3D打印钛孔结构与实体钛结构椎体的体外生物力学测试分析

Comparison of in vitro biomechanical study of porous and entity 3D printing titanium artificial vertebral body

目的通过对3D打印钛孔结构与实体钛结构椎体植入猪腰椎后进行体外生物力学测试,评价其活动范围情况及即刻生物力学稳定性。方法选取18具新鲜成年猪脊柱标本（L1~L6）随机分配到以下三组：对照组（未置换）、钛孔结构椎体置换组（取出L3椎体行钛孔结构椎体植入,简称钛孔结构组）、实体钛结构椎体置换组（取出L3椎体行实体钛结构椎体植入,简称实体钛组）。测试标本的前屈、后伸、侧屈、轴向旋转角位移运动变化。结果实体钛组、钛孔结构组分别与对照组在各方位角位移运动范围比较,差异均有统计学意义（均P〈0.05）;钛孔结构组与实体钛组在各方位的角位移运动范围比较,差异均无统计学意义（均P〉0.05）,且两种固定状态下各方位的即刻稳定指数比较,差异均无统计学意义（均P〉0.05）。结论两种3D打印人工椎体方法均能获得良好的即刻稳定性,但3D打印的钛孔结构人工椎体在融合方面优于实体钛结构。

Objective To evaluate the range of activity and immediate hiomechanical stability through the in vitro biomechanical test by replacement of the 3D printing porous titanium vertebral body and the 3D printing entity titanium vertebral body in porcine models. Methods Eighteen fresh similar porcine spinal specimens （Ll-I4） were divided into 3 groups randomly： control group （without replace- ment）, porous titanium vertebral body replacement group （L3 replacement with porous titanium vertebral body）, and entity titanium vertebral body replacement group （L3 replacement with entity titanium vertebral body）. The displacement and angle variation in flexion, extension, left/right lateral bending and left/right torsion were tested respectively. Results The results of displacement and angle variation in porous titanium vertebral body replacement group and entity titanium vertebral body replacement group were significantly different from those in control group in forward flexion, extension, left/right lateral bending （all P〉0. 05）. Comparison of the angle variation displacement in porous titanium vertebral body replacement group and entity titanium vertebral body replacement group showed no statistically significant difference （all P〉0. 05）, and the comparison of immediate stability index between porous titanium vertebral body replacement group and entity titanium vertebral body replacement group was had no significant difference （all P〉0. 05）. Conclusion Two replacement methods of 3D printing artificial vertebral body can guarantee the immediate stability of spine biomechanics, but 3D printing porous titanium vertebral body is superior to entity titanium vertebral body in fusion.