股骨头坏死髂骨瓣移植与旋转截骨的有限元分析△

Finite element analysis of iliac bone flap transplantation and rotational osteotomy for femoral head necrosis

摘要:

[目的]采用有限元分析法（fine element analysis, FEA）比较带血管蒂髂骨瓣移植术和经股骨颈基底部旋转截骨术的生物力学差异。[方法] 将中日友好医院分型 （China-Japan Friendship Hospital, CJFH） L2 型的股骨头坏死患者 CT 数据导入 Mimics 21.0 建立股骨模型（坏死组）。经 Geomagic 优化后，在 Solidworks 2021 中模拟带血管蒂髂骨瓣放置股骨头内部与冠状面向前成 20°的位置建立带血管蒂髂骨瓣移植术模型（移植组），模拟前旋 90°经股骨颈基底部旋转截骨术并置入股骨颈内固定系统 （femoral neck system, FNS） 建立经股骨颈基底部旋转截骨术后模型 （截骨组）。比较三组等效应力值及位移变化情况。[结果] 坏死组股骨模型应力的峰值 69.56 MPa 最大，集中在受力区，其次为移植组的 59.97 MPa，截骨组的应力峰值最小 57.91 MPa。 最大位移依次为坏死组（1.85 mm）＞移植组（1.37 mm）＞截骨组（1.23 mm）。[结论] 经股骨颈基底部旋转截骨术与带血管蒂髂骨瓣移植术，均能够减少坏死区域的应力集中，并且能够改善和恢复股骨头的内部生物力学状态。股骨颈基底部旋转截骨术对股骨头力学的改善优于带血管蒂髂骨瓣移植术。

Abstract:

[Objective] To compare the biomechanical differences between vascular pedicled iliac flap grafting and femoral neck baserotation osteotomy by fine element analysis (FEA). [Methods] The the proximal femur model (necrosis group) was established by importingthe CT data of a patient with China-Japan Friendship Hospital (CJFH) type L2 femoral head necrosis into Mimics 21.0. After Geomagic op-timization, the vascular pedicled iliac flap transplantation model (graft group) was established in Solidworks 2021 to simulate the position ofvascular pedicled iliac flap placed inside the femoral head at 20° forward in the coronal plane. The model of femoral neck rotation osteoto-my (osteotomy group) was established with 90° anterior rotation through the base of the femoral neck and fixed by femoral neck system(FNS). The mechanical changes of the three models were compared and analyzed in ANSYS 17.0. [Results] The peak stress of the femurmodel in the necrotic group (69.56 MPa) was the largest and concentrated in the stress region, followed by that in the graft group (59.97MPa), and that in the osteotomy group was the smallest (57.91 MPa). The maximum displacement was in the necrotic group (1.85 mm) ＞ thegraft group (1.37 mm) ＞ the osteotomy group (1.23 mm). [Conclusion] Both rotary osteotomy at the base of the femoral neck and vascular-ized iliac flap grafting can reduce stress concentration in the necrotic area, and improve and restore the internal biomechanical status of thefemoral head. The femoral neck base rotation osteotomy is superior to vascular pedicled iliac flap grafting in improving the mechanics offemoral head