单椎体复位固定系统治疗腰椎峡部崩裂及滑脱的相关基础研究与远期临床疗效

The basic research and long term follow up study of lumbar spondylolysis and isthmic spondylolisthesis treated with direct repair and fixation with single vertebra reduction and fixation system

目的对腰椎峡部崩裂及滑脱单椎体复位固定系统进行生物力学研究和三维有限元分析;对直接使用单椎体复位固定系统治疗的病例进行远期随访,探讨单椎体复位固定的有效性。方法测试单椎体复位固定系统的生物力学特性,建立腰椎峡部崩裂及滑脱的三维有限元模型,观察行单脊椎复位固定后脊椎的应力变化规律。自1992年4月～1995年12月,应用单椎体复位固定系统治疗腰椎峡部崩裂和滑脱32例,其中单纯峡部裂18例,合并滑脱14例;年龄28～46岁,平均36.4岁。结果生物力学研究和三维有限元分析表明,单椎体复位固定系统复位效果优良,固定坚强;所有患者均得到随访,平均5.6年,最终X线片示,有29例获得骨性愈合,无螺钉断裂和拔出。临床疗效按Henderson标准评价,优22例,良6例,可2例,差2例。结论腰椎峡部崩裂及滑脱单椎体复位固定系统固定坚强可靠,植骨融合率高。对青壮年腰椎峡部崩裂及滑脱患者,直接修复行单椎体复位固定可取得较好疗效,其内固定简单,手术创伤小,可减少继发性脊柱疾患的发生率。

Objective To conduct biomechanical study and three dimensional finite element analysis on lumbar spondylolysis and spondylolisthesis treated with single vertebra reduction and fixation system(LSRF), and to evaluate the long term outcome of isthmic spondylolisthesis treated with direct repair and fixation with LSRF. Methods Biomechanical characteristics of LSRF was tested, and three dimensional finite element model of lumbar spondylolysis and isthmic spondylolisthesis was established, the stress of lumbar in spondylolisthesis was observed after fixation and reduction. Thirty two patients with spondylolysis and isthmic spondylolisthesis were treated with direct repair and fixation with LSRF designed by the authors from 1992 to 1995. Eighteen cases had spondylolysis, and the others accompanied with spondylolisthesis. The patients age was 28-46 years, with an average of 36.4 years. Results The biomechanical study and three dimensional finite element analysis showed that LSRF has good ability in reduction and rigid fixation. All patients were followed up for an average of 5.6 years. The latest radiographs showed that bony union occurred in 29 cases. There was no breakage and pullout of screws except dislocation of hook in 2 patients. By Henderson standard, the result was excellent in 22, good in 6, fair in 2, poor in 2. Conclusion LSRF has stronger fixation strength and higher fusion rate. Direct repair and fixation with LSRF is a good procedure for younger and middle aged patients with spondylolysis and isthmic spondylolisthesis.