新型多段式股骨植入体周围骨应力分布的三维有限元分析

3D FE analysis of bone stress around multi-part osseointegrated implant used for femur

应用于植入性下肢假肢的骨植入体多为一段式结构,长期使用下产生的应力屏蔽效应容易引起骨质疏松,继而导致植入体植入失败.设计了一种新型的多段式结构的植入体,并基于人体CT扫描数据建立了相关股骨残肢骨和骨内植入体模型,在步行最大生理载荷情况下,采用三维有限元分析方法,对新设计周围的骨应力进行了分析研究.结果表明相比于一段式植入体,新型植入体植入后应力屏蔽和应力集中的程度得到了有效减轻,且与自然骨的应力较为接近,而且还能保持其在体内的稳定性,是比较理想的新型植入体设计.

One-part implant widely used for osseointegrated artificial lower limb attachment would lead to osteoporosis caused by stress shielding after a long time of implantation, and result in failure. To reduce shielding influence, a new type of implant-multi-part implant was devised and now is introduced in this article. Based on CT data and under the maximal load during a normal walking cycle, the stress distribution of bone around the new implant was evaluated by way of 3D finite element analysis. Results reveal that, compared with the traditional one-part implant, stress shielding and stress concentration under the new type of implant are reduced effectively and the stress distribution is much close to the natural bone. Meanwhile, the stability in vivo can also be maintained with the multi-part implant. The new implant is promising in application to prosthetic limb.