Magnesium alloy advancements for trailblazing biodegradable solutions in orthopedic implants

Magnesium alloys have emerged as promising biodegradable materials for orthopedic implant applications due to their favorable mechanical properties, biocompatibility, and osteoconductivity. However, their rapid corrosion in physiological environments remains a critical limitation, leading to premature degradation and loss of mechanical integrity. This review presents a critical and integrated analysis of the key factors influencing the performance of Mg-based alloys, including corrosion mechanisms, alloying strategies, surface modification techniques, and processing methods. It is found that while alloying elements such as Zn, Ca, and Sr can enhance mechanical properties and biocompatibility, they are insufficient on their own to ensure controlled degradation. Surface modification techniques, particularly advanced coatings, provide more effective corrosion resistance, although their long-term performance depends strongly on coating stability and processing conditions. The analysis further indicates that degradation behaviour is governed by the combined effects of microstructure, composition, and environmental conditions, rather than any single modification approach. Despite promising experimental and early clinical outcomes, challenges related to rapid corrosion, variability in performance, and limited long-term clinical data continue to hinder widespread clinical adoption. Future research should focus on the development of multifunctional and durable surface coatings, integrated alloy design strategies, and advanced manufacturing techniques such as additive manufacturing to achieve controlled and predictable degradation. Overall, this review provides critical insights into current limitations and emerging directions, supporting the development of next-generation biodegradable Mg-based orthopedic implants.