腰椎峡部裂及滑脱单椎体复位固定系统的生物力学研究

Biomechanical study of lumbar spondylolysis and spondylolisthesis single vertebrae reduction fixation system

目的 评价腰椎峡部裂及滑脱单椎体复位固定系统（lumbarspondylolysisandspondylolis-thesis single vertebraereduction fixation system,LSRF）的生物力学性能,探讨其复位机制。方法 采用 24具成人L4、L5脊柱标本,峡部断裂后应用LSRF、Hefti、Salib法固定,进行生物力学测试;取4具成人L2～S2脊柱标本,L5双侧峡部裂后加载,建立滑脱模型,应用LSRF进行复位试验。结果LSRF固定强度为Hefti的1.6倍,Salib的2.7倍,且具有良好的复位功能。MRF的复位机制为以椎板钩与椎板接触点为支点,利用椎弓根螺钉将滑脱椎体向后上提拉,使椎体前移复位。结论LSRF具有坚强固定和良好的复位作用,为椎弓峡部崩裂及滑脱的治疗提供了新的有效的固定方法。

Objective To evaluate biomeehanic characteristics of lumbar spondylolysis and spondylolisthesis single vertebrae reduction fixation system (LSRF), and discuss its mechanism of reduction. Method Twenty-four adult isthmus lumbar vertebrae specimen were disconnected and fixed with LSRF, Hefti, Salib's method respectively, and the biomechanic characteristics of the fixation devices were tested. Isthmus of L5 in 4 adult spine specimen was destroyed under loading to produce the spondylolisthesis model, and reduction by LSRF. Result The LSRF has a good ability for reduction and its strength for reduction is 1.6, 2.7 times as high compared with the Hefti, Salib's methods respectively. The mechanism of reduction is that the LSRF used contacted point of lamina by lamina hook as the fulcrum, through the pedicle screw to pull the spondylolisthetic vertebrae, and reduce the anterior displacement of vertebrae. Conclusion LSRF gives rigid fixation and good reduction, and provides a new and effective method for lumbar spondylolysis and isthmic spondylolisthesis.