STRUCTURAL ALLOGRAFTING IN REVISION TOTAL KNEE ARTHROPLASTY

Between 1985 and 1991, 15 patients underwent structural allografting a s part of revision total knee arthroplasty. All patients had large seg mental, cavitary, or combination defects of the femur and/or tibia. Se ven distal femurs and 12 proximal tibias required allografting. Patien ts were evaluated with physical examination, radiographs, and The Hosp ital for Special Surgery knee rating scale. Three patients died, leavi ng 15 allografts for follow-up study. The average age at surgery was 6 3 years. The follow-up period averaged 47 months (range, 30-101 months ). Average range of motion before surgery was 4 degrees to 93 degrees, and after surgery, 2 degrees to 104 degrees Average knee score was 47 before and 86 after surgery. Preoperative alignment averaged 5 degree s varus, ranging from 25 degrees valgus to 20 degrees varus, and posto perative alignment averaged 4 degrees valgus, ranging from neutral to 6 degrees valgus. All patients, except one, had improvement of pain an d stability. All of the 15 allografts healed to host-bone and 13 showe d evidence of incorporation. There were no infections or fractures of the allografts. One complication directly related to the allograft occ urred; that patient had a tibial component fracture over a proximal ti bial allograft 3 years after surgery. Three other complications occurr ed. One was tibial loosening in a patient who received a distal femora l allograft, the second was a proxi mal tibial fracture in a patient w ho received a distal femoral allograft, and the third was an intraoper ative patellar tendon avulsion. These results suggest that structural allografting can provide a satisfactory method of managing large bone defects in the failed total knee arthroplasty.