Finite Element Analysis of Lateral Plate, Intramedullary Nail, and Nail-Plate Combination Techniques in Osteoporotic Distal Femur Fractures

Background: Osteoporotic distal femur fractures are associated with high mechanical complication rates. This study used finite element analysis to compare three fixation methods—lateral plate, intramedullary nail, and nail–plate combination—in an osteoporotic distal femur model. Fracture displacement, implant stress, and fatigue behavior were examined under two loading conditions.Methods: A 3D femur model was created using Materialise Mimics Medical 21.0®. Models of intramedullary nails, lateral plates, and screws were designed with SolidWorks 2021 SP4.1®. Three fixation groups were formed by combining the fracture model with either a lateral plate, intramedullary nail, or nail–plate combination. Total deformation under loading was measured, implant stress distribution was evaluated, and fatigue failure was defined as breakage under cyclic loading.Results: In compression analysis, maximum total deformation was 101.1 mm for the nail, 110.4 mm for the lateral plate, and 50.3 mm for the nail–plate combination. Maximum implant stress values were 1132 MPa for the nail, 1278 MPa for the plate, 671 MPa for the nail, and 595 MPa for the plate in the combined model. Fatigue failure occurred after 4110 cycles for the nail, 2523 cycles for the plate, and 1692900 cycles for the nail–plate combination.Conclusion: The nail–plate combination may reduce mechanical complications in osteoporotic distal femur fractures by lowering fracture displacement, reducing implant stress, and improving cyclic strength. Randomized clinical studies are needed to further evaluate these findings.