ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

The aim of the current study was to examine the correlation between lumbar lordosis, spinal fusion, and functional outcome in patients suffering from severe low back pain, treated by posterolateral spinal fusion with or without pedicle screw instrumentation. One hundred thirty patients were randomly allocated to posterolateral lumbar fusion with or without Cotrel-Dubousset instrumentation. Functional outcome was assessed preoperatively, and 1 and 2 years postoperatively. Lordosis angles of the lumbar spine and fusion rates were assessed at the 1- and 2-year follow-up. No difference in lordosis angle was found between the two groups at any time. Lordosis was unchanged at 2 years compared with preoperative status in both groups. In the instrumented group, nonunion (23%) was followed by a decrease in lordosis at follow-up (p < 0.05). However, in the noninstrumented group, nonunion (14%) resulted in increased lordosis (p < 0.05). No correlation was found between functional outcome and lordosis angle. The current study showed no correlation between functional outcome and lordosis angle either before or after posterolateral spinal fusion. Use of instrumentation did not influence lumbar spinal alignment compared with noninstrumented fusions. The sagittal alignment was stable both 1 and 2 years after solid fusion. The failure mode of instrumented fusions was a reduced degree of lordosis in contrast to an increased degree of lordosis in patients with noninstrumented fusion.

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Although radial tear of the annulus fibrosus can be detected on T2-weighted and Gd-DTPA-enhanced magnetic resonance (MR) images, the association between the annular tear on MR images and the symptomatic discs is unclear. The purpose of this study was to investigate the relationship between T2-weighted, gadolinium-DTPA-enhanced MR images and pain response through discography in patients with chronic low back pain. A total of 56 lumbar discs from 23 patients with chronic low back pain (13 to 47 years old) underwent MR imaging (T2-weighted, gadolinium-DTPA-enhanced MR images) followed by provocative discography. The sensitivity, specificity, positive predictive value, and negative predictive value of T2-weighted and gadolinium-DTPA-enhanced MR images in detecting the symptomatic discs were calculated. The sensitivity, specificity, positive predictive value, and negative predictive value of T2-weighted images in detecting the symptomatic disc were 94%, 71%, 59%, and 97%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of gadolinium-DTPA-enhanced images were 71%, 75%, 56%, and 86%, respectively. The high sensitivity and the high negative predictive value of T2-weighted MR imaging in detecting the symptomatic disc indicated that MR imaging can be a useful screening tool in avoiding unnecessary discography in patients with chronic low back pain.

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Lumbopelvic fixation in spinal and pelvic surgery relies on rods or screws as an iliac anchor. Secure placement of screws with maximum diameter and length for the greatest pullout strength requires knowledge of the iliac structure and of intraoperative fluoroscopic landmarks for secure placement. Therefore, the authors evaluated the intrailiac length, inner width, and cortical thickness of three different transiliac screw anchor paths aimed toward the anterior inferior iliac spine and initiated at the iliac tubercle, posterior superior iliac spine, or posterior inferior iliac spine. Measurements were made using two- and three-dimensional computed tomographic reformations in 40 consecutive trauma patients (27 measurements in 21 males, 16 to 75 years old; 28 measurements in 19 females, 16 to 78 years old). In addition, fresh and dry human cadaveric specimens were marked with metal wires at the previously determined optimal screw path to determine fluoroscopic landmarks for easiest and best controlled transiliac screw placement. The posterior superior iliac spine–anterior inferior iliac spine path had the largest bony canal lengths, with 141 mm in male and 129 mm in female patients. Two stereotypic iliac constrictions allowed placement of 8-mm implants in male and 6- to 7-mm implants in female patients. Cortical thickness at that optimal extraarticular path was 5.2 mm in the male and 4.7 mm in the female patients. Transiliac screws can be placed during operation under fluoroscopic control using standard lateral and obturator oblique–outlet views, the latter presenting a stereotypical teardrop figure above the acetabulum.

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Implant retrieval programs have been effective in understanding implant failure and biomaterial compatibility in joint arthroplasty; however, its application has not been extended extensively to the assessment of spinal constructs and implants. The objective of this study is to determine the efficacy of implant retrieval analysis as a standard for the assessment of explanted spinal implants. The limitations of clinical radiographic assessment of fusion through metal interbody devices are also identified. The implant analysis protocol is shown through a case report of a titanium mesh spinal fusion cage retrieved from a 54-year-old woman who had a pseudoarthrosis at the T12 cage interface. The implant analysis techniques include backscattered electron imaging, high-resolution contact radiography, histology, and fluorochrome analysis. An implant retrieval analysis program similar to the one discussed in the presented case study will enable an accurate assessment of outcomes of these commonly used implants and will guide future development.

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Many Cobb measurements have been reported at various levels for the thoracic kyphosis, but geometric models of the shape of kyphosis are rare. Thoracic vertebral bodies were digitized on 80 normal lateral full-spine radiographs to obtain the mean thoracic kyphosis. Global and segmental angles were determined. Computer iteration processes passed geometric shapes through the posterior body coordinates of the mean thoracic kyphosis to determine the best fit model in the least squares sense. The kyphosis was closely modeled with ellipses. The T1 and T12 areas tended to be flatter in curvature when compared with T2–T11, indicating these are inflection points. Mean global angles were CobbT1–T12= 44.2°, CobbT2–T11= 39.9°, and CobbT3–T10= 33.3°. The T2–T11 kyphotic region was closely modeled with approximately a 70° portion of an ellipse, with minor axis to major axis ratios of 0.6 to 0.72, and with major axis parallel to the posterior body margin of T11.

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

The aim of this work was to evaluate the efficacy of dynamic anterior cervical plates following one-level anterior corpectomy with fusion (ACF) (i.e., C5–7) and two- to four-level ACF with posterior wiring and fusion (PWF). Dynamic plates (ABC Aesculap, Tuttlingen, Germany), allowing for 10 mm of cephalad and 10 mm of caudad plate migration, were applied for one-level ACF (28 patients) and multilevel ACF/PWF (20 patients). Two (7%) dynamic plates failed after one-level ACF. One pseudarthrosis and one plate extrusion occurred, both in morbidly obese patients. No multilevel ACF/PWF failed. The 7% failure rate for dynamic plates applied for one-level ACF is somewhat high, whereas the 0% failure rate for multilevel ACF/PWF with halo immobilization proves more promising. Perhaps PWF with halo stabilization for morbidly obese individuals undergoing one-level ACF would avoid future plate-related problems.

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1536-0652    

出版商:OVID    

年代:2002

数据来源: OVID