Effect of tissue culture storage on the in vivo survival of canine osteochondral allografts.

In vitro studies in our laboratory have shown that the biomechanical and biochemical characteristics of osteochondral grafts can be preserved for as long as 28 days under tissue culture conditions. This study represents an attempt to extend these results to an in vivo model. In adult mongrel dogs, either an autograft, a fresh allograft, or a stored allograft was placed in a standardized defect on the weight-bearing surface of the medial femoral condyle. The stored grafts were kept at 4 degrees C in tissue culture medium for 14 days prior to implantation. The animals were killed at 12 weeks. Cartilage from the contralateral knee served as a control. The modulus and permeability of the cartilage were assessed with confined compression creep tests. The collagen and glycosaminoglycan contents were measured, and the cartilage was analyzed histologically with hematoxylin and eosin and safranin O stains. Grossly, the cartilage appeared viable at harvest. The histologic results were similar in the treatment groups, with the same spectrum of mild degenerative changes being noted in each group. The glycosaminoglycan content was significantly less in the autograft group than in its control group and than in the fresh allograft group. The glycosaminoglycan content did not differ significantly between fresh and stored allografts. The collagen content, modulus, and permeability did not differ either between experimental and control groups or between graft types. Our results support the conclusion that osteochondral allografts can be stored for as many as 14 days without significantly affecting the results of the procedure.