Supracondylar Fracture in Children

Supracondylar fracture is a fracture of the distal humerus just above the elbow, the commonest elbow fracture in children, usually after a fall on an outstretched hand.

• It peaks at ages 5 to 7 years.
• About 95 percent are extension type (the distal fragment displaced posteriorly), with the rest flexion type.
• The Gartland classification: type I undisplaced; type II displaced with intact posterior cortex; type III completely displaced with no cortical contact.
• Neurovascular injury is frequent in displaced fractures: the anterior interosseous branch of the median nerve (most common), then radial and ulnar nerves, and brachial artery.
• Compartment syndrome and Volkmann ischaemic contracture are the feared complications.

Presentation follows a fall.

• Severe elbow pain, swelling, bruising and refusal to move the arm.
• S-shaped deformity of the elbow in displaced fractures; puckering of the skin anteriorly suggests brachialis penetration.
• Hold the arm in extension; the child guards it.
• Check the pulses (radial), capillary refill and warmth of the hand, and nerve function: anterior interosseous nerve (cannot flex the thumb interphalangeal joint and index distal joint, "OK sign" lost), radial nerve (wrist and thumb extension), ulnar nerve (finger abduction, sensation of little finger).
• Differential diagnosis: elbow dislocation, lateral condyle fracture, medial epicondyle fracture, radial head subluxation, forearm fracture, elbow sprain and non-accidental injury.
• Complications: brachial artery injury, pulseless pink hand, nerve palsy, compartment syndrome, Volkmann contracture, malunion (cubitus varus, "gunstock deformity"), stiffness, myositis ossificans and pin site infection.

Diagnosis is by X-ray with careful neurovascular assessment.

• Anteroposterior and true lateral elbow views. On the lateral view, the anterior humeral line should cross the middle third of the capitellum. A fat pad sign (posterior or sail sign) suggests occult fracture.
• Baumann angle on anteroposterior view (normal 64 to 81 degrees) assesses varus.
• If the X-ray is normal but fat pad is present, presume an occult fracture and repeat X-ray in 7 to 10 days.
• Doppler and CT angiography or ultrasound if the hand is white and pulseless after reduction.
• Document neurovascular status before and after any manipulation.

Management is by type; displaced fractures are surgical emergencies.

• Supportive: analgesia, splint the elbow in about 20 to 30 degrees of flexion (avoid hyperflexion, which impairs circulation), elevate, keep nil by mouth when surgery is likely, and observe neurovascular status hourly.
• Pharmacological: paracetamol 15 mg/kg every 6 hours, morphine 0.1 mg/kg intravenously for severe pain, and cefazolin 25 to 50 mg/kg intravenously for open fractures or before surgery.
• Type I: above-elbow cast with elbow flexed 60 to 90 degrees for 3 weeks.
• Type II: closed reduction, then casting if stable or percutaneous pinning if unstable.
• Type III: closed reduction and percutaneous pinning with crossed or lateral Kirschner wires under general anaesthesia, ideally within 24 hours; urgent surgery within hours for a pulseless, cold hand, open fracture or neurological compromise.
• Pulseless pink hand: reduce the fracture; if circulation does not return, explore the brachial artery.
• Special groups: floating elbow (ipsilateral forearm fracture), open fractures and bilateral injuries need specialist care.
• Red flags: cold, white or pulseless hand, severe pain not relieved by analgesia, pain on passive finger stretch, tense forearm, tingling or numbness, open wound and delayed presentation.
• Follow-up: pin removal and cast removal at 3 to 4 weeks, then mobilisation. X-ray at 1 week. Physiotherapy only if stiffness persists. Assess carrying angle for varus deformity.