Department of Orthopedics, Songjiang District Central Hospital, Shanghai, China.
Department of Orthopedics, Pudong New Area People's Hospital Affiliated With Shanghai Health University, Shanghai, China.
Comput Methods Biomech Biomed Engin. 2023 May;26(7):846-853. doi: 10.1080/10255842.2022.2092727. Epub 2022 Jun 25.
This study compared the biomechanical characteristics of different treatment strategies based on finite element analysis. Posterior tilt and valgus angle were measured on X-ray from ten valgus-impacted femoral neck fractures, and 7 finite element models that were generated to compare the stress and displacement. The results showed that in the intact femur, von Mises stress was concentrated at the medial and inferior sides of the femoral neck. In valgus-impacted femoral neck fractures, von Mises stress was at the same locations but was 5.66 times higher than that in the intact femur. When 3 cannulated screws were used for internal fixation, anatomic reduction diminished the stress at the fracture end from 140.6 to 59.14 MPa, although displacement increased from 0.228 to 0.450 mm. When the fracture was fixed with a sliding hip screw (SHS) + cannulated screw, there was less stress at the fracture end and greater displacement with anatomic reduction than that without reduction (stress: 15.9 vs 37.9 MPa; displacement: 0.329 vs 0.168 mm). Therefore, the SHS + cannulated screw has superior biomechanical stability than 3 cannulated screws, and is recommended following anatomic reduction to treat valgus-compacted femoral neck fractures.
本研究通过有限元分析比较了不同治疗策略的生物力学特征。对 10 例股骨颈骨折的 X 射线后倾和外翻角进行了测量，并生成了 7 个有限元模型以比较其应力和位移。结果表明，在完整的股骨中，von Mises 应力集中在股骨颈的内侧和下侧。在股骨颈骨折的外翻影响下，von Mises 应力位于相同位置，但比完整股骨高 5.66 倍。当使用 3 根空心螺钉进行内固定时，解剖复位将骨折端的应力从 140.6 MPa 降低至 59.14 MPa，尽管位移从 0.228 增加至 0.450 mm。当使用滑动髋螺钉 (SHS) + 空心螺钉固定骨折时，解剖复位的骨折端应力和位移均小于未复位的情况（应力：15.9 比 37.9 MPa；位移：0.329 比 0.168 mm）。因此，与 3 根空心螺钉相比，SHS + 空心螺钉具有更好的生物力学稳定性，建议在解剖复位后用于治疗外翻压缩性股骨颈骨折。
