Clinical efficacy and finite element analysis of dynamic crossing screw system in the treatment of non-displaced femoral neck fractures in elderly patients with osteoporosis

Controversy persists regarding the optimal fixation approach for non-displaced femoral neck fractures in elderly osteoporotic patients. While clinical experience with femoral neck system (FNS) is growing, biomechanical validation remains incomplete. This retrospective study included 80 elderly osteoporotic patients with non-displaced femoral neck fractures treated from 2019 to 2024 - 40 with FNS and 40 with CCS. We evaluated healing time, hip function, pain levels, and complications. Additionally, finite element models constructed from computed tomography (CT) scans of an elderly osteoporotic volunteer compared the biomechanical performance of both fixation methods in Garden I and II fracture patterns. FNS patients demonstrated faster healing and superior functional outcomes at 6 months. Complications including femoral neck shortening and fixation failure occurred less frequently with FNS. Finite element analysis revealed lower stress concentrations at the fracture site with FNS compared to CCS, indicating better mechanical stability. FNS showed advantages over conventional cannulated screws in this patient population, achieving faster healing, improved function, and reduced complications.