摘要:

Study Design.We measured concentrations of specific molecules reflecting matrix synthesis and degradation in normal and scoliotic intervertebral discs and endplates.Objectives.The aim of this work was to quantitate markers of matrix turnover in normalversusadolescent idiopathic scoliotic intervertebral discs and cartilaginous endplates.Summary of Background Data.Changes in the intervertebral disc and endplate composition have been implicated as possible etiologic factors in the pathogenesis of adolescent idiopathic scoliosis. To better understand this process, it is important to compare the turnover of matrix components in scoliotic and normal intervertebral disc and endplate tissues. This comparison may help to improve our understanding of the role that disc and endplate tissues may play in the induction and/or progression of idiopathic scoliosis.Methods.Fifteen scoliotic and 17 normal intervertebral discs and endplates were analyzed for their water, collagen, proteoglycan, and protein content. In addition, newly synthesized aggrecan and collagen Types I and II were measured. Percent total denatured collagen was also determined.Results.The total collagen content was significantly lower in the scoliotic anulus and endplate regions, whereas glycosaminoglycan (GAG) content was significantly lower in the scoliotic endplates and nucleus regions. Conversely, total protein content was significantly higher in scoliotic endplates and elevated in scoliotic nucleus regions. Water content was significantly lower in the scoliotic anulus and endplate regions. When comparing the concave and convex regions of scoliotic endplates, there was no significant difference in concentration of any matrix component. The major difference in the synthetic marker levels relates to the synthesis of Type II collagen, which was higher in the nucleus, anulus, and endplate regions of scoliotic discs than in the corresponding regions of normal tissues. By contrast, the percent total denatured collagen was significantly elevated in the nucleus of normal tissues compared with the scoliotic ones.Conclusions.The higher collagen Type II synthetic levels and increased total protein content with no matrix turnover suggest that scoliotic changes are due to an altered and ineffective synthetic response to a pathologic mechanical environment.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Prospective randomized comparison of anterior lumbar interbody fusion (ALIF) plus transpedicular instrumentation plus posterolateral fusion (PLF) (360° fusion) to ALIF plus transpedicular instrumentation without PLF (270° fusion).Objectives.To compare the clinical outcomes, costs, and utilization of health resources of 360°versus270° fusions.Background.The 360° fusion is effective, but its costs and utilization of health resources are high. The PLF often resorbs and may not be necessary.Methods.Before and after surgery pain was measured by the Numerical Rating Scale (NRS), and function was measured by the Oswestry Low Back Disability Index (OSI). Costs were calculated by billing records. Operating times, blood loss, and hospital stays were measured at the time of hospital discharge.Results.There were 48 patients: 21 women and 27 men. Mean age was 42 years. Follow-up averaged 35 months (range 24–45 months). In both 360° and 270° fusions, there were significant improvements in NRS and OSI, and the percentage of solid ALIF was high. Only 14% of PLF appeared solid bilaterally and 18% appeared solid on one side only. There were no significant differences in changes in NRS, changes in OSI, or percentage solid ALIF between the 360° and 270° fusions. However, the 270° fusion group had significantly less blood loss, shorter operative times, shorter hospital stays, and lower professional fees, and although hospital charges were lower, this difference was not significant.Conclusion.Both the 360° and 270° fusions significantly reduce pain and improve function, and there are no significant clinical differences between them. However, there were shorter operating times, less blood loss, lower costs, and less utilization of health care resources associated with the 270° fusions.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A case report of nerve root entrapment due to pigmented villonodular synovitis of lumbar facet joint is reported for which excision was performed.Objective.To report a rare cause for nerve root claudication.Summary of Background Data.Pigmented villonodular synovitis is an uncommon synovial abnormality with an estimated incidence of 1.8 cases per million. Large joints, such as knee and hip, are commonly affected. Involvement of the facet joint is very rare. In our case a high index of suspicion from CT and MRI helped us in the appropriate management.Methods.A 71-year-old man presented with severe back pain and right-sided L5 sciatica. CT and MRI scans showed a cystic lesion arising from the L5–S1 facet joint. Excision and adequate decompression in the form of undercutting facetectomy were done.Results.The patient had symptomatic improvement with surgery, and at the 3-year follow-up he showed no signs of recurrence.Conclusion.Unless pigmented villonodular synovitis is considered in the differential diagnosis of tumors of the vertebral column causing nerve root claudication, it may be overlooked.