Finite Element Analysis of PFNA and PFNA Combined with Locking Plate in the Treatment of Femoral Intertrochanteric Fractures with Lateral Wall Fracture

Abstract

Objective: This study aimed to compare the biomechanical characteristics of Proximal Femoral Nail Antirotation (PFNA) and PFNA combined with Proximal Humerus Locking Plate (PHLP) in the treatment of femoral intertrochanteric fractures with lateral wall fractures using finite element analysis. The biomechanical strength, stress distribution, and displacement patterns of the two internal fixation methods were evaluated.
Methods: A three-dimensional finite element model of the femur, PFNA, and PHLP was constructed based on CT scan data from a healthy middle-aged female patient. A simulated AO 31-A3.3 femoral intertrochanteric fracture was created, and two internal fixation models (PFNA and PFNA+PHLP) were assembled. The von Mises stress and displacement distributions were analyzed under static and dynamic loading conditions.
Results: Compared to PFNA , PFNA+PHLP fixation reduced the maximum von Mises stress by approximately 40%, with minimal changes in maximum displacement. Stress at the fracture site and main nail decreased significantly, particularly at the main nail (reduction of 40%). The von Mises stress in the femoral head, femoral neck, medial wall, and spiral blade showed minimal changes. The total displacement of the femoral head, femoral neck, lateral wall, and spiral blade in the PFNA+PHLP model decreased slightly but not significantly.
Conclusion: PFNA+PHLP fixation demonstrates higher fixation strength and more reasonable stress distribution compared to PFNA in the treatment of femoral intertrochanteric fractures with lateral wall fractures.