• Clinical science

General principles of fractures


A fracture is a partial or complete interruption in the continuity of bone. The most common causes are trauma and diseases (e.g., osteoporosis) that result in weakened bone structure. The latter results in pathologic fractures, which are fractures that would not usually occur if the bone structure was not weakened. Open fractures, in which the bone is exposed due to severe soft tissue injury, are associated with a significant risk of infection and poor wound healing. Fracture management can be conservative (e.g., cast or splint) or surgical, and generally involves anatomic reduction, fixation, and/or immobilization. Complications include acute nerve and vascular injury and compartment syndrome, as well as long-term complications such as avascular necrosis and nonunion.




Fracture classification is based on the following:

  • Anatomy
  • Extent
    • Complete
    • Incomplete
  • Orientation: transverse, oblique, spiral
  • Displacement: nondisplaced, displaced, angulated
    • Rotated = rotation around the longitudinal axis
    • Angulated = angulation of the axis
    • Translated = lateral movement of the bone fragments
    • Longitudinal displacement of bone fragments
      • Distraction = elongation
      • Impaction = shortening
  • Fragmentation
  • Soft tissue involvement
  • Growth plate involvement (pediatric fractures): Salter-Harris fractures

AO classification system

The AO Foundation (Association for the Study of Internal Fixation) classifies long bone fractures according toanatomical location, position, and complexity of the fracture. It provides a numerical coding system for the anatomical location and position of the fracture, and an additional letter to denote the complexity of the fracture.

Anatomical location


  • 1 = Proximal
  • 2 = Diaphyseal
  • 3 = Distal


  • A = Simple or extra articular
  • B = Wedged or partial articular
  • C = Complex or complete articular


Overview of common fractures

Common fractures in children

See “Pediatric fractures” for details.

Common fractures in adults


Clinical features

  • Pain, redness, and swelling at the site of injury
  • Deformity and axis deviation
  • Bone fragments penetrating the skin
  • Palpable step-off or gap
  • Bone crepitus
  • Concomitant soft tissue injuries
  • Neurovascular compromise below site of injury


  • Clinical assessment
  • Imaging
    • X-ray
      • Conditions:
        • 2 joints (if limb fracture)
        • 2 times (prereduction and postreduction)
      • Radiographic signs of a fracture include a radiolucent fracture line and cortical disruption
      • Describe fracture based on the anatomic location, alignment , angulation, and articular involvement (see “Classification” above for details)
      • X-ray imaging has a low sensitivity for detecting stress fractures
    • CT/MRI (not routine)
      • Indications: preoperative planning for complicated fractures, assessment of associated injuries, and inconclusive x-ray findings.



General approach

Conservative fracture management

Surgical fracture management

  • Indications
    • Open fractures
    • Unstable fractures
    • Severe displacements (e.g., rotational deformities) and displaced fragments
    • Inadequate manual reduction and fixation
  • Procedure: anatomic reduction; of the fracture and subsequent fixation and immobilization using external or internal fixation devices (e.g., plates, screws, wires)




We list the most important complications. The selection is not exhaustive.