgical outcomes of SIJ fusion include a high percentage of patients who had lumbar/lumbosacral fusion or surgery before, although well-controlled clinical studies are necessary to assess the efficacy of surgical treatment. Taking these findings into consideration, the possibility that the SIJ is the source of pain should be considered in patients with failed back surgery syndrome after lumbar/lumbosacral fusion.

  7. Microscopy-assisted interspinous tubular approach for lumbar spinal stenosis.

    PubMed

    Soriano-Sánchez, José-Antonio; Quillo-Olvera, Javier; Soriano-Solis, Sergio; Soriano-Lopez, Miroslava-Elizabeth; Covarrubias-Rosas, Claudia-Angélica; Quillo-Reséndiz, Javier; Gutiérrez-Partida, Carlos-Francisco; Rodríguez-García, Manuel

    2017-03-01

    Various minimally invasive techniques have been reported as an alternative to conventional lumbar decompression. The major advantage of these minimally invasive procedures lies in their reduction of unnecessary exposure and tissue trauma. Our objective was to describe a minimally invasive procedure for lumbar spinal stenosis decompression by enlarging the lumbar interspinous space, approaching it with a tubular retractor, and assisting with microscopy. Thoracolumbar fascia and paravertebral muscles are preserved throughout the whole procedure. Iatrogenic instability of the spine can be avoided if during the procedure both joints are just undercut in order to decompress the subarticular space. The approach described in this manuscript could be used as an alternate minimally invasive surgical procedure for the treatment of central and lateral lumbar spinal stenosis.

  8. Quantitative magnetic resonance imaging of the lumbar intervertebral discs.

    PubMed

    Hwang, Dosik; Kim, Sewon; Abeydeera, Nirusha A; Statum, Sheronda; Masuda, Koichi; Chung, Christine B; Siriwanarangsun, Palanan; Bae, Won C

    2016-12-01

    Human lumbar spine is composed of multiple tissue components that serve to provide structural stability and proper nutrition. Conventional magnetic resonance (MR) imaging techniques have been useful for evaluation of IVD, but inadequate at imaging the discovertebral junction and ligamentous tissues due primarily to their short T2 nature. Ultrashort time to echo (UTE) MR techniques acquire sufficient MR signal from these short T2 tissues, thereby allowing direct and quantitative evaluation. This article discusses the anatomy of the lumbar spine, MR techniques available for morphologic and quantitative MR evaluation of long and short T2 tissues of the lumbar spine, considerations for T2 relaxation modeling and fitting, and existing and new techniques for spine image post-processing, focusing on segmentation. This article will be of interest to radiologic and orthopaedic researchers performing lumbar spine imaging.

  9. Microscopy-assisted interspinous tubular approach for lumbar spinal stenosis

    PubMed Central

    Soriano-Sánchez, José-Antonio; Soriano-Solis, Sergio; Soriano-Lopez, Miroslava-Elizabeth; Covarrubias-Rosas, Claudia-Angélica; Quillo-Reséndiz, Javier; Gutiérrez-Partida, Carlos-Francisco; Rodríguez-García, Manuel

    2017-01-01

    Various minimally invasive techniques have been reported as an alternative to conventional lumbar decompression. The major advantage of these minimally invasive procedures lies in their reduction of unnecessary exposure and tissue trauma. Our objective was to describe a minimally invasive procedure for lumbar spinal stenosis decompression by enlarging the lumbar interspinous space, approaching it with a tubular retractor, and assisting with microscopy. Thoracolumbar fascia and paravertebral muscles are preserved throughout the whole procedure. Iatrogenic instability of the spine can be avoided if during the procedure both joints are just undercut in order to decompress the subarticular space. The approach described in this manuscript could be used as an alternate minimally invasive surgical procedure for the treatment of central and lateral lumbar spinal stenosis. PMID:28435920

  10. Quantitative magnetic resonance imaging of the lumbar intervertebral discs

    PubMed Central

    Hwang, Dosik; Kim, Sewon; Abeydeera, Nirusha A.; Statum, Sheronda; Masuda, Koichi; Chung, Christine B.; Siriwanarangsun, Palanan

    2016-01-01

    Human lumbar spine is composed of multiple tissue components that serve to provide structural stability and proper nutrition. Conventional magnetic resonance (MR) imaging techniques have been useful for evaluation of IVD, but inadequate at imaging the discovertebral junction and ligamentous tissues due primarily to their short T2 nature. Ultrashort time to echo (UTE) MR techniques acquire sufficient MR signal from these short T2 tissues, thereby allowing direct and quantitative evaluation. This article discusses the anatomy of the lumbar spine, MR techniques available for morphologic and quantitative MR evaluation of long and short T2 tissues of the lumbar spine, considerations for T2 relaxation modeling and fitting, and existing and new techniques for spine image post-processing, focusing on segmentation. This article will be of interest to radiologic and orthopaedic researchers performing lumbar spine imaging. PMID:28090450

  11. 49 CFR 572.19 - Lumbar spine, abdomen and pelvis.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... rotation joints by the attachments shown in Figure 18. Tighten the mountings so that the pelvis-lumbar joining surface is horizontal and adjust the femur ball-flange screws at each hip socket joint to 50...

  12. 49 CFR 572.19 - Lumbar spine, abdomen and pelvis.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... rotation joints by the attachments shown in Figure 18. Tighten the mountings so that the pelvis-lumbar joining surface is horizontal and adjust the femur ball-flange screws at each hip socket joint to 50...

  13. 49 CFR 572.19 - Lumbar spine, abdomen and pelvis.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... rotation joints by the attachments shown in Figure 18. Tighten the mountings so that the pelvis-lumbar joining surface is horizontal and adjust the femur ball-flange screws at each hip socket joint to 50...

  14. 49 CFR 572.19 - Lumbar spine, abdomen and pelvis.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... rotation joints by the attachments shown in Figure 18. Tighten the mountings so that the pelvis-lumbar joining surface is horizontal and adjust the femur ball-flange screws at each hip socket joint to 50...

  15. 49 CFR 572.19 - Lumbar spine, abdomen and pelvis.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... rotation joints by the attachments shown in Figure 18. Tighten the mountings so that the pelvis-lumbar joining surface is horizontal and adjust the femur ball-flange screws at each hip socket joint to 50...

  16. Saturn's rings - A new survey

    NASA Technical Reports Server (NTRS)

    Cook, A. F.; Franklin, F. A.

    1977-01-01

    Observations of radar returns from Saturn's rings, together with radio interferometry of their absorption of radiation from the disk, combine to require an effective radius of ring particles of about 6 cm or larger. It is suggested that the ring particles may also include, in addition to the known ice constituent, a mixture of the clathrated hydrate of methane and ammonia hydrate. A two-density model for ring particles is possible in which a matrix of low density contains many nodules of higher-density ice particles; in this case, radii nearly as large as the observed ring thickness would be possible. Improved resolution in radio observations at 21 cm or, if necessary, at longer wavelengths for narrow ring openings is perhaps the most useful method for determining upper limits on the particle size.

  17. Ring current and radiation belts

    NASA Technical Reports Server (NTRS)

    Williams, D. J.

    1987-01-01

    Studies performed during 1983-1986 on the ring current, the injection boundary model, and the radiation belts are discussed. The results of these studies yielded the first observations on the composition and charge state of the ring current throughout the ring-current energy range, and strong observational support for an injection-boundary model accounting for the origins of radiation-belt particles, the ring current, and substorm particles observed at R less than about 7 earth radii. In addition, the results have demonstrated that the detection of energetic neutral atoms generated by charge-exchange interactions between the ring current and the hydrogen geocorona can provide global images of the earth's ring current and its spatial and temporal evolution.

  18. Reversible Rings with Involutions and Some Minimalities

    PubMed Central

    Fakieh, W. M.; Nauman, S. K.

    2013-01-01

    In continuation of the recent developments on extended reversibilities on rings, we initiate here a study on reversible rings with involutions, or, in short, ∗-reversible rings. These rings are symmetric, reversible, reflexive, and semicommutative. In this note we will study some properties and examples of ∗-reversible rings. It is proved here that the polynomial rings of ∗-reversible rings may not be ∗-reversible. A criterion for rings which cannot adhere to any involution is developed and it is observed that a minimal noninvolutary ring is of order 4 and that a minimal noncommutative ∗-reversible ring is of order 16. PMID:24489510

  19. Clinical Outcomes of Posterior Lumbar Interbody Fusion versus Minimally Invasive Transforaminal Lumbar Interbody Fusion in Three-Level Degenerative Lumbar Spinal Stenosis

    PubMed Central

    Fan, Guoxin; Wu, Xinbo; Yu, Shunzhi; Sun, Qi; Zhang, Hailong; Gu, Xin

    2016-01-01

    The aim of this study was to directly compare the clinical outcomes of posterior lumbar interbody fusion (PLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in three-level lumbar spinal stenosis. This retrospective study involved a total of 60 patients with three-level degenerative lumbar spinal stenosis who underwent MIS-TLIF or PLIF from January 2010 to February 2012. Back and leg visual analog scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) scale were used to assess the pain, disability, and health status before surgery and postoperatively. In addition, the operating time, estimated blood loss, and hospital stay were also recorded. There were no significant differences in back VAS, leg VAS, ODI, SF-36, fusion condition, and complications at 12-month follow-up between the two groups (P > 0.05). However, significantly less blood loss and shorter hospital stay were observed in MIS-TLIF group (P < 0.05). Moreover, patients undergoing MIS-TLIF had significantly lower back VAS than those in PLIF group at 6-month follow-up (P < 0.05). Compared with PLIF, MIS-TLIF might be a prior option because of noninferior efficacy as well as merits of less blood loss and quicker recovery in treating three-level lumbar spinal stenosis. PMID:27747244

