Synopsis
Assess ankle trauma without missing fracture, syndesmotic instability or proximal fibular injury, use Ottawa criteria and weight-bearing imaging appropriately, and deliver early functional rehabilitation with timely escalation of unstable patterns.
- Do not begin with the label sprain: inspect deformity and skin, document pulses and nerves, palpate the entire fibula, malleoli, navicular, fifth-metatarsal base and Achilles, then test function.
- Use the Ottawa ankle and foot rules to decide first-line radiography in alert adults: posterior malleolar, navicular or fifth-base tenderness or inability to take four steps warrants films.
- Lateral sprain produces tenderness over the anterior talofibular and sometimes calcaneofibular ligaments; delayed anterior drawer or talar tilt may be more informative after acute guarding settles.
- Syndesmotic injury causes pain above the mortise with external rotation, dorsiflexion or calf squeeze and often a slower recovery than an ordinary lateral sprain.
- First-line management of an uncomplicated lateral sprain is short protection, compression and elevation followed promptly by weight-bearing as tolerated, range, strength and balance rehabilitation.
- First-line imaging for suspected unstable syndesmosis is weight-bearing ankle radiography when safe, with full-length tibia-fibula views for proximal tenderness; MRI is the reference soft-tissue test when instability remains uncertain.
- Restrict weight-bearing and arrange urgent orthopaedic review when syndesmotic diastasis, associated fracture, deltoid disruption or marked clinical instability is suspected; fixation may be required.
- Prevent recurrence with progressive peroneal and calf strength, dorsiflexion, balance, hopping and sport-specific change-of-direction work, adding taping or a brace for higher-risk return.
Key red flags
A deformed ankle, tented skin, open wound, cool foot, delayed refill or new sensory and motor loss requires immediate reduction and orthopaedic care.
Pain above the ankle joint, positive external-rotation or squeeze provocation and inability to bear weight out of proportion to swelling raises syndesmotic injury.
Tenderness along the proximal fibula or medial ankle after rotational trauma suggests a Maisonneuve pattern and requires full-leg imaging.
Bony tenderness at the posterior malleolar edges, navicular or base of fifth metatarsal, or inability to take four steps activates Ottawa radiography criteria.
Persistent severe pain, tense swelling, passive-stretch pain or worsening neurology requires compartment and occult fracture assessment.
A hot swollen ankle with fever, skin breach or bacteraemic risk needs septic-joint evaluation, not a routine sprain pathway.
Investigation priorities
Select patients who need ankle or foot radiographs after acute injury while screening for rule exclusions.
Detect malleolar, talar, fifth-metatarsal, navicular and alignment injury.
Management branches
An acute ankle injury presents without immediate need for trauma resuscitation.
- Inspect skin and alignment and document pulses, refill, sensation and motor function before stress testing.
- Apply Ottawa criteria, palpate the entire fibula and assess Achilles, midfoot and fifth-metatarsal base.
- Obtain ankle, foot or full-leg radiographs according to the anatomical findings and restrict loading until important injury is excluded.
- Reduce and escalate immediately for deformity, threatened skin or neurovascular compromise rather than waiting for routine imaging.
Fracture and unstable syndesmotic injury are unlikely and the pattern is an isolated stable lateral sprain.
- Use a supportive brace, compression, elevation and compatible analgesia, allowing weight-bearing as pain permits.
- Begin ankle range promptly, then progress calf and peroneal strength and single-leg balance.
- Advance to hopping, landing and change-of-direction tasks before full sport or hazardous work.
- Reassess in one to two weeks if weight-bearing and function are not improving or if locking and deep pain emerge.