TREATMENT OF PERIPROSTHETIC SUPRACONDYLAR KNEE FRACTURES WITH A DISTAL FEMUR ALLOGRAFT AND TOTAL KNEE ARTHROPLASTY

Abstract

Purpose: Prevalence of supracondylar fractures above a total knee arthroplasty (TKA) is increasing due to the increasing age of treated patients and the larger number of implants. We report the functional results in a series of thirteen patients treated with a distal femoral graft (DFG) associated with revision TKA.

Material and methods: Between 1990 and 2001, thirteen patients (twelve women and one man), mean age 65 years (24–93) were treated with DFG associated with revision TKA. All fractures were type III using the Lewis classification and involved severe osteoporotic bone associated with loosening of the femoral piece. Before fracture, the patients had had two operations on average (1–4). The fracture occurred as a result of a fall in nine patients, low-energy trauma in three, and during mobilisation under general anaesthesia in one. The functional results were noted prospectively using the modified HSS score and the SF-36 quality-of-life questionnaire. Radiographic assessment of bone healing and implant stability was performed by two independent observers (kappa=0.75, p=0.02).

Results: At mean follow-up of 60 months (12–144), the mean HSS score was 75 (64–86). Mean knee flexion was 100° (50–115°). One patient required subsequent amputation due to infection. Using our classification, functional outcome was good or excellent in seven patients, fair in four and poor in two. For nine patients, x-rays showed no sign of loosening. In three patients, there was minimal to moderate periprosthetic bone resorption.

Discussion: Treatment of periprosthetic fractures of the knee is a therapeutic challenge. Osteoporosis and comminution is a complex association making stable osteo-synthesis difficult with conventional methods. Massive knee prosthesis using a DFG and a standard TKA is an attractive alternative. This technique allows restoration of the bone stock by bone healing and constitutes a less aggressive therapeutic solution.

Conclusion: Despite the risk of infection, we believe that composite prostheses can be an attractive option for the treatment of periprosthetic supracondylar fractures of the knee.