RESUMO
Fracture is a common orthopedic disease in clinical practice,and the resulting nonunion or delayed union of frac-tures is a major challenge in clinical treatment.In the process of fracture healing,there is a complex interaction between angio-genesis and osteogenesis,which is called the"angiogenesis-osteogenesis coupling"mechanism.In recent years,a new capillary subtype characterized by high expression of platelet endothelial cell adhesion molecule-1(PECAM-1/CD31)and salivary glyco-protein(EMCN),namely type H blood vessel,has been identified and found to play an important role in regulation of the angio-genesis-osteogenesis coupling.In this review,the mechanism of type H blood vessels promoting angiogenesis-osteogenesis cou-pling,the related molecules and signal pathways regulating type H blood vessels regeneration were discussed,in order to provide new ideas and methods for promoting fracture healing.