Abstract:

BACKGROUND: There are no ideal substitutes for meniscus. Meniscal allograft transplantation has become a feasible method to retain meniscal function following injury. Currently, the meniscus conservancy methods include fresh meniscus, low temperature preserved meniscus; freeze-dried meniscus.
OBJECTIVE: To observe the long-term effects of meniscus allograft transplantation by different methods.
METHODS: A total of 70 adult New Zealand rabbits were used, and 30 were selected as meniscus donors. The remaining 40 rabbits were divided into 4 groups (n=10): after meniscectomy, control group was not treated; fresh group underwent fresh meniscus allograft transplantation; low temperature group underwent low temperature preserved meniscus allograft transplantation; freeze-dried group underwent freeze-dried meniscus allograft transplantation. Of 30 donors, 10 received fresh meniscus transplantation, and the other received temperature preserved meniscus and freeze-dried meniscus transplantation 1 week after low temperature and freeze dried preservation. The rabbits were sacrificed 12 months after surgery for gross and histological observation.
RESULTS AND CONCLUSION: The meniscus allografts of rabbits healed well, and no rabbits died. Gross observation showed that the appearance and elasticity of fresh meniscus group was similar to normal meniscus; tibial plateau was covered well, with no additional wearing in the cartilage of tibial plateau or condyles of femur. In low temperature and freeze-dried preservation groups, the meniscus grafts healed well, but their volume was small and the elasticity was poor; tibial plateau was only partially covered. Pathological observation suggested that fresh meniscus group had orderly arranged collage fiber and similar chondrocyte appearance, number and distribution to normal meniscus, while sparse collagen fiber and small number of meniscus grafts were observed in the other groups. Results show that meniscal allografting can survive, retain certain function and structure and prevent the degenerative changes of the knee joint. Moreover, fresh meniscal grafts exhibit best effects, as the grafts following low temperature or freeze-dried preservation degenerate and their volume diminish 1 year following meniscectomy.