Fan Jixing, Cao Yuan, Cui Zengzhen, Gao Shan, Lv Yang, Zhou Fang
Department of Orthopedics, Peking University Third Hospital, Beijing, China.
Engineering Research Center of Bone and Joint Precision Medicine, Ministry of Education, Beijing, China.
Front Bioeng Biotechnol. 2025 May 21;13:1559765. doi: 10.3389/fbioe.2025.1559765. eCollection 2025.
The AO/OTA 31-A3.3 is the most unstable type with a lesser trochanteric fragment and a broken lateral femoral wall (LFW), which constitute a four-part unstable intertrochanteric fracture. Implant failure remains one of the catastrophic consequences after surgical treatment. A novel nail-plate construct, called proximal femoral universal nail system (PFUN), is proposed by our team to fix comminuted LFW fracture fragment and lesser trochanteric fragment. The aim of this study is to evaluate the biomechanical properties of PFUN compared with proximal femoral nails anti-rotation (PFNA) for the treatment of AO/OTA 31-A3.3 intertrochanteric fractures.
An AO/OTA 31-A3.3 intertrochanteric fracture model was established by computed tomography images. The models of implant (PFUN and PFNA) were created and virtually inserted into the A3.3 fracture model. The von Mises stress on the proximal femur, fracture end, implant and the total displacement of the device components were evaluated and compared for both PFUN and PFNA models.
The maximum von Mises stress in the proximal femur of the PFNA model increased by 85.81% when compared with the PFUN model in A 3.3 intertrochanteric fractures. The peak von Mises stress was located at the medial-inferior part of the fracture ends in the PFUN and PFNA models and the maximum von Mises stress in the PFUN model and PFNA model was 27.27 MPa and 49.95MPa, respectively. The PFUN model and PFNA model had similar peak von Mises stress in the implant. Furthermore, the maximum displacement in the PFUN model was much smaller than that in the PFNA model.
The PFUN exhibited a lower peak von Mises stress in the proximal femur and fracture end, and a smaller maximum model displacement than PFNA in A3.3 intertrochanteric fractures. Our findings might provide valuable references for clinical decision making in surgical treatment of complex intertrochanteric fractures.
AO/OTA 31-A3.3型骨折是最不稳定的类型，伴有小转子骨折块和股骨外侧壁（LFW）破裂，构成四部分不稳定型转子间骨折。植入物失败仍然是手术治疗后灾难性的后果之一。我们团队提出了一种新型钉板结构，称为股骨近端通用钉系统（PFUN），用于固定粉碎性LFW骨折块和小转子骨折块。本研究的目的是评估PFUN与股骨近端抗旋转髓内钉（PFNA）治疗AO/OTA 31-A3.3型转子间骨折的生物力学性能。
通过计算机断层扫描图像建立AO/OTA 31-A3.3型转子间骨折模型。创建植入物（PFUN和PFNA）模型并虚拟插入A3.3骨折模型。评估并比较PFUN和PFNA模型中股骨近端、骨折端、植入物上的von Mises应力以及装置组件的总位移。
在A 3.3型转子间骨折中，与PFUN模型相比，PFNA模型股骨近端的最大von Mises应力增加了85.81%。PFUN和PFNA模型中，von Mises应力峰值位于骨折端的内下部分，PFUN模型和PFNA模型的最大von Mises应力分别为27.27MPa和49.95MPa。PFUN模型和PFNA模型在植入物中的von Mises应力峰值相似。此外，PFUN模型中的最大位移远小于PFNA模型。
在A3.3型转子间骨折中，PFUN在股骨近端和骨折端的von Mises应力峰值较低，最大模型位移比PFNA小。我们的研究结果可能为复杂转子间骨折手术治疗的临床决策提供有价值的参考。
