摘要:

Study Design.An analysis of lateral radiographs in the upright, flexion–extension position.Objectives.To document and define the differences in cervical flexion–extension kinematics as they relate to changes of alignment in upright cervical lordosis.Summary of Background Data.No previous study has reported the association between sagittal plane cervical rotation kinematics and changes of alignment in upright cervical lordosis.Methods.Lateral radiographs were classified into five groups (Group A, lordosis; Group B, straight; Group C, kyphosis; Group D, S-curve with lordotic upper cervical and kyphotic lower cervical spine; and Group E, S-curve with kyphotic upper cervical and lordotic lower cervical spine) by changes of alignment in upright position. Sagittal cervical rotation angles were measured by a computer-assisted method in the fully flexed and extended positions.Results.Group A revealed the largest angle of lordosis at extension and the smallest angle of kyphosis at flexion, whereas Group C revealed the smallest angle of lordosis at extension and the largest angle of kyphosis at flexion. When Group D adopted the flexion–extension position, the curvature of the upper cervical spine was the same as Group A, whereas the lower cervical spine showed the same curve as Group C. Similarly, the cervical rotation kinematics in Group E were a combination of motion of upper cervical spine in Group C and that of lower spine in Group A.Conclusion.The results suggest that alterations in the static alignment of the cervical curvature cause alterations in the dynamic kinematics of the cervical spine during cervical flexion–extension. This information should aid in the interpretation of kinematic studies of the cervical spine.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.This was a case of spinal subdural granuloma ofCandida albicans. A high cerebrospinal fluid protein level without pleocytosis (albuminocytologic dissociation) was observed. This case proved difficult to diagnose and treat.Objectives.To clarify the important issues in regard to the diagnosis and treatment of possible spinal subdural granuloma resulting fromC. albicans.Summary of Background Data.Reports on subdural infection ofC. albicansare very rare. Moreover, there are no reports of cases in which patients have survived this type of infection.Methods.A 66-year-old man developed paralysis in the lower limbs, as well as vesicorectal disorder (anuresis). There were no obvious causes. Signs of meningeal irritation later appeared. A high cerebrospinal fluid protein level without pleocytosis was observed through a laboratory test. The cause of these disorders was unclear, and a final diagnosis could not be made on the basis of the test results and angiograph. Possible diagnoses included tumor, infection, and others such as Guillain-Barré syndrome. The authors therefore carried out surgery to reduce the pressure on the spinal cord and ultimately make a definitive diagnosis.Results.The final diagnosis was spinal subdural granuloma ofC. albicans. Granuloma was widespread (T3–T10). Surgery, various drug treatments, and hyperbaric oxygen therapy all contributed to saving the patient’s life.Conclusion.This was a very rare case of spinal subdural granuloma resulting fromC. albicans, and the authors had difficulty diagnosing and treating the patient. A distinctive gadolinium-enhanced MRI was obtained. The effect of treatment by drugs alone was limited. An intraoperative ultrasonography proved useful. The authors concluded that a combination of early surgery and hyperbaric oxygen therapy was effective.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.Descriptive.Objective.To outline a novel multimodality approach for a difficult surgical resection of a giant cell tumor in the cephalad portion of the sacrum.Summary of Background Data.Giant cell tumors of the sacrum are rare primary bone tumors. Recent reports have demonstrated diminished giant cell tumor recurrence with cryosurgery by using a “direct pour” technique with liquid nitrogen. Although successful in decreasing tumor recurrence, this technique is accompanied by a 4%–8% rate of skin necrosis and high rates of pathologic fracture. The authors describe resection and a novel, controlled method of argon-based cryotherapy (followed by a unique pelvic reconstruction) for a large, difficult giant cell tumor of the sacrum.Methods.A 29-year-old woman presented with complaints of right foot drop and decreased sensation of the right buttock, posterior thigh, posterior calf, and lateral aspect of the right foot. Radiographic evaluation revealed a mass in the right sacrum; histologic examination of CT-guided biopsy revealed a giant cell tumor. A combined anterior abdominal and posterior sacral approach was performed, the tumor was resected, and the margin of the cavity was treated with controlled argon-based cryotherapy. The combination of thermocouples, electromyographic monitoring, and rapid freeze–thaw cycles allowed a controlled ablation of the tumor margin while ensuring that surrounding structures, such as the rectal wall, sacral nerves, and gluteal muscles, were not damaged. Posterior spinal fusion L4 to sacrum, posterior spinal instrumentation L4 to pelvis, and allograft reconstruction of the right sacrum were performed.Results.The patient recovered well without skin necrosis or pathologic fracture. Urinary and fecal continence were preserved. At the 20-month follow-up the patient has no evidence of local tumor recurrence and is fully ambulatory without a brace or narcotic medication.Conclusion.A novel multimodality approach, consisting of resection, controlled cryosurgery, and a unique lumbopelvic reconstruction, was safe and successful in managing a challenging proximal sacral giant cell tumor. Twenty months after surgery the patient has excellent bowel and bladder control, no tumor recurrence, and functional ambulation without a brace or pain.