Foot / Ankle

Lateral Ankle Sprain

Name: Lateral Ankle Sprain
Creator: Dr. Kwang Lee

발목 염좌

Lateral ankle ligament injury — ATFL most commonly involved. Most frequent sports injury

Written and edited by Dr. Kwang Lee, D.C., L.Ac. · Updated 2026-10-04

How common: Very common
Typical age: Ages 10–50

What is it?

Ankle inversion injury damages lateral ligament complex (ATFL > CFL > PTFL). ATFL is most vulnerable

Commonly affected: ATFL (anterior talofibular ligament), CFL (calcaneofibular ligament), PTFL (posterior talofibular ligament)

How it develops

Inversion MechanismAnkle inversion + plantarflexion combination → excessive tension on lateral ligaments
ATFL InjuryATFL (anterior talofibular ligament) injured first and most commonly (anterior lateral ankle pain)
CFL Concurrent InjurySevere inversion may additionally tear CFL (calcaneofibular ligament), causing inferior lateral ankle pain
Joint InstabilityAnkle instability proportional to ligament damage (Grade 1: microtears → Grade 3: complete tear)

Symptoms

Lateral Ankle PainPain around lateral malleolus — ATFL: anterior, CFL: inferior
Immediate SwellingLateral ankle swelling immediately after inversion injury — ligament rupture hemorrhage
Difficulty Weight BearingWalking difficulty due to pain (Ottawa Ankle Rules criterion)
BruisingBruising over lateral ankle and lateral foot (appears within 48-72 hours)

How it is examined

Anterior Drawer Test (ATFL)Anterior pull on ankle in plantarflexion → excessive anterior translation if ATFL torn
Inversion Stress Test (CFL)Apply inversion stress → excessive varus tilt if CFL torn (talar tilt)
Ottawa Ankle RulesAssess fracture risk: tenderness over posterior/distal 6cm of malleoli OR inability to weight bear → X-ray indicated
Fibula/5th MT Base TendernessTenderness at fibula tip or 5th metatarsal base → avulsion fracture differential

Imaging

Selective X-ray based on Ottawa Ankle Rules

Ligament injury itself not visible on X-ray
Distal fibula avulsion fracture
5th metatarsal base fracture (Jones/avulsion)
Talar osteochondral lesion (high resolution)

Assess ligament damage, cartilage injury, talar osteochondral lesion — for chronic instability or pre-surgical

ATFL/CFL T2 hyperintensity or discontinuity (tear)
Talar osteochondral lesion may coexist
Peroneal tendon injury assessment

Non-surgical care

RICE ProtocolAcute phase: Rest, Ice, Compression, Elevation
Functional RehabilitationEarly weight bearing and balance training — superior to complete immobilization. Balance board training
Ankle BraceLateral ankle support brace (lace-up) — prevents re-injury and provides functional support
Proprioception TrainingBalance exercises to restore proprioception — essential for preventing recurrence

Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.

When surgery is considered

Chronic ankle instability (conservative treatment fails >3 months), grade 3 acute injury in athletes

Procedures that may be discussed

Brostrom procedure (anatomic ligament repair) — gold standard
Modified Brostrom-Gould (inferior extensor retinaculum augmentation)
Ligament reconstruction (with graft)

Outlook

85-90% acute sprains improve with conservative treatment in 2-4 weeks. Proprioception training is key to preventing recurrence (40-70% re-injury rate)