  20. Lumbar Scoliosis Combined Lumbar Spinal Stenosis and Herniation Diagnosed Patient Was Treated with “U” Route Transforaminal Percutaneous Endoscopic Lumbar Discectomy

    PubMed Central

    Zhang, Shaobo; Lian, Qingquan; Yan, Haibo; Lin, Xianfa

    2017-01-01

    The objective was to report a case of a 63-year-old man with a history of low back pain (LBP) and left leg pain for 2 years, and the symptom became more serious in the past 5 months. The patient was diagnosed with lumbar scoliosis combined with lumbar spinal stenosis (LSS) and lumbar disc herniation (LDH) at the level of L4-5 that was confirmed using Computerized Topography and Magnetic Resonance Imaging. The surgical team preformed a novel technique, “U” route transforaminal percutaneous endoscopic lumbar discectomy (PELD), which led to substantial, long-term success in reduction of pain intensity and disability. After removing the osteophyte mass posterior to the thecal sac at L4-5, the working channel direction was changed to the gap between posterior longitudinal ligament and thecal sac, and we also removed the herniation and osteophyte at L3-4 with “U” route PELD. The patient's symptoms were improved immediately after the surgical intervention; low back pain intensity decreased from preoperative 9 to postoperative 2 on a visual analog scale (VAS) recorded at 1 month postoperatively. The success of the intervention suggests that “U” route PELD may be a feasible alternative to treat lumbar scoliosis with LSS and LDH patients. PMID:28203471

  1. Lumbar supports for prevention and treatment of low back pain.

    PubMed

    van Duijvenbode, I C D; Jellema, P; van Poppel, M N M; van Tulder, M W

    2008-04-16

    Lumbar supports are used in the treatment of low-back pain patients, to prevent the onset of low-back pain (primary prevention) or to prevent recurrences of a low-back pain episode (secondary prevention). To assess the effects of lumbar supports for prevention and treatment of non-specific low-back pain. We updated the search in the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and CINAHL to December 2006. We also screened references given in relevant reviews and identified trials, and contacted experts to identify additional RCTs. Randomized controlled trials that reported on any type of lumbar supports as preventive or therapeutic intervention for non-specific low-back pain. One review author generated the electronic search. Two review authors independently identified trials that met the inclusion criteria. One review author extracted data on the study population, interventions, and final results. The methodological quality and the clinical relevance were independently assessed by two review authors. Because it was not possible to perform a quantitative analysis, we performed a qualitative analysis in which the strength of evidence on the effectiveness of lumbar supports was classified as strong, moderate, limited, conflicting, or no evidence. Seven preventive studies (14,437 people) and eight treatment studies (1361 people) were included in this updated review. Overall, the methodological quality of the studies was rather low. Only five of the fifteen studies met 50% or more of the internal validity items. There was moderate evidence that lumbar supports are not more effective than no intervention or training in preventing low-back pain, and conflicting evidence whether lumbar supports are effective supplements to other preventive interventions. It is still unclear if lumbar supports are more effective than no or other interventions for the treatment of low-back pain. There is moderate evidence that lumbar supports are not more effective than

  2. Saturn's rings and associated ring plasma cavity: Evidence for slow ring erosion

    NASA Astrophysics Data System (ADS)

    Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.

    2017-08-01

    We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C-ring, leading to field-aligned plasma transport to Saturn's ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma 'fountains'. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >109 years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

  3. Saturn's Rings and Associated Ring Plasma Cavity: Evidence for Slow Ring Erosion

    NASA Technical Reports Server (NTRS)

    Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.

    2017-01-01

    We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C- ring, leading to field-aligned plasma transport to Saturns ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma fountains. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >10(exp 9) years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

  4. Technique for Performing Lumbar Puncture in Microgravity Using Portable Radiography.

    PubMed

    Lerner, David J; Parmet, Allen J; Don, Steven; Shimony, Joshua S; Goyal, Manu S

    2016-08-01

    Visual Impairment and Intracranial Pressure Syndrome (VIIP) has caused symptomatology during and after long duration missions on the International Space Station (ISS). Only indirect measurements of intracranial pressure (ICP), such as ultrasound, have been performed on ISS. Discussion and interest has happened at NASA about performing lumbar puncture (LP) in microgravity. Only the "blind" palpation approach and the ultrasound-assisted approach have been discussed. This article, as proof of concept, discusses the possibility of portable radiography to assist lumbar punctures in microgravity. An anthropomorphic radiological phantom of an adult lumbar spine was made containing a fluid-filled space in the spinal canal with a latex membrane which simulated the dural sac and cerebrospinal fluid. A portable direct-digital radiography system with wireless transmitting image receptor and screen was used to perform image-guided lumbar puncture. Using the same equipment and technique, this procedure was then performed on a cadaver for final proof of concept. Technical success was achieved in all approaches on the first try without needle redirection. There was no difference between the cadaver model and the phantom model in terms of difficulty in reaching the fluid space or visually confirming needle location. Portable radiography via proof of concept has the potential to guide lumbar puncture while minimizing volume and mass of equipment. This could be ideal for assisting in performing lumbar puncture in microgravity, as this is the standard of care on Earth for difficult or failed "blind" lumbar punctures. Lerner DJ, Parmet AJ, Don S, Shimony JS, Goyal MS. Technique for performing lumbar puncture in microgravity using portable radiography. Aerosp Med Hum Perform. 2016; 87(8):745-747.

  5. Lumbar intervertebral disc degeneration and related factors in Korean firefighters

    PubMed Central

    Jang, Tae-Won; Ahn, Yeon-Soon; Byun, Junsu; Lee, Jong-In; Kim, Kun-Hyung; Kim, Youngki; Song, Han-Soo; Lee, Chul-Gab; Kwon, Young-Jun; Yoon, Jin-Ha; Jeong, Kyoungsook

    2016-01-01

    Objectives The job of firefighting can cause lumbar burden and low back pain. This study aimed to identify the association between age and lumbar intervertebral disc degeneration and whether the association differs between field and administrative (non-field) firefighters. Methods Subjects were selected using a stratified random sampling method. Firefighters were stratified by geographic area, gender, age and type of job. First, 25 fire stations were randomly sampled considering regional distribution. Then firefighters were stratified by gender, age and their job and randomly selected among the strata. A questionnaire survey and MRI scans were performed, and then four radiologists used Pfirrmann classification methods to determine the grade of lumbar intervertebral disc degeneration. Results Pfirrmann grade increased with lumbar intervertebral disc level. Analysis of covariance showed that age was significantly associated with lumbar intervertebral disc degeneration (p<0.05). The value of β (parameter estimate) was positive at all lumbar intervertebral disc levels and was higher in the field group than in the administrative group at each level. In logistic regression analysis, type of job was statistically significant only with regard to the L4–5 intervertebral disc (OR 3.498, 95% CI 1.241 to 9.860). Conclusions Lumbar intervertebral disc degeneration is associated with age, and field work such as firefighting, emergency and rescue may accelerate degeneration in the L4–5 intervertebral disc. The effects of field work on lumbar intervertebral disc degeneration were not clear in discs other than at the level L4–5. PMID:27354080

  6. Degenerative lumbar spinal stenosis and its imposters: three case studies

    PubMed Central

    Ammendolia, Carlo

    2014-01-01

    Degenerative lumbar spinal stenosis causing neurogenic claudicaton is a common condition impacting walking ability in older adults. There are other highly prevalent conditions in this patient population that have similar signs and symptoms and cause limited walking ability. The purpose of this study is to highlight the diagnostic challenges using three case studies of older adults who present with limited walking ability who have imaging evidence of degenerative lumbar spinal stenosis. PMID:25202160

  7. Split ring containment attachment device

    DOEpatents

    Sammel, Alfred G.

    1996-01-01

    A containment attachment device 10 for operatively connecting a glovebag 200 to plastic sheeting 100 covering hazardous material. The device 10 includes an inner split ring member 20 connected on one end 22 to a middle ring member 30 wherein the free end 21 of the split ring member 20 is inserted through a slit 101 in the plastic sheeting 100 to captively engage a generally circular portion of the plastic sheeting 100. A collar potion 41 having an outer ring portion 42 is provided with fastening means 51 for securing the device 10 together wherein the glovebag 200 is operatively connected to the collar portion 41.

  8. Saturn's Rings Edge-on

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.

    For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.

    The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.

    This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).

    Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.

    The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science

  9. Formation of lunar basin rings

    USGS Publications Warehouse

    Hodges, C.A.; Wilhelms, D.E.

