Impaired Angiogenesis, Early Callus Formation, and Late Stage Remodeling in Fracture Healing of Osteopontin-Deficient Mice

This study showed multiple, stage-dependent roles of OPN during fracture healing. We conclude that OPN deficiency alters the functionality of multiple cell types, resulting in delayed early vascularization, altered matrix organization and late remodeling, and reduced biomechanical properties. These findings contribute to an improved understanding of the role of OPN in vivo and provide new insight into mechanistic control of vascularization and bone regeneration during fracture repair.