Ankle and Foot Injury

Key considerations: Open fracture, Compartment syndrome (foot), Lisfranc injury

Cannot miss

Open fracture
Compartment syndrome (foot)
Lisfranc injury
Talar fracture with avascular necrosis risk
Pilon fracture
Achilles tendon rupture

Likely diagnoses

Ankle sprain (lateral ligament)
Lateral malleolus fracture
Fifth metatarsal fracture
Metatarsal stress fracture
Plantar fasciitis
Contusion

Red flags

Inability to bear weight (4 steps)
Bony tenderness at posterior malleoli
Bony tenderness at navicular or base of 5th metatarsal
Foot deformity suggesting dislocation
Neurovascular compromise distally
High-energy mechanism
Open wound near fracture

Workup

history: Mechanism: inversion (lateral sprain/fracture), eversion, direct blow, fall from height; Weight-bearing status: able to walk 4 steps?; Swelling, bruising progression; Pop or snap heard (Achilles rupture, ligament tear); Prior ankle injuries / chronic instability; Return to activity requirements; exam: Ottawa Ankle Rules assessment — determines need for X-ray; Palpate: lateral malleolus, medial malleolus, posterior edge of distal 6cm of both malleoli; Palpate: base of 5th metatarsal, navicular bone; Squeeze test: proximal fibula squeeze causes distal pain (Maisonneuve fracture); Anterior drawer test: ATFL integrity (anterior talofibular ligament); Thompson test: squeeze calf — no plantar flexion = Achilles rupture; Neurovascular exam: dorsalis pedis, posterior tibial pulses, sensation; Lisfranc exam: pain with passive pronation-abduction of midfoot; labs: Not typically needed for isolated ankle/foot injuries; imaging: Ottawa Ankle Rules determine need for X-ray:; • Ankle X-ray if: bone tenderness at posterior edge of distal 6cm of either malleolus, OR inability to bear weight 4 steps immediately and in ED; • Foot X-ray if: bone tenderness at base of 5th metatarsal OR navicular, OR inability to bear weight 4 steps; CT: complex fracture patterns, Lisfranc injury assessment, surgical planning; MRI: occult fracture, ligament injury, Achilles tendon (usually outpatient); bedside: Ottawa Rules assessment (ankle and foot); Neurovascular exam; Point tenderness localization

Management

immediate: Assess neurovascular status — document pulses, sensation, motor; Reduce dislocations immediately if neurovascular compromise; Open fractures: tetanus prophylaxis, IV antibiotics (cefazolin), emergent orthopedic consult; Splint unstable fractures; general: RICE: Rest, Ice, Compression, Elevation; Ankle sprain: weight-bearing as tolerated, ankle brace or air stirrup; Fractures: posterior splint or stirrup splint, non-weight-bearing, orthopedic follow-up; Pain control: NSAIDs (ibuprofen, naproxen), acetaminophen; specific: diagnosis: Lateral Ankle Sprain; steps: Grade I-II: functional rehabilitation, ankle brace, weight-bearing as tolerated; RICE protocol for 48-72 hours; Early mobilization improves outcomes over prolonged immobilization; Physical therapy referral for recurrent sprains; Grade III (complete tear): consider short-leg cast or boot, orthopedic referral; diagnosis: Lateral Malleolus Fracture; steps: Isolated infra-syndesmotic (Weber A): weight-bearing boot, orthopedic follow-up; Trans-syndesmotic (Weber B): short leg splint, non-weight-bearing, orthopedic follow-up within 1 week; Supra-syndesmotic (Weber C): unstable, non-weight-bearing, likely needs surgery; diagnosis: Fifth Metatarsal Fracture; steps: Zone 1 (tuberosity avulsion): hard-soled shoe, weight-bearing as tolerated; Zone 2 (Jones fracture): short leg cast or boot, non-weight-bearing 6-8 weeks, HIGH risk of non-union; Zone 3 (shaft): walking boot, weight-bearing as tolerated; diagnosis: Lisfranc Injury; steps: Often missed on initial X-ray — maintain high suspicion with midfoot pain; Weight-bearing X-rays or CT for definitive diagnosis; Non-weight-bearing splint, orthopedic consult; Most require surgical fixation; diagnosis: Achilles Tendon Rupture; steps: Positive Thompson test (no plantar flexion with calf squeeze); Posterior splint in slight plantar flexion; Orthopedic referral within 1 week; Operative vs non-operative treatment decision by orthopedics

Disposition

admit: Open fracture (emergent OR); Dislocation unable to be reduced; Compartment syndrome; Neurovascular compromise; discharge: Sprain with functional weight-bearing; Stable fracture with appropriate splinting; Orthopedic follow-up arranged within 1 week; Written instructions for RICE, weight-bearing status, and return precautions; Return if: worsening pain, numbness/tingling, toes turning blue/white, cast too tight; consults: Orthopedics: all fractures requiring reduction or surgery, Lisfranc injury, Achilles rupture; Orthopedics emergent: open fracture, irreducible dislocation, compartment syndrome

Clinical pearls

Ottawa Ankle Rules have ~98% sensitivity for fractures — if negative, X-ray is not needed. This saves time and radiation
Jones fracture (5th metatarsal Zone 2) has HIGH non-union rate — these need strict non-weight-bearing and close orthopedic follow-up
Lisfranc injury is commonly missed — suspect with midfoot pain, swelling, and inability to bear weight. Weight-bearing X-rays are more sensitive
Squeeze test: compress fibula at mid-calf — if pain at ankle, suspect Maisonneuve fracture (proximal fibula fracture with syndesmotic disruption) → get full-length tibia/fibula films
Achilles rupture: patient may still actively plantar flex using other tendons — Thompson test is the key clinical test

Source and review

Ottawa Ankle Rules (Stiell et al. 1992), AO Foundation Fracture Classification, AAOS Clinical Practice Guidelines. Last reviewed: 2024-11-01