The evaluation of osteoconductive WE43 magnesium as a therapeutic approach for nonunion treatment

Aims: Nonunion is a challenging condition marked by impaired bone healing and vascularization. While magnesium-based biomaterials show osteogenic and angiogenic potential, their role in nonunion remains controversial. Controlled modification of magnesium-based implants may enable regenerative osteogenesis. Methods: Here, WE43, a magnesium alloy, was investigated in a standardized femoral nonunion model in C57Bl/6 mice. Three groups were compared: WE43 alone, WE43 with cancellous bone (WE43+), and cancellous bone alone (control, CTR). Bone healing was assessed at eight and 12 weeks using micro-CT, histology, and immunohistochemistry. Key outcomes included defect bridging, bone volume, mineralization, trabecular metrics, osteoclast/osteoblast activity, and vascularization. Results: WE43+ significantly reduced defect size and improved bone formation and microvascular density, nearing control levels. In contrast, WE43 alone showed high osteoclast activity, poor mineralization, and fibrotic healing. Magnesium's regenerative performance depended strongly on degradation rate and osteoconductive support. Combining WE43 with cancellous bone improved osseointegration and angiogenesis. Conclusion: WE43 requires interaction with cancellous bone to support regeneration. Future studies should clarify which properties of cancellous bone enhance magnesium-based healing.