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Dr. Ketan DeshpandeRegistrar
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BONE HEALING
Ketan D Deshpande Dept. of Orthopedics ESIPGIMSR MGM Hospital
Bone Histology
Cells in Bone
Bone Histology
Periosteum & Endosteum
BONE
Two forms of bone tissue
Cortical or compact bone Cancellous or trabecular bone
Two types of bone formation in healing(mechanical & biological properties)
Woven or immature bone Lamellar or mature bone
WOVEN BONE
More rapid rate of deposition & resorption Irregular woven pattern of matrix collagen fibril Four times the number of osteocyte per unit volume Irregular pattern of matrix mineralization
Less stiff & more easily deformed
FRACTURE HEALING
Sequence of fracture healing
Inflammation Repair Remodeling
Fracture HealingInflammation
Fracture damages the bone, blood vessels, bone matrix and surrounding soft tissue
Haematoma Inflammatory mediators
- Dilatation blood vessel- Plasma exudat- inflammatory cells- PMN lecocytes- Macrophages- Lymphocytes
Release byplatelets inj.cells
FRACTURE HEALING
Inflammation
MacrophageDegranulating platelets release
- Cytokines (PDGF, TGF ß )- Interleukin 1 & 6- Prostaglandin E2 (PGE2)
Invitiation of the repair process
FRACTURE HEALING
INFLAMMATION
Inflammatory Necrosis Tissue and Exudate Resorbed
Fibroplasty & Chondrocytes Appears
Produce new matrix(The fracture callus)
BONE HEALING
REPAIR
Growth factors Fibroblast Growth factor Angiogenesis Osteoclast Osteoblast Bone formation Mesenchymal cells Hard callus intramembranous bone Soft callus endochondral ossification Fracture callus matrix glycosaminoglycans, proteoglycans and collagen type I & III
BONE HEALING
REPAIR
Bone Healing
First phase of woven bone formation
Later phase in woven bone formation
Bone Healing
Chronology of mineralization in subchondral bone
BONE HEALING
Remodelling
Replacement of woven bone by lamellar bone Resorption of unneeded callus mechanical Stability
BONE HEALINGREMODELING
Remodeling of bone trabecula
Accretion and remodeling of bone
BONE HEALING
BONE HEALING
Fracture healing with rigid stabilization
* Healing with primary bone healing mechanism Gap healing Haversian remodeling
Osteoclast resorb fracture line deposition osteoblast
Blood vessels formation
new bone matrix + osteocytes form new Haversian
Systems or primary osteons
Bone Healing
Direct bone formation in stabilized gap bone
Courtesy AO Risert laboratory
BONE HEALING
Variables Influence Fracture Healing
INJURY VARIABLES
* Open Fractures
Impeding or preventing formation # Hematoma Delaying formation repair tissue Risk of infection
* Severity of Injury
Retard fracture healing
* Intra articular fractures
If the alignment & congruity joint surface is not restored Delayed healing or non union Joint stiffness
* Segmental fractures
* Soft tissue interposition
* Damage to the blood supply
INJURY VARIABLES
BONE HEALING
BONE HEALING
Variables Influence Fracture Healing
Patient Variables
* Age* Nutrition
Healing process needs
- Energy- Proteins & carbohydrates
WOLFF’s Law
The principle that every change in the form and the Function of a bone or in the Function of the Bone alone leads to changes in its Internal Architecture and in
its External Form
T H A N K Y O U !