目的 通过测量腰椎峡部裂模型上位脊椎间盘压力,研究峡部裂上位脊椎稳定性。方法 实验材料为9具成人新鲜腰椎标本，造成实验模型，通过MTS-858生物力学测试机对正常组及峡部裂组标本进行中心垂直、前屈、后伸及侧屈压力加载，对不同状态椎间盘进行压力测试，分析比较峡部裂组及正常组上位椎间盘压力。结果 峡部裂组上位脊椎（L4/5）间盘压力在中心垂直正压状态下(600、800、1 000 N加载)与正常组椎间盘压力均值比较，P＞0.05，无显著性差异，分别增加了1.3％，1.5％，1.7％。前屈15°状态下(300、500、700 N加载)与正常组椎间盘压力均值比较，P均＜0.001，有显著性差异，分别增加了20.97％，24.45％，28.79％。后伸15°状态下(300、500、700 N加载))与正常组椎间盘压力均值比较，P＜0.001，有显著性差异，分别增加了14.15％，17.86％，24.92％。侧屈15°状态下(300、500、700 N加载)与正常组压力比较，P＞0.05，无显著性差异，分别增加了3.54％，2.12％，1.14％。 结论 腰椎峡部裂不仅对同序脊椎具有重要力学影响，而且对上位脊椎同样具有重要力学影响，从而可以影响同序及上位脊椎的稳定性。

Objective To study the stability of upper lumbar vertebra in spondylolysis by measuring the upper vertebra pressure on lumbar spondylolysis models. Method Nine freshfrozen human lumbar spinal specimens were used as experimental models. The pressure on upper vertebral discs of lumbar vertebrae was measured by the material testing machine (MTS858 Bionix test system)with extension, flexion and axial, bilateral compression being applied on two groups of specimens: 1) intact spine; 2) lumbar spondylolysis. Results Compared with the intact specimens, the pressure of upper lumbar vertebra in spondylolysis was increased by 1.3％，1.5％，1.7％ in axial compression with 600, 800, 1 000 N (the differences were not significant (P＞0.05)), by 20.97％，24.45％，28.79％ in 15°of extension with 300, 500, 700N (the differences were significant (P < 0.01)), by 14.15％，17.86％，24.92％ in 15°of flexion with 300, 500, 700N (the differences were significant (P < 0.01)), by 3.54％，2.12％，1.14％ in 15°of bilateral compression with 300, 500, 700N (the differences were not significant (P＞0.05)). Conclusions Lumbar spondylolysis has a significant mechanical influence on lumbar spine not only at the involved level but also at the upper adjacent level, which can affect the stability of lumbar spine correspondingly.