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A case report of a man with a gigantic cellular schwannoma in the sacrum treated with high sacral amputation accompanied by careful nerve root-sparing dissection.Objectives.To describe the atypical clinical course of an intrasacral cellular schwannoma and the surgical procedure of high sacral amputation performed in a way to prevent needless sacrifice of functionally essential nerve roots.Summary of Background Data.Fundamentally, a cellular schwannoma is a benign tumor, but the clinical course is atypical. The symptoms are mild and the clinicopathologic features often mislead us to make a diagnosis of malignancy. The occurrence rate of intraosseous cellular schwannoma was reported to be 0.2% of all bony tumors, and the main location was the retroperitoneal space in the pelvis. Forty-one cases of giant intrasacral schwannomas have been reported so far. Among them, large sacral schwannoma with anterior cortex erosion and associated intrapelvic extension was extremely rare.Methods.The patient presented with a 5-year history of right leg and buttock pain, which did not disturb his daily activities. After a histopathologic diagnosis and a complete set of image studies, high sacral amputation with preservation of uninvolved nerve roots was performed at S1–S2 through a combined anterior and posterior approach. Both S1 nerve roots and the right S2–S3 nerve roots were saved using a threaded saw. The lumbar spine was stabilized to the pelvic girdle using spinal instrumentation with posterolateral fusion.Results.Eighteen months after the tumor was resected the patient had a very good clinical outcome, and there were no radiologic signs of instability or recurrence of the tumor. Locomotor function of both lower extremities and bowel and urinary functions were well maintained. The patient returned to his previous work.Conclusions.High sacral amputation following a combined anteroposterior approach provided good results without causing any disability. A detailed preoperative planning and careful dissection of uninvolved nerve roots prevented unnecessary neurologic impairment in locomotion and the detrusor and anorectal function.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A case report.Objective.To show that an intramedullary lesion was the cause of cervical spondylotic amyotrophy.Summary of Background Data.Cervical spondylotic amyotrophy is the clinical syndrome characterized by muscle wasting and weakness in the upper extremities without a remarkable sensory loss or spastic tetraparesis. It is still unclear whether the ventral roots or the anterior horn are selectively damaged.Methods.Magnetic resonance imaging and delayed computed tomographic myelography were performed on a patient who showed severe wasting of the left triceps muscle without any sensory disturbance or long tract sign.Results.On sagittal magnetic resonance images, a linear area was noted within the spinal cord at C6 and C7 spinal segments, which showed low signal intensity on T1-weighted image and high signal intensity on T2-weighted image. On axial T1-weighted image intramedullary low signal intensity area was observed, which was located in the left anterior horn. On axial T2-weighted image the area showed high signal intensity. A delayed (6 hours) computed tomographic scan after intrathecal injection of metrizamide revealed intramedullary enhancement in the area corresponding to the left anterior horn, which would represent cavitation or cystic necrosis.Conclusions.This is the first case report of cervical spondylotic amyotrophy, in which intramedullary lesion was confirmed only at the affected side of the spinal cord.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Dorsal root ganglion (DRG) neurons that have dichotomizing axons to the lumbar facet joint and to the sciatic nerve were investigated in rats using a double fluorescent labeling technique.Objectives.To clarify the existence of DRG neurons with dichotomizing axons projecting to the lumbar facet joint and to the sciatic nerve in rats.Summary of Background Data.DRG neurons having dichotomizing axons have been reported in several species and are considered to be related to referred pain. However, such DRG neurons have not been investigated in the lumbar spine. Clinically, pain from the lumbar facet joint is sometimes referred to the lower extremities innervated by the sciatic nerve.Methods.Two kinds of neurotracers (DiI and FG) were used in the present double-labeling study. DiI crystals were placed in the left L5–L6 facet joint, and FG was applied to the ipsilateral sciatic nerve or along the midline of the L5 dermatome. Bilateral DRGs T13–S1 were observed by fluorescence microscope.Results.DRG neurons double labeled with DiI and FG were recognized only in the ipsilateral DRGs from L3 to L6 levels. Approximately 3% of DRG neurons innervating the L5–L6 facet joint had other axons to the sciatic nerve. By contrast, no double-labeled neurons were observed after FG was applied to the L5 dermatome.Conclusions.In rats approximately 3% of DRG neurons innervating the lumbar facet joints have dichotomized axons projecting to the sciatic nerve.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Surgically obtained cervical herniated intervertebral discs were examined histologically and immunohistochemically. The production of nitric oxide (NO) in the local tissue was examined using the electron spin resonance (ESR) method.Objectives.To investigate the local histologic and immunohistochemical changes in cervical disc herniation, including NO production, and to compare such changes with those in autopsy cases.Summary of Background Data.Very little is known about the histopathologic processes of cervical disc herniation. In addition, no information is available on the level ofin vivoNO production in cervical disc herniation.Methods.Thirty-six herniated cervical discs obtained from 31 patients were immunohistochemically examined for localization of blood vessels, matrix metalloproteinase (MMP)-3, and inducible NO synthetase (iNOS). We also compared the production of NO, measured by the ESR method, in eight specimens with that of five control discs obtained from fresh cadavers.Results.The presence of herniated discs correlated with the degeneration of cartilaginous endplate and torn anulus fibrosus. Formation of new blood vessels around the herniated discs was detected, using von Willebrand factor antibody, in seven uncontained hernias and 20 contained hernias. Immunohistochemical studies showed the presence of cells positive for MMP-3 (chondrocytes), iNOS (chondrocytes and granulation tissue) in cervical disc hernias. ESR analysis showed a significantly higher NO production in herniated cervical discs than in disc samples of fresh cadavers.Conclusions.Herniated cervical intervertebral disc is characterized by the presence of an inflammatory process associated with neovascularization and increased expression of MMP-3. Production of NO was markedly high in both contained- and uncontained-type hernias.