1. Bone Repair

2. Fracture a break in a bone 4 classification
position of the ends after fracture
nondisplaced: normal alignment
displaced: bone ends out of alignment
completeness of break
complete: bone broken through
incomplete: bone partially broken
orientation of break relative to long axis
linear: breaks parallel to long axis
transverse: breaks perpendicular to long axis
penetration of skin
opened (compound): bone breaks through skin
closed (simple): bone does not break through skin

4. Bone Repair hematoma - blood clot
new blood vessels begin to invade
osteoblasts begin building spongy bone
osteoclasts start cleaning up
cartilaginous callus - fibrocartilage
fills in gap between bone parts
bony callus
replaces fibrocartilage (endochondral)
bone remodelling
osteoclasts remove excess bone

5. Treatment reduction - realignment of broken bone ends
closed (external) - doctor physically realigns the bone ends
open - bone ends are secured together surgically with pins or wires
casts to immobilize fractured bones
Philadelphia 1876
healing time depends on type of break
typically 6-8 weeks