The fracture is the commenst defect of bone that due to delayed union or non-union losses its actual menchanical furction. Now-a-days different methods of internal and external fixation, electrical stimulation, medical regimen, bone graft and etc have been used for acceleration of fractures healing. Bone grafting that acts as scaffold at fracture-site and has potency of osteogenesis, acccelerates cellular differentiation considered to be the latest and commenst method for osteogenesis and shortening healing period. In this study 10 clinically healthy adult mongreal dogs of either sex between 30.0±4.4 months of age and weighting 25.0±5.12 kg Bw were divided into two groups (I&II) of 5 animals each. In group I after removal of 0.5 cm fragment of mid-shaft from lefl radial bone the space was filled up by bone marrow whereas in group II cancellous rib bone was used to cover the gap. Radial bone was fixed with bone plate in all animals of both groups. There was much more callus formation in group II than group I. The Compactness of callus tissue in group I (bone marrow) was much better than group II with less periosteal reaction Than group II. There was less fibro cartilages Callus tissue with Collagen and bony trabeculae in group I than group II. There was primary and imrnatured with different diameter bony trabeculae in both groups having active osteoblastic cells with basophilic cytoplasm nearby bony trabeculae indicating continuation of osteogenesis in animal of both groups. These changes were more compact and near normal in group I animals.
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