摘要:

Study Design.Statistical analysis of various measurement techniques for thoracolumbar burst fracture kyphosis on lateral radiograph.Objective.To determine the most reliable measurement technique.Summary of Background Data.The treatment of thoracic and lumbar burst fractures involves many factors, including the degree of resultant kyphosis. Although various methods have been described, no study has directly compared these methods for reliability and reproducibility.Methods.Fifty lateral radiographs of thoracic and lumbar burst fractures were randomly selected and measured on two separate occasions by three spine surgeons using five different measurement techniques. Radiograph quality, fracture type, and the center beam location were determined. Statistical analysis included analysis of variance for repeated measures and analysis of variance using a generalized linear model.Results.Intraclass correlation coefficients were most consistent for Method 1 (rho = 0.83–0.94) followed by Method 4 (rho = 0.65–0.89) and Method 5 (rho = 0.73–0.85). Intraobserver agreement (% of repeated measures within 5° of the original measurement) ranged between 72% and 98% for all techniques for all three observers, with Method 1 showing the best agreement (84%–98%). Paired comparisons between observers varied considerably with interobserver reliability correlation coefficients ranging from 0.52 to 0.93. Method 1 showed the highest interobserver reliability coefficient (0.81, range 0.71–0.93) followed by Method 5 (0.71, range 0.68–0.75). Method 1 also had the highest percentage of agreement within categories (90% within 5°).Conclusions.Method 1 (measuring from the superior endplate of the vertebral body one level above the injured vertebral body to the inferior endplate of the vertebral body one level below) showed the best intraobserver and interobserver reliability overall.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Asymptomatic patients with a positive Hoffmann’s reflex were prospectively studied with cervical radiographs and magnetic resonance imaging.Objectives.To determine a relationship between a positive Hoffmann’s reflex and cervical pathology in asymptomatic patients and to evaluate if further work-up was necessary in this patient population.Summary of Background Data.A positive Hoffmann’s reflex usually implies an upper motor neuron lesion from spinal cord compression. Although this reflex is commonly tested, the significance of this reflex in asymptomatic patients is not known.Methods.Sixteen patients without cervical pain or radiculopathy and a positive Hoffmann’s reflex were prospectively studied with cervical radiographs and magnetic resonance imaging. Positive findings were correlated with a detailed neurologic examination.Results.All 16 patients were asymptomatic. Fourteen patients (87.5%) demonstrated spondylosis on cervical radiographs. The magnetic resonance imaging studies showed pathologic findings in all 16 patients. Fifteen patients (94%) had cervical involvement with cord compression from a herniated nucleus pulposus. The remaining patient had a T5–T6 thoracic disc with resultant compression. No treatment was instituted, and the clinical course of each patient was not affected.Conclusions.Although the presence of cervical cord impingement is extremely high in these patients, no treatment was rendered specifically to address the cervical pathology. Therefore, the presence of a positive Hoffmann’s reflex in asymptomatic patients strongly suggests underlying cervical pathology, but it does not warrant further evaluation with either cervical radiographs or magnetic resonance imaging since the management and clinical course are not affected by positive studies.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A longitudinal study using patient questionnaires was performed.Objective.To compare the discriminatory power and responsiveness of the Aberdeen Back Pain Scale (ABPS), the Roland Disability Questionnaire (RDQ), and the EuroQol in patients with low back pain.Summary of Background Data.A number instruments specific to low back pain have not been compared for measurement properties. The EuroQol is a widely used generic instrument that has not been compared with specific instruments in patients with back pain.Methods.A questionnaire incorporating the Aberdeen Back Pain Scale, the Roland Disability Questionnaire, and the EuroQol was completed by patients taking part in a clinical trial of exercise treatments for back pain. Patients completed follow-up questionnaires at 6 weeks, 6 months, and 1 year. The discriminatory power of these instruments was assessed against variables relating to activity limitations, medication, and comorbidity. Responsiveness was assessed using standardized response means.Results.The questionnaire was completed by 187 patients taking part in the clinical trial. The Aberdeen instrument was found to be the most powerful at discriminating between different groups of patients on variables relating to activity