Characteristics of Mg-based screws with potential application in spine fusion systems

Magnesium (Mg) and its alloys, including AZ۳۱, WE۴۳, pure Mg, Mg-Ca, and Mg-Ca-Zn, have gainedattention as promising materials for biodegradable pedicle screws in spinal surgery. These alloys offer the advantage ofgradual biodegradation, eliminating the need for secondary surgeries to remove implants, and closely match themechanical properties of bone, which reduces the risk of stress shielding and promotes osseointegration. AZ۳۱, a widelyused Mg alloy, provides a balance of strength and corrosion resistance, making it suitable for biomedical applications.WE۴۳, an alloy with rare-earth elements, exhibits improved strength and corrosion resistance, particularly in highstressenvironments. Pure Mg, while biocompatible, has limitations in mechanical strength and corrosion resistance,which can be enhanced through alloying. Mg-Ca alloys, especially those with calcium content between ۰.۵% and ۱.۰%,show improved mechanical properties and corrosion resistance, promoting better bone healing and stability. Mg-Ca-Znalloys further optimize these characteristics, with zinc playing a key role in reducing corrosion rates while enhancingmechanical properties. The response of these alloys in the body is influenced by their composition, with variations incorrosion rates and mechanical strength. Mg-Ca-Zn alloys, in particular, have shown promising results in balancingstrength and biodegradability, although further research into surface treatments and alloy optimization is needed tocontrol degradation rates and improve long-term clinical performance. In conclusion, Mg-based alloys, includingAZ۳۱, WE۴۳, pure Mg, Mg-Ca, and Mg-Ca-Zn, offer significant potential for biodegradable pedicle screws, combiningbiocompatibility, mechanical stability, and the ability to degrade safely within the body.

کلیدواژه ها:

Pedicle screws ، Biodegradability ، Bone regeneration ، Antibacterial activity ، Stress shielding