Fresh osteochondral allograft transplantation has been an effective treatment option with promising long-term clinical outcomes
for focal posttraumatic defects in the knee for young, active individuals. We examined histologic features of 35 fresh osteochondral
allograft specimens retrieved at the time of subsequent graft revision, osteotomy, or TKA. Graft survival time ranged from
1 to 25 years based on their time to reoperation. Histologic features of early graft failures were lack of chondrocyte viability
and loss of matrix cationic staining. Histologic features of late graft failures were fracture through the graft, active and
incomplete remodeling of the graft bone by the host bone, and resorption of the graft tissue by synovial inflammatory activity
at graft edges. Histologic features associated with long-term allograft survival included viable chondrocytes, functional
preservation of matrix, and complete replacement of the graft bone with the host bone. Given chondrocyte viability, long-term
allograft survival depends on graft stability by rigid fixation of host bone to graft bone. With the stable osseous graft
base, the hyaline cartilage portion of the allograft can survive and function for 25 years or more.
Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest,
patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
Each author certifies that his or her institution has approved the human protocol for this investigation and that all investigations
were conducted in conformity with ethical principles of research.