Osteosynthesis Failure in a Lower Limb Open Fracture: Knee Megaprosthesis Implant and Ipsilateral Total Hip Replacement – A Case Report

We present the case of a 44-year-old male with a complex orthopedic history following a major trauma in 2018, which resulted in comminuted fractures of the distal femur and tibial plateau. Following the initial surgical treatment, the patient later developed a hypertrophic aseptic nonunion of the distal femur, treated with revision of the osteosynthesis with a new plate. In 2021, he underwent osteosynthesis with three cannulated screws for a non-displaced medial femoral neck fracture. Approximately 4 months later, a peri implant infection due to Staphylococcus aureus was diagnosed, confirmed by positive labeled leukocyte scintigraphy, leading to removal of all hardware in 2022. Two months later, the patient presented with left knee pain without trauma and was diagnosed with a distal femoral stress fracture on pre-existing hypertrophic nonunion. Surgical treatment included implantation of a distal femoral modular megaprosthesis. In 2024, despite good knee function, the patient reported left hip pain; after thorough clinical and radiological assessment, a total hip arthroplasty was performed adding a trochanteric plate. The patient currently shows good overall joint function.