Experimental repair of segmental bone defects in rabbits by demineralized allograft covered by free autogenous periosteum.

Using an experimental model of segmental bone defect in the ulna of rabbits we investigated the effect on bone healing of fresh cancellous autograft (FCA), demineralized deep-frozen allograft (DDA), and demineralized deep-frozen allograft covered with free autogenous periosteum (DDAwP). Radiologically, it was found that the results of the FCA and DDAwP groups were superior to those of the DDA group. This superiority was statistically significant after the 3rd to the 9th week for the FCA group, and the 6th to the 9th week for the DDAwP group. However, bone formation and union in the DDA group reached the same level of those in the other groups after 12 weeks. When the all histological findings were compared at the 12th week, the FCA and DDAwP groups were statistically superior to the DDA group in terms of proximal union. On distal union, the FCA group was statistically superior to the DDA group. Biomechanically, the FCA and DDAwP groups were statistically superior to the DDA group in terms of maximum torque and energy absorption. The DDAwP group was superior to the DDA group in term of stiffness. We conclude that ossification could be more easily achieved if demineralized deep-frozen allograft is covered with periosteum when faced with the need for quicker and better quality bone integration.