In vitro dynamic degradation behavior of new magnesium alloy for orthopedic applications.

We report on methodologies for use in the design of a biodegradable Mg alloy appropriate for load-bearing but temporary orthopedic implant applications. Comparative studies of Mg-5Ca and Mg-5Ca-1Zn were conducted to explore the effects of a combination of minor alloying and hot extrusion, on the alloy's mechanical properties and corrosion resistance. The extruded Mg-5Ca-1Zn exhibited high ultimate compressive strength of 385 MPa and suffered no significant structural degradation even after immersion in simulated body fluid for 30 days. Mg-5Ca-1Zn alloy showed the mechanical strength and controlled corrosion rate to be considered as an ideal candidate for biodegradable orthopedic implant material.