Posterior Short-Segment Instrumentation of Thoracic and Lumbar Bursting Fractures: Retrospective study related with Load-Sharing classification / 대한척추외과학회지

STUDY DESIGN: The authors designed the retrospective study with the Load-Sharing Classification in 47cases of the bursting thoracic-lumbar fractures, which were operated using the pedicle screws. OBJECTIVE: To judge the effectiveness of posterior short segment instrumented fusion in thoracic-lumbar fractures according to the Load-Sharing classification. MATERIAL AND METHOD: From 1995 through 1998, 47 patients who had been operated with short segment transpedicular instrumentation including fractured vertebra were selected and they were divided two groups, one below 6 point of Load-Sharing score, the other above 7 point. In follow up of average 39 months, the guide of reduction loss, which include the change of anterior vertebral body height and sagittal index were analysed statistically with the Student T-test at the postoperative time and the last follow-up time. RESULTS: In group below 6 point, the average of anterior vertebral body height was 56.2% before the operation and reduced 77.6% after the operation and measured 76.4% at final follow-up. The reduction loss was 1.2%. The sagittal index of preoperative 19.4degree became 10.6degree after the operation and measured 11.8degree at the last follow-up. The loss of correction angle was 1.2degree . In the other group above 7 point, anterior vertebral body height was average 51.7% before the operation and reduced 75% after the operation and measured 71.2% in last follow up, so reduction loss was 3.8%. Sagittal index was average 21.6degree before the operation and corrected 12.6 after the operation and measured 14.6degree in last follow up. All of 19 patients with neurologic deficits improved by over the one Frankel grade except grade A. CONCLUSION: Although the additional study is needed, there were no significant difference of statistical analysis about indexes between two groups.

Comparison of Short and Long-Segment Fusion in Thoracic and Lumbar Fractures / 대한척추외과학회지

STUDY DESIGN: A retrospective study was designed to evaluate the clinical result and difference between short segment and long segment fixation, which was undertaken by posterior approach for thoracic and lumbar spine fractures. OBJECTIVE: To determine and compare the mechanical maintenance and ability of correction, and clinical and neurologic recov-ery between short segment and long segment fusion group. SUMMARY OF BACKGROUND DATA: The long segment instrumentation is a cause of decrease of motion segment in thoracic and lumbar spine. In short segment fusion, screw failures were reported. MATERIALS AND METHODS: From 1989 thorough 1997, 54 patients who had been operated on by the posterior approach with transpedicular screw fixation for spine injuries were divided into two groups. The authors applied the short segment transpedic-ular instrumentation including fractured vertebra. Short segment group included 35 cases, and long segment group, 19 cases. The mean follow-up period was one year and eight months for short segment group, two years and seven months for long segment one. The results were evaluated by comparing the anterior vertebral height, sagittal index in simple roentgenogram and neurologic recovery. RESULTS: The average of anterior vertebral height which was 50.7% at preoperation, became 78.7% after the operation and measured 74.9% at final follow-up in long segment fusion group, while in short segment fusion group it was 59.7%, 79.3% and 77.7%, respectively. The average of sagittal index of 17.5degreeat preoperation became 6.7degreeafter the operation, and measured 8degreeat final follow-up in long segment fusion group, while in short segment fusion group it was 19.9degree, 10.4degree, and 12.1degree, respectively. Overall clinical results had no statistical significant difference between two groups. Of the thirty-six patients with neurologic deficits, twenty-two improved by over the one Frankel grade. CONCLUSIONS: The authors conclude that the short segment transpedicular instrumentation including fractured vertebra is a successful method of thoracolumbar and lumbar burst fractures.