Supracondylar fracture

Background

  • Most common elbow fx in pts age <8yr
  • 95% are extension type (FOOSH mechanism)

Gartland Classification

  • Type I
    • Nondisplaced with evidence of elbow effusion (ant sail sign and/or posterior fat pad)
  • Type II
    • Displaced w/ intact posterior periosteum
    • Anterior humeral line is displaced anteriorly relative to capitellum
  • Type III
    • Displaced w/ disruption of anterior and posterior periosteum
      • If distal fragment is posteromedially displaced: radial nerve injury
      • If distal fragment is posterolaterally displaced: median nerve, brachial artery injury

Diagnosis

Clinical Features

  • Do not encourage active/passive elbow movement until displaced fx has been ruled-out
  • Pain, swelling, very limited range of motion
  • Non-displaced fx may have limited swelling, but child will refuse to move arm
  • TTP of posterior, distal humerus
  • If evidence of S-shape configuration or skin dimpling, splint before xray

Imaging

Normal pediatric elbow alignment
"Sail sign"
  • True lateral elbow
    • Anterior humeral line should intersect with middle third of capitellum (see pediatric elbow alignment)
      • If not, consider supracondylar fx or lateral condyle fx
    • Line drawn along axis of radial head and neck should pass through middle of capitellum
      • If not, consider fx of lateral condyle, radial neck, Monteggia, or elbow dislocation
    • Fat Pads
      • Anterior may be normal or if large may be abnormal ("sail sign")
      • Posterior is always abnormal
  • Forearm/wrist views
    • Co-injuries are common w/ elbow fx

Differential Diagnosis

Humerus Fracture Types

Humeral anatomy

Elbow Diagnoses

Radiograph-Positive

Radiograph-Negative

Pediatric

Treatment

  • Type I
    • Immobilize using double sugar tong or long-arm posterior splint x3wk
      • Elbow at 90degrees, forearm in pronation or neutral rotation
    • Refer to ortho w/in 48hr
  • Types II & III
    • Orthopedic consult in the ED
    • Admit

Complications

Vascular

  • Volkmann Ischemic Contracture (Compartment Syndrome of forearm)
    • Occurs more commonly when forearm is also fractured
    • Mere lack of a radial pulse does not indicate ischemia unless accompanied by:
      • Refusal to open hand
      • Pain w/ passive extension of fingers
      • Forearm tendernes
  • Brachial artery injury
    • Suggested by ecchymosis over anteromedial aspect of forearm

Neurologic

  • Majority of nerve injuries are neurpraxias without long-term sequelae
  • Median nerve injury
    • Motor: Weakness of hand flexors (difficulty making "OK" sign), abduction of thumb
    • Sensory: Altered two-point sensation on palmar surface of thumb, IF, MF
  • Radial nerve injury
    • Motor: Weakness of wrist extension, thumb extension (thumbs up)
    • Sensory: Altered sensation in dorsal thumb-index web space
  • Ulnar nerve injury
    • Motor: Weakness of index finger abduction
    • Sensory: Altered two-point discrimination over tip of little finger

See Also

Source