Epiphyseal replacement in a murine model.

Epiphyseal replacement was performed via knee transplantation using donor tissue of different developmental times in a murine model. The performance of syngeneic donor tissue in a resection defect in 4-day-old mice of the same inbred strain was assessed over 2 weeks for cell viability, tritiated thymidine incorporation, and ability to attract a host blood supply, and at 2 months, with the existence of a joint and growth. Although there was variability within experimental groups, the syngeneic transplant was able to survive pending vascular invasion from the host. Growth occurred, although it never equaled normal growth. One possible approach to the difficult problem of joint reconstruction in the immature skeleton is to divide the endeavor into two parts: develop models of syngeneic joint transplantation in inbred strains of animals to assess the various problems that would occur were this tissue available and develop models of joint "synthesis" with autogeneic chondrocytes.