Surgical Management of a Periprosthetic Femoral Fracture Above a Total Knee Arthroplasty: A Case Report.

Periprosthetic distal femur fractures above total knee arthroplasty (TKA) are challenging due to compromised bone quality and the need to preserve the prosthesis. With increasing TKA volumes, the incidence of these injuries is rising. A 78-year-old female patient presented with left thigh pain and inability to bear weight following a fall. Imaging revealed a comminuted distal femur fracture proximal to a well-fixed TKA. Open reduction and internal fixation was performed using the AxSOS 3 Ti Distal Lateral Femur Plating System (Stryker, Portage, MI) via a lateral approach. Fixation was achieved without compromising the implant. The patient progressed to partial weight-bearing at six weeks and full weight-bearing by 12 weeks. At four months, she regained pain-free ambulation with radiographic union and no evidence of implant failure. This case highlights the successful use of locking plate fixation for a distal femur periprosthetic fracture. It emphasizes the importance of selecting fixation over distal femur replacement when bone stock is adequate and the prosthesis is stable.