Short-term immunosuppression with fresh segmental fibular allografts in dogs
Burchardt, H.; Glowczewskie, F.P.; Enneking, W.F.
Journal of Bone and Joint Surgery. American Volume 63(3): 411-415
1981
ISSN/ISBN: 0021-9355 PMID: 7204440 Document Number: 175308
The present investigation was undertaken to determine the effects of short-term immunosuppression on the incorporation of fresh allografts. Adult mongrel dogs (35) in 3 groups were used to compare autografts and allografts at 1 yr after transplantation. Group I dogs had a fresh autograft on the left and a fresh allograft on the right without any azathioprine therapy; group II dogs had a fresh autograft on the left and a fresh allograft on the right with 3 wk of azathioprine therapy and group III dogs had a fresh autograft on the left and a fresh allograft on the right with 6 wk of azathioprine therapy. The grafts were analyzed biweekly by roentgenograms to determine the times of graft-host union, fatigue failure and the general features of repair. One yr after transplantation the animals were killed and repair processes were analyzed quantitatively using tetracycline and microradiographic procedures. The physical strength of each transplant was determined by torsional stress-testing. The successful incorporation of fresh allografts was significantly enhanced when the allografts were placed in continuously immunosuppressed recipients. The results of the present study indicated that short-term immunosuppression with azathioprine in dogs is as effective in abrogating the rejection of a segmental fresh cortical allograft as is long-term immunosuppression. The results of this study indicate that short-term immunosuppression with azathioprine is partially effective in preventing rejection of fresh segmental cortical bone allografts in dogs. Until the long-term consequences of immunosuppression are understood clinical trials would be premature.