Fracture healing

1

Initial fracture: Bleeding in bone

2

Fracture haematoma forms in medullary cavity and btween ends of bone fragments

3

Necrosis occurs, bone and periosteal cells die at fracture site

4

Inflammatory response and cellular invasion follows. New blood capillaries grow into the blood clot - a procallus forms

5

Influx of phagocytic cells. Fibroblasts lay down collagen fibre

6

A mass of repair tissue bridges broken end of bone. This is due to fibrocartilage transforming procallus into a fibrocartilaginous callus.

7

Osteoblasts produce spongy bone in gap between broken bones. Fibrocartilaginous callus turns into spongy bone. Making it a bony callus.

8

Remodelling of bony callus takes place. Dead portions of original fragments are gradually reabsorbed by osteoclasts,

9

Compact bone replaces spongy bone and excessive bone is replaced.