ARCHITECTURAL REMODELING IN DEEP-FROZEN MENISCAL ALLOGRAFTS AFTER TOTAL MENISCECTOMY

This study assesses the biological characteristics of cell repopulatio n and matrix remodeling in deep frozen meniscal allografts after total meniscectomy and allograft transplantation. Thirty-two mature New Zea land White rabbits were operated on, and the allografts were assessed at 12 and 26 weeks postsurgery. Before transplantation, fresh medial m enisci were placed into liquid nitrogen to kill all intrinsic cells. F rozen meniscal allografts showed collagen remodeling coincident with r evascularization and cellular repopulation. Biochemical characterizati on showed active collagen remodeling of the allografts at 12 and 26 we eks, In situ hybridization showed that expression of types I and III p rocollagen mRNAs were increased at 12 weeks, especially near the regio n of the synovial capsule. At 26 weeks after transplantation, the patt ern of collagen-type expression progressed toward normal; that is, typ e I procollagen mRNA expression was prominent, whereas only a small am ount of type III procollagen mRNA was observed. These data indicate th e adaptation of the repopulating cells from the host to the frozen all ograft at 26 weeks after transplantation.