Ankle fractures in children

Key points

• Ankle fractures account for about 5.5% of fractures in children and 15% of physeal injuries; they are twice as common in boys and peak between eight and 15 years.
• Treatment aims to restore a congruent, well-aligned joint and to protect the physis (growth plate) to avoid later deformity or length discrepancy.
• Computed tomography (CT) should be routine when the joint surface is involved, especially in triplanar and juvenile Tillaux fractures.
• Non-displaced fractures are treated conservatively with close radiological follow-up; surgery is considered for substantial physeal or joint displacement.

Overview

This open-access narrative review summarises the developmental anatomy, assessment, classification and management of paediatric ankle fractures. It is a review rather than a formal guideline and includes the authors' own recommendations. Fracture patterns depend largely on age and on the stage of closure of the distal tibial physis.

Assessment and imaging

The history should match the examination; injuries before walking age or metaphyseal corner avulsions strongly suggest non-accidental injury. A full neurovascular examination is needed, compartment syndrome must be ruled out (anxiety, agitation and an increasing need for analgesia are warning signs), and extensor retinaculum syndrome requires urgent treatment. The Ottawa criteria showed 100% sensitivity for substantial injuries in children, whereas the Low Risk Ankle Rules were reportedly not sensitive enough. Radiographs include anteroposterior, lateral and mortise views; in young children with strong suspicion, radiography is repeated after two weeks. The radiation dose of ankle CT is considered equivalent to 0.9 chest radiographs; the role of magnetic resonance imaging remains uncertain.

Classification

The Salter–Harris system is the most widely used; the risk of physeal arrest is lower in types I and II than in types III to V. Type I injuries make up about 15% of ankle fractures (arrest risk below 5%), type II injuries 40% of distal tibial fractures (physeal bar risk 16–25%), and types III and IV about 25% each. Transitional fractures occur while the distal tibial physis closes: triplanar fractures (4–10% of paediatric ankle fractures) and juvenile Tillaux fractures (3–5%, usually at 11–15 years, more frequent in girls).

Treatment

Non-displaced fractures are immobilised for 4–6 weeks with a radiograph at 7–10 days to exclude late displacement; a removable ankle immobiliser was found more effective than a short leg cast for functional recovery. Closed reduction of a physeal injury should not be repeated more than once. Below about 10 years, less than 15° of angulation is considered tolerable. Surgery should be considered for varus or valgus of 5° or more, antecurvatum or recurvatum of 10° or more, physeal displacement above 3 mm and/or a joint gap above 2 mm. Medial malleolus fractures with 1 mm or more displacement are fixed; juvenile Tillaux and triplanar fractures with a joint gap below 2 mm can be treated conservatively, while larger gaps need reduction and screw fixation after CT planning.

Complications

Premature physeal closure, mainly after Salter–Harris III or IV injuries, can cause limb length discrepancy or angular deformity; Park–Harris lines that diverge from the physis suggest growth disturbance. Up to 11% of type II injuries may heal with angular malunion, and nonunion is a risk in type III and IV medial malleolus fractures, so internal fixation is recommended for these.

Frequently asked questions

Why are ankle fractures in children different from those in adults?

The open physis and developing bone produce age-specific patterns, and injury to the physis can lead to later deformity or length difference, so protecting it is a key goal.

When is a CT scan needed?

The review recommends CT for injuries involving the joint surface, particularly triplanar and juvenile Tillaux fractures, to measure displacement and plan surgery.

Can a removable brace replace a cast?

For low-risk injuries, a cited randomised trial found a removable ankle immobiliser more effective than a short leg cast for functional recovery, with earlier return to activities.

Source

Cancino B, Sepúlveda M, Birrer E. Ankle fractures in children. EFORT Open Rev 2021;6(7):593-606. doi:10.1302/2058-5241.6.200042. Open access, CC BY-NC 4.0. Narrative review. Summary prepared by Medpresso from the original publication; it is not a substitute for the full text or for medical advice.