Outcome of donor bone after vascularized allograft bone transplantation / 中国组织工程研究

ABSTRACT

AIM: To observe the outcome of donor bone after vascularized allograft bone transplantation under immunoregulation. METHODS: The experiment was conducted at the Microsurgery Institute, Medical College, Wuhan University from December 2002 to March 2004. Totally 21 male flap-eared Japanese rabbits were selected as donor and 42 female ones as recipients. Recipients were composed of 21 rabbits in the experimental group and 21 rabbits in the control group. ①Anastomotic vascularized massive shaft of femur allograft was performed in Japanese flap-eared rabbits of either sex. ②The experimental animals were assigned into experimental group (treated with ciclosporin A, 25 mg orally, once a day, for 3 weeks) and control group (no any immunosuppressive agent). ③X-ray and histology examinations were performed at months 1, 4 and 9 after operation. Bone grafts were analyzed with Sry semi-quantitative polymerase chain reaction. RESULTS: A total of 42 rabbits were involved in the result analysis. ①X-ray manifestation at different time points after rabbit transplantation in the two groups X-ray showed typical fracture healing mode at different phases after operation in the experimental group, whereas the increase of bone graft density, and around by a mass of bony callus in the control group. ②Histology manifestation of rabbits in the two groups after operation At different time phases it showed typical fracture healing mode in the experimental group after operation, and 9 months later the marrow cavity was filled with myeloid tissues, and the internal and external cortex was flat; Haversian canal had revered to the normal size; Bone cells appeared in the bone lacuna; Peripheral cortex was wrapped with fibrous tissues. In the control group, it showed inflammatory cell infiltration with rejection, bone marrow necrosis in marrow cavity, formation of fibra tissues, bone cell loss in bone lacuna, and the bone grafts were wrapped with woven bone that was from recipients. ③Outcome of Sry semi-quantitative PCR analysis: The Sry semi-quantitative PCR analysis showed that the relation between the ratio of male DNA and the postoperative period was positive; the ratio of experimental group at month 9 postoperative was near to 100%, while control group only reached 11.8%. CONCLUSION: Under the immunoregulation, bone graft can unite with the recipient bone in an earlier postoperative period and replace by recipient bone rapidly in vascularized allograft bone transplantation.