Comparative effectiveness of bone, cartilage and osteochondral xenograft (calf fetal) on healing of the critical bone defect in a rabbit model

Finding a suitable replacement tissue for bone loss in comminuted fractures and bone tumors with large bone defect or for treatment of delayed unions and non-unions is still the main challenge for orthopedic surgeons. The present study has been designed in vivo to evaluate the effects of xenogenic calf fetal bone and cartilage grafts in treatment of experimental critical bone defect in a rabbit model. 30 native male rabbits, 12 months old, weighing 3.0±0.5 kg were used in this study. Rabbits were randomly divided into five groups of six (negative control (NC), osteochondral group (OstCar), bone group (Ost), cartilage group (Car), and positive control (PC)). In the NC group the created empty space was left intact. In the OstCar group the osteochondral fragment of the same size as the expulsion was inserted into place. In the Ost group, the bone fragment of the fetal calf replaced the extracted bone fragment from the radius bone. The created defects were filled in 6 rabbits of the Car group with cartilage fragments of the fetal calf. In the PC group, after separating the fragment of radius bone midsection and removing from the site, it was re-placed at the site. This study investigated three types of replacement tissue for the missing bone and compared the results of radiology, CT scan, biomechanics and histopathology evaluations with positive and negative control groups. In conclusion, this study demonstrated that the calf’s fetal bone fragment could promote bone regeneration in the long bone defects like the autograft in the rabbit model.