摘要:

Study Design.A case report.Objective.To illustrate a rare case of bow hunter’s syndrome in a patient with significant contralateral vertebral artery (VA) occlusive disease.Summary of Background Data.Bow hunter’s syndrome is an uncommon condition in which the VA is symptomatically occluded during neck rotation. This case is interesting in that the patient had what appeared to be a normal right VA and occluded left VA when the head was in the neutral position. When the head was rotated 45° to the left, the patient’s right VA was occluded (bow hunter’s finding), and it became apparent that the left VA was not completely occluded (as it appeared in the neutral position angiogram) but rather was 90% stenosed. The complete occlusion appearance in the neutral position was an angiographic phenomenon caused by competitive flow through the open right VA. When the patient rotated his head to the left, he occluded his right VA and had insufficient blood flow through the left VA, thus creating a symptomatic ischemic state.Methods.This case was studied using dynamic computed tomography imaging, single-photon emission computed tomography, transcranial Doppler ultrasound, brain stem auditory evoked potentials, and dynamic range-of-motion cerebral angiographyResults.The patient demonstrated bow hunter’s syndrome as documented on clinical examination and history. Transcranial Doppler studies, dynamic computed tomography scanning, and cerebral/cervical angiography confirmed the diagnosis and revealed an interesting angiographic pattern, which explained the patient’s symptoms and findings only when angiographic flow patterns were taken into consideration.Conclusions.Bow hunter’s syndrome should be suspected when a patient presents with reproducible vertebrobasilar symptoms on rotating the neck. Quantitative documentation using imaging and electroneurophysiologic tests is important when assessing this subjective process. Careful evaluation of the angiographic imagescan often help explain an odd flow pattern and provide the physician with a range of treatment options.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.This report documents a case of asymptomatic esophageal perforation, secondary to a dislocated and then migrated cervical screw after anterior plating, and reviews the relevant Western literature.Objectives.To report a rare and potentially dangerous complication and suggest mechanisms of asymptomatic esophageal perforation and healing.Summary of Background Data.Anterior surgical approaches to the cervical spine have become popular and safer during the past decade. Materials and devices for anterior stabilization have improved in quality and safety. Nevertheless, failure of the devices may occur either because of technical mistakes or rupture. Reoperation is not always necessary, as spontaneous recovery is possible.Methods.Our patient was operated on for severe cervical spondylotic myelopathy. One year after surgery, one of the screws migrated and was found anteriorly to the spine. Six months later, the screw could no longer be identified, and we concluded that an esophageal perforation had occurred and that the screw had been eliminated through the intestinal tract. The results of esophagoscopy were normal.Results.The neurologic conditions of our patient improved constantly, and his spine alignment was maintained despite the missing screw.Conclusions.This case demonstrates that a serious complication may not need any treatment. Each case of screw displacement in anterior cervical spine surgery should be evaluated separately in conjunction with the clinical symptoms of the patient, as spontaneous resolution is possible.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.Three case reports of solitary spinal osteochondromas in middle-aged and elderly patients.Objectives.To describe the treatment of three rare cases of spinal osteochondromas in patients significantly older than the cases previously reported in the literature.Summary of Background Data.Osteochondromas arising in the vertebral column are considered rare. The mean age of clinical appearance is said to be in the second or third decade of life.Methods.Clinical history, physical examinations, plain radiographs, magnetic resonance imaging, myelography, computed tomographic myelography, and histopathologic findings for each case were reviewed in conjunction with previous cases reported in the literature.Results.Total removal of the tumor was effective in causing the symptoms to disappear.Conclusions.Spinal osteochondromas are rare and tend to appear in young adults. Three cases of spinal osteochondromas that were unusual in terms of age at clinical presentation and localization were reported, suggesting a continuous growth of the tumor beyond skeletal maturity.