General principles of fractures

A fracture is a partial or complete interruption in the continuity of bone. The most common cause is trauma, followed by 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.

• Trauma: mechanical stress and/or loading
• Weakened bone structure: osteoporosis, bone tumors, metastasis, Paget disease

References:^[1]

Fracture classification

Based on the following characteristics:

• Anatomy
  • Location: affected bone (proximal, distal)
  • Position: diaphysis, metaphysis, epiphysis
• Extent
  • Complete
  • Incomplete
• Orientation: transverse, oblique, spiral
• Displacement
  • 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
  • Comminuted fracture: more than two fracture lines resulting in multiple bone fragments
  • Segmental fracture: two fracture lines with a bone fragment between the proximal and distal portions of the bone
• Soft tissue involvement
  • Closed fracture (simple fracture)
  • Open fracture
• Growth plate involvement (pediatric fractures): Salter-Harris fractures

Common fractures in children

See “Pediatric fractures” for details.

Common fractures in adults

Pathologic fracture

• Definition: a spontaneous fracture following mild physical exertion or minor trauma; (e.g., lifting something, bending over, or sneezing/coughing) due to abnormal weakness of the bone that is caused by an underlying condition
• Etiology
  • Disorders affecting bone metabolism
    • Osteoporosis (most common cause)
    • Paget disease of bone
    • Osteopetrosis
    • Osteomalacia
    • Osteogenesis imperfecta
  • Masses
    • Malignant bone tumors and bone metastases
    • Benign bone tumors (including bone cysts)
  • Infection: chronic osteomyelitis
• Common locations: spine (vertebral compression fractures), hip, wrist

Open fracture ^[2]

• Definition
  • A fracture in which bone fragments break through the skin
  • Associated with significant soft tissue injury and an increased risk of complications (infection, poor healing)
• Etiology: secondary to trauma

Other fractures

• Stress fracture
• Forearm fractures
  • Colles fracture: distal radius ± distal ulna
  • Smith fracture: distal radius
  • Monteggia fracture: proximal one-third of the ulna and dislocation of the radial head
  • Galeazzi fracture: distal radial shaft and dislocation of the distal radioulnar joint
• Boxer fracture
• Scaphoid fracture
• Ankle fracture
• Tibial fracture
• Femoral shaft fracture
• Femoral neck fracture
• Pelvic fracture
• Vertebral fractures (including compression fractures)

• 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 the site of injury

Clinical assessment

• Assess for signs of a fracture and concomitant injuries
• Assess for neurovascular compromise and compartment syndrome with the 6 Ps: pain, pallor, pulselessness, paresthesia, paralysis, and poikilothermia

Imaging

• X-ray
  • Requirements
    • 2 views
    • 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): indicated in preoperative planning for complicated fractures, assessment of associated injuries, and inconclusive x-ray findings

General approach

• Wound care
• Pain management (e.g., non-opioid analgesics, opioids)
• Fracture care (conservative or surgical)
  1. Anatomic reduction
  2. Fixation
  3. Immobilization

Conservative fracture management

• Indications
  • Stable fractures
  • Mainstay management of pediatric fractures (see “Pediatric fractures” for details)
• Procedure: closed reduction; and, if necessary, immobilization with a cast or splint of the fractured bone and adjacent joints

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
  • External fixation: immobilizing a fracture using pins or screws that are secured outside the skin
  • Internal fixation: immobilizing a fracture using implants (e.g., plates, screws, wires)
  • Open reduction and internal fixation: realignment of the ends of a fracture, and stabilization of the fracture using implants (e.g., plates, screws, wires)

Acute complications

• Neurologic and vascular injury (e.g., bleeding, hematoma, seroma)
• Compartment syndrome
• Wound infection, osteomyelitis
• Secondary dislocation

Long-term complications

• Avascular necrosis
• Post-traumatic osteoarthritis
• Complex regional pain syndrome
• Joint stiffness/contracture
• Joint instability
• Heterotopic ossification
• Children: growth disturbances after growth plate injury (Salter-Harris fracture)

Nonunion ^[3]

• Definition: incomplete healing of a fracture which results in the creation of a false joint (pseudarthrosis)
• Risk factors
  • Poor vascular supply
  • Insufficient immobilization
  • Comorbidities (e.g., diabetes mellitus, osteoporosis)
  • Open fractures
  • Infection
  • Smoking
• Clinical features
  • Pain, swelling
  • Limited weight-bearing capacity
  • Reduced range of motion persisting after the normal duration of healing (usually 6–9 months)
• Types
  • Hypertrophic nonunion: callus formation in the fracture zone
  • Atrophic nonunion: atrophic bone without callus formation
• Treatment
  • Debridement and resection
  • Osteosynthesis (fixation)
  • Antibiotics in the case of infected nonunion

Complications due to immobilization

• Thrombosis, pulmonary embolism
• Infections (e.g., pneumonia, urinary tract infection)

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

1. Open Fractures. http://orthoinfo.aaos.org/topic.cfm?topic=A00582. Updated: June 1, 2011. Accessed: February 7, 2017.
2. Wick JY. Spontaneous fracture: multiple causes. Consult Pharm. 2009; 24 (2): p.100-113. doi: 10.4140/TCP.n.2009.100 . | Open in Read by QxMD
3. Stewart SK. Fracture Non-Union: A Review of Clinical Challenges and Future Research Needs.. Malaysian orthopaedic journal. 2019; 13 (2): p.1-10. doi: 10.5704/MOJ.1907.001 . | Open in Read by QxMD