个性化钛合金短柄股骨假体的生物力学研究

Biomechanical Study on Personalized Titanium Alloy Short Femoral Prosthesis

目的通过有限元方法评价个性化钛合金短柄股骨假体的生物力学性能。方法在已验证有效性的股骨有限元模型基础上,模拟股骨颈基底部截骨,通过置入不同短柄股骨柄假体,分别建立4种人工髋关节置换(total hip replacement,THR)手术模型:SMF柄模型(模型A)、BE1柄模型(模型B)、MINI柄(模型C)、个性柄模型(模型D)。对4组THR模型施加同样的载荷和约束,计算分析模型von Mises应力分布和变形,比较各组模型的力学稳定性。结果所有THR模型变形都比生理状态模型要小。模型B、C变形量接近,模型A、D变形量接近。模型C应力峰值高于其他组模型,达到95.55 MPa,整体应力趋势是模型C>模型B>模型D>模型A>生理状态模型。结论个性化短柄股骨假体应力峰值、应力分布与SMF柄相当,应力分布合理,对股骨近端应力遮挡小,应力下假体整体变形度及剪切应力最小,其有效性和稳定性能满足人体生物力学要求,可为关节外科医生和假体研发人员提供参考。

Objective To evaluate biomechanical properties of the personalized titanium alloy short femoral prosthesis by finite element analysis. Methods Based on the validated femoral finite element model,the base of the femoral neck was simulated,and by inserting different short femoral prostheses,four total hip replacement( THR) models,namely,the SMF stem model( Model A),BE1 stem model( Model B),MINI stem model( Model C) and personalized stem model( Model D) were established,respectively. The same loads and constraints were applied to four groups of models,and the von Mises stress distribution and deformation were calculated and analyzed,so as to compare mechanical stability of each model. Results The deformation of all THR models was smaller than that of the femur model under physiological state. The deformation of Model B was close to that of Model C,and the deformation of Model A was close to that of Model D. The peak stress of Model C was higher than that of the other 3 models,reaching 95. 55 MPa. The overall stress trend was Model C > Model B > Model D> Model A > Model under physiological state. Conclusions The peak stress,stress distribution of personalized short femoral stem were similar to that of SMF stem,with reasonable stress distribution,small stress shielding of the proximal femur,minimum overall deformation and shear stress of the prosthesis,and its effectiveness and stability could meet the requirements of human biomechanics,which could provide references for joint surgeons and prosthesis researchers.