    1978-01-01

    The origin of the multiple concentric rings that characterize lunar impact basins, and the probable depth and diameter of the transient crater have been widely debated. As an alternative to prevailing "megaterrace" hypotheses, we propose that the outer scarps or mountain rings that delineate the topographic rims of basins-the Cordilleran at Orientale, the Apennine at Imbrium, and the Altai at Nectaris-define the transient cavities, enlarged relatively little by slumping, and thus are analogous to the rim crests of craters like Copernicus; inner rings are uplifted rims of craters nested within the transient cavity. The magnitude of slumping that occurs on all scarps is insufficient to produce major inner rings from the outer. These conclusions are based largely on the observed gradational sequence in lunar central uplifts:. from simple peaks through somewhat annular clusters of peaks, peak and ring combinations and double ring basins, culminating in multiring structures that may also include peaks. In contrast, belts of slump terraces are not gradational with inner rings. Terrestrial analogs suggest two possible mechanisms for producing rings. In some cases, peaks may expand into rings as material is ejected from their cores, as apparently occurred at Gosses Bluff, Australia. A second process, differential excavation of lithologically diverse layers, has produced nested experimental craters and is, we suspect, instrumental in the formation of terrestrial ringed impact craters. Peak expansion could produce double-ring structures in homogeneous materials, but differential excavation is probably required to produce multiring and peak-in-ring configurations in large lunar impact structures. Our interpretation of the representative lunar multiring basin Orientale is consistent with formation of three rings in three layers detected seismically in part of the Moon-the Cordillera (basin-bounding) ring in the upper crust, the composite Montes Rook ring in the underlying

  10. Ground Movement in SSRL Ring

    SciTech Connect

    Sunikumar, Nikita; /UCLA /SLAC

    2011-08-25

    Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

  11. Statistical ring current of Saturn

    NASA Astrophysics Data System (ADS)

    Carbary, J. F.; Achilleos, N.; Arridge, C. S.

    2012-06-01

    The statistical ring current of Saturn has been determined from the curl of the median magnetic field derived from over 5 years of observations of the Cassini magnetometer. The main issue addressed here is the calculation of the statistical ring current of Saturn by directly computing, for the first time, the symmetrical part of the ring current J from the Maxwell equation ∇ × B = μ0J from assembling the perturbation magnetic field B from 2004 through 2010. This study validates previous studies, based on fewer data and not using ∇ × B, and shows that the ring current flows eastward (in the +ϕ or corotation direction) and extends from ˜3 RS to at least ˜20 RS (1 RS = 60,268 km), which is the vicinity of the dayside magnetopause; that the ring current has a peak strength of ˜75 pA/m2 at ˜9.5 RS; and that the ring current has a half-width of ˜1.5 RS. Two outcomes of this study are that the ring current bends northward, as suggested by the “bowl” model of Saturn's plasma sheet, and that the total ring current is 9.2 ± 1.0 MA. In the context of future endeavors, the statistical ring current presented here can be used for calculations of the magnetic field of Saturn for particle drifts, field line mapping, and J × B force.

  12. Fingering inside the coffee ring

    NASA Astrophysics Data System (ADS)

    Weon, Byung Mook; Je, Jung Ho

    2013-01-01

    Colloidal droplets including micro- and nanoparticles generally leave a ringlike stain, called the “coffee ring,” after evaporation. We show that fingering emerges during evaporation inside the coffee ring, resulting from a bidispersed colloidal mixture of micro- and nanoparticles. Microscopic observations suggest that finger formation is driven by competition between the coffee-ring and Marangoni effects, especially when the inward Marangoni flow is overwhelmed by the outward coffee-ring flow. This finding could help to understand the variety of the final deposition patterns of colloidal droplets.

  13. Comparative study of Mm. Multifidi in lumbar and thoracic spine.

    PubMed

    Bojadsen, T W; Silva, E S; Rodrigues, A J; Amadio, A C

    2000-06-01

    Imbalance of Mm. Multifidi may play a role in spinal disorders such as scoliosis in the thoracic spine, and lumbar disc herniation and lower back pain in the lumbar spine. Even though changes in these muscles are related to the etiology of these disorders, their anatomy is still poorly understood, especially in the upper regions of the spine. With the aim of gaining a better understanding of the anatomy of Mm. Multifidi in the lumbar and thoracic spine, 12 fresh and two embalmed cadavers were dissected. Our results indicate that Mm. Multifidi present differences in lumbar and thoracic spines concerning their deepness, fibre trajectory, muscle length, muscle mass and tendinous tissue. In the lumbar spine Mm. Multifidi are a superficial, thick and fleshy mass, and their fibres are more vertical in relation to the spinous processes. In the thoracic spine Mm. Multifidi are deeper, thinner, and their fibres are more tendinous and oblique than in the lumbar spine. These differences have implications on Mm. Multifidi architecture and consequently for their function in these two regions of the spine.

  14. [Ossification of the posterior longitudinal ligament of the lumbar spine].

    PubMed

    Albisinni, U; Chianura, G; Merlini, L; Calzolari, S; Othsuka, K; Terayama, K

    1988-05-01

    The ossification of the cervical posterior longitudinal ligament (OPLL) is widely known and studied in Japan where a roentgenological incidence of 2.06% adults affected has been found. Data concerning the ossification of the lumbar posterior longitudinal ligament are few and occasional. An epidemiological survey on lumbar OPLL was performed by the authors in Matsumoto, Japan, on a total of 792 subjects, 554 of whom over the age of 35, by means of X-ray of the lumbar spine. Ossification of the lumbar posterior longitudinal ligament was detected in 23 subjects (2.9%), with no significant difference between males (3.0%) and females (2.8). Lumbar OPLL was absent in the 238 subjects aged less than 34; it was the most prevalent after the age of 45 (5.1% in males and 4.5% in females). The ossification developed in two ways: continuous ossified layer extending over several vertebrae; circumscribed ossification of the ligament corresponding to the level of the intervertebral disk (retrodiscal type). The result of this epidemiological survey showed a roentgenological incidence of lumbar OPLL of the same magnitude than that of cervical OPLL.

  15. Sensitivity of lumbar spine loading to anatomical parameters.

    PubMed

    Putzer, Michael; Ehrlich, Ingo; Rasmussen, John; Gebbeken, Norbert; Dendorfer, Sebastian

    2016-04-11

    Musculoskeletal simulations of lumbar spine loading rely on a geometrical representation of the anatomy. However, this data has an inherent inaccuracy. This study evaluates the influence of defined geometrical parameters on lumbar spine loading utilising five parametrised musculoskeletal lumbar spine models for four different postures. The influence of the dimensions of vertebral body, disc, posterior parts of the vertebrae as well as the curvature of the lumbar spine was studied. Additionally, simulations with combinations of selected parameters were conducted. Changes in L4/L5 resultant joint force were used as outcome variable. Variations of the vertebral body height, disc height, transverse process width and the curvature of the lumbar spine were the most influential. These parameters can be easily acquired from X-rays and should be used to morph a musculoskeletal lumbar spine model for subject-specific approaches with respect to bone geometry. Furthermore, the model was very sensitive to uncommon configurations and therefore, it is advised that stiffness properties of discs and ligaments should be individualised.

  16. Midline Lumbar Fusion with Cortical Bone Trajectory Screw

    PubMed Central

    MIZUNO, Masaki; KURAISHI, Keita; UMEDA, Yasuyuki; SANO, Takanori; TSUJI, Masanori; SUZUKI, Hidenori

    2014-01-01

    A novel cortical bone trajectory (CBT) screw technique provides an alternative fixation technique for lumbar spine. Trajectory of CBT screw creates a caudo-cephalad path in sagittal plane and a medio-lateral path in axial plane, and engages cortical bone in the pedicle. The theoretical advantage is that it provides enhanced screw grip and interface strength. Midline lumbar fusion (MIDLF) is composed of posterior mid-line approach, microsurgical laminectomy, and CBT screw fixation. We adopted the MIDLF technique for lumbar spondylolisthesis. Advantages of this technique include that decompression and fusion are available in the same field, and it minimizes approach-related damages. To determine whether MIDLF with CBT screw is as effective as traditional approach and it is minimum invasive technique, we studied the clinical and radiological outcomes of MIDLF. Our results indicate that MIDLF is effective and minimum invasive technique. Evidence of effectiveness of MIDLF is that patients had good recovery score, and that CBT screw technique was safety in clinical and stable in radiological. MIDLF with CBT screw provides the surgeon with additional options for fixation. This technique is most likely to be useful for treating lumbar spondylolisthesis in combination with midline decompression and insertion of an interbody graft, such as the transforaminal lumbar interbody fusion or posterior lumbar interbody fusion techniques. PMID:25169139

  17. Posture of patients with lumbar spinal canal stenosis.

    PubMed

    Truszczyńska, Aleksandra; Drzał-Grabiec, Justyna; Płszewski, Maciej; Rąpała, Kazimierz; Tarnowski, Adam

    2015-01-01

    The available literature is lacking in reports on the quantitative analysis of posture in patients with lumbar stenosis. The aim of this study was to analyze body posture in patients with lumbar spinal canal stenosis. The study involved 100 people: 49 persons with severe lumbar spine stenosis and 51 control subjects without any history of back pain. All participatants were evaluated by a photogrammetric method. Photogrammetric measurements showed statistically significant differences in the shape of the anterior-posterior curvatures of the spine. In the study group thoracic kyphosis was significantly greater (p = 0.043), and the depth of lumbar lordosis was significantly smaller (p = 0.038). The inclination of the thoracolumbar segment was also significantly lower (p = 0.013). 1. Measurements of body posture indicate a deepening of thoracic kyphosis and flattening of lumbar lordosis in lumbar stenosis patients. 2. Flattening of physiological lordosis seems to be caused by enlargment of the space of the spinal canal and dural sac in this position.