limitations, medication, and comorbidity. The specific instruments demonstrated good levels of responsiveness, with the Aberdeen instrument producing the largest standardized response means. The Aberdeen instrument was more responsive to the smaller changes experienced by the control group, but was less powerful than the Roland at measuring differences in the levels of change between the two groups of patients at two of the three follow-up assessments in the trial. The EuroQol demonstrated a moderate level of responsiveness.Conclusions.The two specific instruments are capable of greater levels of discrimination between groups of patients, and are more responsive over time than the generic EuroQol. The Aberdeen instrument performed most satisfactorily in relation to these criteria, but the Roland instrument was more sensitive to differences between the two groups in the clinical trial. The measurement properties of these two instruments reflect their origin: The Aberdeen instrument is based on clinical questions, whereas the Roland instrument is based on the generic Sickness Impact Profile. Instrument content should be carefullyconsidered when selecting instruments for applications, including clinical trials.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A prospective cohort design was used to evaluate the Functional Rating Index in a multicentered setting with 139 participants. The Functional Rating Index is a self-reporting instrument consisting of 10 items, each with 5 possible responses that express graduating degrees of disability.Objectives.The goal of this study was to evaluate the psychometric qualities of the Functional Rating Index.Summary of Background Data.The Functional Rating Index combines the concepts of the Oswestry Low Back Disability Questionnaire and the Neck Disability Index and seeks to improve on clinical utility (time required for administration).Methods.One hundred thirty-nine subjects with spinal complaints participated in four different cohorts to study reliability, validity, responsiveness, and clinical utility.Results.Reliability: Test-retest: Intraclass correlation coefficient was excellent (ICC3,k= 0.99); interitem correlation: Item efficiency was good, ranging between 0.54 and 0.82, with a moderate correlation among all items; Cronbach’s alpha was excellent (0.92).Validity: construct: The Functional Rating Index correlated with the Disability Rating Index (0.76), the Short Form-12 Physical Component Score (0.76), and the Short Form-12 Mental Component Score (0.36).Responsiveness: Overall, the size effect was 1.24, which is commendable.Clinical utility: Time required by the patient and staff averaged 78 seconds per administration, which is noteworthy.Effect of Sociodemographics:Total scores were not affected by education, gender, nor age, suggesting minimal external validity bias.Conclusions.The Functional Rating Index appears to be psychometrically sound with regard to reliability, validity, and responsiveness and is clearly superior to other instruments with regard to clinical utility. The Functional Rating Index is a promising useful instrument in the assessment of spinal conditions.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A retrospective clinical study was performed.Objective.To study clinical and radiologic late results after posterior stabilization of thoracolumbar fractures with internal fixator and interbody fusionviatranspedicular bone grafting.Summary of Background Data.The posterior approach, using an internal fixator, is a standard procedure for stabilizing the injured thoracolumbar spine. Transpedicular bone grafting was invented by Daniaux in 1986 for achieving an interbody fusion. Pedicle screw fixation with additional transpedicular fusion has remained controversial because of inconsistent reports and a lack of late results.Methods.Between January 1989 and July 1992, 76 patients with thoracolumbar fractures were operatively treated, and after a mean of more than 3 years, 56 of 62 patients (90%) still alive who had their implants removed were examined.Results.According to the Magerl classification, 33 patients sustained Type A, 13 Type B, and 10 Type C fractures. Three patients with incomplete paraplegia returned to normal. In one case of complete paraplegia, no change occurred. The mean operative time was 3 hours. In this study, two complications (3.6%) were observed: one iatrogenic vertebral arch fracture without consequences and one deep infection.Compared with the preoperative status, follow-up examinations demonstrated permanent physical and social sequelae: The percentage of individuals able to do physical labor was reduced by half (22 to 11 patients), whereas the share of unemployed or retired patients doubled (4 to 8 patients). At the time of follow-up examination, only 21 of 42 patients continued in sports. The assessment of reported problems and functional outcome with the Hannover spine score reflected a significant difference between the status before injury (96.6/100 points) and at the time of