The in-vivo biomechanical properties of intact rabbit tibial bone plated with a novel resorbable phosphate glass fibre reinforced composite plate

摘要

Modem treatment of bone fractures commonly employs metal plates to hold the broken bone ends in the correct position during the healing process. The presence of these relatively stiff implants has been shown to interfere with the bone's normal mechanical environment inducing profound structural changes which can progress with the duration of implantation. These changes can include cortical thinning and reduced density in intact bone where rigid plates have been applied. Although plates with reduced stiffness are theoretically desirable to reduce this "stress shielding" phenomenon, they carry a risk of mechanical failure before the bone has healed. Bioresorbable plates offer the theoretical benefits of achieving transitional mechanical properties. Initial high stiffness prevents bone displacement during healing. As the plate degrades, stiffness reduces with increased stress transfer to the underlying bone thereby minimising stress shielding. Phosphate glass fibre (PGF) reinforced PLA composites have been shown to have initial mechanical properties of cortical bone enabling high load bearing applications with in vitro degradation characteristics which can be tailored by modifying composite design and fibre chemistry. The aim of the current study was to determine the in-vivo biomechanical effects of a novel resorbable PGF composite plate on intact rabbit tibia.