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.This report describes two cases of acute spondylodiscitis, caused bySerratia marcescens, complicating two different conditions: microdiscectomy for herniated nucleus pulposus and decompressing laminotomy for spinal stenosis.Objective.To describe a rare and life-threatening spinal infection and discuss its successful management.Summary of Background Data.To our knowledge, no published reports in the English language have described this potentially devastating infection as a complication of elective noninstrumented discectomy or decompressive laminotomy.Methods.Two cases of a very early onset of acute spondylodiscitis, caused byS. marcescens, after minimally invasive lumbar spine surgeries are presented. The elapsed time between these two complications was 1 week. The clinical presentation was characteristically stormy in both cases. On postoperative day 2, the patients developed high fever with intense chills and concomitant acute low back pain rapidly increasing in severity. The overall clinical appearance was alarming. The patients were carefully investigated immediately and scrutinized for possible origin of the infection. Treatment consisted of prompt intravenous antibiotics and surgical debridement.Results.The history and clinical manifestations of postoperative spondylodiscitis were corroborated with magnetic resonance imaging findings and bacteriologic and hematologic laboratory examination. Blood cultures revealedS. marcescensas the responsible pathogenic microorganism. The source of the pathogens was contaminated normal saline used for surgical lavage. Both patients were able to completely resume their previous occupations after aggressive surgical debridement/irrigation and 3 months of antibiotic treatment.Conclusions.Serratia marcescensmay become a potential pathogen, causing severe spinal infection after elective surgery. For prompt diagnosis and effective treatment of this life-threatening infection, one should maintain high index of suspicion and should not procrastinate in initiating treatment, which should consist of appropriate intravenous antibiotics and surgical debridement.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.A case report of a lumbar dumbbell tumor that showed a sequential change in histology from ganglioneuroma into rhabdomyosarcoma after long-term dormancy.Objective.To present a case of non-neurogenic malignancy arising from ganglioneuroma.Summary of Background Data.Ganglioneuromas rarely form the dumbbell variety. Whereas conversion of ganglioneuroma into neurogenic malignancies occurs occasionally, between ganglioneuroma and mesenchymal malignancies it has so far been limited to a case in which ganglioneuroma developed after chemo- and radiotherapy for orbital rhabdomyosarcoma.Methods.A 61-year-old man was referred with a recurrent retroperitoneal tumor that had been excised as ganglioneuroma. Using imaging, histologic, and immunohistochemical studies, a comparative analysis of the primary and recurrent tumors was performed.Results.A total of 44 histologic sections were examined for the primary and the recurrent tumors that had been excised surgically, with an 8-month interval between resections. Histologic and immunohistochemical findings in the primary tumor were consistent with ganglioneuroma, whereas those in the recurrent tumor indicated rhabdomyosarcoma.Conclusions.It is assumed that the rhabdomyosarcoma arose from a dumbbell ganglioneuroma as a component of malignant ectomesenchymoma.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.A histologic study on age-related changes of the human lumbar intervertebral disc was conducted.Objectives.To investigate comprehensively age-related temporospatial histologic changes in human lumbar intervertebral disc, and to develop a practicable and reliable classification system for age-related histologic disc alteration.Summary of the Background Data.No comprehensive microscopic analysis of age-related disc changes is available. There is no conceptual morphologic framework for classifying age-related disc changes as a reference basis for more sophisticated molecular biologic analyses of the causative factors of disc aging or premature aging (degeneration).Methods.A total of 180 complete sagittal lumbar motion segment slices obtained from 44 deceased individuals (fetal to 88 years of age) were analyzed with regard to 11 histologic variables for the intervertebral disc and endplate, respectively. In addition, 30 surgical specimens (3 regions each) were investigated with regard to five histologic variables. Based on the semiquantitative analyses of 20,250 histologic variable assessments, a classification system was developed and tested in terms of validity, practicability, and reliability. The classification system was applied to cadaveric and surgical disc specimens not included in the development of the classification system, and the scores were assessed by two additional independent raters.Results.A semiquantitative analyses provided clear histologic evidence for the detrimental effect of a diminished blood supply on the endplate, resulting in the tissue breakdown beginning in the nucleus pulposus and starting in the second life decade. Significant temporospatial variations in the presence and abundance of histologic disc alterations were observed across levels, regions, macroscopic degeneration grades, and age groups. A practicable classification system for age-related histologic disc alterations was developed, resulting