股骨头骨坏死范围对髋关节表面置换术后股骨近端力学分布的影响

目的探讨髋关节表面置换术后股骨头骨坏死范围对股骨近端与假体松动或股骨颈骨折相关的应力分布的影响。方法依据基于连续CT断层图像构建的股骨三维图形和髋关节表面置换假体，采用计算机辅助技术，建立股骨头部无坏死和前后位坏死角分别为60°、80°、100°、120°、140°的表面置换三维有限元模型，单腿负重条件下，模拟坏死骨未清除及清除后填充骨水泥的情形进行受力分析。结果骨坏死范围对股骨颈部的应力分布影响微小。股骨头近端骨质出现明显的应力遮挡。当坏死角≤80°时，骨水泥界面和头颈交界骨质中的Von Mises等效应力峰值变化较小；当坏死角≥100°时，应力峰值变化明显，其中水泥层外上缘的峰值增幅为22．3％和27．3％（坏死角120°和140°），头颈交界外上缘骨质的峰值增幅为13．2％、28．3％和53．3％（坏死角100°、120°和140°）。填充骨水泥后，主要应力集中区的等效应力峰值逐渐减小或变化不明显。结论髋关节表面置换术改变了股骨头内应力分布；股骨头近端出现明显的应力遮挡，允许股骨头负重区出现小的骨坏死（坏死角≤80°）；坏死角≥100°的骨坏死，是否适于髋关节表面置换术还需深入研究。

The effects of osteonecrosis extent of femoral head on the stress distribution in proximal femur after hip resurfacing

Objective To observe the effects of osteonecrosis extent of the femoral head on the stress distribution related to femoral neck fracture or prosthesis aseptic loosening in proximal femur after hip resurfacing.Methods Three-dimensional finite element models of resurfaced femoral head were constructed through computer aid design technology using femur three-dimensional model based on serial computed tomographic pictures and hip resurfacing prosthesis.Six resurfaced models including the normal femoral head and...