Comparison of the bone response to xenogenic bone screws and metallic screws in canine femur.

The study compared the bone response to xenogenic screws and metallic screws of a similar design in a canine femur. The xenogenic bone screws and metallic bone screws were inserted into the femur diaphyses of dogs. Radiological and histological responses to the xenogenic bone screws were determined in canine bone and micro-computed tomography evaluation of bone mass and bone density parameter was performed 36 weeks after fixation of the xenogenic and metallic bone screws. There was no osteolysis and foreign body reaction associated with either bone screw. The radiological and histological results showed that the xenogenic bone screws formed a bony rim around the screws and facilitated incorporation of host bone. By micro-computed tomography, the bone volume was observed to be significantly ( P < 0.01) increased at the screw-bone interface surface of xeno - genic screws, compared to metallic screws. The bone mineral density of the metallic screw-bone interface was significantly (P < 0.01) higher than that of the xenogenic bone screw. The advantages of the clinical application of the xenogenic bone screw are the possibility of its resorption and incorporation. Therefore, additional surgery to remove the screw is not required.