不同扭矩对腰椎融合后邻近上节段生物力学影响的实验研究

目的　探讨腰椎融合后不同扭矩对邻近上节段椎间盘内压、关节突关节压力的影响。 方法　选取12具猪腰椎，随机分成2组，比较融合（L4/5）前、后两种状态下三种不同扭矩加载邻近上节段（L3/4）椎间盘内压、关节突关节压力的差异。 结果 融合后随着扭矩的增加椎间盘内压增加，扭矩越大椎间盘内压变化越明显(P=0.023)； 非融合组及融合组伴随着扭矩的增加关节突关节压力逐渐增加， 扭矩越大关节突关节压力越大。融合组较非融合组关节突关节压力变化明显（P=0.046）。 结论 腰椎融合后， 随着扭矩的增加邻近上节段腰椎间盘内压呈增高趋势； 关节突关节压力随着扭矩的增加关节突压力而增加。

The study on biomechanical effect of different torsion torque on the adjacent segment after lumbar fusion

Objective　To evaluate the effects of small different torsion torques on intradiscal pressure（IDP）and pressure in the facet joints (PFJ )on the upper adjacent segment before and after lumbar spinal fusion.　Methods　Twelve lumbar porcine cadaveric motion segments were divided into two groups and loaded in the neutral position with 300 N of axial compression. IDP and PFJ at L3/4 measurements were obtained at 0, 1.0, and 2.0 Nm of torsion before and after lumbar spinal fusion (L4/5). Results The IDP increased with the increase of torsion torques. The changes of IDP in different torsion torques had statistically significant difference. Both non fusion group and fusion group, the PFJ become more and higher, the larger torsion torque, the higher PFJ. The changes of PFJ in the fusion group and non-fusion group both had statistically significant difference.　Conclusions　The IDP in the fusion group increases with the torsion torque increasing. The PFJ increases with the torsion torque increasing in non-fusion group and fusion group.