The Results of Treatment of Supracondylar Fracture Above Total Knee Arthroplasty

This study analyzes the results of treatment of 22 patients with 24 supracondylar femur fractures above a total knee arthroplasty. Ten knees were treated by closed methods utilizing traction and then a cast, 10 knees with immediate open reduction and internal fixation, 2 knees with a custom total knee integrated with a distal femoral allograft, 1 knee with external fixation, and 1 knee with primary arthrodesis. Nine fractures treated by closed means and 5 fractures treated by open reduction and internal fixation healed primarily. Two of the 5 surgical failures healed after replating and bone graft. The 3 failures of surgical therapy were salvaged utilizing custom total knee arthroplasty, 2 of which required integration with a distal femoral allograft. One knee treated with external fixation developed a deep infection necessitating implant removal and arthrodesis. Twelve of the 14 femoral fractures that united primarily healed with the femoral component in varus with respect to the long axis of the anatomic femur. Nine of these 12 implants developed progressive radiolucent lines at the tibial component. Three of these knees have required implant revision due to progressive loosening of the tibial and/or femoral components. The results of this evaluation indicate that fractures above a well-fixed total knee arthroplasty are difficult to manage. If anatomical alignment cannot be achieved by simple closed techniques, then primary open reduction and internal fixation should be considered. However, because of the complexity of the problem, the surgeon should be prepared to perform a primary arthrodesis or revision using custom components with or without a distal femoral allograft.