Low Ankle Sprains (Lateral Ankle Ligament Injuries)

MD Murat BIRINCI· Umraniye Training and Research Hospital, Department of Ortopaedics and Traumatology, Istanbul
Apr 22, 2026

SUMMARY

Low ankle sprains are common twisting injuries, particularly in athletes, and represent the most frequent cause of missed athletic participation.
They most commonly involve the anterior talofibular ligament (ATFL), the weakest component of the lateral ligament complex.
Diagnosis is primarily clinical, with radiographs indicated only when Ottawa Ankle Rules criteria are met.
Treatment is usually nonoperative, emphasizing early functional rehabilitation, while surgery is reserved for chronic instability or associated pathology.


EPIDEMIOLOGY

Incidence

• Most common sports-related injury
• >90% of all ankle sprains

Demographics

• Common in all athletic populations
• Most frequent injury in dancers
• High incidence in indoor court sports (basketball, volleyball)

Risk Factors

Patient-related
• Limited ankle dorsiflexion
• Decreased proprioception
• Balance deficits
• Prior ankle sprain

Environmental
• Indoor court surfaces
• Jumping and cutting sports


ETIOLOGY & PATHOPHYSIOLOGY

Mechanism of Injury

Inversion injury, typically on a plantarflexed foot

Ligament Involvement

• (Anterior talofibular ligament) ATFL – most commonly injured
• (Calcaneofibular ligament) CFL – second most common
• (Posterior talofibular ligament) PTFL – rarely involved

Pathophysiology

• Recurrent sprains may lead to functional or mechanical instability
• Loss of ligamentous restraint alters ankle biomechanics
• Associated neuromuscular deficits contribute to chronic instability


ANATOMY

Lateral Ligament Complex

ATFL

  • Primary restraint to anterior talar translation

  • Tight in plantarflexion

  • Most vulnerable to injury

CFL

  • Stabilizes ankle and subtalar joints

  • Tight in dorsiflexion

  • Injury contributes to subtalar instability

PTFL

  • Strongest lateral ligament

  • Rarely injured except in severe trauma


CLASSIFICATION

Clinical Grading of Low Ankle Sprains

Grade

Ligament Injury

Swelling/Ecchymosis

Weight Bearing

I

No tear

Minimal

Normal

II

Stretch/partial tear

Moderate

Mild pain

III

Complete tear

Severe

Severe pain


PRESENTATION

Symptoms

• Pain with weight bearing
• Swelling and ecchymosis
• Recurrent instability
• Catching or popping sensation (suggests intra-articular pathology)

Physical Examination

• Focal tenderness over involved ligaments
Anterior drawer test

  • Assesses ATFL

  • Best performed in plantarflexion

Talar tilt test

  • Excessive inversion (>15°) compared with contralateral side indicates ATFL and CFL injury


IMAGING

Radiographs

Indications (Ottawa Ankle Rules):
• Inability to bear weight
• Medial or lateral malleolar tenderness
• 5th metatarsal base tenderness
• Navicular tenderness

Views
• AP, lateral, and mortise ankle views (weight-bearing preferred)

MRI

Indications
• Persistent pain after 6–8 weeks
• Suspected osteochondral injury
• Peroneal tendon pathology

Findings
• Lateral ligament attenuation or tear
• Bone bruising in severe sprains


TREATMENT

Nonoperative (First-Line)

Initial Management
• The traditional RICE protocol has largely been replaced by the PEACE & LOVE (Protect, Elevate, Avoid anti-inflammatories, Compress, Educate and Load, Optimism, Vascularization, Exercise)
PEACE & LOVE protocol for acute injury management, emphasizing protection, patient education, and early functional recovery
Short-term immobilization using a walking boot or brace, as needed for pain control and protection
Early protected weight bearing, progressed as symptoms allow
Physical therapy, focusing on:

·       Peroneal muscle strengthening

·       Proprioception and balance training

Immobilization
• Short period (≈1 week) in walking boot or brace
• Grade III injuries may require up to 10 days of casting

Rehabilitation
• Early range-of-motion exercises
• Progressive strengthening
• Proprioceptive and balance training
• Peroneal muscle strengthening

Outcomes
• Early functional rehab allows fastest return to activity
• Supervised PT improves early outcomes
• No reliable predictors of chronic instability


Operative

Indications
• Chronic pain and instability despite extensive nonoperative treatment
• Symptomatic osteochondral lesions
• Bony avulsion fractures

Procedures
Modified Broström–Gould

  • Anatomic repair of ATFL ± CFL

  • Reinforced with extensor retinaculum

Nonanatomic reconstructions

  • Tendon transfers (Evans, Chrisman–Snook)

  • Reserved for failed prior repairs


COMPLICATIONS

• Chronic ankle instability
• Osteochondral lesions of the talus
• Peroneal tendon pathology
• Missed fractures (5th metatarsal, talus, calcaneus)
• Neuropathic pain due to stretch neurapraxia


PROGNOSIS

• Pain decreases rapidly within first 2 weeks
• 5–33% report residual symptoms at 1 year
• Increased risk of recurrent sprains in both ankles