follow-up evaluation (71.4/100 points) (P< 0.001).The radiographic assessment in the lateral plane (Cobb technique) demonstrated a significant (P< 0.001) mean restoration from an initial angle of −15.6° (kyphosis) to +0.4°(lordosis). Serial postoperative radiographicfollow-up assessment showed progressive loss of correction. At follow-up examination, a mean difference from the postoperative angle of 10.1° was found (P< 0.001). Compared with the preoperative deformity, a mean improvement of 6.1° (average, −9.7°) at follow-up examination was noted. The addition of transpedicular cancellous bone grafting did not decrease the loss of correction. Computed tomography scans after implant removal were performed in nine cases: Only three of nine patients showed evidence of intervertebral fusion. No correlation could be found between the Magerl classification and radiographic outcome. However, the preoperative wedge angle of the vertebral body correlated significantly with the postoperative loss of reduction.Conclusions.Because of the disappointing results from this study, the authors cannot recommend the additional transpedicular cancellous bone grafting as an interbody fusion technique after posterior stabilization in cases of complete or incomplete burst injury to the vertebral body.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Three groups of six embalmed cadaver spines underwent placement of lumbar interbody fusion cages centered either at midline, 10% lateral of midline, or 20% lateral of midline. The spines were evaluated for evidence of neuroforamen violation or nerve root impingement.Objectives.To determine the potential for foraminal violation or nerve root impingement after correct placement and lateral misplacement of lumbar interbody fusion cages.Summary of Background Data.Radicular symptoms after anterior cage placement have raised some concern about the potential for inadvertent device-related foraminal violation not adequately appreciated by intraoperative fluoroscopy.Methods.Preoperative computed tomography scanning and plain radiography was used to measure endplate dimensions at L4–L5 and to template the appropriately sized interbody fusion cages. The cadaveric specimens were randomly divided into three groups of six (Groups I–III) and instrumented at L4–L5 either at midline (I) or 10% (II) or 20% (III) lateral of midline. Postoperative computed tomography and plain radiography was evaluated for evidence of neuroforamen violation, followed by dissection of the specimens.Results.Foraminal violation occurred in one of six spines in group II (10% off midline) and in three of six spines in group III (20% off midline). Two of the three cadavers in group III with foraminal violation also were noted to have nerve root abutment on computed tomography scans and spinal dissection.Conclusions.Excessive lateral placement of lumbar interbody fusion cages may result in foraminal violation and possible nerve encroachment. The “safe zone” for centering the cages extends approximately 5 mm on either side of midline.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.This study compared the effects of isoflurane and nicardipine on regional blood flow of the lumbar paraspinal muscles.Objectives.The purpose of this study was to determine whether treatment with hypotensive agents result in ischemia of the lumbar paraspinal muscles, thereby facilitating surgical procedures.Summary of Background Data.Despite the general acceptance of controlled hypotension as effective in reducing blood loss during spinal surgery, the changes of blood flow that occur at the lumbar paraspinal muscles when this technique is applied remain unclear. The use of laser Doppler flowmetry allows changes of muscle blood flow to be easily detected in real time with minimal invasion, thereby allowing differences among distinct pharmacological approaches for induction and maintenance of controlled hypotension to be evaluated.Methods.The prehypotensive and hypotensive (reduction of mean arterial pressure by 20 mm Hg) blood flow of the lumbar paraspinal muscles were assessed with a laser Doppler flowmeter in 40 patients undergoing lumbar spinal surgery. The first half of the patients (n = 20) received isoflurane, whereas the second half received nicardipine to achieve arterial hypotension.Results.Compared with the prehypotensive state, during the hypotensive state, patients in the isoflurane group exhibited a 17% to 46% (mean, 33.7%) decrease in lumbar paraspinal muscle blood flow, whereas patients in the nicardipine group exhibited a 24% to 177% (mean, 82.5%) increase in lumbar paraspinal muscle blood flow. Statistical analysis showed a significant difference in the changes of flux after induced hypotension between the isoflurane and nicardipine group (P< 0.001).Conclusions.Depending on the pharmacological treatment used to achieve arterial hypotension in spine surgery, there will be either a reduction in paraspinal muscle blood flow (ischemia) or an enhancement of this blood flow (hyperemia).

