Experimental studies on half-joint transplantation. Antigenicity of fresh allografted articular cartilage and changes in the articular cartilage.

This study was undertaken to examine the fate of articular cartilage in isogenic half-joint grafts implanted after storage by two-stage freezing. The antigenicity was evaluated quantitatively with regard to humoral and cellular immunological responses: none was seen in allogenic cartilage grafts. In the half-joint transplantations, the antigenicity of the cartilage need not be considered; only the antigenicity of cortical and cancellous bone must be reduced. Histologically, half-joint grafts stored at -196 degrees C were superior to fresh allografts. Two-stage freezing, therefore, appears to be useful for the storage of articular cartilage.