Injury To Bone

Question 1

3 Overlapping Stages of Bone Healing

*Is the same for all bone

Answer 1

1. Inflammation
2. Bone Production (proliferation phase)
3. Bone Remodelling (maturation phase)

Question 2

Explain the Inflammatory Phase

Answer 2

Starts Immediately for days

1. Bone fractured–bleeding
2. Bleeding–inflammation and clotting of site
3. Necrosis occur at end of bone
   
   • inadequate blood supply by torn BV
4. Hematoma/Clot forms in medullary canal
   - Provides initial structural stability for producing new bone

Question 3

Explain the Proliferation Phase

Answer 3

1. Hematoma serves as a basis for fibrin network—Granulation Tissue Grows
   - capillaries extend into tissue
   - Phagocytotic cells remove debris
   - Fibroblasts lay down collagen
   - Chondroblasts lay down cartilage
2. Formation of Procallus splints two bone ends together
3. Osteoblasts from periosteum and endosteum generate new bone to fill the gap
4. Bony callus replaces procallus
   * Damaged is repaired by new bone formation, not scar tissue

Question 4

Explain the Remodelling Phase

Answer 4

*Several Months 
Osteoblast/Osteoclast Activity
-excessive callus bone removed
-more compact bone
-blood circulation improves
-eventually, normal appearance
*Usually takes 6-8 weeks to heal a significant degree

Question 5

Complications affecting bone healing

Answer 5

• Muscle Spasms
• Infection
• Ischemia
• Compartment Syndrome
• Fat Emboli
• Nerve Damage
• Failure to heal

Question 6

Factors Promoting Bone Healing

Answer 6

• Immobilization
• Physical Therapy once adequately healed
• Cast Fit/Swelling
• Shift of Approximated Ends
• Compression

Question 7

Common Fracutes

Answer 7

Potts, Galeazzi, Colles