[Osteochondral allograft transplantation in the knee]

Despite significant improvements for the past 20 years in the treatment of full-thickness chondral defects with the use of chondroprotective biological methods (microfracture, autologous chondrocyte transplantation, osteochondral autograft, and periosteal graft), the treatment of large osteochondral defects in young and physically active population is still challenging. Alternatives for the treatment of chondral defects exceeding 3 cm in size are limited, and among them, allografts have been used longer than any other treatment methods with the most favorable results. The success rates for osteochondral allograft transplantation have been reported as 95%, 71%, and 66% at 5, 10, and 20 years, respectively. Factors that adversely affect long-term results include advanced age, allograft transplantation to both sides of the joint, inappropriate loading, osteoarthritis, and osteonecrosis due to steroid use. Today, as a result of improvements in tissue-organ transplantation, increased availability of fresh tissue from donors, and increased demand from patients and physicians, there has been growing interest in the use of osteochondral allografts in selected patients to delay arthroplasty for chondral defects.