摘要:

Study Design.In vivoflexion-extension and axial rotation magnetic resonance imaging (MRI) studies of the cervical spine were performed inside a positioning device.Objective.To determine the functional changes of neuroforaminal size that occur during flexion-extension and axial rotation of the cervical spine in healthy persons.Summary of Background Data.Kinematic MRI studies of the cervical spine were performed to obtain detailed information about the functional changes that occur in neuroforaminal size during flexion-extention and axial rotation. The results were compared with published data ofin vitrofunctional flexion-extension and axial rotation studies of the cervical spine.Methods.Inside a positioning device, the cervical spines of 30 healthy persons were examined in a whole-body magnetic resonance scanner from 40° of flexion to 30° of extension at nine different angle positions. In addition, axial rotation was performed at neutral position (0°) and at 20° and 40° of axial rotation to both sides. The images were analyzed with respect to the neuroforaminal size at each position using a reformatted 3D-FISP sequence.Results.At flexion, widening of the neuroforaminal size of up to 31% (compared with neutral position, 0°) was observed. Conversely, at extension a decrease in the size of the neuroforamen of up to 20% was recognized. At 20° and 40° of ipsilateral rotation of the head, a reduction in the neuroforaminal size of up to 15% and 23%, respectively, compared with the neutral position was noted. In contrast, a widening of the foraminal size was recognized on the contralateral side of 9% and 20% at 20° and 40° rotation. Statistically significant differences (p ≦ 0.05) were found in the neuroforaminal size between different degrees of flexion and extension and in addition for axial rotation compared to neutral position (0°).Conclusion.Compared with the results of previous biomechanical studies of human cadaver cervical spines, kinematic MRI provides additional noninvasive data concerning the physiological changes of the neuroforaminal size during flexion-extension and axial rotation in healthy individuals.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Correlation between compressed spinal cords on magnetic resonance imaging (MRI) and electrophysiological findings in cervical spondylotic myelopathy patients.Objective.To clarify the correlation between spinal-cord-evoked potentials and MRI measurements of compressed spinal cords in patients with cervical spondylotic myelopathy.Summary of Background Data.Compression of the spinal cord does not always cause clinical symptoms and it is difficult to infer the degree of dysfunction of the spinal cord from MRI findings.Methods.Seventeen patients with cervical spondylotic myelopathy were examined with MRI and spinal-cord-evoked potentials before surgery. Using abnormality in spinal-cord-evoked potentials as indicators of spinal cord morphology, spinal-cord transverse area and compression ratios (central and 1/4-lateral) were measured on T1-weighted axial imaging. The correlations between these dimensions and electrophysiological findings were investigated.Results.The mean preoperative transverse area of the spinal cord was 47.13 mm2.The mean preoperative central compression ratio of the spinal cord was 34.4%. The mean preoperative 1/4-lateral compression ratio of the spinal cord was 27.5%. A correlation (Spearman r=0.65,P< 0.01) was observed between the 1/4-lateral compression ratio of the spinal cord and the amplitude ratio of spinal-cord-evoked potentials after electric stimulation of the brain (Br(E)-SCEPs).Conclusions.The preoperative 1/4-lateral compression ratio of the spinal cord was found to reflect the degree of dysfunction of the corticospinal tracts.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Case report and literature review.Objectives.Clinicians use methylmethacrylate vertebroplasty to treat vertebral hemangiomas, metastases, and osteoporotic fractures. Cement may leak out of the vertebral body and compress the adjacent spinal cord and nerve roots. We review a case of nerve-root and cord compression from methylmethacrylate extrusion during vertebroplasty.Summary of Background Data.A 50-year-old female presented with disabling thoracic back pain. A metastasis to T1 was discovered, with collapse of the vertebral body but without cord compression. Methylmethacrylate vertebroplasty was performed. After injection, portable computed tomography (CT) showed a leakage of methylmethacrylate into the C8 and T1 foramina and spinal canal. Radiculopathy and myelopathy developed. Surgical decompression using the anterior approach was necessary.Methods.Case report.Results.Early surgical intervention decompressed the neural elements and relieved the neurological deficits.Conclusions.Neurologic complications of methylmethacrylate vertebroplasty necessitate active involvement of spine surgeons in patient evaluation and management.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A case report.Objectives.To report and discuss a case of contained rupture of the aneurysm of common iliac artery associated with pyogenic vertebral spondylitis, so that investigators and practitioners may avoid the diagnostic and therapeutic pitfalls associated with pyogenic vertebral spondylitis and aortic disease.Summary of Background Data.Pyogenic vertebral spondylitis is a rare disorder that may have serious consequences, including death, if it is not diagnosed promptly and treated effectively. The association of pyogenic vertebral spondylitis with infection of the aorta is a rare but potentially fatal condition that requires prompt diagnosis and aggressive surgical and medical therapy. To our knowledge, this is the first report of a contained rupture of the aneurysm of common iliac artery case associated with pyogenic vertebral spondylitis resulting from an infection withBacteroides fragilis,althoughSalmonellaeinfections are commonly associated with vertebral osteomyelitis and lesions of the contiguous aorta.Methods.A 60-year-old man with chronic lower back pain began to experience a severe pain and had increased difficulty in walking. An MRI scan showed an increased signal in the L4–L5 disc space and an abscess extending into the spinal canal. The presumptive diagnosis was infective spondylitis. While performing a CT-guided needle biopsy, an unexpected contained rupture of the aneurysm of common iliac artery was discovered.Results.A wide resection of all infected tissue, including the right common iliac artery and bony lesions, was performed in combination with antimicrobial therapy. A cryopreserved aortic allograft was used to reconstruct the artery, and an iliac strut graft was used to fill the debrided vertebral cavity. The patient’s postoperative recovery was uneventful.Conclusion.The coexistence of pyogenic vertebral spondylitis and lesions of the aorta is rare, but may be lethal if not diagnosed promptly and treated effectively. Even if a patient’s condition is stable and the hematocrit is normal, it is important to consider the possibility of a contained rupture of a mycotic abdominal aneurysm in all patients with vertebral osteomyelitis who have acute episodes of unusual severe back pain. CT is sometimes more beneficial than MRI in the identification and characterization of contained rupture of aneurysms.