  18. Radiographic Morphometry of the Lumbar Spine in Munich Miniature Pigs†

    PubMed Central

    Engelke, Elisabeth C; Post, Christina; Pfarrer, Christiane D; Sager, Martin; Waibl, Helmut R

    2016-01-01

    The incidence of human spinal column disease remains high, and animal models still play important roles in prophylactic, diagnostic, and therapeutic research. Because of their similar size to humans, pigs remain an important spine model. For pigs to serve as a model for the human spine, basic similarities and differences must be understood. In this study, morphometric data of the lumbar spine of Munich miniature pigs (Troll) were recorded radiologically, evaluated, and compared with recorded human data. Whereas humans have a constant number of 5 lumbar vertebrae, Munich minipigs had 5 or 6 lumbar vertebrae. Compared with their human counterparts, the lumbar vertebral bodies of the minipigs were remarkably larger in the craniocaudal (superior–inferior) direction and considerably smaller in the dorsoventral and laterolateral directions. The porcine vertebral canal was smaller than the human vertebral canal. The spinal cord extended into the caudal part of the porcine lumbar vertebral canal and thus did not terminate as cranial, as seen in humans. The lumbar intervertebral spaces of the pig were narrower in craniocaudal direction than human intervertebral spaces. These differences need to be considered when planning surgical actions, not only to avoid pain and irreversible damage to the minipigs but also to achieve accurate scientific results. PMID:27177570

  19. [Lumbar herniated disks treated with a dynamic interspacer].

    PubMed

    Cueva-del Castillo Mendoza, J F; Franco-López, E A; Hinojosa-Sandoval, F; de León-Martínez, U A; Cueva-del Castillo Mendoza, F J

    2013-01-01

    Lumbar herniated disks result in lumbar pain with neurologic involvement. Medical treatment and rehabilitation provide improvement for this type of lumbar pain at the early stages. When conservative treatment fails, the surgical option offers the possibility of improving patients' health status. Moojen considers that the application of interspinous spacers provides good results. The purpose of this research is to assess the clinical and imaging results in patients with contained lumbar herniated disk treated with the DYNAMIC INTERSPACER interspinous spacer, a Mexican product. The efficacy of the interspinous device was assessed by means of a near-investigational and longitudinal study conducted at "General Ignacio Zaragoza" ISSSTE Regional Hospital in patients with a diagnosis of lumbar pain. The mean age of the sample is 46.1 years, with an age range of 26-55 years. The treated levels were 6 L5-S1 and 5 L4-L5; two levels were treated in two patients. The mean preoperative VAS score was 8.1. The mean VAS score at postoperative year three was 1.6. Multiple types and brands of foreign interspinous devices are applied in Mexico which results in patients' clinical improvement. We proved that the use of the Mexican interspinous device can clinically improve patients with lumbar pain due to herniated disk. A decrease in the compression of the sac or the nerve roots by the hernia was observed in the comparative preoperative and postoperative MRI images.

  20. Rings Around the Pole

    NASA Image and Video Library

    2005-01-20

    Atmospheric features in Saturn's north polar region are revealed in spectacular detail in this Cassini image, taken in the near infrared spectral region, where methane gas is not very absorbing. The dark shadows of Saturn's rings drape across the planet, creating the illusion of atmospheric bands. Dots of bright clouds give the appearance that this is an active place. The image was taken with the Cassini spacecraft wide angle camera on Dec. 14, 2004, at a distance of 717,800 kilometers (446,100 miles) from Saturn through a filter sensitive to wavelengths of infrared light centered at 939 nanometers. The image scale is about 43 kilometers (27 miles) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA06567

  1. Black ring deconstruction

    SciTech Connect

    Gimon, Eric; Gimon, Eric G.; Levi, Thomas S.

    2007-06-22

    We present a sample microstate for a black ring in four and five dimensional language. The microstate consists of a black string microstate with an additional D6-brane. We show that with an appropriate choice of parameters the piece involving the black string microstate falls down a long AdS throat, whose M-theory lift is AdS_3 x S2. We wrap a spinning dipole M2-brane on the S2 in the probe approximation. In IIA, this corresponds to a dielectric D2-brane carrying only D0-charge. We conjecture this is the firstapproximation to a cloud of D0-branes blowing up due to their non-abelian degrees of freedom and the Myers effect.

  2. A familiar ring?

    SciTech Connect

    Camack, M.J.

    1995-05-01

    These days, the 1984 divestiture of the regional Bell operating companies from AT&T and the succeeding competitive struggles among long-distance companies and equipment providers seem to ring loud and clear for those in the electric power business. The similarities are compelling: Advancements in technology, the clamor of customers for choice, and other natural pressures in the marketplace challenge the traditional structure of a natural monopoly, creating an opening for competition. Voila, deregulation. To gain expertise from the divestiture experience, several electric utility companies have dialed up former telecommunications executives and managers for their insights, hiring them for key positions in senior management. Veterans of telecommunications have instructive views on the similarities, differences, and lessons learned, especially in the areas of marketing and customer focus.

  3. Ring around the colloid

    NASA Astrophysics Data System (ADS)

    Cavallaro, Marcello, Jr.; Gharbi, Mohamed A.; Beller, Daniel A.; Čopar, Simon; Shi, Zheng; Kamien, Randall D.; Yang, Shu; Baumgart, Tobias; Stebe, Kathleen J.

    In this work, we show that Janus washers, genus-one colloids with hybrid anchoring conditions, form topologically required defects in nematic liquid crystals. Experiments under crossed polarizers reveal the defect structure to be a rigid disclination loop confined within the colloid, with an accompanying defect in the liquid crystal. When confined to a homeotropic cell, the resulting colloid-defect ring pair tilts relative to the far field director, in contrast to the behavior of toroidal colloids with purely homeotropic anchoring. We show that this tilting behavior can be reversibly suppressed by the introduction of a spherical colloid into the center of the toroid, creating a new kind of multi-shape colloidal assemblage.

  4. Relationship of the lumbar plexus branches to the lumbar spine: anatomical study with application to lateral approaches.

    PubMed

    Tubbs, Richard Isaiah; Gabel, Brandon; Jeyamohan, Shiveindra; Moisi, Marc; Chapman, Jens R; Hanscom, R David; Loukas, Marios; Oskouian, Rod J; Tubbs, Richard Shane

    2017-07-01

    Injuries to the lumbar plexus during lateral approaches to the spine are not uncommon and may result in permanent deficits. However, the literature contains few studies that provide landmarks for avoiding the branches of the lumbar plexus. The present anatomical study was performed to elucidate the course of these nerves in relation to lateral approaches to the lumbar spine. This is a quantitative anatomical cadaveric study. The lumbar plexus and its branches were dissected on 12 cadaveric sides. Metal wires were laid on the nerves along their paths on the posterior abdominal wall. Fluoroscopy was performed in the anteroposterior and lateral positions. The relationships between regional bony landmarks and the branches of the lumbar plexus were observed. When viewed laterally, the greatest concentration of nerves occurred from the posteroinferior aspect of L4, inferior along the posterior one-third of the body of L5, then at the level of the sacral promontory. On the basis of our study, approaches to the anterior two-thirds of the L4 vertebra and anterior third of L5 will result in the lowest chance of lumbar plexus nerve injury. In addition, lateral muscle dissection through the psoas major should be in a superior to inferior direction in order to minimize nerve injury. Laterally, the widest corridor between branches in the abdominal wall was between the subcostal and iliohypogastric nerves. The findings of our cadaveric study provide surgeons who approach the lateral lumbar spine with data that could decrease injuries to the branches of the lumbar plexus, thus lessening patient morbidity. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Effects of dynamic lumbar stabilization exercises following lumbar microdiscectomy on pain, mobility and return to work. Randomized controlled trial.

    PubMed

    Demir, S; Dulgeroglu, D; Cakci, A

    2014-12-01

    Various lumbar exercise programs are prescribed for rehabilitation purposes following microdiscectomy applied for the treatment of lumbar disk herniation. The literature contains several studies on this subject. However, there are no studies investigating the effects of supervised dynamic lumbar stabilization exercises on fear and fear/regression attitudes of patients and on their return to work. This study investigates the effects of supervised dynamic lumbar stabilization exercises during postoperative rehabilitation on spinal mobility, pain, functional status, return to work, quality of life, and fear/regression attitude of patients who underwent lumbar microdiscectomy for the first time. The study was conducted at physical therapy and rehabilitation clinics. A randomized clinical trial comparing exercise programs after lumbar microdiscectomy. Forty-four lumbar microdiscectomy patients were randomized into two groups. Each group was assessed in terms of low back pain, leg pain, spinal mobility, Oswestry Disability Index (ODI), and Nottingham Health Profile (NHP), at the postoperative first, second, and sixth months. Fear/regression beliefs and level of pain were evaluated through the Fear Avoidance Belief Questionnaire (FABQ). Forty-four patients were randomly divided into two equal groups of 22 subjects, respectively, as a study group with Dynamic Lumbar Stabilization (DLS) exercises and home exercises, and a control group with only home exercises for a period of four weeks. Leg pain decreased more in the study group compared with the control group (P=0.004). Spinal mobility scores demonstrated greater increases in the study group (P<0.001). Statistically greater reductions were observed in the study group regarding ODI and FABQ scores (P<0.017). DLS exercises may be recommended to patients following spinal surgery due to their benefits in reducing pain, increasing spinal mobility, and ensuring faster return to work periods.

  6. The Saturn Ring Observer: In situ studies of planetary rings

    NASA Astrophysics Data System (ADS)

    Nicholson, P. D.; Tiscareno, M. S.; Spilker, L. J.

