Total Femur Replacement as a Salvage Procedure for Failed Distal Femur Megaprosthesis: A Case Report and Literature Reviews.

Total femoral replacement (TFR) is not a common surgery and most indications are for oncological pathologies. However, there are few instances where non-oncological indications might necessitate TFR; this may be a salvage surgery for failed previous hip and/or knee surgeries with consequent significant femur bone loss. We present a 59-year-old obese woman with right thigh pain and difficulty with walking of 5 years duration. She had undergone bilateral total knee replacement 10 years earlier on account of severe knee osteoarthritis. She had a fall 3 years prior to presentation and sustained a periprosthetic fracture around the right knee which was managed with a fixed angle blade plate and screws. This was complicated by implant breakage and non-union. She subsequently had implant removal and a right distal femur replacement (DFR) surgery 2 years prior to presentation. A year after the DFR surgery, she began to experience "start-up" pain, instability around the knee and difficulty with walking without support. A clinical and radiologic diagnosis of aseptic loosening of the distal femur megaprosthesis was made and she was offered a revision DFR surgery which also failed due to poor cementing technique, bone loss at the proximal femur, and severe osteoporosis. Patient ended up with a right total femur replacement to salvage the limb. She had improved Lower Extremity Functional Score of 27 after 12-month follow-up. TFR is a viable salvage procedure for severely compromised femur and/or significant bone loss from multiple non-oncological surgeries of the femur.