Fractures

Fractures 150 150 Tony Guo

Fractures

 

  • Disruption or break in continuity of structure of bone
  • Majority of fractures from traumatic injuries 
  • Some fractures secondary to disease process
    • Cancer or osteoporosis

 

Classifications

  • Classification according to external environment
    • Open fracture
      • The skin is broken and bone exposed, causing soft tissue injury
    • Closed fracture
      • The skin remains intact
  • Fractures can be classified as 
    • Complete
      • if the break goes completely through the bone
    • Incomplete
      • Fracture occurs partly across a bone shaft but the bone is still intact. 
      • An incomplete fracture is often the result of bending or crushing forces applied to a bone.
  • Based on direction of fracture line
    • Linear
    • Oblique
      • The line of the fracture extends across and down the bone
    • Transverse
      • The line of the fracture extends across the bone shaft at a right angle to the longitudinal axis
    • Longitudinal
    • Spiral
      • The line of the fracture extends in a spiral direction along the bone shaft.
  • Displaced or nondisplaced
    • Displaced: two ends separated from one another
      • Often comminuted or oblique
    • Nondisplaced: periosteum is intact and bone is aligned.
      • Usually transverse, spiral , or greenstick

 

Clinical manifestation

  • Localized pain
  • Decreased function
  • Inability to bear weight or use 
  • Guard against movement
  • May or may not have deformity
  • Immobilize if suspected fracture

 

Manifestation Description Significance
Edema and swelling Disruption or penetration of skin or soft tissues by bone fragments, or bleeding into surrounding tissues Unchecked bleeding and swelling in closed space can occlude blood vessels and damage nerves (e.g., increased risk of compartment syndrome).
Pain and Tenderness Muscle spasm due to involuntary reflex action of muscle, direct tissue trauma, increased pressure on nerves, movement of fracture fragments. Pain and tenderness encourage the patient to splint muscle around fracture and reduce motion of injured area.
Muscle Spasm  Irritation of tissues and protective response to injury and fracture. Muscle spasms may displace nondisplaced fracture or prevent it from reducing spontaneously
Deformity Abnormal position of extremity or part as result of original forces of injury and action of muscles pulling fragment into abnormal position. Seen as a loss of normal bony contours. Deformity is cardinal sign of fracture. If uncorrected, it may result in problems with bony union and restoration of function of injured part.
Contusion Discoloration of skin (bruising) as a result of extravasation of blood in subcutaneous tissues. Bruising may appear immediately after injury and may appear distal to injury. Reassure patient that process is normal and discoloration will eventually resolve.
Loss of Function Disruption of bone or joint, preventing functional use of limb or part. Fracture must be managed properly to ensure restoration of function to limb or part
Crepitation Grating or crunching of bony fragments, producing palpable or audible crunching or popping sensation Crepitation may increase chance for nonunion if bone ends are allowed to move excessively

Micromovement of fragments (postfracture) assists in osteogenesis (new bone growth).

 

Fracture healing

  • Multistage healing process (union)
    • Fracture hematoma
      • Bleeding creates a hematoma that surrounds the ends of the bone fragments
      • The hematoma is extravasated blood that changes from a liquid to a semisolid clot. 
      • This occurs in the first 72 hours after injury.
    • Granulation tissue
      • Active phagocytosis absorbs the products of local necrosis. 
      • The hematoma converts to granulation tissue. 
      • Granulation tissue (consisting of new blood vessels, fibroblasts, and osteoblasts) forms the basis for new bone substance (osteoid) during days 3 to 14 after injury.
    • Callus formation
      • As minerals (calcium, phosphorus, and magnesium) and new bone matrix are deposited in the osteoid, an unorganized network of bone is formed and woven about the fracture parts. 
      • Callus is primarily composed of cartilage, osteoblasts, calcium, and phosphorus. 
      • It usually appears by the end of the second week after injury
    • Ossification
      • Callus ossification is sufficient to prevent movement at the fracture site when the bones are gently stressed. 
      • During this stage of clinical union, the patient may be allowed limited mobility or the cast may be removed.
    • Consolidation
      • As callus continues to develop, the distance between bone fragments decreases and eventually closes
      • Ossification continues and can be equated with radiologic union, which occurs when an x-ray shows complete bony union.
      • Can occur up to 1 year after the injury
    • Remodeling
      • Excess bone tissue is resorbed in the inal stage of bone healing, and union is complete. 
      • Gradual return of the injured bone to its preinjury structural strength and shape occurs.
  • Factors influencing healing
    • Displacement and site of fracture
    • Blood supply to area
    • Immobilization
    • Internal fixation devices
    • Infection or poor nutrition
    • Age 
    • Smoking
  • Complication of fracture healing
    • Delayed union
      • Fracture healing progresses more slowly than expected. Healing eventually occurs.
    • Nonunion
      • Fracture fails to heal despite treatment. No x-ray evidence of callus formation
    • Malunion
      • Fracture heals in expected time but in unsatisfactory position, possibly resulting in deformity or dysfunction
    • Angulation

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