    2010-12-01

    As part of the Planetary Science Decadal Survey recently undertaken by the NRC's Space Studies Board for the National Academy of Sciences, studies were commissioned for a number of potential missions to outer planet targets. One of these studies examined the technological feasibility of a mission to carry out in situ studies of Saturn's rings, from a spacecraft placed in a circular orbit above the ring plane: the Saturn Ring Observer. The technical findings and background are discussed in a companion poster by T. R. Spilker et al. Here we outline the science goals of such a mission. Most of the fundamental interactions in planetary rings occur on spatial scales that are unresolved by flyby or orbiter spacecraft. Typical particle sizes in the rings of Saturn are in the 1 cm - 10 m range, and average interparticle spacings are a few meters. Indirect evidence indicates that the vertical thickness of the rings is as little as 5 - 10 m, which implies a velocity dispersion of only a few mm/sec. Theories of ring structure and evolution depend on the unknown characteristics of interparticle collisions and on the size distribution of the ring particles. The SRO could provide direct measurements of both the coefficient of restitution -- by monitoring individual collisions -- and the particles’ velocity dispersion. High-resolution observations of individual ring particles should also permit estimates of their spin states. Numerical simulations of Saturn’s rings incorporating both collisions and self-gravity predict that the ring particles are not uniformly distributed, but are instead clustered into elongated structures referred to as “self-gravity wakes”, which are continually created and destroyed on an orbital timescale. Theory indicates that the average separation between wakes in the A ring is of order 30-100 m. Direct imaging of self-gravity wakes, including their formation and subsequent dissolution, would provide critical validation of these models. Other

  7. Results of lumbar spondylodeses using different bone grafting materials after transforaminal lumbar interbody fusion (TLIF).

    PubMed

    vonderHoeh, Nicolas Heinz; Voelker, Anna; Heyde, Christoph-Eckhard

    2017-05-25

    Can a mixture of hydroxyapatite (HA) and autologous bone from decompression sites produce similar results when used for transforaminal lumbar interbody fusion (TLIF)? In the current literature, autologous iliac crest bone grafts (ICBGs) have been reported the gold standard for this procedure. Indeed, to date, no clinical data have confirmed that a mixture of equal volumes of HA and local autologous bone produce similar results in term of fusion as the same volume of autologous ICBG alone. Study design/setting This study was approved by the local ethics committee and completed in a prospective, randomized, single-blinded manner. The results of lumbar fusion using TLIF and different bone grafting materials were compared. Patient sample The patient sample included patients with spinal lumbar degenerative disease. Outcome measures The clinical outcome was determined using the Oswestry Low Back Pain Disability Questionnaire (ODI) and Visual Analog Scale (VAS). The radiological outcomes and fusion rates were determined with radiographs evaluated using the McAfee criteria and computed tomography (CT) data evaluated by the Williams criteria. Three blinded investigators (one radiologist and two orthopedic surgeons) assessed the data. The secondary variables included donor site morbidity. Methods The patients were admitted to our department for orthopedic surgery with degenerative lumbar pathologies (L2-S1) that required stabilization in one or two segments using a TLIF procedure. The patients were 18-80 years old. Only those patients who had degenerative lumbar pathologies and agreed to be educated about the study were included. The patients were divided into the following two randomized groups: group A: TLIF procedure using autologous ICBGs alone; and group B: TLIF procedure using local bone from decompression site mixed with hydroxyapatite. Each group received equal graft volumes. The mixture in group B consisted of equal volumes of local autograft (5 cc) and synthetic

  8. 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

  9. Biomechanical effect of altered lumbar lordosis on intervertebral lumbar joints during the golf swing: a simulation study.

    PubMed

    Bae, Tae Soo; Cho, Woong; Kim, Kwon Hee; Chae, Soo Won

    2014-11-01

    Although the lumbar spine region is the most common site of injury in golfers, little research has been done on intervertebral loads in relation to the anatomical-morphological differences in the region. This study aimed to examine the biomechanical effects of anatomical-morphological differences in the lumbar lordosis on the lumbar spinal joints during a golf swing. The golf swing motions of ten professional golfers were analyzed. Using a subject-specific 3D musculoskeletal system model, inverse dynamic analyses were performed to compare the intervertebral load, the load on the lumbar spine, and the load in each swing phase. In the intervertebral load, the value was the highest at the L5-S1 and gradually decreased toward the T12. In each lumbar spine model, the load value was the greatest on the kypholordosis (KPL) followed by normal lordosis (NRL), hypolordosis (HPL), and excessive lordosis (EXL) before the impact phase. However, results after the follow-through (FT) phase were shown in reverse order. Finally, the load in each swing phase was greatest during the FT phase in all the lumbar spine models. The findings can be utilized in the training and rehabilitation of golfers to help reduce the risk of injury by considering individual anatomical-morphological characteristics.

  10. Clinical study of bilateral decompression via vertebral lamina fenestration for lumbar interbody fusion in the treatment of lower lumbar instability.

    PubMed

    Guo, Shuguang; Sun, Junying; Tang, Genlin

    2013-03-01

    The aim of this study was to observe the clinical effects of bilateral decompression via vertebral lamina fenestration for lumbar interbody fusion in the treatment of lower lumbar instability. The 48 patients comprised 27 males and 21 females, aged 47-72 years. Three cases had first and second degree lumbar spondylolisthesis and all received bilateral vertebral lamina fenestration for posterior lumbar interbody fusion (PLIF) using a threaded fusion cage (TFC), which maintains the three-column spinal stability. Attention was given to ensure the correct pre-operative fenestration, complete decompression and the prevention of adhesions. After an average follow-up of 26.4 months, the one year post-operative X-ray radiographs suggested that the successful fusion rate was 88.1%, and this was 100% in the two-year post-operative radiographs. Moreover, the functional recovery rate was 97.9%. Bilateral vertebral lamina fenestration for lumbar interbody fusion is an ideal surgical method for the treatment of lower lumbar instability. The surgical method retains the spinal posterior column and middle column and results in full decompression and reliable fusion by a limited yet effective surgical approach.

  11. Clinical study of bilateral decompression via vertebral lamina fenestration for lumbar interbody fusion in the treatment of lower lumbar instability

    PubMed Central

    GUO, SHUGUANG; SUN, JUNYING; TANG, GENLIN

    2013-01-01

    The aim of this study was to observe the clinical effects of bilateral decompression via vertebral lamina fenestration for lumbar interbody fusion in the treatment of lower lumbar instability. The 48 patients comprised 27 males and 21 females, aged 47–72 years. Three cases had first and second degree lumbar spondylolisthesis and all received bilateral vertebral lamina fenestration for posterior lumbar interbody fusion (PLIF) using a threaded fusion cage (TFC), which maintains the three-column spinal stability. Attention was given to ensure the correct pre-operative fenestration, complete decompression and the prevention of adhesions. After an average follow-up of 26.4 months, the one year post-operative X-ray radiographs suggested that the successful fusion rate was 88.1%, and this was 100% in the two-year post-operative radiographs. Moreover, the functional recovery rate was 97.9%. Bilateral vertebral lamina fenestration for lumbar interbody fusion is an ideal surgical method for the treatment of lower lumbar instability. The surgical method retains the spinal posterior column and middle column and results in full decompression and reliable fusion by a limited yet effective surgical approach. PMID:23407794

  12. Lumbar nerve rootlet entrapment by an iatrogenically spliced percutaneous intra-thecal lumbar cerebrospinal fluid catheter.

    PubMed

    Yue, James J; Castro, Carlos A; Scott, David

    2015-01-01

    Complications associated with the use of percutaneous intra-thecal lumbar indwelling spinal catheters include infection, hematoma, neurologic dysfunction, and persistent undesired retention among others. A case of iatrogenic splicing associated with neurologic dysfunction with the use of a percutaneous intra-thecal indwelling spinal catheter is presented in this study. Single case study review. Review of case materials indicate Y pattern splicing/fragmentation of an indwelling intra-thecal catheter causing neurologic dysfunction and resistance to removal during attempted removal. Pain and weakness were evident soon after insertion of the catheter and were amplified with attempted catheter removal. Computed tomography revealed a double dot sign on axial view and a Y appearance on sagittal view. Surgical findings revealed entrapment of nerve rootlets in the axilla of the spliced catheter. Splicing/fragmentation causing neurologic dysfunction as well as catheter retention is described as a potential complication of intra-thecal indwelling cerebrospinal fluid catheters. A symptom of fragmentation of a catheter may include neurologic dysfunction including pain and weakness of a lumbar nerve root. If resistance is experienced upon attempted catheter removal, with or without associated neurologic dysfunction, further attempts at removal should not be attempted. In those cases in which pain and/or lumbar weakness are evident post catheter placement and/or following attempted removal, computed tomography should be performed. If fragmentation of a catheter is evident on CT scan, spinal surgical consultation should be obtained. Recommended spinal surgical intervention includes an open durotomy and visualization of catheter fragments and nerve rootlets and removal of catheter fragments. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Functional properties of lumbar preganglionic neurones.

