[Viable meniscus transplantation]

The integrity of the semilunar cartilages has proved to be the best safeguard against mechanical degenerative changes. One can postulate that restoring normal congruency between the femur and tibia with intact menisci would be the ideal solution to many mechanical knee problems. Several semilunar cartilages have been transplanted with good functional results in medial and lateral compartmental meniscal disease. However, this form of chondroprotection in the load-bearing area of the femur and tibia can only be properly evaluated after 10 to 20 years of follow-up. In order to obtain functional results, meniscal allografts have to be incorporated in the knee joint by intimate meniscofemoral synovial bonding. The synovial fibroblasts must grow into the collagen meshwork of the meniscal allograft. Such ingrowth has been shown in freeze-dried and deep-frozen meniscal allografts. However, in a small number of transplants shrinking has been observed on repeat arthroscopy at 6 months. Satisfactory incorporation of meniscal allografts has been obtained with fresh allografts, but availability remains a problem when this method is used for meniscal substitution. For this reason viable meniscal allograft implantation was initiated in a series of 25 patients and the value of this method studied. The meniscal allograft can be kept in an adequate semisynthetic nutrient medium for approximately 2-3 weeks without apparent loss of viability, during which period the appropriate recipient can be selected and prepared, a thorough laboratory screening can be conducted, and the culture results and disease transmission factors can be evaluated. In this way, live transplant hazards can be avoided, resulting in a higher success rate.