TLIF、PLIF、ALIF三种椎间融合术后腰椎即刻稳定性的比较

Biomechanical comparison of the initial stability after anterior,posterior and transforaminal interbody fusion

目的比较三种椎间融合方式后腰椎即刻稳定性差异。方法选用20具新鲜小牛标本,分为4组,每组5个标本,模拟临床行前路椎间融合术(ALIF)、后路椎间融合术(PLIF)、椎间孔入路椎间融合术(TLIF),在腰椎三维力学机上测试其生物力学特性。结果ALIF组的平均应变较对照组增加17.6%(P<0.05),平均应力增加15.2%;ALIF、PLIF、TLIF平均轴向刚度和水平剪切刚度分别下降28.3%、18.4%、11.5%和21.6%、17.5%、5.9%(P<0.05);ALIF、PLIF、TLIF的扭矩强度分别下降38.6%、49.1%、27.3%(P<0.05)。结论ALIF、PLIF、TLIF术后,腰椎的稳定性能明显下降。在轴向载荷压缩、屈伸、侧弯运动工况下,PLIF优于ALIF;在扭转力学性能上ALIF优于PLIF。

Objective To compare the stability of the lumbar intervertebral segmental stiffness after interbody fusion with three types of approach （ALIF, PLIF and TLIF）. Methods Twenty bovine lumbars were divided into 4 groups of intact , ALIF , PLIF, and TLIF. Nondestructive tests were performed in pure compression, flexion, extension, and lateral bending on each group. Results Compared with intact group, the mean strainness and stiffness were separately increased by 17.6% and 15.2% in ALIF group, in ALIF , PLIF, and TLIF groups the mean axis compression stiffness was decreased by 28. 30/4,18. 4%, and 11.5% （P〈0. 05）, the mean anteroposterior shear stiffness decreased by 21.6 %, 17.5 %, and 5.9 % （P〈 0. 05）, and the axial rotational stiffness decreased by 38. 6%,49.1%,and 27.3% （P〈0.05）, respectively. Conclusion The initial stability of anterior, posterior and transforarninal interbody fusion with ALTF, PLTF or TLIF approach is less than that with conventional intact approach. During resisting flexion , extension, lateral bending and anteroposterior shear, PLTF approach provides more stability than ALTF. During resisting rotation , ALIF approach is better than PLIF.