DESTRUCTION OF A CRYOPRESERVED MENISCAL ALLOGRAFT - A CASE FOR ACUTE REJECTION

A cryopreserved nontissue-antigen-matched medial meniscus was transpla nted arthroscopically into the knee of a 33-year-old cyclist. The pati ent had previously had an open medial menisectomy 19 years earlier and had significant symptoms. Ten weeks postoperatively, the patient unde rwent a second-look arthroscopy for a persistent effusion. Intraoperat ive cultures were obtained and all ultimately tested negative. The gra ft was found to be frayed throughout its length and significantly decr eased in size. Its central portion had become detached from the periph eral repair while both the anterior and posterior bone blocks remained intact. Dense, inflammatory, hypertrophic synovium enveloped the enti re joint. Histologically, the graft was found to be necrotic and acell ular centrally, whereas the periphery was infiltrated with inflammator y leukocytes and giant cells. This histologic appearance is classical for an acute or subacute type rejection of allograft tissue.