单侧小关节分级切除对腰椎稳定性影响的三维有限元分析

目的研究单侧小关节分级切除对腰椎稳定性的影响。方法采用三维有限元法建立腰椎活动节段（L4～5）的数学力学模型。结果a）在前屈和后伸状态下，各实验切除组与正常对照组无显著性差异（P〉0．05）；b）在左／右侧弯和左／右轴向旋转状态下，小关节切除1／2以上的各组均与正常组有显著性差异（P〈0．05或P〈0．01）。结论a）单侧小关节分级切除对腰椎节段的前屈、后伸稳定性无显著性影响；b）当腰椎小关节切除范围超过1／2，对腰椎节段侧弯运动有显著性影响，尤其以向对侧侧屈为甚；c）当一侧小关节切除超过1／2后，由于失去了小关节和关节囊的限制，导致腰椎活动节段轴向旋转范围增加显著。

Three-dimensional Finite Element Analysis of Unilateral Graded Facetectomy on Lumbar Spinal Stability

Objective To observe the biomechanical effects of unilateral graded facetectomy on lumbar spinal stability. Methods L4-L5 three-dimensional finite element model was used. Results a）There hadn＇t obvious difference between every test groups and normal group in anterior flexion and posterior extension（P〉0.05）. It indicated that unilateral graded facetectomy on lumbar spinal hadn＇t obvious effects in the stability of anterior flexion and posterior extension, b）There had obvious difference between 1/2,3/4,total facetectomy of left-lateral small vertebral joints groups and normal group in left/right lateral flexion and left/right axial direction（P〈0.05 or P〈0.01）. Conclusion a）Unilateral graded facetectomy on lumbar spinal had some influence to the stability of anterior flexion and posterior extension. But it couldn＇t lead to destabilizing, b）There had obvious difference between test groups if the range of graded facetectomy exceed 1/2 and normal group in left/right lateral curvature especially in opposite side lateral flexion. c）The range of movement of lumbar vertebrae increased significantly because of losing the constraint of small joint and articular capsule if the range of graded facetectomy exceeding 1/2.