Ankle Fractures

Patients present with pain, swelling, and inability or reluctance to weight-bear after a twisting injury or fall. The injured limb may show obvious deformity, ecchymosis, or skin tenting in displaced fractures.

Examine systematically:

• •Inspection: deformity, swelling, ecchymosis, skin integrity (open versus closed)
• •Palpation: lateral malleolus, medial malleolus, base of 5th metatarsal, navicular, the entire fibula to the knee (to exclude Maisonneuve), syndesmosis, and deltoid origin
• •Movement and weight-bearing: ability to bear weight at the scene AND in the ED for 4 steps (the validated Ottawa criterion is BOTH)
• •Special tests: syndesmosis squeeze test, external rotation stress test
• •Neurovascular status: dorsalis pedis and posterior tibial pulses, capillary refill, sensation, motor function

Do not miss: open fracture (BOAST 4 emergency); fracture-dislocation with skin tenting (urgent reduction in ED to protect skin and neurovascular structures); Maisonneuve fracture; pilon fracture (high-energy intra-articular distal tibia - CT and specialist input); diabetic neuropathic fracture (late presentation, minimal pain, high complication risk); compartment syndrome (rare but possible after high-energy trauma).

Comorbidities materially alter risk and treatment choice. Neuropathic patients may have deceptively little pain, delayed presentation, skin compromise, fixation failure, infection, Charcot change, and higher amputation risk - senior orthopaedic input and cautious immobilisation are required.

Imaging is guided by the Ottawa Ankle Rules (NICE NG38). An ankle X-ray series is indicated if there is malleolar-zone pain AND any one of bone tenderness at the posterior edge or tip of either malleolus, or inability to bear weight immediately and in the ED for 4 steps. Note the AND criterion for weight-bearing: the patient must have been unable to bear weight both at the scene and in the ED. A foot X-ray is indicated if there is midfoot-zone pain AND tenderness at the base of the 5th metatarsal or over the navicular, or inability to bear weight as above. Imaging is also warranted when clinical concern persists despite negative Ottawa rules - high-energy trauma, deformity, neurovascular compromise, open injury, suspected syndesmosis or Maisonneuve injury, or unreliable examination.

Standard ankle X-ray series comprises AP, lateral, and mortise views (15 to 20 degrees internal rotation). The mortise view is especially important for assessing talar shift and medial clear space. Assess fibular fracture level (Weber classification), medial malleolar fracture, talar shift, medial clear space (widening greater than 4 mm or greater than the superior clear space suggests deltoid disruption - interpret with stress views where uncertain), posterior malleolar fragment on the lateral view, and tibiofibular overlap and clear space (syndesmotic integrity).

CT is preferred whenever posterior malleolar involvement is suspected and is indicated for trimalleolar and pilon fractures and for surgical planning. It characterises fragment morphology, articular impaction, and posterior incisura involvement (PITFL attachment), which inform the modern decision to fix the posterior malleolus.

Stress radiographs detect occult instability in apparently isolated Weber B fractures with medial-side tenderness or borderline clear space. Weight-bearing stress views are increasingly preferred over gravity stress because they apply true physiological load, where the patient can tolerate it. MRI is rarely required acutely.

Initial management for all fractures: ABCDE in any high-energy mechanism; reduce dislocations promptly to restore neurovascular status and protect skin; splint in a well-padded backslab or boot; re-check neurovascular status after every reduction or splint application; VTE risk assessment per NICE NG89, with LMWH or fondaparinux for lower-limb immobilisation when VTE risk outweighs bleeding risk (consider stopping if immobilisation continues beyond 42 days).

Open fractures (BOAST 4): IV antibiotics within 1 hour (typically co-amoxiclav, or clindamycin/teicoplanin plus gentamicin if penicillin-allergic); photograph then cover with saline-soaked gauze and an occlusive dressing; splint; check tetanus status; urgent senior orthopaedic review via the local open-fracture or orthoplastic pathway, with plastic surgery input for significant soft-tissue injury, contamination, vascular compromise, or coverage concerns. Do NOT irrigate or scrub in the ED - definitive debridement happens in theatre.

Stable fractures (Weber A, isolated lateral malleolus without talar shift, undisplaced medial malleolus): non-operative in a removable walking boot. NICE NG38 supports immediate weight-bearing as tolerated for non-surgical unimalleolar fractures. Virtual fracture clinic pathways with safety-netting may suffice where stability is clearly evident; where stability is uncertain, arrange review within 2 weeks with weight-bearing radiographs.

