Figure 1.

Smoking’s effects on Fracture Healing. Cigarette smoking affects every stage of fracture healing. First, it alters the formation of the fracture hematoma, impairing the process of angiogenesis. Second, it adversely affects the migration, proliferation, and differentiation of mesenchymal stem cells (MSCs) into chondrocytes, fibroblasts, and osteoblasts, impairing soft callus formation and the subsequent transition into a hard callus. Finally, smoking causes an imbalance between the activity of osteoblasts and osteoclasts, promoting the process of bone resorption and leading to a delay in fracture healing.