healing of bone

1. Principles of fractures
(classification, bone healing)
Dr Kishore Vemula
Senior Resident
Department Of Orthopaedics
Apollo Medical College, Chittoor

2. • Orthos= straight
• paedics=child
• Orthopaedics deals with injuries of
• Bones
• Joints
• Muscles & tendons
• Ligaments
• nerves

3. • A fracture is defined as a break in continuity
of bone
• Mc cause ….. Trauma like RTA, fall from height,
train accidents, fire arm injuries etc.,

4. Mechanism vs pattern of fracture
• Direct force
(high soft tissue injury)
• Indirect force
(less soft tissue injury)
Twisting force
Spiral #
Compresson force
Oblique#
Bending with axial loading
Communited # with butterfly
fragment
Distraction force
Transverse #

5. Classification of fractures
• Traumatic
»High stress on normal bone
• Pathological(insufficiency)
»</≈ Normal stress on weak bone
• Stress
»Repeated stress on normal bone

6. Pathological fractures
(low or normal stress on a weak bone)
• Osteoporosis(mc)
• Bone tumours
» Benign- bone cysts, osteochondroma ,fibrous dysplasia, chronic
myxoid fibroma
» Malignancy– bone secondaries , ostepsarcoma, ewings sarcoma,
chandrosarcoma
• Metabolic bone diseases – rickets, osteomalacia
• Infection- chronic osteomyelitis
• Pagets, osteogenesis imperfecta
• drugs(bisphosphonates)

7. Pathological fractures

8. Stress fracture
• Repeated normal stress on a normal bone
• Eg … march fracture
Initial x ray After 2 weeks

9. Open vs closed fracture
• Closed/ simple #
Fracture which is not communiting with
external environment with minimal or no damage to
skin and soft tissue
• Open/ compound #
Fracture which communicates with external
environment with moderate to severe damage to skin
and soft tissues
Contamination is major issue ,results in
infections and delay in fracture healing
Healing is further affected due to disturbed
blood supply ie.,soft tissue injury

10. Displaced vs undisplaced fractures
Undisplaced fractures
no displacement at fracture site
most can treated conservatively
Displaced fractures
displacement of fracture
fragments
most need operative fixation

11. Why do a fracture displace???
• Force
• Gravity
• Muscle pull
force
gravity

12. What are the displacements occur at
fracture site
• Shift/ translation
• Axial – impaction/proximal shift
• Coronal – medial/lateral
• Sagittal – posterior or anterior
• Tilt/ angulation
• Anterior/ post/ med/ lateral
• Rotation

13. FRACTURES IN CHILDREN
• Bone is soft
• Periosteum is thick and elastic
• Healing occurs fast
• High remodelling potential
1. Incomplete fractures
Green stick fractures
Torus/buckling fractures
Bowing fracture
2. Complete fractures= physeal fractures

14. Incomplete paediatric fractures
• Green stick fractures
• Transverse fracture of cortex
• extends into mid portion of bone
• No break in other cortex
• Usually by bending forces
• Torus/buckling fractures;
• Usually impaction injury(axial forces)
• Fall on outstreched hand
• Protruberance on one side of bone
• No prominent break in both cortices

15. Complete
paediatric
fractures
prognosis bad for type v
thurston holland fragment or
shiny corner sign is a
triangular metaphyseal
fragment with epiphyseal
injury in type II, IV injuries

16. Fracture healing
• Primary/ direct / endosteal:
» No callus formation
» Occurs in stable, aligned,closely opposed fracture
fragments ( absolute stability)
• Secondary/ indirect/ periosteal:
» callus formation present
» Occurs in stable , aligned # but with relative
stability(micromotion)

17. Stages of bone healing
• Stage of haematoma formation(0-1 weeks)
• Stage of inflammation/granulation( 1-3 weeks)
• Stage of callus formation (3weeks – 3 months)
• Stage of consolidation (1-2 years)
• Stage of remodelling( many years)

18. • Heamatoma initiates inflammation&
migration of inflammatory cells that releases inflammatory
Mediators
• Stimulates angiogenesis, activates macrophages,
fibroblasts and forms matrix
• Granulation tissue( slowly replaces haematoma)
• Chondrocytes forms osteoid tissue
• Osteoblasts mineralises matrix
• Callus formation(woven bone)
• Maturation of woven bone to lamellar bone(consolidation)
• Bone matures in line of stress (wollf’s law)
• Osteocytes resorbs bone in out of stress and shape itself,
medulla reorganises
Remodells over years
• Proliferation &
Activation of
mesenchymal cells
• Formation of
chondroblasts,
osteoblasts,
fibroblasts

20. Which is a feature of haematoma
formation in fracture healing??
• It is due to rupture of intraosseous blood vessels
• Temporarily clot immobilises fracture site
• It forms a fibrin scaffold/ framework over which bone is
formed(osteoconduction)
• Stimulates the mesenchymal stem cells to differentiate to
osteoblast,chondroblast,fibroblasts( osteoinduction)
• It helps in migration of inflammatory cells to fracture
site(chemotaxis)

21. Factors affecting fracture healing
Injury variables
• Open #
• High grade or more severity
of injury
• Intraarticular #
• Segmental #
• Severe damage to soft tissues
• Damage to blood supply
Patient variables
• Age
# unite fast in children
• Nutrition
• Harmones
Gh/insulin- promotes
Steroids delays healing
• Smoking(nicotine),
alcoholism, DM delays bone
healing

22. Factors affecting bone healing
Tissue variables
• Cancellous bone heals fast
than cortical bone(no callus
forms in cancellous bone
healing)
• Bone diseases like
osteoporosis,metastasis
delays healing
• Local infection delays bone
healing
Treatment variables
• Fracture reduction (close
apposition)
• Good stabilisation
• Micromotion at # site
• Bone grafting
• PRP injections
Promotes bone healing

23. Thank you for your kind (blind)
attention…