in moderate to excellent reliability (&kgr; values, 0.49–0.98) depending on the histologic variable. Application of the classification system to cadaveric and surgical specimens demonstrated a significant correlation with age (P< 0.0001) and macroscopic grade of degeneration (P< 0001). However, substantial data scatter caution against reliance on traditional macroscopic disc grading and favor a histology-based classification system as a reference standard.Conclusions.Histologic disc alterations can reliably be graded based on the proposed classification system providing a morphologic framework for more sophisticated molecular biologic analyses of factors leading to age-related disc changes. Diminished blood supply to the intervertebral disc in the first half of the second life decade appears to initiate tissue breakdown.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.The impact of various levels of mental processing and pacing (during lifting) on spine loading was monitored under laboratory conditions.Objectives.To explore how mental demands and pacing influence the biomechanical response and subsequent spine loading and, to determine whether individual characteristics have a modifying role in the responses.Summary of Background Data.Modern work often requires rapid physical exertions along with demands of mental processing (both psychosocial stressors). While the effect of physical workplace factors on spine loading has been widely documented, few studies have investigated the impact that interaction of psychosocial factors and individual factors has on spine loads.Methods.For this study, 60 subjects lifted boxes while completing two types of mental processing tasks: 1) series tasks with decisions occurring before the act of lifting, and 2) simultaneous tasks with decisions occurring concurrently with the lift. For both of these mental processing conditions, two intensities of mental load were evaluated: simple and complex. Task pacing was also adjusted under slow and fast conditions. Finally, individual characteristics (personality and gender) were evaluated as potential modifiers. An electromyographically assisted model evaluated the three-dimensional spine loads under the experimental conditions.Results.Simultaneous mental processing had the largest impact on the spine loads, with the complex intensity resulting in increases of 160 N with lateral shear, 80 N with anteroposterior shear, and 700 N with compression. Increased task pace produced greater lateral shear (by 20 N), anteroposterior shear (by 60 N), and compression loads (by 410 N). Gender and personality also influenced loadings by as much as 17%.Conclusions.Mental processing stress acted as a catalyst for the biomechanical responses, leading to intensified spine loading. Mental stress appeared to occur as a function of time pressures on task performance and resulted in less controlled movements and increases in trunk muscle coactivation. These adjustments significantly increased spine loading. These results suggest a potential mechanism for the increase in low back pain risk resulting from psychosocial stress caused by modern work demands.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.Randomized efficacy trial comparing two types of noninstrumented posterolateral fusion between L5 and S1 in patients with L5 spondylolysis and vertebral slip less than 50%, as evaluated by radiostereometric analysis.Objective.To determine whether osteogenic protein-1 (BMP-7) in the OP-1 Implant yields better stabilizing bony fusion than autograft bone.Summary of Background Data.Animal studies of osteoinductive proteins in noninstrumented posterolateral fusions have shown high fusion rates. No similar conclusive study on humans has been performed.Methods.For this study, 20 patients were randomized to fusion with either OP-1 Implant or autograft bone from the iliac crest, 10 in each group. The patients were instructed to keep the trunk straight for 5 months after surgery with the aid of a soft lumbar brace. At surgery 0.8-mm metallic markers were positioned in L5 and the sacrum, enabling radiostereometric follow-up analysis during 1 year. The three-dimensional vertebral movements, as measured by radiostereometric analysis induced by positional change from supine posture to standing and sitting, were calculated with an accuracy of 0.5 to 0.7 mm and 0.5° to 2.0°. Conventional radiography was added.Results.No significant difference was noted between the radiostereometric and radiographic results of fusion with the OP-1 Implant and fusion with autograft bone. There was a significant relation between reduced vertebral movements and better bone formation. No adverse effects of the OP-1 Implant occurred. Persistent minor pain at the iliac crest was noticed in one patient.Conclusions.There was no significant difference between the two fusion versions. Thus, the OP-1 Implant did not yield better stabilizing bony fusion than autograft bone.