Supracondylar humerus fracture (child)

AO PCCF 13-M/3

Paediatric, extension type

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The commonest elbow fracture in children (age 5–7). The thin bone between the olecranon and coronoid fossae breaks; in the extension type the distal fragment displaces posteriorly and the proximal spike can injure the brachial artery and the median nerve.

Supracondylar humerus fracture in a child. Lateral elbow showing the displaced distal fragment. — James Heilman, MD, CC BY-SA 3.0, via Wikimedia Commons.

Mechanism

Fall on the outstretched hand with the elbow hyperextended (extension type, 95%).

Clinical findings

Check the hand: perfused and pink vs white; radial pulse; anterior interosseous nerve ("OK" sign) most often injured, then radial and ulnar nerves.
Pucker sign: the proximal fragment has pierced brachialis (difficult reduction).
Watch for compartment syndrome of the forearm.

Imaging

AP and true lateral of the elbow.
On the lateral: anterior humeral line (should cross the middle third of the capitellum), posterior fat pad sign in occult fractures.
Comparison views of the other elbow are rarely needed. Neurovascular status first: radial pulse and AIN (OK sign).

AP and lateral elbow. Anterior humeral line should pass through the middle third of the capitellum; posterior fat pad sign = occult fracture; Baumann angle on the AP view.

Classification

Gartland I: Undisplaced.
Gartland II: Displaced with an intact posterior hinge.
Gartland III: Completely displaced.
Gartland IV: Unstable in flexion and extension (periosteum torn all round).

Types shown in 3D

Gartland I: Undisplaced; only a posterior fat pad may show. Above-elbow cast 3 weeks.
Gartland II: Angulated with an intact posterior cortex (hinge): the anterior humeral line misses the capitellum. Closed reduction and pinning if the angulation is unacceptable.
Gartland III: Completely displaced, usually posteromedially; the proximal spike threatens the brachial artery and median nerve. Urgent closed reduction and K-wires.

Treatment

Gartland I: Above-elbow cast at 90° for 3 weeks.
Gartland II–IV: Closed reduction and percutaneous K-wire fixation (two or three lateral wires, or crossed wires with a small medial incision to protect the ulnar nerve). Pink pulseless hand: urgent reduction, then reassess. White pulseless hand: emergency reduction and vascular exploration if not perfused.

Aftercare

Wires removed at 3–4 weeks.

Complications

Cubitus varus (gunstock deformity)
Volkmann ischaemic contracture
Nerve palsies (mostly recover)