[Experimental study of the treatment of avascular osteonecrosis]

The results of treating avascular necrosis of the femoral head of 32 mongrel dogs with 4 different methods were compared. The treating methods differed only in the type of tissues transplanted into the femoral head specimens: (1) with blood vessel and muscle pedicled bone graft, (2) with muscle pedicled bone graft, (3) with vascular bundle transplant and (4) with free bone-piece graft. The results showed that graft of type 1 or 2 or 3 transplantation brought about new bone formation and dead bone replacement in different degrees and varying activity, obviously more potent in those with type 1 and 2 than those with type 3. While those with type 4 showed little living activity and the grafted bone-piece remained dead. These differences may be based on the facts that transplants type 1 & 2 carry with them living tissues, active bone-forming cells and many other bone growth stuffs and factors necessary for conduction and induction for new bone formation, in addition to blood supply. While type 4 transplant can meet nutritional needs of metabolism and tissue growth only. Accordingly, transplantation of type 1 or 2 graft could be a preferable choice of treating clinical cases with femoral head necrosis.