Variation of cortical hypertrophy depending on the medullary filling material. An experimental study of canine tibial diaphysis.

In order to evaluate the mineralization of bone after polymethyl methacrylate cementation, measurements of the periosteal apposition were made histologically and measurements of the bone-mineral content were made by dual-photon absorptiometry of the tibial diaphysis in 15 adult mongrel dogs in paired studies. Six dogs were investigated 4 weeks after intramedullary reaming of both sides and obturation of the medullary cavity with bone-wax on one side. Nine dogs were reamed on both sides. The medullary cavities were filled with polymethyl methacrylate bone-cement and bone-wax, respectively. The authors found (1) an increased bone-mineral content and an increased periosteal apposition after filling with bone-wax in comparison with the reamed side and (2) a decreased bone-mineral content and a decreased periosteal apposition on the cemented side in comparison with bone-wax. These findings are interpreted as consequential upon repair processes with a high remodeling and mineralization rate after reaming or filling with bone-wax, whereas remodeling in inhibited after filling with acrylic bone-cement.