Computational Biomechanical Comparison of Conventional and Novel Fixation Techniques for Pauwels Type Iii Femoral Neck Fractures Publisher Pubmed



Fallah A ; Nourani A ; Kalantar SH ; Farrahi GH
Source: Journal of Biomechanics Published:2026

Abstract

Pauwels type III vertical femoral neck fractures (FNFs), common in young patients after high-energy trauma, pose major challenges in orthopedic surgery. This study evaluates the biomechanical performance of a new fixation method (KFeNS) compared to the standard dynamic hip screw + anti-rotation screw (DHS + AS) using finite element analysis. A proximal femoral model was created from CT scan images. A 70° Pauwels FNF was simulated and stabilized using KFeNS and DHS + AS methods. Three loading scenarios were applied to the femoral head. A modified boundary condition was introduced by restricting horizontal displacement of the femoral head in the axial loading to better replicate the in-vivo mechanical environment. Key parameters, including the maximum von Mises stress (MVS), the maximum displacement of the femoral head and internal fixation implant, strain energy density, and interfragmentary motion (IFM), were compared between the two methods. The MVS of DHS + AS is 40% and 14.2% higher than that of KFeNS under axial loading and anterior-posterior (A-P) bending, respectively, but 19.9% lower under rotation. The average IFM of KFeNS is 28.7% and 14.2% lower than that of DHS + AS in axial loading and A-P bending, while both are similar in torsion. The maximum femoral head displacement is 5.8% higher in DHS + AS under axial loading, 7.4% higher in KFeNS in torsion, and similar in A-P bending. Within the investigated finite element framework, the KFeNS technique demonstrates improved mechanical stability compared to the DHS + AS method for Pauwels type III FNFs, supporting its mechanical feasibility as an alternative fixation concept. © 2026 Elsevier Ltd