摘要:

Study Design.A series of four case reports are presented.Objective.The case reports document completion of lumbar discography with gadolinium contrast followed by successful computed tomography scanning of intradiscal gadolinium.Summary of Background Data.Lumbar discography using gadolinium in cases of iodinated contrast allergy with magnetic resonance imaging used to visualize intradiscal gadolinium after the procedure has been described. To the authors’ knowledge, there are no reports of gadolinium discography followed by computed tomography scanning of intradiscal gadolinium.Methods.The reported cases involved a chart review, performance of discography with gadolinium under fluoroscopic guidance, and postdiscography computed tomography scanning of the discs injected during the procedure.Results.Gadolinium was visible under fluoroscopy in all four cases. It was visualized on postdiscography computed tomography scans performed both early and late after the procedure. Normal discs retained gadolinium for a longer period than discs with anular disruption.Conclusions.Gadolinium discography is a safe, viable alternative to conventional discography in the setting of a patient with iodinated contrast allergy. Postdiscography computed tomography scans adequately visualize intradiscal gadolinium in a more timely and cost-effective manner than magnetic resonance imaging.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Study Design.A histologic and functional study on cauda equina adhesion induced by multiple-level laminectomy was performed using rats.Objective.To assess the relation between the extent of laminectomy and histologic and functional changes of the cauda equina induced by laminectomy.Summary of Background Data.It has been demonstrated that laminectomies may induce cauda equina adhesion, transiently or permanently. However, the relation between the extent of laminectomy and histologic and functional changes of the cauda equina induced by laminectomy is still unclear.Methods.Sprague–Dawley rats (250–300 g) were used. They were divided into four groups: no-laminectomy group (n = 5) and single, double, and triple level laminectomy groups (n = 20, respectively). At 24 hours and 1, 3, and 6 weeks after laminectomy, rats in each group were killed, and specimens were obtained from L4 to L6. The histologic changes were assessed using the classification of Yamagami. Walking durations on treadmill test and ascending spinal nerve–evoked potential were assessed in laminectomy groups before laminectomy, then weekly for 1 to 6 weeks after laminectomy.Results.With the greater extent of laminectomy, the decrease in cauda equina adhesions was more delayed. There was no difference in walking durations and ascending spinal nerve–evoked potential between pre- and postlaminectomy.Conclusions.The extent of laminectomy was related to recovery time of induced cauda equina adhesion. However, a delay in recovery from cauda equina adhesion may not produce a recognizable delay in recovery from clinical symptoms.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Study Design.Six cases are reported in which the clinical presentation of a prolapsed intervertebral disc was found to be caused by a localized venous plexus.Objectives.To emphasize the fact that the clinical presentation of a localized plexus of epidural veins in the lumbar spine can resemble that of an acute disc prolapse.Summary of Background Data.The finding of enlarged epidural veins during lumbar disc decompression is relatively common, but it is only recently that they have been implicated as the cause of the presenting symptoms.Methods and Results.Six individuals presented with severe pain in the lower back accompanied by sciatica, which had begun acutely. Physical examination in most of these patients showed the presence of neurologic signs in the affected leg. The initial clinical assessment was that of an acute prolapse of a lumbar disc. This diagnosis appeared to be borne out by the MRI scans, which demonstrated a “prolapsed disc” at the relevant level of the spine. However, at surgery, the intervertebral disc appeared to be relatively normal, but at the spine was found a large, localized plexus of epidural veins whose configuration matched the MRI image. The symptoms were relieved by decompression of the spine and ablation of the veins.Conclusions.Any pathologic process in the lumbar spine compressing a nerve root can cause localized pain in the back accompanied by sciatica. Most of these conditions can be differentiated by means of an MRI scan. The MRI image of a localized plexus of epidural veins, however, closely resembles that of a prolapsed intervertebral disc, which may be diagnostically misleading.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Study design.A biomechanical comparison of 12-, 14-, and 16-mm self-tapping and self-drilling screws in cadaveric cervical spines was performed.Objective.This study compared self-drilling and self-tapping screw designs used in anterior cervical locking plates in terms of insertion torque and pullout strength. In addition to screw design, the effects of screw length (12, 14, and 16 mm) and bone mineral density were examined.Methods.A total of 201 screws were implanted and tested. Nineteen cadaver spine specimens (C2 through C7) were radiographed and their bone mineral density measured. In each vertebral level, two screws of the same length were implanted and their insertion torque measured. One of each screw design (self-drilling or self-tapping) was randomly placed in each vertebra for side-by-side comparison. Vertebrae then were individually potted and mounted on an MTS machine for accurate measurement of maximum pullout strength.Results.Pullout strength was strongly related to screw length (P= 0.0002). There was no significant difference in pullout strength between the self-drilling and self-tapping screw designs at any length (P= 0.9352). A significant correlation (P≤ 0.0077) exists between insertion torque and bone mineral density for the self-drilling and self-tapping 14- and 16-mm screws. A significant correlation exists between pullout strength and bone mineral density for 14- and 16-mm screw lengths of both screw types (P< 0.0001).Conclusions.It would appear that the longest screw feasible should always be used clinically for maximum pullout strength. There is no difference in pullout strength between self-drilling and self-tapping screws. Bone mineral density significantly influences screw performance.