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.A case report with a review of the literature is presented demonstrating the imaging findings of a patient with recent onset, progressive spinal cord compression at T6 caused by a giant arachnoid cyst that was successfully treated.Objective.To present the imaging findings of a giant anterior cervicothoracic intradural arachnoid cyst using several methods before and after treatment.Summary of Background Data.This case demonstrates the imaging findings of the largest described anterior cervical arachnoid cyst straddling the cervicothoracic junction. It presented with spinal cord compression in a 26-year-old diagnosed by MRI and successfully treated surgically.Methods.The patient experienced progressive left-sided sensory and motor deficits below T6. Pain and temperature sensation were decreased. Reflexes were increased in both lower extremities with clonus. Preoperative MRI was followed by laminectomy and cyst fenestration with subsequent postoperative myelogram and CT.Results.Imaging confirmed the presence of a giant arachnoid cyst straddling the cervicothoracic junction. Postoperative imaging documented relief of spinal cord compression. Symptoms improved progressively after surgery. By the time of discharge all residual neurologic deficits had resolved.Conclusion.Anterior arachnoid cysts straddling the cervicothoracic junction have yet to be reported, and arachnoid cysts involving the cervical region are extremely rare. Imaging demonstrated the cyst and its response to treatment. This patient responded well to surgery and was discharged without neurologic sequelae.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.To evaluate the clinical outcome respective of the type of bone graft used, 69 patients undergoing instrumented lumbar spinal fusion were randomized to receive either their own bone (harvested from the iliac crest) or allograft bone (fresh-frozen femoral head from donors undergoing total hip joint arthroplasty). Self-completed questionnaires were administered before surgery and at intervals thereafter.Objectives.To compare the clinical outcome of lumbar spinal fusion carried out using either allograft or autograft bone.Summary of Background Data.Previous studies have suggested that allograft bone is effective in cervical and thoracic fusion operations but that it is less effective in lumbar spinal fusions. Most of these studies used a radiographic means of determining fusion. However, no reliable radiologic assessment method has yet been agreed upon. It has also been shown that radiographic appearance does not correlate with clinical outcome.Methods.A total of 69 patients undergoing instrumented posterolateral lumbar spinal fusion surgery were randomized to receive either allograft bone from the North East of Scotland Blood Transfusion Service or autologous bone from the iliac crest. The patients were then followed up at 1-year intervals over 6 years regarding clinical outcome.Results.Patients receiving allograft bone had outcome scores similar to those who had received their own bone, except that in the autograft group there was a significant incidence of donor site pain that was persistent in about one sixth of patients.Conclusions.Allograft bone, in the form of fresh-frozen human femoral head, gives clinical results at least as good as autograft bone in instrumented posterolateral lumbar spinal fusion and completely avoids any donor site complications.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.These studies were designed to examine the role of central neuroimmune activation and neuroinflammation in a rat model of lumbar radiculopathy.Objectives.In the present study the authors investigated the role of neuroimmune activation using immunocytochemistry to detect expression of major histocompatibility complex Class II, cluster determinant 4, intracellular adhesion molecule-1 (ICAM-1), and platelet endothelial cellular adhesion molecule-1 (PECAM-1). The role of central neuroinflammation was investigated using radiation bone marrow chimeric rats.Summary of Background Data.The pathologic mechanisms resulting in painful lumbar radiculopathy secondary to nerve root injury remain obscure. There is a growing body of evidence that central neuroimmune activation and neuroinflammation may play a key role in the initiation and maintenance of various pain states, including lumbar radiculopathy.Methods.Male Holtzman rats undergoing mechanical sensitivity testing were divided into two groups: a sham group and a chromic gut suture group. Animals were killed on day 14 post surgery. Male Holtzman rats, used to detect cluster determinant 4, major histocompatibility complex Class II, and CAM spinal expression, were divided into three groups: a normal group, a sham surgery group, and a chromic group. The male Brown Norway rats used to make the radiation bone marrow chimeras were divided into two groups: a sham group and a chromic group. Animals were killed at 1, 3, 7 or 14 days following surgery.Results.Nerve root injury in the rat produced increased spinal major histocompatibility complex Class II, cluster determinant 4, ICAM-1, and PECAM-1 immunoreactivity and increased bilateral sensitivity to tactile stimuli. Leukocyte trafficking into the spinal parenchyma was observed, which increased over time after nerve root injury.Conclusions.The presence of bilateral mechanical allodynia and spinal neuroimmune changes following nerve root injury supports the hypothesis that central sensitization through activation of immune mediators, coupled with macrophage traffic across the blood–brain barrier, plays a key role in the development and maintenance of radicular pain.