基于有限元分析方法的Vancouver B1型假体周围骨折内固定方式的比较

Comparison of internal fixation for Vancouver type B1 fracture based on a finite-element analysis

[目的]用有限元方法研究人工髋关节置换术后Vancouver B1型股骨假体周围骨折不同内固定方式的稳定性及生物力学情况。[方法]模拟人工髋关节置换术后Vancouver B1型股骨假体周围骨折,并模拟不同方式的锁定钛板螺钉内固定术,模拟部分负重及完全负重情况对装配体施加载荷,并进行组间比较。[结果]随着钛板及螺钉数量增加,骨折端位移减小,内固定稳定性增加,钛板上分布的Von Mises应力峰值逐渐减小,单八孔钛板、单十孔钛板及双八孔钛板固定组间比较差异有统计学意义,但双十孔钛板与双八孔钛板固定组间比较差异无统计学意义;同时,假体上分布的Von Mises应力峰值逐渐增大,但各组间比较均差异无统计学意义。[结论]对于Vancouver B1型股骨假体周围骨折,若采用锁定钛板螺钉内固定方式进行治疗,双重钛板可比单一钛板提供更高的稳定性,同时使得钛板上分布的应力峰值减低,但过长的双重钛板(双十孔)并无必要。

[Objective] To compare different fixation methods for Vancouver type B1 periprosthetic fractures after hip arthroplasty using a finite-element analysis. [Methods] CT data of the femur from 30 elderly healthy volunteers were collected. Different types of internal fixation methods for Vancouver type B1 periprosthetic fracture were simulated. These models were then input into finite element analysis software. Different loads referred to partial or full weight bearing were applied. Then the results were analyzed and compared. [Results] When more plates and screws were used, the displacement of fracture and the maximum Von Mises stress became smaller.Statistically significant difference was observed between single 8-hole, single 10-hole and double 8-hole plate fixation group, but no statistically significant difference between double 8-hole and double 10-hole plate fixation group. Meanwhile, no statistically significant difference could be found on maximum Von Mises stress on the stem between each two groups. [Conclusion] In the treatment of Vancouver type B1 periprosthetic fracture, double plate fixation has better stability and less maximum Von Mises stress. However, double 10-hole plate seemed not necessary.