College of Biomedical Engineering, Taiyuan University of Technology, No.79, Yingze West Road, Taiyuan, Shanxi, 030024, China.
College of Biomedical Engineering, Taiyuan University of Technology, No.79, Yingze West Road, Taiyuan, Shanxi, 030024, China.
Injury. 2021 Apr;52(4):705-712. doi: 10.1016/j.injury.2020.10.102. Epub 2020 Oct 28.
Intramedullary nails are the common treatment options for femoral intertrochanteric fractures. However, aseptic loosening is considered to be one of the primary forms of failure that can be caused by the stress shielding between the bone and implants. The matching in mechanical properties of implant and bone is a key issue to prevent this failure. Polyetheretherketone (PEEK) and Function-graded (FG) materials are widely used in clinical because of their excellent mechanical properties. In this study, to investigate the biomechanical behaviors of intramedullary nails made of Ti-6Al-4V alloy, Stainless Steel (SS), PEEK and two FG materials, three-dimensional finite element models of intertrochanteric fracture femur with intramedullary nail were constructed with ABAQUS. The maximum von Mises stress on the femoral fracture surface fixed by PEEK intramedullary nail was the largest, followed by FG intramedullary nail, which help stimulate bone growth and subsequently reduce fracture healing time. Compared with traditional metal intramedullary nails, PEEK and FG implants might increase von Mises stress along the same path in the proximal femur. The results showed that PEEK and FG intramedullary nails obviously changed the stress distributions in the bone and reduced stress shielding. This finding indicated that PEEK and FG intramedullary nails have the potential to become alternatives to the conventional metal intramedullary nails.
髓内钉是治疗股骨转子间骨折的常用方法。然而，无菌性松动被认为是主要失效形式之一，可能是由骨与植入物之间的应力屏蔽引起的。植入物和骨的机械性能匹配是防止这种失效的关键问题。聚醚醚酮（PEEK）和功能梯度（FG）材料由于其优异的机械性能而广泛应用于临床。在这项研究中，为了研究 Ti-6Al-4V 合金、不锈钢（SS）、PEEK 和两种 FG 材料制成的髓内钉的生物力学行为，使用 ABAQUS 构建了带有髓内钉的转子间骨折股骨的三维有限元模型。用 PEEK 髓内钉固定的股骨骨折面的最大 von Mises 应力最大，其次是 FG 髓内钉，这有助于刺激骨生长，从而缩短骨折愈合时间。与传统金属髓内钉相比，PEEK 和 FG 植入物可能会增加股骨近端沿相同路径的 von Mises 应力。结果表明，PEEK 和 FG 髓内钉明显改变了骨内的应力分布，减少了应力屏蔽。这一发现表明，PEEK 和 FG 髓内钉有可能成为传统金属髓内钉的替代品。
