[Advances in biodegradable medical magnesium alloys for orthopedic applications]

To systematically review the current research status of biodegradable medical magnesium alloys as orthopedic implant materials, clarify key advances in composition design, fabrication processing, surface modification, and biological mechanisms, and identify the major scientific questions and engineering challenges in clinical translation, thus providing a theoretical foundation for future product development and clinical application.

The literature on magnesium alloy implants both domestically and internationally in recent years was extensively reviewed, with a particular focus on alloying strategies, advanced fabrication techniques, and surface modification processes and their effects on corrosion behavior and bioactivity, as well as the molecular evidence of magnesium ion (Mg ²⁺)-mediated regulatory pathways governing osteogenesis and osteoclastogenesis.

Alloy design and process optimization significantly improve the mechanical properties and degradation controllability of magnesium alloys, while surface modification effectively retards initial corrosion and enhances biocompatibility. Biological studies confirm that Mg ²⁺ promotes osteogenic differentiation and angiogenesis through multiple signaling cascades while concurrently suppressing osteoclast activity. Furthermore, the mildly alkaline microenvironment generated during degradation, together with H ₂ evolution, contributes to antibacterial activity. Clinically, magnesium alloy implants have received regulatory approval in countries including Germany and China, and have shown promising preliminary outcomes in fracture fixation and bone defect repair.

Biodegradable magnesium alloys hold considerable promise for orthopedic implantation; however, precise matching of degradation kinetics with bone healing timelines, rigorous evaluation of long-term biosafety, and customization for patient-specific applications remain the primary bottlenecks hampering widespread clinical translation. Future efforts should integrate materials engineering, biological sciences, and digital manufacturing technologies to advance intelligent, personalized therapeutic strategies.