MANAGEMENT OF PERIPROSTHETIC FEMORAL FRACTURES AFTER TOTAL KNEE REPLACEMENT USING A DISTAL FEMORAL ALLOGRAFT

Abstract

We reviewed and discussed the results of thirteen distal femoral allografts in conjunction with revision total knee arthroplasty for the treatment of periprosthetic femoral supracondylar fractures associated with poor bone stock. The mean follow up time was six years. We looked at graft survivorship, functional outcome, radiographic assessment, and complications. We concluded that this is a viable salvage procedure for this type of injury.

The incidence of periprosthetic supracondylar fractures of the femur is rising due to the aging population, and the increased number of total knee arthroplasties (TKA) being performed. One option for the treatment of severe fractures, associated with poor bone stock, is the use of a distal femoral allograft (DFA) in conjunction with revision TKA. The purpose of this study was to review and discuss the results of thirteen consecutive patients who were treated at our center between 1990 and 2001.

Data was obtained from a prospective database. Ten of the thirteen patients were available for follow up. The average age was sixty-five years (range twenty-four to ninety-three) and the mean length of follow up was six years (range one to twelve). A chart review was performed to identify complications and graft survivorship. Functional assessment was made on the basis of the modified Hospital for Special Surgery knee score (HSS) and the MOS 36-ITEM Short Form Health Survey (SF-36). Patients were evaluated radiographically by two independent observers (kappa = 0.75, P = 0.02) in an attempt to determine union between the graft and host bone, graft resorption, and component loosening. The average postoperative HSS score and SF-36 were seventy-five and eighty-eight respectively. Mean flexion was 100°. One had an amputation due to the recurrence of infection. X-rays showed no migration, no loosening, good interface union in nine cases and mild to moderate resorption in three cases. We concluded that this is a viable salvage procedure for this type of injury.