Meniscal transplantation using fresh and cryopreserved allografts--an experimental study in the genetically defined...

The purpose of this study is to examine the possibilities of meniscal allograft and the effects of cryopreservation on grafts in rats (Lewis and Fisher). Transplants were carried out on three minor mismatched groups of rats with: 1) 16 fresh meniscal allografts, 2) 16 fresh meniscal allografts with immunosuppression, and 3) 16 cryopreserved meniscal allografts. As a control, 16 Fisher rats received isograft menisci transplants. Four transplanted grafts each were evaluated histologically 4, 8, 12 and 21 weeks after grafting. Isograft meniscal transplantations were judged to have been successful. At 21 weeks, all of the fresh allografts had survived in the immunosuppressed rats, however, without immunosuppression, virtually all fresh allografts became scar tissue. On the other hand, all cryopreserved meniscal allografts survived; three out of the four grafts showed no degenerative changes 21 weeks after transplantation and produced the best results in those rats without immunosuppression.