Fracture
Fracture is a break in the structural
continuity of bone or periosteum.
Fracture
results in loss of its mechanical stability and also partial destruction of
blood supply.
CLASSIFICATION OF FRACTURE
•Open
or Closed
•Complete
or Incomplete
•Simple
or Comminuted
•Traumatic
or Pathologic
FRACTURE
HEALING
•Fracture
healing is defined
as repair and regeneration of the fractured bone.
•Fracture
healing starts as soon as bone breaks and continues modelling for
many years.
STAGES
OF FRACTURE HEALING
•TISSUE
DESTRUCTION AND HAEMATOMA FORMATION
• INFLAMATION AND CELLULAR PROLIFERATION
•
STAGE OF CALLUS FORMATION
•
STAGE OF COSOLIDATION
•
STAGE OF REMODELLING
TISSUE
DESTRUCTION AND HAEMATOMA FORMATION
•Torn blood vessels hemorrhage
•A mass of clotted blood (hematoma) forms at the
fracture site
•Site becomes swollen, painful, and inflamed
Inflamation And Cellular Proliferation
•Within
8 hours inflammatory reaction starts.
•
Proliferation and differentiation of mesenchymal stem cells.
•
Secretion of TGF-B , PDGF and various BMP factors.
CALLUS FORMATION
•Fibrocartilaginous
callus forms
•Granulation
tissue (soft callus) forms a few days after the fracture
•Capillaries
grow into the tissue and phagocytic
cells begin cleaning debris
STAGE OF COSOLIDATION
•New
bone trabeculae
appear in the fibrocartilaginous
callus
•Fibrocartilaginous
callus converts into a bony (hard) callus
•Bone
callus begins 3-4 weeks after injury, and continues until firm union is formed
2-3 months later
STAGE OF REMODELLING
•Excess
material on the bone shaft exterior and in the medullary canal is removed
•Compact
bone is laid down to reconstruct shaft walls
•Poor
blood supply to the fractured area; could lead to avascular or
aseptic necrosis
•Poor
immobilization of fracture site may cause misalignment or deformity
•Infection
– more common with open fractures
COMPLICATIONS
OF FRACTURE HEALING
•Malunion:
due to inaccurate reduction & poor
immobilization.
•Non-union:
if soft tissue comes in between fracture
ends.
•Delayed
union:
due to infection, poor nutrition,
inadequate blood supply, old age, movement.