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Surface electromyographic reflex responses associated with mechanical force, manually assisted (MFMA) spinal manipulative therapy were analyzed in this prospective clinical investigation of 20 consecutive patients with low back pain.Objectives.To characterize and determine the magnitude of electromyographic reflex responses in human paraspinal muscles during high loading rate mechanical force, manually assisted spinal manipulative therapy of the thoracolumbar spine and sacroiliac joints.Summary of Background Data.Spinal manipulative therapy has been investigated for its effectiveness in the treatment of patients with low back pain, but its physiologic mechanisms are not well understood. Noteworthy is the fact that spinal manipulative therapy has been demonstrated to produce consistent reflex responses in the back musculature; however, no study has examined the extent of reflex responses in patients with low back pain.Methods.Twenty patients (10 male and 10 female, mean age 43.0 years) underwent standard physical examination on presentation to an outpatient chiropractic clinic. After repeated isometric trunk extension strength tests, short duration (<5 msec), localized posteroanterior manipulative thrusts were delivered to the sacroiliac joints, and L5, L4, L2, T12, and T8 spinous processes and transverse processes. Surface, linear-enveloped electromyographic (sEMG) recordings were obtained from electrodes located bilaterally over the L5 and L3 erector spinae musculature. Force–time and sEMG time histories were recorded simultaneously to quantify the association between spinal manipulative therapy mechanical and electromyographic response. A total of 1600 sEMG recordings were analyzed from 20 spinal manipulative therapy treatments, and comparisons were made between segmental level, segmental contact point (spinousvs.transverse processes), and magnitude of the reflex response (peak–peak [p-p] ratio and relative mean sEMG). Positive sEMG responses were defined as >2.5 p-p baseline sEMG output (>3.5% relative mean sEMG output). SEMG threshold was further assessed for correlation of patient self-reported pain and disability.Results.Consistent, but relatively localized, reflex responses occurred in response to the localized, brief duration MFMA thrusts delivered to the thoracolumbar spine and SI joints. The time to peak tension (sEMG magnitude) ranged from 50 to 200 msec, and the reflex response times ranged from 2 to 4 msec, the latter consistent with intraspinal conduction times. Overall, the 20 treatments produced systematic and significantly different L5 and L3 sEMG responses, particularly for thrusts delivered to the lumbosacral spine. Thrusts applied over the transverse processes produced more positive sEMG responses (25.4%) in comparison with thrusts applied over the spinous processes (20.6%). Left side thrusts and right side thrusts over the transverse processes elicited positive contralateral L5 and L3 sEMG responses. When the data were examined across both treatment level and electrode site (L5 or L3, L or R), 95% of patients showed positive sEMG response to MFMA thrusts. Patients with frequent to constant low back pain symptoms tended to have a more marked sEMG response in comparison with patients with occasional to intermittent low back pain.Conclusions.This is the first study demonstrating neuromuscular reflex responses associated with MFMA spinal manipulative therapy in patients with low back pain. Noteworthy was the finding that such mechanical stimulation of both the paraspinal musculature (transverse processes) and spinous processes produced consistent, generally localized sEMG responses. Identification of neuromuscular characteristics, together with a comprehensive assessment of patient clinical status, may provide for clarification of the significance of spinal manipulative therapy in eliciting putative conservative therapeutic benefits in patients with pain of musculoskeletal origin.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Biomechanics of posterolateral spinal fusion were studied in anin vivorabbit model.Objectives.To determine the extent of stabilization produced by posterolateral lumbar fusion and to test the hypothesis that motions are not completely eliminated after successful fusion.Summary of Background Data.Previous human cadaveric studies, clinical studies, and animal studies have attempted to characterize the biomechanics of posterolateral fusion. Such studies have been limited by either methods of fusion modeling or methods of stability testing. No previous study has examined biologic fusion with a physiologic biomechanical testing technique.Methods.Ten adult New Zealand white rabbits underwent L5–L6 intertransverse process fusion using autogenous iliac crest bone graft. Rabbits were killed 5 weeks after surgery. Only one time point was studied. This time point was chosen because previous pull-apart studies have shown plateauing of rabbit fusion mass strength and stiffness around this time. Spines were then harvested and evaluated with manual palpation and an established flexibility testing protocol. Resulting data were compared with previously acquired, nonoperative spine flexibility data.Results.Two animals were excluded because of complications. Of those that were fused (n = 5), biomechanical testing revealed significant decreases in flexion (81%), extension (61%), and right and left lateral bending (67% and 83%, respectively) (P< 0.01).Conclusions.These findings define the amount of motion reduction that can be expected with posterolateral fusions in the rabbit model at 5 weeks. These results suggest that motion was significantly decreased but was not eliminated.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID