In Silico Evaluation of Treatment of Periprosthetic Fractures in Elderly Patients After Hip Arthroplasty.

The aim of this study was to investigate the soundness of in silico finite element model (FEM) in the assessment of strain in the femur and in the components fixing the periprosthetic fracture in elderly patients after hip arthroplasty. From a group of 55 patients, aged 27-95, treated due to fractures after hip replacement in 2012-2018, 18 patients were separated out, aged over 85, out of whom 7 had type C fractures, according to the Vancouver classification. These seven patients formed the study group. The fractures were stabilized with a locking compression plate system and wire loops or by replacement of the endoprosthesis stem. The FEM was performed by processing radiological images of the femur, considering the stabilization type and osteoporotic bone characteristics. Each patient's FEM was counter compared to virtual in silico control showing a non-osteoporotic bone structure. We found that the strain was distinctly greater at the bone-implant interface after surgical stabilization with a multi-hole plate and cerclage wire loops in osteoporotic periprosthetic fractures when compared to the virtual non-osteoporotic bone. We conclude that the in silico model enables the assessment of strain distribution at the bone-implant interface, which helps identify the biomechanical incongruity of traditional bone stabilization methods in patients with osteoporotic bones.