Four Different Fixation Strategies for Ipsilateral Femoral Neck and Shaft Fractures: A Finite Element Analysis

Background: Ipsilateral femoral neck and shaft fractures (IFNSF) are complex injuries resulting from high-energy trauma mechanisms. Despite the availability of multiple fixation strategies, the optimal surgical management remains a subject of ongoing debate, and comparative biomechanical data are notably lacking. The present study aimed to evaluate the stability of four commonly utilized internal fixation constructs through patient-specific finite element analysis (FEA), thereby providing a robust biomechanical rationale for surgical decision-making. Methods: Patient-specific finite element analysis (FEA) models were reconstructed from the CT data of eight individual patients to simulate a complex injury pattern involving an ipsilateral Pauwels type III femoral neck fracture combined with a comminuted femoral shaft fracture. The study evaluated four distinct internal fixation strategies consisting of proximal femoral nail antirotation (PFNA), compression plate with cannulated screws (CP-CS), antegrade intramedullary nail with cannulated screws (AN-CS), and long proximal femoral locking plate (LPFLP). Stability parameters were subsequently quantified under simulated axial and torsional loading conditions to assess the mechanical performance of each construct. Results: Under both loading conditions, the AN-CS group consistently maintained relatively low levels of femoral and implant displacement while demonstrating a more uniform stress distribution and the minimum interfragmentary motion at the femoral neck fracture site. Conclusion: AN-CS exhibits the most superior comprehensive biomechanical performance among the four tested methods. It effectively balances interfragmentary stability with uniform stress distribution, making it the optimal strategy for the treatment of ipsilateral femoral neck and shaft fractures