Fracture Healing

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Fracture Healing
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Terminology

• Osteoblast

• Osteocytes forms and destroys bone on-going
  remodeling of bone

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• Osteoclasts

• Intercambium layer serves as a foundation for
  blood vessels and provides a place for muscular
  attachment

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• Exudate fluid with a high protein content and
  containing cellular debris
• that comes from blood vessels and accumulates in
  the are of injury.
•  

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Hematoma Formation (1st)

• 4 days (acute inflammation)
• Hematoma forms in medullary canal and surrounding
  soft tissue in first 48-72 hours

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Hematoma Form. continues

• Dead bone and tissue inflammatory reaction
  including vasodilation, plasma exudate, and
  inflammatory cells

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Cellular Formation Phase(2nd)

• Acidic environment but turning neutral

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Cellular form. continued

• Influx of endosteal cells from cambium layer
  produce a fibrous callus (environment has high
  oxygen tension) then cartilage (has a low oxygen
  tension environment) and

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Callus Formation Phase (3rd)

• Fibroblast deposit collagen in the granulation
  tissue
• Soft Callus is formed (Unorganized network of
  woven bone)

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• Internal callus (grows quickly to create rigid
  immobilization)

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Callus Phase continued

• The hard callus lasts 3-4 months.
• Hard callus a gradual connection of bone
  filament to the woven bone (Acts like a temporary
  splint)
• Bone is beginning to strengthen and immobilize
• If proper immobilization does not occur
  cartilage will form instead of bone

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Ossification Phase (4th)

• will occur with adequate immobilization
• Bone ends become crossed with a new Haversian
  system that will eventually lead to the laying
  down of primary bone

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• Fracture is bridged and united

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Remodeling Phase (5th)

• Remodeling hard callus to compact bone
• May take a few years
• Completed when the fractured bone has been
  restored to its original form or shape or when it
  can withstand the imposed stresses placed on it

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Conditions that interfere with fracture healing

• Poor blood supply to the fractured area could
  lead to avascular or aseptic necrosis
• Poor immobilization of fracture site may cause
  misalignment or deformity
• Infection more common with open fractures