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Study Design.A case report is presented.Objectives.To describe a typical case of acute adolescent torticollis in which a disc lesion was detected with magnetic resonance imaging.Summary of Background Data.Acute torticollis is attributed to atlantoaxial rotary fixation of unknown etiology. The current view is that the lesion is caused by synovial fold entrapment in the C1–C2 interspace.Methods.In a 15-year-old male adolescent, magnetic resonance imaging was performed a few hours after the onset of torticollis, and 3 weeks after resolution of symptoms.Results.Increased signal intensity compatible with a fluid collection was seen in the right uncovertebral region at C2–C3. This lesion was probably linked to a sudden disruption of the disc collagen fibers, and had caused excessive lateral pressure, pushing C2 toward the left. Magnetic resonance imaging at 3 weeks was unremarkable.Conclusions.The authors think that the observed disruption was a sudden and abnormal instance of a normal and, usually, very slow process of cleft formation with extension into the fibrocartilaginous core in the uncovertebral region. It is felt that this lesion may be a frequent cause of torticollis in adolescents.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Study Design.A retrospective review was performed of a single surgeon’s experience with partial corpectomy over a 9-year period. The measures evaluated included fusion rate, complications, and neurologic symptoms.Objective.To demonstrate the safety and efficacy of partial corpectomy for multilevel cervical spondylosis.Summary of Background Data.Strategies for the surgical management of cervical spondylosis have included laminectomy, multilevel corpectomy, and multilevel discectomy. All have significant disadvantages, including high nonunion rates and late deformity. A procedure incorporating multilevel discectomy, partial corpectomy, strut graft, and plating is described. By removal of the anterior two thirds of the intervening vertebral body, visualization of the interface between the dura and the disc or PLL is enhanced, and osteophytes can be easily removed. Fusion rates are improved.Methods.All partial corpectomy cases with a 2-year follow-up evaluation managed by the senior author for multilevel cervical spondylosis from 1991 to June 1999 were reviewed for the number of levels decompressed, graft source, use of plating, fusion success, and neurologic status.Results.Most of the patients (n = 97) were managed with two-level discectomies, with 42 requiring treatment of three levels and 5 requiring treatment of four or more levels. Allograft was used in 60%. The remainder received iliac crest bone graft. The majority (81%) were plated. Of the cases with 2-year follow-up evaluation, the fusion rate was 95.8%, independent of the number of levels fused. Among the 11% who had continued problems, most had improved. Nonunions were higher in smokers.Conclusions.Partial corpectomy is an effective strategy for treating multilevel cervical disc disease. It is associated with a high fusion rate. In addition, partial corpectomy facilitates a complete decompression by providing excellent visualization of the dural interface.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Study Design.A case of thoracic hyperkyphosis is reported as an atypical presentation of otherwise typical adolescent idiopathic scoliosis that showed a large syringomyelia on magnetic resonance imaging.Objective.To review atypical curve patterns that indicate the need for more intensive preoperative workup including a magnetic resonance imaging scan.Summary of Background Data.The literature on atypical curve patterns of adolescent “non-idiopathic” scoliosis is reviewed. No report in the literature describes patients with an idiopathic coronal plane and thoracic hyperkyphosis as an atypical feature found to have a large syringomyelia and Chiari I malformation on magnetic resonance imaging examination.Methods.The clinical and radiographic features associated with thoracic hyperkyphosis and juvenile and adolescent scoliosis with syringomyelia are presented.Results.The neurosurgical treatment of the syringomyelia subsequently led to a potentially safer spinal fusion. The patient tolerated the procedures well and at this writing has remained asymptomatic during 3 years of follow-up evaluation.Conclusions.The reported case adds to the hyperkyphosis literature category of unusual spinal deformities seen in scoliosis associated with syringomyelia and should further help to categorize adolescent idiopathic scoliosis as a diagnosis of exclusion.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Study Design.A case report is presented.Objective.To report a previously undescribed complication related to use of a neurogenic motor-evoked potential monitoring electrode and electrosurgery during spinal surgery.Summary of Background Data.Although electrosurgery is one of the most commonly used technologies in the operating room, its electrophysical properties, including the potential for complications, are poorly understood by many surgeons. Complications related to the use of electrosurgical instruments, monitoring electrodes, and radiofrequency current are underreported in the literature.Methods.Clinical case analysis and investigation report were used.Results.A case of third-degree skin burn at the site of a neurogenic motor-evoked potential monitoring electrode during posterior spinal fusion surgery is described.Conclusions.A burn resulting from a neurogenic motor-evoked potential monitoring electrode is rare. However, surgeons and electrophysiologists should be familiar with this potential complication in order to prevent it.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Study Design.Measurement of intradiscal pressure was performed after placement of an interspinous implant in a cadaver model.Objective.To understand the likelihood of accelerated adjacent-level disc degeneration as a result of the implant.Summary of Background Data.An interspinous implant has been developed to treat lumbar neurogenic claudication secondary to spinal stenosis that places the stenotic segment in slight flexion and prevents extension. Previous biomechanical studies demonstrated that fusing one level may significantly increase the intradiscal pressures at adjacent levels. Moreover, clinical studies have reported an increased incidence of adjacent-level degeneration after lumbar spinal fusion.Methods.Eight cadaver lumbar specimens (L2–L5) were loaded in flexion, neutral, and extension. A pressure transducer measured intradiscal pressure and annular stresses during each of the three positions at each of the three disc levels. An appropriately sized implant was placed at L3–L4, and the pressure measurements were repeated.Results.The pressures at the adjacent discs were not significantly affected by the interspinous implant insertion. There was a significant decrease in intradiscal pressure at the L3–L4 disc in the posterior annulus and nucleus in the neutral and extended positions.Conclusions.The implant does not significantly change the intradiscal pressures at the adjacent levels, yet it significantly unloads the intervertebral disc at the instrumented level in the neutral and extended positions. On the basis of the current findings, it does not appear that the implant causes accelerated disc degeneration at the adjacent levels.

ISSN:0362-2436    

出版商:OVID    

年代:2003

数据来源: OVID