    PubMed

    Jänig, W; Szulczyk, P

    1980-03-17

    Lumbar preganglionic neurones projecting through WRL2 and L3 to lumbar ganglia caudal to L4 were investigated for those functional properties which are typical for postganglionic vasoconstrictor neurones supplying muscle and skin and for post ganglionic sudomotor neurones. The properties tested were the cardiac rhythmicity of the activity and the reactions to systemic hypoxia, to noxious stimulation of skin and (in part of the experiments) to vibrational stimuli. Furthermore, resting activity and conduction velocities of the asons were measured. 426 neurones were investigated. 311 (73%) of them were silent and could -- as far as tested -- not be excited by the afferent stimuli used. The conduction velocities of the axons of these neurones ranged from 0.5 to about 16 m/sec. 115 neurones had resting activity of 0.1--4.6 impulses/sec. The conduction velocities of their axons ranged from 0.5 to about 12 m/sec. 80 preganglionic neurones with resting activity were classified on the basis of the reflexes in these neurones to afferent stimuli. Preganglionic neurones reacting like postganglionic vasoconstrictor neurones to muscle (excited by systemic hypoxia and/or by noxious stimulation of skin; with cardic rhythmicity) were classified as type 1 neurones (26 from 80 neurones tested). The resting activity of these neurones was 1.8 +/- 1.3 impulses/sec (mean +/- 1 S.D.). Their axons conducted with 3.9 +/- m/sec. Preganglionic neurones reacting like the majority of the postganglionic vasoconstrictor neurones to hairy and hairless skin (inhibited by systemic hypoxia and/or noxious cutaneous stimuli) were classified as type 2 neurones (48 from 80 neurones investigated). In 40% of these neurones the activity had cardiac rhythmicity. The resting activity was 0.9 +/- 0.6 impulses/sec. The distribution of the conduction velocities of the axons of these neurones was bimodal. They conducted on the average with 1.3 +/- 0.6 m/sec and 6.6 +/- 1.1 m/sec respectively. A few neurones were

  14. Minimally invasive percutaneous posterior lumbar interbody fusion.

    PubMed

    Khoo, Larry T; Palmer, Sylvain; Laich, Daniel T; Fessler, Richard G

    2002-11-01

    The wide exposure required for a standard posterior lumbar interbody fusion (PLIF) can cause unnecessary trauma to the lumbar musculoligamentous complex. By combining existing microendoscopic, percutaneous instrumentation and interbody technologies, a novel, minimally invasive, percutaneous PLIF technique was developed to minimize such iatrogenic tissue injury (MIP-PLIF). The MIP-PLIF technique was validated in three cadaveric torsos with six motion segments decompressed and fused. Preoperative variables measured from imaging included interpedicular distance, pedicular height and width, interspinous distance, lordosis, intervertebral height, Cobb angle, and foraminal height and volume. Using the METRx and MD spinal access systems (Medtronic Sofamor Danek, Memphis, TN), bilateral laminotomies were performed using a hybrid of microsurgical and microendoscopic techniques. The intervertebral disc spaces were then distracted and prepared with the Tangent (Medtronic Sofamor Danek) interbody instruments. Either a 10 or 12 by 22 mm interbody graft was then placed. Using the Sextant (Medtronic Sofamor Danek) system, percutaneous pedicle screw-rod fixation of the motion segment was completed. We then applied MIP-PLIF in three patients. For segments with preoperative intervertebral/foraminal height loss, MIP-PLIF was effective in restoring both heights in all cases. The amount of improvement (9.7 to 38% disc height increase; 7.7 to 29.9% foraminal height increase) varied directly with the size of the graft used and the original degree of disc and foraminal height loss. Segmental lordosis improved by 29% on average. Graft and screw placement was accurate in the cadavers, except for a single Grade 1 screw violation of one pedicle. The average operative time was 3.5 hours per level. In our three clinical cases, the MIP-PLIF procedure required a mean of 5.4 hours, estimated blood loss was 185 ml, and inpatient stay was 2.8 days, with no intravenous narcotic use after 2 days in

  15. How Jupiter's Ring Was Discovered.

    ERIC Educational Resources Information Center

    Elliot, James; Kerr, Richard

    1985-01-01

    "Rings" (by astronomer James Elliot and science writer Richard Kerr) is a nontechnical book about the discovery and exploration of ring systems from the time of Galileo to the era of the Voyager spacecraft. One of this book's chapters is presented. (JN)

  16. Uranus Rings in False Color

    NASA Image and Video Library

    1996-01-29

    This false-color view of the rings of Uranus was made from images taken by NASA Voyager 2 on Jan. 21, 1986. All nine known rings are visible here; the somewhat fainter, pastel lines seen between them are contributed by the computer enhancement. http://photojournal.jpl.nasa.gov/catalog/PIA00033

  17. Nardò Ring, Italy

    NASA Image and Video Library

    2008-04-08

    The Nardò Ring is a striking visual feature from space, and astronauts have photographed it several times. The Ring is a race car test track in Italy. This image was acquired by NASA Terra satellite on August 17. 2007.

  18. Running Rings Around the Web.

    ERIC Educational Resources Information Center

    McDermott, Irene E.

    1999-01-01

    Describes the development and current status of WebRing, a service that links related Web sites into a central hub. Discusses it as a viable alternative to other search engines and examines issues of free speech, use by the business sector, and implications for WebRing after its purchase by Yahoo! (LRW)

  19. Reversible Seeding in Storage Rings

    SciTech Connect

    Ratner, Daniel; Chao, Alex; /SLAC

    2011-12-14

    We propose to generate steady-state microbunching in a storage ring with a reversible seeding scheme. High gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG) are two promising methods for microbunching linac electron beams. Because both schemes increase the energy spread of the seeded beam, they cannot drive a coherent radiator turn-by-turn in a storage ring. However, reversing the seeding process following the radiator minimizes the impact on the electron beam and may allow coherent radiation at or near the storage ring repetition rate. In this paper we describe the general idea and outline a proof-of-principle experiment. Electron storage rings can drive high average power light sources, and free-electron lasers (FELs) are now producing coherent light sources of unprecedented peak brightness While there is active research towards high repetition rate FELs (for example, using energy recovery linacs), at present there are still no convenient accelerator-based sources of high repetition rate, coherent radiation. As an alternative avenue, we recently proposed to establish steady-state microbunching (SSMB) in a storage ring. By maintaining steady-state coherent microbunching at one point in the storage ring, the beam generates coherent radiation at or close to the repetition rate of the storage ring. In this paper, we propose a method of generating a microbunched beam in a storage ring by using reversible versions of linac seeding schemes.

  20. How Jupiter's Ring Was Discovered.

    ERIC Educational Resources Information Center

    Elliot, James; Kerr, Richard

    1985-01-01

    "Rings" (by astronomer James Elliot and science writer Richard Kerr) is a nontechnical book about the discovery and exploration of ring systems from the time of Galileo to the era of the Voyager spacecraft. One of this book's chapters is presented. (JN)

  1. Contraceptive vaginal rings: a review.

    PubMed

    Brache, Vivian; Faundes, Anibal

    2010-11-01

    Development efforts on contraceptive vaginal rings were initiated over 40 years ago based on two principles: the capacity of the vaginal epithelium to absorb steroids and the capacity of elastomers to release these hormones at a nearly constant rate. Numerous models of contraceptive vaginal rings (CVRs) have been studied, but only two have reached the market: NuvaRing, a combined ring that releases etonogestrel (ENG) and ethinylestradiol (EE), and Progering, a progesterone-releasing ring for use in lactating women. The main advantages of CVRs are their effectiveness (similar to or slightly better than the pill), ease of use without the need of remembering a daily routine, user's ability to control initiation and discontinuation, nearly constant release rate allowing for lower doses, greater bioavailability and good cycle control with the combined ring. The main disadvantages are related to the mode of delivery; CVRs may cause vaginal discharge and complaints, ring expulsion is not uncommon, the ring may be felt during coitus and vaginal insertion may be unpleasant for some women. The studies reviewed in this article provide evidence that CVRs are safe, effective and highly acceptable to women. There is no doubt that CVRs offer a new, effective contraceptive option to women, expanding their available choices of hormonal contraception. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Ring Infiltrate in Staphylococcal Keratitis

    PubMed Central

    Wallang, Batriti S.; Sharma, Savitri; Sahu, Srikant K.; Mittal, Ruchi

    2013-01-01

    Smear and culture tests of corneal scrapings from a patient with a ring infiltrate confirmed significant growth of a Staphylococcus species resistant to fluoroquinolones. Because of nonresponse to medical management, the patient underwent therapeutic penetrating keratoplasty. Staphylococcal infection of the cornea may appear as a ring-like infiltrate that is recalcitrant to medical management. PMID:23100354

  3. Biomechanics of Corneal Ring Implants

    PubMed Central

    2015-01-01

    Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. Results: For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. Conclusions: The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus. PMID:26312619

  4. Rings Full of Waves (zoom)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image shows a close-up view of a density wave in Saturn's A ring. It was taken by the narrow angle camera on the Cassini spacecraft after successful entry into Saturn's orbit. The view shows the dark, or unlit, side of the rings.

  5. Fibre ring cavity semiconductor laser

    SciTech Connect

    Duraev, V P; Medvedev, S V

    2013-10-31

    This paper presents a study of semiconductor lasers having a polarisation maintaining fibre ring cavity. We examine the operating principle and report main characteristics of a semiconductor ring laser, in particular in single- and multiple-frequency regimes, and discuss its application areas. (lasers)

  6. Simulating the Smallest Ring World of Chariklo

    NASA Astrophysics Data System (ADS)

    Michikoshi, Shugo; Kokubo, Eiichiro

    2017-03-01

    A ring system consisting of two dense narrow rings has been discovered around Centaur Chariklo. The existence of these rings around a small object poses various questions about their origin, stability, and lifetime. In order to understand the nature of Chariklo’s rings, we perform global N-body simulations of the self-gravitating collisional particle rings for the first time. We find that Chariklo should be denser than the ring material in order to avoid the rapid diffusion of the rings. If Chariklo is denser than the ring material, fine spiral structures called self-gravity wakes occur in the inner ring. These wakes accelerate the viscous spreading of the ring significantly and typically occur on timescales of about 100 {years} for m-sized ring particles, which is considerably shorter than the timescales suggested in previous studies. The existence of these narrow rings implies smaller ring particles or the existence of shepherding satellites.

