Bone fractures

• Classification of fractures: complete

  • Transverse
  • Oblique
  • Spiral
  • Comminute
  • Impacted
  • Avulsion
• Classification of fractures: incomplete

  • Fissure - crack in bone
  • Greenstick - one side broken
  • Depression - broken portion pressed inward
• Bone fracture healing: simple steps

  1. Hematoma formation

  2. Soft callus formation

  3. Bony callus formation

  4. Bone remodelling
• Bone fracture healing: step 1: hematoma formation

  1. Localised clotted blood from broken blood vessels initiates pro-inflammatory reaction

  2. Cell debris cleared by phagocytes

  3. Oesteoclasts remove necrotic bone
• Bone fracture healing: step 2: Soft callus formation

  1. New blood vessels appear

  2. Network of soft spongy bone, fibrous tissue, and cartilage is formed

  3. This fibrocartilaginous callus bridges both sites of fracture
• Bone fracture healing step 3: bony callus formation

  1. The soft callus undergoes ossification

  2. Hardening of the callus peripherally and progressively moves towards centre of fracture
• Bone fracture healing step 4: bone remodelling

  1. Excess spongy bone removed

  2. Spongy bone converted into compact bone
• classification of fractures: complete: Transverse

  Transverse = straight across bone
• classification of fractures: complete: oblique

  oblique - diagonal across bone
• classification of fractures: complete: spiral

  spiral = one or both halves of bone twisted
• classification of fractures: complete: comminute

  comminute = several small pieces
• classification of fractures: complete: impacted

  impacted = one broken end driven into other broken end
• classification of fractures: complete: avulsion

  avulsion = small piece attached to tendon, or ligament gets pulled away from main mass of bone