To examine the fate of cryopreserved meniscus used as orthotopic allograft on alternative to total removal of menisci, the authors have performed replacement of medial meniscus with cryopreserved one which had been preserved at −70℃ for 7 days in right side and with fresh autograft without cryopreservation in left side as a control group.Transplanted menisci were sampled at 4, 8, 12 ,16 weeks, postoperatively to observe their gross and histological findings. At 4 weeks, the allograft was healed to the perioheral capsular tissue and meniscal horn attachments of the host by fibrovascular scar tissue retained their normal appearance in gross findings. It showed an increased cellularity immediately adjacent to its peripheral attachment covered by the vascularized synovial tissues. At 8 weeks, it showed even distribution of cellularity in histological finding. At 12 weeks, gross findings of mild shrinkage and degeneration were seen and those were covered by both synovial and connective tissue with regenerated chondrocyte in histological findings. At 16 weeks, a little difference between allograft and normal meniscus was showed in gross and histological findings. There are regenerated chondrocytes in the deep area some degenerative changes were noted in the tibial and femoral cartilage not covered by meniscus. Above results showed cryopreserved meniscal allograft was able to regenerate and clinically suggest good treatment modality in case of unable to reshape to normal structure after total meniscectomy.
Allografts ; Animals ; Autografts ; Cartilage ; Chondrocytes ; Cicatrix ; Connective Tissue ; Cryopreservation ; Horns ; Knee ; Menisci, Tibial