Unstable fractures (Weber C, bimalleolar, trimalleolar, any with talar shift, deltoid rupture with widened medial clear space): open reduction and internal fixation, aiming for anatomical mortise reduction and stable fixation to allow early mobilisation. NICE NG38 advises surgery on the day of injury or the next day where indicated.

Posterior malleolus fixation: the historical >25 percent fragment rule remains a useful exam shorthand. Modern UK practice is CT-based and considers fragment morphology, articular step-off, intra-articular impaction, talar subluxation, and posterior incisura involvement (PITFL attaches here, so syndesmotic stability often depends on the fragment regardless of size). Syndesmotic injury is confirmed intra-operatively with stress testing and fixed with one or two screws or a flexible suture-button device.

Older adults with fragility fractures: the same biomechanical principles apply, but the method depends on frailty, skin, bone quality, diabetes, neuropathy, vascular status, pre-injury mobility, and weight-bearing compliance. ORIF for the typical independent, medically stable older adult with unstable patterns; close contact casting is a recognised option in selected over-60s (AIM Trial - broadly similar functional outcomes versus surgery in this group); primary hindfoot nail (tibiotalocalcaneal arthrodesis) for the very frail with poor bone stock or major comorbidity. Complex fractures (open, pilon, intra-articular distal tibia) are managed under NICE NG37 through major trauma networks.

Rehabilitation depends on stability and operative versus non-operative pathway, but principles are shared.

Non-operative pathway (typical Weber A or stable Weber B):

• •Weeks 0 to 6: removable walking boot, weight-bearing as tolerated, daily ankle range of motion out of the boot once swelling allows
• •Weeks 6 to 12: wean out of the boot, restore symmetrical gait, progress strength and proprioception
• •Return to running typically 12 to 16 weeks; return to sport is variable

Post-operative pathway (typical ORIF):

• •Weeks 0 to 2: splint or boot, non-weight-bearing or touch weight-bearing per surgeon, elevate
• •Weeks 2 to 6: removable boot, gradual weight-bearing per surgeon and stability
• •Weeks 6 to 12: out of boot, progressive strength and proprioception
• •Return to high-impact sport typically 4 to 6 months

Physiotherapy focuses on ankle range of motion, calf and intrinsic foot strengthening, balance and proprioception (single-leg stand progressions), and gait re-education. Persistent stiffness, post-traumatic osteoarthritis, and hardware-related symptoms are recognised long-term issues, particularly after intra-articular involvement.

• •BOAST 12 (UK orthopaedic consensus on ankle fracture management) - Weber classification, mortise stability assessment, and surgical decision-making for unstable patterns.
• •BOAST 4 (Open Fractures) - IV antibiotics within 1 hour, photograph and cover, no ED irrigation, urgent senior orthoplastic review.
• •NICE NG38 (Fractures, non-complex) - Ottawa Ankle Rules guide imaging; immediate weight-bearing as tolerated for non-surgical unimalleolar fractures; surgery on the day of injury or next day where indicated.
• •AIM Trial (Willett et al., JAMA 2016) - close contact casting gave broadly similar functional outcomes to surgery in selected over-60s with unstable patterns.
• •NICE NG89 - VTE risk assessment is required in lower-limb immobilisation; pharmacological prophylaxis is considered when VTE risk outweighs bleeding risk.

• •Know the Ottawa Ankle Rules verbatim (NICE NG38). The weight-bearing limb is an AND criterion: unable at the scene AND unable in the ED for 4 steps.
• •Weber A/B/C with one-line stability prediction is the highest-yield classification; always palpate the entire fibula in any apparently isolated medial malleolus injury to rule out Maisonneuve.
• •The mortise view is essential for talar shift and medial clear space (widening greater than 4 mm or greater than superior clear space suggests deltoid disruption).
• •Posterior malleolus: the greater than 25 percent rule is exam shorthand; modern UK decision-making is CT-based and centres on fragment morphology, articular step, talar subluxation, and posterior incisura/PITFL involvement.
• •Open fracture = BOAST 4: IV antibiotics within 1 hour, photograph, saline gauze, splint, urgent senior orthoplastic review. Do NOT irrigate in ED.
• •Fragility ankle fractures carry hip-fracture-level mortality risk in some series - manage in a fragility fracture pathway (NICE CG146/NOGG, falls assessment). AIM Trial supports close contact casting in selected over-60s.