  7. The Search for Ringed Exoplanets

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-04-01

    Are planetary rings as common in our galaxy as they are in our solar system? A new study demonstrates how we might search for ringed exoplanets and then possibly finds one!Saturns Elsewhere?Artists illustration of the super ring system around exoplanet J1407b. This is the only exoplanet weve found with rings, but its not at all like Saturn. [Ron Miller]Our solar system is filled with moons and planetary rings, so it stands to reason that exoplanetary systems should exhibit the same features. But though weve been in the planet-hunting game for decades, weve only found one exoplanet thats surrounded by a ring system. Whats more, that system J1407b has enormous rings that are vastly different from the modest, Saturn-like rings that we might expect to be more commonplace.Have we not discovered ringed exoplanets just because theyre hard to identify? Or is it because theyre not out there? A team of scientists led by Masataka Aizawa (University of Tokyo) has set out to answer this question by conducting a systematic search for rings around long-period planet candidates.The transit light curve of KIC 10403228, shown with three models: the best-fitting planet-only model (blue) and the two best-fitting planet+ring models (green and red). [Aizawa et al. 2017]The Hunt BeginsWhy long-period planets? Rings are expected to be unstable as the planet gets closer to the central star. Whats more, the planet needs to be far enough away from the stars warmth for the icy rings to exist. The authors therefore select from the collection of candidate transiting planets 89 long-period candidates that might be able to host rings.Aizawa and collaborators then fit single-planet models (with no rings) to the light curves of these planets and search for anomalies curves that arent fit well by these standard models. Particularly suspicious characteristics include a long ingress/egress as the planet moves across the face of the star, and asymmetry of the transit shape.After applying a series of

  8. Advances in microbicide vaginal rings.

    PubMed

    Malcolm, R Karl; Edwards, Karen-Leigh; Kiser, Patrick; Romano, Joseph; Smith, Thomas J

    2010-12-01

    Vaginal ring devices capable of providing sustained/controlled release of incorporated actives are already marketed for steroidal contraception and estrogen replacement therapy. In recent years, there has been considerable interest in developing similar ring devices for the administration of microbicidal compounds to prevent vaginal HIV transmission. Intended to be worn continuously, such coitally independent microbicide rings are being developed to maintain effective vaginal microbicide concentrations over many weeks or months, thereby overcoming issues around timing of product application, user compliance and acceptability associated with more conventional semi-solid formulations. In this article, an overview of vaginal ring technologies is presented, followed by a review of recent advances and issues pertaining to their application for the delivery of HIV microbicides. This article forms part of a special supplement on presentations covering intravaginal rings, based on the symposium "Trends in Microbicide Formulations", held on 25 and 26 January 2010, Arlington, VA. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Lumbar spine postures in marines during simulated operational positions.

    PubMed

    Berry, David B; Rodríguez-Soto, Ana E; Su, Jeannie; Gombatto, Sara P; Shahidi, Bahar; Palombo, Laura; Chung, Christine; Jensen, Andrew; Kelly, Karen R; Ward, Samuel R

    2017-01-04

    Low back pain has a 70% higher prevalence in members of the armed forces than in the general population, possibly due to the loads and positions soldiers experience during training and combat. Although the influence of heavy load carriage on standing lumbar spine posture in this population is known, postures in other operationally relevant positions are unknown. Therefore, the purpose of this study was to characterize the effect of simulated military operational positions under relevant loading conditions on global and local lumbar spine postures in active duty male US Marines. Secondary objectives were to evaluate if intervertebral disc degeneration and low back pain affect lumbar spine postures. Magnetic resonance images were acquired on an upright scanner in the following operational positions: Natural standing with no external load, standing with body armor (11.3 kg), sitting with body armor, and prone on elbows with body armor. Custom software was used to measure global lumbar spine posture: Lumbosacral flexion, sacral slope, lordosis, local measures of intervertebral angles, and intervertebral distances. Sitting resulted in decreased lumbar lordosis at all levels of the spine except L1-L2. When subjects were prone on elbows, a significant increase in local lordosis was observed only at L5-S1 compared with all other positions. Marines with disc degeneration (77%) or history of low back pain (72%) had decreased lumbar range of motion and less lumbar extension than healthy Marines. These results indicate that a male Marine's pathology undergoes a stereotypic set of postural changes during functional tasks, which may impair performance. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:XX-XX, 2017.

  10. Hepatocellular Carcinoma Supplied by the Right Lumbar Artery

    SciTech Connect

    Miyayama, Shiro Yamashiro, Masashi; Okuda, Miho; Yoshie, Yuichi; Sugimori, Natsuki; Igarashi, Saya; Nakashima, Yoshiko; Matsui, Osamu

    2010-02-15

    This study evaluated the clinical features of hepatocellular carcinoma (HCC) supplied by the right lumbar artery. Eleven patients with HCC supplied by the right lumbar artery were treated with chemoembolization. The patients' medical records were retrospectively analyzed. All patients underwent 6.7 {+-} 3.7 (mean {+-} SD) chemoembolization sessions, and the hepatic arterial branches were noted as being attenuated. The right inferior phrenic artery (IPA) was also embolized in 10 patients. The interval between initial chemoembolization and chemoembolization of the lumbar artery supply was 53.2 {+-} 26.9 months. Mean tumor diameter was 3.1 {+-} 2.4 cm and was located at the surface of S7 and S6. The feeding-branch arose proximal to the bifurcation of the dorsal ramus and muscular branches (n = 8) or from the muscular branches (n = 3) of the right first (n = 10) or second lumbar artery (n = 1). The anterior spinal artery originated from the tumor-feeding lumbar artery in one patient. All feeders were selected, and embolization was performed after injection of iodized oil and anticancer drugs (n = 10) or gelatin sponge alone in a patient with anterior spinal artery branching (n = 1). Eight patients died from tumor progression 10.1 {+-} 4.6 months later, and two patients survived 2 and 26 months, respectively. The remaining patient died of bone metastases after 32 months despite liver transplantation 10 months after chemoembolization. The right lumbar artery supplies HCC located in the bare area of the liver, especially in patients who undergo repeated chemoembolization, including chemoembolization by way of the right IPA. Chemoembolization by way of the right lumbar artery may be safe when the feeder is well selected.

  11. Bias in the physical examination of patients with lumbar radiculopathy

    PubMed Central

    2010-01-01

    Background No prior studies have examined systematic bias in the musculoskeletal physical examination. The objective of this study was to assess the effects of bias due to prior knowledge of lumbar spine magnetic resonance imaging findings (MRI) on perceived diagnostic accuracy of the physical examination for lumbar radiculopathy. Methods This was a cross-sectional comparison of the performance characteristics of the physical examination with blinding to MRI results (the 'independent group') with performance in the situation where the physical examination was not blinded to MRI results (the 'non-independent group'). The reference standard was the final diagnostic impression of nerve root impingement by the examining physician. Subjects were recruited from a hospital-based outpatient specialty spine clinic. All adults age 18 and older presenting with lower extremity radiating pain of duration ≤ 12 weeks were evaluated for participation. 154 consecutively recruited subjects with lumbar disk herniation confirmed by lumbar spine MRI were included in this study. Sensitivities and specificities with 95% confidence intervals were calculated in the independent and non-independent groups for the four components of the radiculopathy examination: 1) provocative testing, 2) motor strength testing, 3) pinprick sensory testing, and 4) deep tendon reflex testing. Results The perceived sensitivity of sensory testing was higher with prior knowledge of MRI results (20% vs. 36%; p = 0.05). Sensitivities and specificities for exam components otherwise showed no statistically significant differences between groups. Conclusions Prior knowledge of lumbar MRI results may introduce bias into the pinprick sensory testing component of the physical examination for lumbar radiculopathy. No statistically significant effect of bias was seen for other components of the physical examination. The effect of bias due to prior knowledge of lumbar MRI results should be considered when an isolated

  12. Cost Utility Analysis of Percutaneous Adhesiolysis in Managing Pain of Post-lumbar Surgery Syndrome and Lumbar Central Spinal Stenosis.

    PubMed

    Manchikanti, Laxmaiah; Helm, Standiford; Pampati, Vidyasagar; Racz, Gabor B

    2015-06-01

    The increase in the number of interventions for the management of chronic pain and associated escalation of healthcare costs has captured the attention of health policymakers, in no small part due to the lack of documentation of efficacy, cost-effectiveness, or cost utility analysis. A recent cost utility analysis of caudal epidural injections in managing chronic low back pain of various pathologies showed a high cost utility with improvement in quality of life years, competitive with various other modalities of treatments. However, there are no analyses derived from high-quality controlled studies related to the cost utility of percutaneous adhesiolysis in the treatment of post-lumbar surgery syndrome or lumbar central spinal stenosis. This analysis is based on 2 previously published controlled studies. To assess the cost utility of percutaneous adhesiolysis procedures in managing chronic low back and lower extremity pain secondary to post-lumbar surgery syndrome and lumbar central spinal stenosis. A private, specialty referral interventional pain management center in the United States. Two controlled studies were conducted assessing the clinical effectiveness of percutaneous adhesiolysis for post-lumbar surgery syndrome and lumbar central spinal stenosis in an interventional pain management setting utilizing contemporary interventional pain management practices. A cost utility analysis was performed with direct payment data for a total of 130 patients in treatment groups over a 2-year period. Various outcome measures were included with significant improvement, defined as at least 50% improvement with reduction in pain and disability status. The results of 2 controlled studies of low back pain with 60 and 70 patients and a 2-year follow-up with the actual reimbursement data showed cost utility for 1 year of quality-adjusted life year (QALY) of USD $2,652 for post-lumbar surgery syndrome and USD $2,649 for lumbar central spinal stenosis. The results of this

  13. [Spontaneous regression of lumbar disk hernia].

