The document discusses fractures, including their classification based on various criteria such as etiology, displacement, and healing processes. It outlines the stages of fracture healing, distinguishing between primary and secondary healing, and explains the physiological requirements for effective healing. Key growth factors and the principles of stability in fracture healing are also addressed.

1. Fracture, classification
and Fracture healing
Dr Dipendra Maharjan

2. What do you see???
Fig. A Fig. B

3. Fracture
 A disruption or break in
the continuity of the
structure of bone
 Traumatic injuries
account for the majority
of fractures

4. How does a fracture occur?
 Results from
 Injury
 Direct (soft tissue injury is common)
 Indirect
 Twisting
 Compression
 Bending
 tension
 Repetitive stress
 Abnormal weakening

5. Classification of fracture
 On the basis of etiology
 On the basis of displacement
 On the basis of communication with external
environment
 On the basis of site of fracture
 On the basis of fracture morphology
 On the basis of stability

6. ‘
 On the basis of
etiology
 Traumatic
 Atraumatic
 Pathological
 Stress
fracture
 Insufficiency
fracture
Stress Fracture
Pathological Fracture
Insufficiency Fracture
Traumatic Fracture

7. Un-displaced Fracture
 On the basis of displacement
 Un-displaced
 Displaced
 Translation
 Angulation
 Rotation
 Length
Displaced Fracture

8.  On the basis of communication with external
environment
 Closed Fracture
 Open Fracture

9.  On the basis of site of fracture
 Epiphyseal fracture
 Metaphyseal
 Diaphyseal
 Upper third
 Middle third
 Lower third
 Junctional

10.  On the basis of fracture morphology
 Transverse
 Spiral
 Oblique
 Comminuted
 Impacted
 Segmental
 Avulsion

11.  On the basis of stability
 Stable
 Occur when a piece of the
periosteum is intact across
the fracture
 Unstable
 Grossly displaced
 Periosteum completely torn

12. AO Classification

13. AO classification

14. Fracture Healing
 Proliferative physiological
state
 Restores the tissue to its
original physical and
mechanical properties
 Influenced by a variety of
systemic and local factors

15. Types of Fracture Healing
 Primary Healing (Direct)
 Secondary Healing (Indirect)
 Distraction Osteogenesis

16. Primary Healing
 Osteonal Healing
 Involves direct attempt by the cortex
to reestablish itself
 Gaps in reduction heal by vessel
ingrowth-mesenchymal cells-
osteoblasts-osteoclast cutting cones
 Direct contact areas heal by cutting
cones allowing passage of vessels
 Resembles normal remodelling
 Occurs only with anatomic reduction &
rigid fixation

17. Secondary healing
 Enchondral Healing
 Response of periosteum/ external soft tissues
 Recapitulation of embryonic intramembranous
ossification and endochondral ossification
 Intramembraneous= peripheral to fracture
 Endochondral= adjacent to fracture
 Motion enhances periosteal response
 External soft tissue forms bridging callus
(Periosteal bridging callus)

18. STAGES OF FRACTURE HEALING
Cortical bone(FROST 1989)
 Inflammation phase
 Stage of Hematoma Formation 1-
2 Days
 Stage of Inflammation 2-7 Days
 Stage of Granulation
 Reparative phase
 Stage of Soft Callus Formation 1-
3 Weeks
 Stage of Hard Callus Formation 3-
6 Weeks
 Remodelling Phase >8. Weeks
 Stage of Remodelling stage
(Consolidation)
 Stage of Modelling stage
(Remodelling)

19. Inflammation Phase
 Hematoma (fibrin clot)
 Macrophages
 Inflammatory leukocytes
 Osteoprogenitor cells
 Hematopoietic cells secrete growth factors
 Granulation tissue

20. Reparative phase
 Primary callus response (2 weeks)
 Inflammation triggers cell division and angiogenesis
 Chondrocytes secrete collagen and proteoglycans
 Creates fibrocartilage
 Bone formation
 Soft callus turns to hard callus (lamellar bone)

21. Re-modelling phase
 Begins during the middle of the repair phase
 Continues up to years
 Allows the bone to assume its normal configuration
 Wolff’s law
 The stresses on the bone is directly proportional to
remodelling

22. Growth Factors
 Bone Morphogenic Protein
 Osteoinductive
 Mesenchymal cells to osteoblasts
 Transforming growth factor beta
 Induces mesenchymal cells and osteoblast to produce
type II collagen
 Regulates cartilage and bone formation in fracture callus

23.  Insulin like growth factor II
 Promote cell proliferation and matrix synthesis by
chondrocytes and osteoblasts
 Responsible for formation of fracture callus
 Platelet derived growth factor
 Stimulate osteoblast or osteoprogenitor cell activity
 Promote bone formation

24. Principles of Fracture Healing

25. Stability and fracture Healing
 Stability determines strain
 Stain
 Strain is defined as change in fracture gap divided by the fracture gap (ΔL/L)
 Highest fracture site strain is seen in a simple fracture
 Stability
 Absolute stability
 Relative stability
 Strain determines type of healing
 Strain less than 2% results in primary bone healing (endosteal healing).
 Strain 2% to 10% results in secondary bone healing (enchondral ossi cation).
 Strain greater than 10% does not permit bone formation.

28. The End!!!