模拟腰椎间盘髓核摘除后疲劳载荷对腰椎稳定性的影响

背景：腰椎间盘髓核摘除术后何时下床活动目前尚无统一标准,实验拟通过腰椎间盘髓核摘除术后早期的生物力学变化来指导患者进行功能锻炼。 目的：观察腰椎间盘髓核摘除后疲劳载荷对腰椎稳定性的影响。 方法：取3具新鲜猪脊柱标本,制成12个脊柱功能单位,随机分为A,B,C组,行单侧椎板开窗髓核摘除后,在不同循环载荷压力(500~1 000 N,500~2 000 N,500~3 000 N)下行疲劳载荷实验。 结果与结论：A,B组椎间盘高度、刚度差异无显著性意义(P > 0.05),应变增大差异有显著性意义(P < 0.05);B,C组椎间盘高度和刚度的降低、应变的增大差异均有显著性意义(P < 0.01)。循环载荷后3组间比较,椎间盘高度、应变、刚度的变化幅度均随载荷压力的增大而变大(P < 0.05)。结果说明髓核摘除后较大的载荷会破坏腰椎的稳定性。

Effects of fatigue load on lumbar stability after simulated lumbar diskectomy

BACKGROUND:At present, there is not a unified standard about when to start ambulation after lumbar diskectomy. In the present experiment, we guided functional exercises of patients after lumbar diskectomy based on early biomechanical changes. OBJECTIVE:To explore the effects of fatigue load on lumbar stability after lumbar diskectomy. METHODS:Twelve functional spinal units were taken from 3 fresh porcine spines and divided into A group, B group and C group randomly. Fatigue load test was performed in all cases with different cycle load pressures (500-1 000 N, 500-2 000 N, 500- 3 000 N) after unilateral lumbar diskectomy. RESULTS AND CONCLUSION:There was no significant difference between A group and B group in disc height and stiffness (P > 0.05), but the increased strain showed significant difference (P < 0.05); Disc height and stiffness in B group and C group was reduced, strain was increased, and all these differences were significant (P < 0.01). Change ranges of disc height, strain and stiffness in the three groups were increased with the increase of the load pressure after cyclic tensile test (P < 0.05). The results showed that a bigger fatigue load can damage lumbar stability after lumbar diskectomy.