Bone Healing

Have you ever wondered what your body does to repair a fracture??? the process can take months!

1) Formation of a # haematoma
a. Blood vessels are broken
b. Blood leaks and forms clot (# haematoma)
c. 6-8 hrs post injury
d. Circulation compromised so bone cells die – inflammatory response
e. Blood capillaries grow onto clot
f. Phagocytes and osteoclasts remove dead and damaged tissue
g. Lasts for several weeks

2) Formation of soft callus
a. New blood capillaries form granulation tissue (procallus)
b. Fibroblasts produce collagen and join ends of bone
c. Phagocytes remove cellular debris
d. Chondroblasts produce fibrocartilage
e. fibrocartilage transformed into fibrocartilagenous callus
f. Lasts 3 weeks

3) Formation of hard callus
a. Osteogenic cells develop into osteoblasts
b. Osteoblasts produce spongy bone trabeculae
c. This joins living and dead bone fragments
d. Fibrocartilage is converted to spongy bone (bone callus)
e. Lasts 3 – 4 months

4) Remodelling
a. Dead portions of bone are reabsorbed by osteoclasts
b. Compact bone replaces spongy bone around # site
c. Bone strengthened along lines of stress
d. Calcium and phosphorus are gradually deposited to harden bone
e. Bone cells grow and reproduce slowly

So if you do ever unfortunately fracture a bone you know exactly what is going on under the surface.