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.To analyze the effects of tumor necrosis factor-&agr;, interleukin-1&bgr;, and interferon-&ggr; on cauda equina function and to define if any of these cytokines could induce nerve root dysfunction comparable with the situation with application of nucleus pulposus.Summary of Background Data.Proinflammatory cytokines derived from the intervertebral disc have been suggested to mediate the nucleus pulposus–induced nerve root injury following local application of nucleus pulposus. However, it is not known if such cytokines may induce similar injury if applied separately.Methods.A total of 29 pigs were used. Nucleus pulposus was harvested from lumbar discs and applied to the sacrococcygeal cauda equina following laminectomy of the first coccygeal vertebra in seven pigs. Five pigs received 1.66 &mgr;g of tumor necrosis factor-&agr;, five pigs received 0.85 &mgr;g of interleukin-1&bgr;, and five pigs received 1.66 &mgr;g of interferon-&ggr;. Seven pigs received autologous fat for control. Nerve conduction velocity was studied by local electrical stimulation and recordings in the tail muscles 7 days after the application.Results.Application of nucleus pulposus and fat induced similar effects as seen in previous studies, with normal nerve conduction velocity for fat and a significant reduction for nucleus pulposus. Application of both interleukin-1&bgr; and IFN-&ggr; induced slight reductions of nerve conduction velocity compared with fat, but they were not statistically significant. Tumor necrosis factor-&agr;, however, induced a reduction of the velocity that was even more pronounced than for nucleus pulposus.Conclusion.Based on previous observations and the data of the present study, one may conclude that tumor necrosis factor-&agr; from nucleus pulposus cells seems to be intimately involved with the basic pathophysiologic events leading to both nerve root dysfunction and pain after local, epidural application of nucleus pulposus. One may therefore also suspect that pharmacologic inhibition of tumor necrosis factor-&agr; may at least theoretically be considered in the clinical situation with disc herniation and sciatica.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.An electrophysiologic study to examine effects of exogenous application of tumor necrosis factor-&agr; (TNF-&agr; ) activities and nociresponses of dorsal horn neurons in the spinal cord at L5.Objectives.To investigate the role of TNF-&agr; in the induction and development of hyperalgesia in neural mechanisms responsible for a radicular pain.Summary of Background Data.TNF-&agr; is found in the herniated disc and known to play a pivotal role in the development of inflammatory hyperalgesia; however, it is not known whether TNF-&agr; causes abnormal discharge in the dorsal horn neurons and enhances nociresponse.Methods.Single-unit activities of neurons in the L5 superficial dorsal horn were extracellularly recorded, using 28 urethane-anesthetized rats. The wide dynamic range and nociceptive-specific neurons activated by stimulation of the hind paw were selected. Effects of exogenous TNF-&agr; were examined regarding 1) spontaneous discharges of wide dynamic range and nociceptive-specific neurons, 2) responses of wide dynamic range neurons to noxious stimulation, and 3) morphologic changes in the dorsal root ganglion.Results.Application of TNF-&agr; to the nerve root induced 1) a significant increase in spikes/sec in spontaneous discharges of wide dynamic range and nociceptive-specific neurons, 2) enhanced responses of wide dynamic range neurons to noxious stimulation, and 3) inflammatory changes in the ganglion.Conclusion.These results suggest the possibility that TNF-&agr; produced in the vicinity of nerve roots due to disc herniation might cause ectopic discharges in primary afferent fibers and thereby induce the prolonged excitation in pain-processing neurons responsible for radicular pain.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.Work presented here used a small animal model to illustrate the feasibility of autologous disc cell implantation.Objectives.To develop a small animal model for autologous disc cell implantation.Summary of the Background Data.The use of autologous disc cells in the potential treatment of disc degeneration offers attractive possibilities for novel therapies. Results are presented on the use of the sand rat (Psammomys obesus), a small rodent that spontaneously develops disc degeneration during aging, in experimental studies in which cells were harvested from a lumbar intervertebral disc, expanded in monolayer tissue culture, labeled with agents that allow subsequent immunolocalization of these cells, and implanted in a second disc site of the donor animal.Methods.Tissue culture, disc surgery, histology, and immunocytochemistry were used. Cells were either engrafted in a bioresorbable carrier tested for cell compatibility or injected into the recipient disc. Results were assessed with radiographic examination of the implantation site and with histology and immunocytochemistry.Conclusion.Data from 15 animals were obtained with engraftment resident in the animal for up to 33 weeks. Immunocytologic identification of engrafted cells showed that they integrated into the disc and were surrounded by normal matrix at time points up to 8 months postengraftment. Engrafted cells exhibited either a spindle-shaped morphology in the annulus or a rounded chondrocyte-like morphology in the nucleus. Although technically challenging, the authors’ experience showed that autologous disc cell implantation can be successful and that the sand rat is a valuable model for autologous disc cell studies.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID