Department of Orthopaedics and Traumatology, Beijing Jishuitan Hospital, Capital Medical University, No. 31 Xinjiekou East Street, Xicheng District, Beijing, 100035, China.
Department of Orthopedics, Peking University Third Hospital, Beijing, 100191, China.
Sci Rep. 2024 Jul 5;14(1):15519. doi: 10.1038/s41598-024-66638-1.
The selection of implants for fixing unstable femoral neck fractures (FNF) remains contentious. This study employs finite element analysis to examine the biomechanics of treating Pauwels type III femoral neck fractures using cannulated compression screws (3CS), biplane double-supported screw fixation (BDSF), and the femoral neck system (FNS). A three-dimensional model of the proximal femur was developed using computed tomography scans. Fracture models of the femoral neck were created with 3CS, BDSF, and FNS fixations. Von Mises stress on the proximal femur, fracture ends, internal fixators, and model displacements were assessed and compared across the three fixation methods (3CS, BDSF, and FNS) during the heel strike of normal walking. The maximum Von Mises stress in the proximal fragment was significantly higher with 3CS fixation compared to BDSF and FNS fixations (120.45 MPa vs. 82.44 MPa and 84.54 MPa, respectively). Regarding Von Mises stress distribution at the fracture ends, the highest stress in the 3CS group was 57.32 MPa, while BDSF and FNS groups showed 51.39 MPa and 49.23 MPa, respectively. Concerning implant stress, the FNS model exhibited greater Von Mises stress compared to the 3CS and BDSF models (236.67 MPa vs. 134.86 MPa and 140.69 MPa, respectively). Moreover, BDSF displayed slightly lower total displacement than 3CS fixation (7.19 mm vs. 7.66 mm), but slightly higher displacement than FNS (7.19 mm vs. 7.03 mm). This study concludes that BDSF outperforms 3CS fixation in terms of biomechanical efficacy and demonstrates similar performance to the FNS approach. As a result, BDSF stands as a dependable alternative for treating Pauwels type III femoral neck fractures.
对于不稳定股骨颈骨折（FNF）固定用植入物的选择仍存在争议。本研究采用有限元分析，比较了空心加压螺钉（3CS）、双平面双支撑螺钉固定（BDSF）和股骨颈系统（FNS）治疗Pauwels Ⅲ型股骨颈骨折的生物力学。通过计算机断层扫描（CT）扫描建立了近端股骨的三维模型。建立了 3CS、BDSF 和 FNS 固定的股骨颈骨折模型。评估和比较了三种固定方法（3CS、BDSF 和 FNS）在正常行走足跟触地时对近端股骨、骨折端、内固定器和模型位移的 Von Mises 应力。与 BDSF 和 FNS 固定相比，3CS 固定时近端骨块的最大 Von Mises 应力显著更高（分别为 120.45 MPa、82.44 MPa 和 84.54 MPa）。关于骨折端的 Von Mises 应力分布，3CS 组的最大应力为 57.32 MPa，BDSF 和 FNS 组分别为 51.39 MPa 和 49.23 MPa。关于植入物的应力，FNS 模型的 Von Mises 应力大于 3CS 和 BDSF 模型（分别为 236.67 MPa、134.86 MPa 和 140.69 MPa）。此外，BDSF 的总位移略小于 3CS 固定（7.19 mm 比 7.66 mm），但略大于 FNS（7.19 mm 比 7.03 mm）。本研究得出结论，BDSF 在生物力学效果方面优于 3CS 固定，与 FNS 方法具有相似的性能。因此，BDSF 是治疗 Pauwels Ⅲ型股骨颈骨折的一种可靠选择。
