Cells and Materials


Weight bearing (WB) is an important factor influencing bone remodelling. The present study evaluates the effects of weight bearing and non-weight bearing (S) (achieved by tail suspension and hindlimb elevation) on the healing of a fibular osteotomy in adult male rats. After 9, 18 or 36 days under WB or S conditions, periosteum near the callus formed at the osteotomy site was compared to periosteum of the contralateral fibula (which did not receive an osteotomy) or to periosteum of fibula of control animals which did not receive an osteotomy. Data show that periosteal bone healing is sensitive to alterations in WB and that the bone alterations over time can be complex. In the presence of an osteotomy under S conditions, bone formation is depressed and resorbing surface elevated compared to alterations in healing which occur under conditions of WB. Data support the accepted opinion that WB is essential for promotion of bone healing and increase our appreciation of the responsiveness of periosteal bone during healing.