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 prospective double-blind randomized controlled trial was performed.Objective.To assess the efficacy of percutaneous radiofrequency articular facet denervation for low back pain.Summary of Background Data.Uncontrolled observational studies in patients with low back pain have reported some benefits from the use of facet joint radiofrequency denervation. Because the efficacy of percutaneous radiofrequency had not been clearly shown in previous studies, a randomized controlled trial was conducted to assess the efficacy of the technique for improving functional disabilities and reduce pain.Methods.For this study, 70 patients with low back pain lasting of more than 3 months duration and a good response after intraarticular facet injections under fluoroscopy were assigned randomly to receive percutaneous radiofrequency articular facet denervation under fluoroscopic guidance or the same procedure without effective denervation (sham therapy). The primary outcomes were functional disabilities, as assessed by the Oswestry and Roland-Morris scales, and pain indicated on a visual analog scale. Secondary outcomes included spinal mobility and strength.Results.At 4 weeks, the Roland-Morris score had improved by a mean of 8.4% in the neurotomy group and 2.2% in the placebo group, showing a treatment effect of 6.2% (P= 0.05). At 4 weeks, no significant treatment effect was reflected in the Oswestry score (0.6% change) or the visual analog pain score (4.2% change). At 12 weeks, neither functional disability, as assessed by the Roland-Morris scale (2.6% change) and Oswestry scale (1.9% change), nor the pain level, as assessed by the visual analog scale (−7.6% change), showed any treatment effect.Conclusions.Although radiofrequency facet joint denervation may provide some short-term improvement in functional disability among patients with chronic low back pain, the efficacy of this treatment has not been established.

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 subanalysis of data derived from a randomized clinical trial was performed.Objective.To evaluate the association of a patient’s expectation for benefit from a specific treatment with improved functional outcome.Summary of Background Data.Psychosocial factors, ambiguous diagnoses, and lack of a clearly superior treatment have complicated the management of patients with chronic low back pain. The authors hypothesized that patient expectation for benefit from a specific treatment is associated with improved functional outcomes when that treatment is administered.Methods.In a randomized trial, 135 patients with chronic low back pain who received acupuncture or massage were studied. Before randomization, study participants were asked to describe their expectations regarding the helpfulness of each treatment on a scale of 0 to 10. The primary outcome was level of function at 10 weeks as measured by the modified Roland Disability scale.Results.After adjustment for baseline characteristics, improved function was observed for 86% of the participants with higher expectations for the treatment they received, as compared with 68% of those with lower expectations (P= 0.01). Furthermore, patients who expected greater benefit from massage than from acupuncture were more likely to experience better outcomes with massage than with acupuncture, andvice versa(P= 0.03).Conclusions.The results of this study suggest that patient expectations may influence clinical outcome independently of the treatment itself. In contrast, general optimism about treatment, divorced from a specific treatment, is not strongly associated with outcome. These results may have important implications for clinical trial design and recruitment, and may help to explain the apparent success of some conventional and alternative therapies in trials that do not control for patient expectations. The findings also may be important for therapy choices made in the clinical setting.

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.Radiographic and histologic analyses of commercially available bone graft materials were performed.Objective.To compare the osteoinductive efficacy of commercially available demineralized bone matrix material.Summary of Background Data.The relativein vivobone formation and toxicology of the nonallograft components the make up various commercially available demineralized bone matrix products are not known.Methods.Anin vivobone formation model was used in 30 athymic rats. Six different bone grafting materials were tested in subcutaneous and intermuscular locations. After 4 weeks, radiographic and histologic testing of bone formation was performed.Results.Eight of nine rats implanted with Grafton demineralized bone matrix products died 1 to 4 days after implantation of the bone graft material. None of the remaining 10 animals implanted with the four other grafting materials died. The experiment was modified and completed with a lower dose of bone graft material. Pathologic analysis indicated that the cause of death was hemorrhagic necrosis of the kidneys, most likely caused by a toxic effect on the glomeruli and tubules. A possible causative factor may have been the glycerol in the graft material.Conclusions.Although the volume of Grafton product per kilogram of body weight used in this study was approximately eight times the maximum volume used in humans, the authors believe that this data must be reported because this product is used substantially in clinical settings. In addition, the osteoinductive performance and relative safety of the nonallograft components in all commercially available demineralized bone grafts are not known.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID