Experimentally created mid diaphyseary fractures in 24 rabbits were treated by intramedullary pinning with K-wires, PMMA implants and intramedullary pinning after stuffing with HA paste and the histopathological changes were recorded. Healing process was not progressive, in control group, as indicated by presence of only a few osteocytes in the matrices, discontinuity in the epithelial layer and extensive vacuolation with occasional presence of giant cells. In PMMA group, healing pattern by endochondral method of ossification was evident by day 30 and by day 60, normal structure of bone with remarkably high osteoid formation and osteocytes proliferation were observed. In HA group, vacuolation and discrete presence of osteocytes separated by interlacing trabeculae when compared to the other two groups were more pronounced. By day 60, endosteal vascularization could be depicted under high power. To conclude, of all the three groups healing was better in PMMA group when compared to the other two groups.