Advancements in Mg-based scaffolds for bone tissue engineering: From design strategies to clinical perspectives

Mg-based scaffolds are emerging as architected, load-bearing constructs that couple temporary mechanical support with bioactive, self-resorbing behavior. This review integrates advances in geometric design, fabrication, and biological translation of Mg-based scaffolds. The study comprehensively discusses key design parameters, including porosity, pore size, pore shape, pore orientation, strut thickness, alloy composition, and hybrid surface modification strategies. It further highlights that triply periodic minimal surfaces and optimized lattices with tailored interconnected porosity achieve cancellous-bone-like mechanics while enhancing permeability, osteogenesis, angiogenesis, and pro-healing immunomodulation. Various fabrication routes including powder metallurgy, replica casting, laser powder-bed fusion and binder-jetting techniques are compared with respect to microstructural control, defect tolerance, corrosion-fatigue, and scalability. Surface modifications, including fluoride/Ca–P conversion layers, layered double hydroxides, and polymer-ceramic hybrid coatings, act as physical barrier and ion-regulating interfaces that slow the initial corrosion burst, buffer local alkalinity, and provide controlled Mg²⁺ release within a therapeutic window. Collectively, in-vitro and in-vivo investigations show that architected Mg scaffolds are biocompatible, generate only transient hydrogen, and degrade in vivo more slowly and uniformly than static immersion predicts. Bone ingrowth tracks the resorption front, enabling progressive load transfer from the scaffold to regenerating tissue. Compared with planar Mg devices, these lattices mitigate stress shielding, conform to irregular defects, and provide orders-of-magnitude greater surface for osseointegration. To address key translational challenges, including synchronizing scaffold degradation with bone healing, ensuring corrosion-fatigue reliability under physiological conditions, and meeting regulator-compliant manufacturing standards, the review highlights the role of Mg-based biocomposite scaffolds with hybrid surface treatments. These surface strategies improve structural persistence and biological compatibility. Together, they strengthen the pathway toward full-scale clinical translation of Mg scaffolds for orthopedic applications.