Fracture Healing

Fracture Healing

Write a short note on fracture healing.
Answer:

Healing of fracture or repairing of bone occur by callus formation. The process is described as:

Fracture healing Procallus Formation

• Hematoma: It forms due to bleeding from torn blood vessels, filling the area surrounding fracture. Loose meshwork is formed by blood and fibrin clot which act as a framework for subsequent granulation tissue formation.
• Local inflammatory response at the site of injury with exudation of fiers, polymorphs and macrophages, fragments of necrosed bone are scavenged by macrophage and osteoclast.
• Ingrowth of granulation begins with neovascularization and proliferation of mesenchymal cell from the periosteum and endosteum. A soft callus is formed which joins the ends of the fracture bone.
• Callus is composed of woven bone and cartilage. The cells of inner layers of the periosteum have estrogenic potential and lay down collagen as well as osteoid matrix. The osteoid undergoes calcification and is called a woven bone callus. The subperiosteal osteoblast may form cartilage at the fracture site.

Fracture healing stages

Fracture healing Osseous Callus Formation

At their place, newly formed blood vessels and osteoblasts involve, laying down osteoid which is calcified and laminar bone is formed by developing a haversian system concentrically around the blood vessels.

Fracture healing Remodeling

During the formation of lamellar bone, osteoblastic laying and osteoclastic removal are taking place remodeling the united bone ends, which after sometime is indistinguishable from normal bone.

Summary of Healing of Bone

Bone healing process