前交叉韧带胫骨棘止点撕脱骨折中钛缆张力带固定的生物力学比较研究

A biomechanicai comparison of cable tension band fixation for tibial avulsion fractures of the anterior cruciate ligament

目的通过生物力学比较分析钛缆张力带固定与其他3种内固定方式治疗胫骨髁间棘撕脱骨折的稳定性。方法取80个新鲜成年猪膝关节样本，随机分为4个组，每组20个；剔除所有软组织，仅保留完整的股骨．前交叉韧带．胫骨复合体。使用摆锯在前交叉韧带胫骨止点区域制造标准的Meyers—MeKeeverⅢ型骨折模型，骨折块分别用空心拉力螺钉、高强缝线、钢丝张力带、钛缆张力带固定。所有标本均在材料力学机器使用60mm／min的负载速率下测试，采集并比较各组内固方式在单循环载荷和多循环载荷测试下的最终失效载荷、屈服载荷、骨折块移位距离。结果钛缆张力带固定比其他3种固定方式有更高的失效载荷、屈服载荷和最小的骨折块移位，差异均有统计学意义（P〈0．05）。结论钛缆张力带固定前交叉韧带胫骨棘止点撕脱骨折比其他3种固定方式有更好的生物力学稳定性，是一种固定牢固、方便经济的固定方式，术后可以早期负重和功能锻炼。

Objective To compare cable tension band fixation with other 3 fixations in terms of biomechanical stability for tibial avulsion fractures of the anterior cruciate ligament （ACL）. Methods Eighty fresh porcine knees were randomized into 4 equal greups （ n = 20）. For each knee, all the soft tissues were removed only to keep the femur-ACL-tibia complex. The knee complexes were used to create fracture models of standard Meyers-Mc Keever type III at the ACL attachment region using a swing saw. The fracture fragments in the 4 groups were subjected to fixation respectively with intramedullary lag screws, high-strength suture, tension band wire and cable tension band. All the specimens were subsequently tested on a Material Testing Machine at a load rate of 60 mm/mm. The 4 groups were compared in terms of ultimate failure load, yield load, and fragmental displacement under single-cycle loading and multi-cyclic loadings. Results Cable tension band fixation displayed significantly higher ultimate failure, higher yield load and lower fragmental displacement than all the other 3 fixations （ P 〈 0. 05） . Conclusion As cable tension band fixation, which is convenient and economical, provides better biomechanical stability than other 3 fixations for tibial avulsion fractures of the ACL, it may allow earlier functional and weight-bearing exercise after operation.