In this study, we have investigated the use of cryopreserved menisci to orthotopically replace the medial menisci in adult beagle dogs. Red cell group typing and white blood cell group typing were determined and beagles were divided into the blood-matching group and the non-matching group. The medial meniscus was replaced with an allograft meniscus that had been preserved at -70 degrees for 7-21 days. As a control, the medial meniscus was removed and reattached after cryopreservation. Replaced menisci were examined macroscopicaly, histologicaly and biochemicaly at an interval of 2 weeks, 1, 3, 6, 12 months postoperatively.
After 6 months, the transplanted menisci had completely healed macroscopicaly. However, chondral erosions of the medial tibial plateau were seen in about one-half of the transplanted knees, and were thought to be caused by improper fixation of the anterior or posterior meniscal horns.
At 12 weeks, an infiltration of fibroblasts and capillaries from the synovial fringe into the meniscus were seen histoloigicaly. The central core of the menisci remained acellular. At 12 months, regenerated chondrocytes in the deep layer and fibrocartilage were seen in the macroscopical good allografted group. In the macroscopical poor group, the extracellular matrix of the meniscus was destroyed and the empty lacunae were presented.
The water content of the macroscopical poor group was significantly greater than that of the control group. In the good group the collagen content was siginificantly greater than that of the poor group.
There were no differences between the blood matching group and the non-matching group macroscopicaly, histologicaly and biochemicaly.

In this study, we have investigated the use of cryopreserved menisci to orthotopically replace the medial menisci in adult beagle dogs. Red cell group typing and white blood cell group typing were determined and beagles were divided into the blood-matching group and the non-matching group. The medial meniscus was replaced with an allograft meniscus that had been preserved at -70 degrees for 7-21 days. As a control, the medial meniscus was removed and reattached after cryopreservation. Replaced menisci were examined macroscopicaly, histologicaly and biochemicaly at an interval of 2 weeks, 1, 3, 6, 12 months postoperatively.
After 6 months, the transplanted menisci had completely healed macroscopicaly. However, chondral erosions of the medial tibial plateau were seen in about one-half of the transplanted knees, and were thought to be caused by improper fixation of the anterior or posterior meniscal horns.
At 12 weeks, an infiltration of fibroblasts and capillaries from the synovial fringe into the meniscus were seen histoloigicaly. The central core of the menisci remained acellular. At 12 months, regenerated chondrocytes in the deep layer and fibrocartilage were seen in the macroscopical good allografted group. In the macroscopical poor group, the extracellular matrix of the meniscus was destroyed and the empty lacunae were presented.
The water content of the macroscopical poor group was significantly greater than that of the control group. In the good group the collagen content was siginificantly greater than that of the poor group.
There were no differences between the blood matching group and the non-matching group macroscopicaly, histologicaly and biochemicaly.