    PubMed

    Lutman, M; Girelli, G

    1991-03-01

    Four cases of spontaneous regression of herniated nucleus polposus are described, which were followed after conservative medical treatment. Three female and one male patients who suffered from severe lumbago were evaluated; their age ranged 24-59 years. From the first CT scan on which herniation was diagnosed to follow-up control after complete regression of symptoms an average period of 14 months elapsed. Comparing ours with literature data, a substantial agreement was observed of both timing of spontaneous regression and location (most often involved was the last lumbar intervertebral space). The age of one of our patients (59 years) is to be stressed, which is well above the mean age reported in literature (35 years). The pathogenesis of regression is still unknown. The most reliable hypothesis seems to be that of dehydration and progressive atrophy of the herniated nucleus polposus. The appearance, in some cases, of the vacuum disk phenomenon seems to support such a thesis. Therefore, the diagnosis of a herniated nucleus polposus of relatively small size, still contained in an intact posterior longitudinal ligament, widely justifies the choice of waiting tactics.

  14. Osteolytic lumbar discal cyst: case report.

    PubMed

    Marushima, Aiki; Uemura, Kazuya; Sato, Naoaki; Maruno, Toru; Matsumura, Akira

    2008-08-01

    A 25-year-old man presented with left lumboischialgia refractory to medical treatment. Neurological examination revealed L5 and S1 radiculopathy which rapidly worsened over a short period. Magnetic resonance imaging demonstrated disk bulging with a discal cyst at the L4-5 intervertebral space and disk herniation at the L5-S1 intervertebral space. Computed tomography showed osteolytic change of the L5 vertebral body adjacent to the cyst. Resection of the cyst and removal of the herniated disk were performed following fenestration of the L4-5 and L5-S1 interlaminar spaces. Bloody serous fluid followed by clear serous fluid was recognized during the aspiration and partial resection of the cyst at the L4-5 level. Histological examination demonstrated a cyst wall consisting of fibrous connective tissue without a single-layer lining of cells, and fibrin deposits. The patient's symptoms disappeared immediately after the operation. This osteolytic lumbar discal cyst possibly occurred subsequent to hemorrhage from the epidural venous plexus following intervertebral disk injury, hematoma encapsulation by connective fibrous tissue, and cyst wall formation in reaction to the disk injury and hemorrhage. The cyst may have enlarged due to the inflow of the serous fluid from the water-containing degenerated disk.

  15. Lumbar Disc Herniation Presented with Contralateral Symptoms

    PubMed Central

    Kim, Pius; Ju, Chang Il; Kim, Hyeun Sung; Kim, Seok Won

    2017-01-01

    Objective This study aimed to unravel the putative mechanism underlying the neurologic deficits contralateral to the side with lumbar disc herniation (LDH) and to elucidate the treatment for this condition. Methods From January 2009 to June 2015, 8 patients with LDH with predominantly contralateral neurologic deficits underwent surgical treatment on the side with LDH with or without decompressing the symptomatic side. A retrospective review of charts and radiological records of these 8 patients was performed. The putative mechanisms underlying the associated contralateral neurological deficits, magnetic resonance imaging (MRI), electromyography (EMG), and the adequate surgical approach are discussed here. Results MRI revealed a similar laterally skewed paramedian disc herniation, with the apex deviated from the symptomatic side rather than directly compressing the nerve root; this condition may generate a contralateral traction force. EMG revealed radiculopathies in both sides of 6 patients and in the herniated side of 2 patients. Based on EMG findings and the existence of suspicious lateral recess stenosis of the symptomatic side, 6 patients underwent bilateral decompression of nerve roots and 2 were subjected to a microscopic discectomy to treat the asymptomatic disc herniation. No specific conditions such as venous congestion, nerve root anomaly or epidural lipomatosis were observed, which may be considered the putative pathomechanism causing the contralateral neurological deficits. The symptoms resolved significantly after surgery. Conclusion The traction force generated on the contralateral side and lateral recess stenosis, rather than direct compression, may cause the contralateral neurologic deficits observed in LDH. PMID:28264243

  16. Movements, lumbar and temporomandibular pain and psychopathology.

    PubMed

    Sundsvold, M O; Vaglum, P; Ostberg, B

    1981-01-01

    157 males and females divided into four psychodiagnostic groups have been examined according to a specially defined physiotherapeutic (ad modum Sundsvold). In this paper, results from the evaluation of passive and active movements in five body significant differences concerning inhibited movements between the four groups were found, the psychotic group being most inhibited followed by the ego-week neurotic group, the substance-abusing group and the healthy control group. With regard to the slack movements, significant differences were found in the two extremity regions. The substance-abusing group had the most slack movements, next came the ego-weak neurotic group, the psychotic group and lastly the control group. Men were more inhibited than women in three regions, mostly in the lumbosacral region. This finding is discussed in relationship to the high frequency of lumbar disc herniation in men. Women were more significantly inhibited in the temporomandibular region, a finding which may explain why mostly women are suffering from the myofacial pain syndrome.

  17. Lubrication regimes in lumbar total disc arthroplasty.

    PubMed

    Shaheen, A; Shepherd, D E T

    2007-08-01

    A number of total disc arthroplasty devices have been developed. Some concern has been expressed that wear may be a potential failure mode for these devices, as has been seen with hip arthroplasty. The aim of this paper was to investigate the lubrication regimes that occur in lumbar total disc arthroplasty devices. The disc arthroplasty was modelled as a ball-and-socket joint. Elastohydrodynamic lubrication theory was used to calculate the minimum film thickness of the fluid between the bearing surfaces. The lubrication regime was then determined for different material combinations, size of implant, and trunk velocity. Disc arthroplasties with a metal-polymer or metal-metal material combination operate with a boundary lubrication regime. A ceramic-ceramic material combination has the potential to operate with fluid-film lubrication. Disc arthroplasties with a metal-polymer or metal-metal material combination are likely to generate wear debris. In future, it is worth considering a ceramic-ceramic material combination as this is likely to reduce wear.

  18. Case report of lumbar intradural capillary hemangioma.

    PubMed

    Unnithan, Ajaya Kumar Ayyappan; Joseph, T P; Gautam, Amol; Shymole, V

    2016-01-01

    Capillary hemangioma is a rare tumor in spinal intradural location. Despite the rarity, early recognition is important because of the risk of hemorrhage. This is a case report of a woman who had capillary hemangioma of cauda equina. A 54 -year-old woman presented with a low backache, radiating to the left leg for 2 months. She had left extensor hallucis weakness, sensory impairment in left L5 dermatome, and mild tenderness in lower lumbar spine. Magnetic resonance imaging (MRI) LS spine showed L4/5 intradural tumor, completely occluding canal in myelogram, enhancing with contrast, s/o benign nerve sheath tumor. L4 laminectomy was done. Reddish tumor was seen originating from a single root. It was removed preserving the root. Postoperatively, she was relieved of symptoms. MRI showed no residue. Histopathology showed lobular proliferation of capillary-sized blood vessels and elongated spindle cells. Immunohistochemistry showed CD34 positivity in endothelial cell lining of blood vessel and smooth muscle actin positivity in blood vessel muscle cells. HPR-capillary hemangioma. Although rare, capillary hemangioma should be in the differential diagnosis of intradural tumors. It closely mimics nerve sheath tumor.

  19. Risk Factors for Recurrent Lumbar Disc Herniation

    PubMed Central

    Huang, Weimin; Han, Zhiwei; Liu, Jiang; Yu, Lili; Yu, Xiuchun

    2016-01-01

    Abstract Recurrent lumbar disc herniation (rLDH) is a common complication following primary discectomy. This systematic review aimed to investigate the current evidence on risk factors for rLDH. Cohort or case-control studies addressing risk factors for rLDH were identified by search in Pubmed (Medline), Embase, Web of Science, and Cochrane library from inception to June 2015. Relevant results were pooled to give overall estimates if possible. Heterogeneity among studies was examined and publication bias was also assessed. A total of 17 studies were included in this systematic review. Risk factors that had significant relation with rLDH were smoking (OR 1.99, 95% CI 1.53–2.58), disc protrusion (OR 1.79, 95% CI 1.15–2.79), and diabetes (OR 1.19, 95% CI 1.06–1.32). Gender, BMI, occupational work, level, and side of herniation did not correlate with rLDH significantly. Based on current evidence, smoking, disc protrusion, and diabetes were predictors for rLDH. Patients with these risk factors should be paid more attention for prevention of recurrence after primary surgery. More evidence provided by high-quality observational studies is still needed to further investigate risk factors for rLDH. PMID:26765413

  20. Black hole ringing, quasinormal modes, and light rings

    NASA Astrophysics Data System (ADS)

    Khanna, Gaurav; Price, Richard H.

    2017-04-01

    Modeling of gravitational waves from binary black hole inspiral has played an important role in the recent observations of such signals. The late-stage ringdown phase of the gravitational waveform is often associated with the null particle orbit ("light ring") of the black hole spacetime. With simple models we show that this link between the light ring and spacetime ringing is based more on the history of specific models than on an actual constraining relationship. We also show, in particular, that a better understanding of the dissociation of the two may be relevant to the astrophysically interesting case of rotating (Kerr) black holes.