Ability of magnesium implants to remodel the osteoporotic immune microenvironment in a murine femoral fracture model

Osteoporotic fractures often exhibit delayed healing and repair difficulties in which the bone immune microenvironment may play a critical role, but direct evidence remains elusive. Recently, magnesium (Mg)‐based alloys have emerged as promising biodegradable materials capable of promoting fracture healing. Herein, we performed internal fixation of high‐purity Mg implants for osteoporotic fractures and used single‐cell studies to investigate and elucidate the cellular heterogeneity and dynamic changes that occurred during osteoporotic fracture repair. We observed an early increase in immature neutrophil numbers, together with anti‐inflammatory changes in lymphocytes and macrophages. A cluster of macrophages exhibited pro‐angiogenic capabilities activated via the TRPM7/S100A4 pathway. These findings provide new theoretical insights into the biological effects of Mg‐based materials on the healing of osteoporotic fractures.