Refrigerated osteoarticular allografts to treat articular cartilage defects of the femoral condyles. A prospective outcomes study.

BACKGROUND Because of concerns about infections with the use of fresh osteoarticular allografts, osteoarticular allografts are currently stored hypothermically for a minimum of fourteen days to allow for serologic and microbiologic testing prior to implantation. Refrigerated osteoarticular allograft transplants are often used to treat symptomatic chondral and osteochondral defects in young, active patients. Chondrocyte viability has been shown to decrease substantially when allografts are stored for longer than twenty-eight days. The purpose of this study was to examine the clinical and functional outcomes of patients receiving refrigerated osteoarticular allografts between fifteen and twenty-eight days after procurement. METHODS Twenty-three consecutive patients (twenty-three knees) who underwent treatment of focal articular cartilage defects of the femoral condyles with refrigerated osteoarticular grafts were prospectively followed for an average of three years. The average age of the implanted refrigerated allografts was 20.3 days. The patients were assessed preoperatively and postoperatively with validated outcome surveys. RESULTS The mean modified Cincinnati knee ratings significantly improved from baseline to the time of the final follow-up, with an increase from 27.3 to 36.5 on the subscale rating for function (p<0.01), from 21.9 to 32.5 on the subscale rating for symptoms (p<0.03), and from 49.2 to 69.0 for the overall score (p<0.02). The mean International Knee Documentation Committee subjective score improved from 52 points at baseline to 68.5 points at the time of the final follow-up (p<0.03). A significant improvement was also found for effusions and functional testing (the single-leg hop) (p<0.001 for both). Radiographic evaluation at the time of the final follow-up revealed that twenty-two of the twenty-three grafts were in stable position with good osseous incorporation into host bone. No graft failure was encountered. CONCLUSIONS Transplantation of refrigerated osteoarticular allografts stored between fifteen and twenty-eight days provides significant functional and clinical improvement after an average follow-up of three years in patients treated for a full-thickness osteochondral defect of the femoral condyle, with similar outcomes to historical reports of patients with fresh allograft implants.