Four different fixation strategies for ipsilateral femoral neck and shaft fractures: a finite element analysis.

BACKGROUND: Ipsilateral femoral neck and shaft fractures are complex injuries that result from high-energy trauma. Despite the availability of multiple fixation strategies, optimal surgical management remains a subject of ongoing debate and comparative biomechanical data are lacking. This study evaluated the stability of four commonly used constructs for internal fixation using patient-specific finite element analysis (FEA) to provide a robust biomechanical rationale for surgical decision-making.

METHODS: Patient-specific FEA models were reconstructed using computed tomography imaging data of eight patients to simulate a complex injury pattern involving an ipsilateral Pauwels type III femoral neck fracture combined with a comminuted femoral shaft fracture. Four distinct internal fixation strategies were evaluated: proximal femoral nail antirotation, compression plate with cannulated screws, antegrade intramedullary nail with cannulated screws (AN-CS), and long proximal femoral locking plate. Stability parameters were 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 low levels of femoral and implant displacement while demonstrating a more uniform stress distribution and minimum interfragmentary motion at the femoral neck fracture site.

CONCLUSION: Of the four fixation methods evaluated in this simulation study, the AN-CS construct exhibited the best biomechanical performance overall. The AN-CS fixation effectively balanced interfragmentary stability with a uniform stress distribution, thereby providing a biomechanical basis to guide subsequent clinical decision-making.