Influence of fibrin sealant (Tisseel) on osteochondral defect repair in the rabbit knee.

Fibrin adhesives have been shown to improve the natural repair of musculoskeletal tissues. Growth hormone (GH) has a chondrogenic effect on immature cartilage. To test if a fibrin adhesive with and without GH could improve the natural repair of a joint surface lesion, we made a 9 x 4 mm2 osteochondral defect in the femoral groove of adult New Zealand rabbits. The defect in one of the knees was filled with the fibrin adhesive Tisseel, while the defect in the other knee was left untreated as a control. Another group of rabbits was treated in both knees with fibrin adhesive with local addition of GH during 1 week on one side. The experiments showed that the fibrin treatment impaired the natural repair of the osteochondral defect and that GH addition had no effect on the healing process. In a second in vitro experiment, chondrocyte migration into the fibrin adhesive Tisseel was compared to migration into rabbit and human blood clots. No cell migration was seen into the fibrin adhesive, while there was migration into the blood clots. We conclude that a fibrin adhesive like Tisseel is not suitable as a scaffold to promote repair of osteochondral defects in the rabbit knee.