Morphological changes in bone following intramedullary implantation of methyl methacrylate. A morphometrical study of...

Adult male Sprague-Dawley rats had a methyl methacrylate implant in their right femur. After 16 weeks a group of rats was given a calcium-deficient diet. The rats were followed for another 31 weeks. Due to calcium deficiency a loss of femoral bone mass occurred which was relatively greater in the non-operated femur, as compensatory periosteal bone apposition and remaining necrotic bone areas contributed to the bone mass in the operated femur. The calcium deficiency did not affect the interface between bone and implant, where a thin sleeve of new bone was formed. While the non-operated femur lost its bone through endosteal resorption, the loss of bone in the operated femur was due to intracortical resorption.