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 a nd biochemical characteristics of osteochondral grafts can be preserve d for as long as 28 days under tissue culture conditions. This study r epresents an attempt to extend these results to an in vivo model. In a dult mongrel dogs, either an autograft, a fresh allograft, or a stored allograft was placed in a standardized defect on the weight-bearing s urface 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 cartila ge were assessed with confined compression creep tests. The collagen a nd glycosaminoglycan contents were measured, and the cartilage was ana lyzed histologically with hematoxylin and eosin and safranin O stains. Grossly, the cartilage appeared viable at harvest. The histologic res ults were similar in the treatment groups, with the same spectrum of m ild degenerative changes being noted in each group. The glycosaminogly can content was significantly less in the autograft group than in its control group and than in the fresh allograft group. The glycosaminogl ycan content did not differ significantly between fresh and stored all ografts. The collagen content, modulus, and permeability did not diffe r either between experimental and control groups or between graft type s. Our results support the conclusion that osteochondral allografts ca n be stored for as many as 14 days without significantly affecting the results of the procedure.