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BOAST Guidelines
BOAST 12
Foot and Ankle

The Management of Ankle Fractures

Jointly developed by the BOA and BOFAS, this guideline establishes evidence-based standards for the emergency reduction, clinical assessment, definitive operative vs non-operative decision-making, and rehabilitation of acute ankle fractures.

Key standards

  • ›Perform immediate closed reduction and splinting for clinically deformed or dislocated ankles.
  • ›Obtain true lateral and mortise radiographs centered on the ankle joint prior to reduction, unless delay threatens limb viability or skin envelope.
  • ›Order full-length tibia and fibula radiographs when proximal fibular tenderness suggests a Maisonneuve fracture.
  • ›Formally record baseline neurovascular status, soft tissue condition, and key systemic comorbidities (e.g., diabetes, peripheral neuropathy, smoking).
  • ›Identify fracture stability; stable isolated lateral malleolar injuries should be managed with functional support and immediate weight-bearing.
  • ›Execute operative internal fixation early before soft tissue swelling precludes safe wound closure, or stage with temporary external fixation if significantly unstable with adverse soft tissues.
  • ›Provide clear guidance regarding weight-bearing status, venous thromboembolism (VTE) prophylaxis, driving restrictions, and expected recovery milestones.
  • ›Ensure an accessible mechanism for rapid patient self-referral back to the fracture clinic if complications or poor functional progress arise.

Introduction

Ankle fractures represent one of the most common acute orthopaedic injuries, frequently resulting from low-energy torsional trauma. The primary objective is to restore and maintain normal ankle mortise alignment and joint congruency, thereby optimising functional outcomes and mitigating the risk of post-traumatic osteoarthritis.

Assessment and Initial Management

  • Clinical Evaluation: Document the mechanism of trauma, skin integrity, soft tissue envelope state, and baseline neurovascular examination (specifically distal perfusion and sensation).
  • Comorbidity Profiling: Identify and record patient factors that dictate management choice and complications, including baseline mobility, peripheral neuropathy, diabetes mellitus, peripheral arterial disease, osteoporosis, end-stage renal disease, and smoking or alcohol misuse.
  • Deformity and Closed Reduction: Clinically deformed ankles must undergo urgent closed reduction and immobilisation in a well-padded splint. Pre-reduction radiographs should be obtained unless doing so causes an unacceptable delay to restoring distal perfusion or relieving severe soft-tissue compromise.

Imaging and Diagnostic Standards

  • Standard Series: Initial plain radiographic series must centre on the ankle joint and comprise true lateral and mortise (15–20° internal rotation) projections.
  • Extended Projections: Obtain full-length tibia/fibula radiographs whenever tenderness or swelling suggests a high fibular fracture (Maisonneuve variant). Additional foot or knee radiographs should be acquired if clinically indicated.
  • Cross-Sectional Imaging: CT scans should be utilised selectively to evaluate complex articular anatomy, multi-fragmentary injuries, or posterior malleolar morphology to guide surgical strategy.

Stability and Treatment Pathways

  • Unstable Fractures: Fractures exhibiting subluxation, dislocation, or joint incongruity require anatomic reduction and stable fixation (or formal non-operative close contact casting where surgery is contraindicated).
  • Isolated Lateral Malleolar Fractures: Isolated distal fibular fractures without medial tenderness or widening of the medial clear space on mortise/stress radiographs are inherently stable and can be managed functionally with immediate protected weight-bearing as tolerated.
  • Operative Timing: Surgery should ideally be carried out within the first 24 to 48 hours before significant soft-tissue swelling and fracture blisters develop, or delayed until swelling subsides and the wrinkle sign returns.

Postoperative Care and Follow-up

  • Rehabilitation: Unless precluded by complex fixation instability or severe soft-tissue injury, early protected mobilisation and weight-bearing protocols should be instituted.
  • Discharge Planning: Patients must receive formal instructions outlining expected functional recovery timelines, driving advice, and work restrictions, alongside an established mechanism for rapid self-referral if symptoms or progress deviate from expectations.

Exam-tested points

  • ›A widened medial clear space (>4 mm or greater than the superior joint clear space) on a mortise view indicates deltoid ligament rupture and an unstable bimalleolar equivalent pattern requiring surgical stabilization.
  • ›Always palpate the proximal fibular head to avoid missing a Maisonneuve fracture, which requires whole-leg radiographs and syndesmotic stabilization.
  • ›Recognising diabetic neuropathy as an independent predictor of severe complications: neuropathic ankle fractures carry high risks of nonunion, Charcot arthropathy, and hardware failure, frequently requiring rigid/augmented fixation constructs and prolonged immobilization.
  • ›Differentiating between stable Weber B fibula fractures (intact medial clear space, no medial tenderness) suitable for functional weight-bearing in a boot, and unstable Weber B bimalleolar equivalents requiring ORIF.
  • ›Assessing posterior malleolar involvement: fragment size, impaction, and joint congruence dictate operative indication, often mandating preoperative CT scanning and direct postero-lateral buttress plating.
Official BOA source
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