Abstract
INTRODUCTION: Periprosthetic fractures (PPF) of the proximal femur are a leading cause of revision after total hip arthroplasty. Internal fixation may be chosen if the hip implant is stable or if a stable fixation may be obtained. Preservation of bone perfusion and adequate stability are essential for successful fracture healing. As presented, plate design and application may induce both osteonecrosis and atrophy of the bone. CASE REPORT: An 82-year-old female sustained a PPF of the proximal femur after cemented hemiarthroplasty. The fracture was treated by plate fixation with cerclages applied at the level of the femoral stem. While the fracture healed without loosening of the components, pronounced atrophy of the whole femur developed, with devitalized areas of the bone underlying the plate. The plate used had no undercuts and probably had excessive stiffness. CONCLUSION: When not strictly applied as an internal fixator at a distance from the bone, the plate model used in this case may disturb periosteal blood flow, causing osteonecrosis. Furthermore, high bending rigidity of the plate-bone construct may lead to stress shielding and atrophy. Design and mechanical properties of a plate are relevant in fracture healing.