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.A prospective randomized clinical study was conducted.Objective.To determine whether the dose and carrier that were successful in rhesus monkeys could induce consistent radiographic spine fusion in humans.Summary of Background Data.Preclinical studies have demonstrated that recombinant human bone morphogenetic protein-2 (rhBMP-2), an osteoinductive bone morphogenetic protein, is successful at generating spine fusion in rabbits and rhesus monkeys.Methods.For this study, 25 patients undergoing lumbar arthrodesis were randomized (1:2:2 ratio) based on the arthrodesis technique: autograft/Texas Scottish Rite Hospital (TSRH) pedicle screw instrumentation (n = 5), rhBMP-2/TSRH (n = 11), and rhBMP-2 only without internal fixation (n = 9). On each side, 20 mg of rhBMP-2 were delivered on a carrier consisting of 60% hydroxyapatite and 40% tricalcium phosphate granules (10 cm3/side). The patients had single-level disc degeneration, Grade 1 or less spondylolisthesis, mechanical low back pain with or without leg pain, and at least 6 months failure of nonoperative treatment.Results.All 25 patients were available for follow-up evaluation (mean, 17 months; range 12–27 months). The radiographic fusion rate was 40% (2/5) in the autograft/TSRH group and 100% (20/20) with rhBMP-2 group with or without TSRH internal fixation (P= 0.004). A statistically significant improvement in Oswestry score was seen at 6 weeks in the rhBMP-2 only group (−17.6;P= 0.009), and at 3 months in the rhBMP-2/TSRH group (−17.0;P= 0.003), but not until 6 months in the autograft/TSRH group (−17.3;P= 0.041). At the final follow-up assessment, Oswestry improvement was greatest in the rhBMP-2 only group (−28.7,P< 0.001). The SF-36 Pain Index and PCS subscales showed similar changes.Discussion.This pilot study is the first with at least 1 year of follow-up evaluation to demonstrate successful posterolateral spine fusion using a BMP-based bone graft substitute, with radiographs and CT scans as the determinant. Consistently, rhBMP-2 was able to induce bone in the posterolateral lumbar spine when delivered at a dose of 20 mg per side with or without the use of internal fixation. Patients with spondylolisthesis classified higher than Meyerding Grade 1 or with more than 5 mm of translational motion may still require internal fixation. Some patients did smoke during the postoperative period, and all in the rhBMP-2 groups still obtained solid fusions.Conclusions.Consistently, rhBMP-2 with the biphasic calcium phosphate granules induced radiographic posterolateral lumbar spine fusion with or without internal fixation in patients whose spondylolisthesis did not exceed Grade 1. Statistically greater and quicker improvement in patient-derived clinical outcome was measured in the rhBMP-2 groups.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Study Design.A prospective randomized clinical study with a 2-year follow-up period was conducted.Objective.To analyze the effects of circumferential fusion using ALIF radiolucent carbon fiber cages and titanium posterior instrumentation on functional outcome, fusion rate, complications, and lumbar lordosis.Summary of Background Data.Circumferential fusion has become a common procedure in lumbar spine fusion, both as a primary and salvage procedure. However, the claimed advantages of ALIF plus PLF over conventional PLF lack scientific documentation.Methods.From April 1996 through November 1999, a total of 148 patients with severe chronic low back pain were randomly selected for either posterolateral lumbar fusion with titanium CD-Horizon (posterolateral group) or circumferential fusion with a ALIF Brantigan cage plus posterior instrumentation. The Dallas Pain Questionnaire (DPQ), the Low Back Pain Rating Scale (LBPR), and a questionnaire concerning work status assessed their outcomes.Results.Both groups showed highly significant improvement in all four categories of life quality (DPQ) as well as in the back pain and leg pain index (LBPR), as compared with preoperative status. There was a clear tendency toward better overall functional outcome for patients with the circumferential procedure (P< 0.08), and this patient group also showed significantly less leg pain at the 1-year follow-up evaluation (P< 0.03) and less peak back pain at 2 years (P< 0.04). Sagittal lordosis was restored and maintained in the circumferential group (P< 0.01). The circumferential fusion patients showed a higher posterolateral fusion rate (92%) than the posterolateral group (80%)(P< 0.04). The repeat operation rate including implant removal was significantly lower in the circumferential group (7%) (P< 0.009) than in the posterolateral group (22%).Conclusions.Circumferential lumbar fusion restored lordosis, provided a higher union rate with significantly fewer repeat operations, showed a tendency toward better functional outcome, and resulted in less peak back pain and leg pain than instrumented posterolateral fusion. The clinical perspective of the current study implies a recommendation to favor circumferential fusion as a definitive surgical procedure in complex lumbar pathology involving major instability, flatback, and previous disc surgery in younger patients, as compared with posterolateral fusion with pedicle screws alone.

ISSN:0362-2436    

出版商:OVID    

年代:2002

数据来源: OVID