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A histopathologic examination of a specimen that showed hypertrophy of the posterior longitudinal ligament of the cervical spine.Objectives.To illustrate the possibility of hypertrophy of the posterior longitudinal ligament as a prodromal condition to ossification of the posterior longitudinal ligament.Summary of Background Data.Despite much study, the pathology of ossification of the posterior longitudinal ligament still remains unclear. Hypertrophic change often is seen in the part of the ossified ligament; however, there have been few histopathologic reports on hypertrophy of the posterior longitudinal ligament. Some reports have suggested that hypertrophy of the posterior longitudinal ligament is a prodrome of ossification of the posterior longitudinal ligament.Methods.A 64-year-old man was admitted to the hospital because of gait disturbance and developed oliguria. In a plain radiograph, segmental ossification of the posterior longitudinal ligament was found at C4, C5, and C6. Computed tomograph myelogram revealed a soft tissue shadow, maximum 3.8 mm in diameter, on the dorsal side of the ossification of the posterior longitudinal ligament at C5 and C6. Magnetic resonance T1-weighted image (T1WI) showed an equivalent signal with the intervertebral disc on the dorsal side of ossification of the posterior longitudinal ligament. This lesion was enhanced with Gd-DTPA and confirmed as hypertrophy of the posterior longitudinal ligament. Cervical anterior decompression and fusion were performed using Yamaura’s technique. The ossified and thickened lesion was elevated and removed en bloc. Then, hematoxylin–eosin and toluidine blue staining was performed to detect metachromasia.Results.Macroscopic examination of the specimen revealed that soft tissue formation was connected with the C4–C5 intervertebral space and extended downward to C6–C7. Histopatholgically, collagen fibers were proliferating in the long-axis direction on both ventral and dorsal sides. This was surrounded by extended nucleus pulposus-like chondrocyte tissue, where endplate cartilage was detected around the C4 pedicle. Roux staining was low, and partial vascular and cellular infiltration was observed, although it was not marked.Conclusion.The herniated nucleus pulposus involving endplate cartilage from C4–C5 was limited to the superficial layer, and proliferation of nucleus pulposus-like chondrocytes occurred in the herniated tissue, where they might undergo a change in cell phenotype. The results of the present study support the hypothesis that hypertrophy of the posterior longitudinal ligament is a prodromal condition to ossification of the posterior longitudinal ligament.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.This report describes four cases of symptomatic cerebral spinal fluid leak after lumbar microdiscectomy where ADCON®-L was used.Objectives.To report that ADCON®-L may exacerbate cerebral spinal fluid leak from unrecognized, small dural tears after lumbar discectomy.Summary of Background Data.ADCON®-L is a porcine-derived polyglycan that is used with increasing frequency in spinal surgery. It is advocated to reduce postoperative peridural fibrosis and adhesions.Methods.Four cases of symptomatic cerebral spinal fluid leak after lumbar microdiscectomy were identified. Information on these patients was obtained by chart review.Results.Three patients had small, inadvertent durotomies that were not appreciated at surgery even with the aid of a microscope. The dural violation in the fourth patient occurred at the previous epidural steroid injection site located on the contralateral side of the laminotomy.Conclusion.ADCON®-L may inhibit dural healing and exacerbate cerebral spinal fluid leak from microscopic durotomies not recognized at the time of surgery.

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