The effects of intramedullary implants on bone strains and remodeling in the femur.

Bone remodeling and strain distribution in the femur was studied after implantation of LTI pyrolytic carbon, bioglass coated Co-Cr-Mo alloy, and carbon coated porous Co-Cr-Mo alloy intramedullary plugs. Mechanical testing and finite element analysis has shown that the intramedullary stems significantly alter the strain pattern in the femur. However, no statistically significant differences were observed among the implant groups. The analytical and experimental results were found to be in good agreement. Radiographically, differences were observed in the bone remodeling around the carbon implant compared to either of the Co-Cr-Mo based implants. Both internal and external bone remodeling takes place when an intramedullary implant is present.