OSTEOARTICULAR ALLOGRAFTS TO TREAT DISTAL FEMORAL OSTEONECROSIS

Allografts, which are among the limited number of treatment options fo r young patients with large defects of the distal femur, offer a physi ologic method of restoring knee function. Since 1980, 21 patients youn ger than 50 years old who had osteonecrosis involving large portions o f the distal femur were treated with fresh-frozen osteoarticular surfa ce replacements. This retrospective review evaluated the 15 patients ( 17 knees) whose followup time was greater than two years. The patients were reevaluated at regular intervals by one or more of the authors. Follow-up time ranged from two to nine Sears (mean, 4.2 years). Outcom e was classified as either excellent, good (occasional complaints, unl imited walking without aids, functional range of motion), fair (interm ittent pain, ambulatory tolerance limited), or failure. There were sev en excellent results, five good results, one fair result, and four fai lures. There were no infections, nonunions, or wound complications. At this early follow-up period, 12 (70%) of the 17 knees have been succe ssfully treated. The authors' success rate with frozen allografts is c omparable to the results of fresh allograft resurfacing. Use of frozen allografts allows time for thorough testing for viral and bacterial i nfections, is more practical, and the allografts are available for use in elective surgery. Failure in this series was principally the resul t of degeneration of the allograft's articular cartilage, or fracture of the allograft.