利用镍钛记忆合金椎体复位器治疗椎体压缩性骨折

目的探讨一种全新设计的镍钛记忆合金椎体复位器用以治疗椎体压缩性骨折的可行性。方法采用成人新鲜冷冻尸体标本,制成实验性胸、腰椎压缩骨折单位模型后分成对照组、经皮椎体后凸骨水泥成形术组(PKP组)及经皮置入镍钛记忆合金椎体复位器术组(镍钛复位器组)。分别在手术操作前后测量椎体高度,比较两种不同术式对压缩椎体复位程度的影响;以对照组为测量基值,分别测量两种手术后椎体标本的峰值载荷并加以比较。结果与对照组相比,两种手术组均能显著地复位塌陷的椎体终板,PKP组和镍钛复位器组的椎体高度分别从术前的(2.01±0.21)和(2.00±0.18)cm复位至术后的(2.27±0.18)和(2.31±0.17)cm。PKP组和镍钛复位器组的椎体峰值载荷分别为(2 880.75±126.17)和(2 888.00±144.69)N,均显著高于对照组(2 017.17±163.71)N,但两种术式之间无显著性差异。结论镍钛记忆合金椎体复位器能有效地复位塌陷的椎体终板,并保持足够的即刻脊柱生物力学稳定性,减少椎体后凸成形术时因使用骨水泥所带来的副反应。

Using Ni-Ti shape memory alloy vertebral reduction fixator to treat vertebral compression fractures

Objective To investigate the feasibility of a novel Ni-Ti shape memory alloy vertebral reduction fixator for treating vertebral compression fractures. Methods The experimental thoracic-lumbar fracture units made from adult fresh-frozen cadaver vertebral specimens were randomly assigned to 3 groups for testing: control group, percutaneous kyphoplasty group (PKP group) and percutaneous vertebral body reduction fixator group (Ni-Ti fixator group). The vertebral height and peak load on the specimens were measured before and after the two kinds of operations, respectively, to compare the restoration of compression fractures. Results Compared with the control group, both the PKP and Ni-Ti fixator groups could significantly restore the collapse of the vertebral endplate. The vertebral height of the PKP group and Ni-Ti fixator group was raised from (2.01±0.21) and (2.00±0.18)cm before the operation to (2.27±0.18) and (2.31±0.17) cm after the operation, respectively. The peak loads on the vertebrae for the PKP and Ni-Ti fixator group were (2 880.75±126.17) and (2 888.00±144.69) N, respectively, with no statistical differences found in between, while those for the control group were (2 017.17±163.71) N. Conclusions The Ni-Ti shape memory alloy vertebral reduction fixator can effectively restore the collapse of the vertebral endplate, maintaining the immediate biomechanical stability of the vertebrae, and reducing the adverse reactions due to the injection of polymethyl methacrylate (PMMA) cement during percutaneous kyphoplasty.