Study of activity induced bone remodelling

Clinically, extensive bone loss noted adjacent to stiff hip implants has been attributed to a lack of stress (or strain) on the bone. Cortical wall thinning occurs when the stiff implant carries the load in the neck region of the femur since the load is transferred down the implant rather than the bone and cortical wall thickening is observed in the region where the bone must again assume the load conditions. Bone formation has also been observed in athletes who placed above normal loads on their bones. In order to understand this process referred to as strain induced bone remodelling, exercised greyhounds were studied. Loading and bone shape changes due to exercise were examined and correlated using gait and motion analysis, in vivo strain gauging, CT scans, and histology.