High Ankle Sprain: Risks and Prognosis Everyone Who Twists Their Ankle Should Know

A high ankle sprain is a form of syndesmotic injury that disrupts the internal stability of the ankle. This stability is supported mainly by the anterior and posterior tibiofibular ligaments and the interosseous membrane, and the injury is usually caused by sudden external rotation and excessive dorsiflexion of the ankle from an outside force. Managing and following up this injury matters, because it can lead to long absences from training, may even require surgical intervention, and is associated with long-term ankle dysfunction.

Stability is maintained jointly by the bony and ligamentous relationship between the distal tibia and fibula. The fibula sits within a concave triangular groove (the notch) of the tibia, and the anterior inferior tibiofibular ligament (AITFL), the interosseous ligament (IOL), the interosseous membrane, the posterior inferior tibiofibular ligament (PITFL), and the inferior transverse tibiofibular ligament together form the syndesmotic complex. The deltoid ligament also contributes to the stability of the syndesmosis.

Epidemiology

• A high ankle sprain accounts for roughly 1 to 10 percent of all ankle sprains, and may be more common in contact sports, at about 25 to 35 percent.

Etiology

• The main mechanisms include forced external rotation or excessive dorsiflexion of the ankle, causing the talus to press against the fibula and tear the syndesmotic ligaments.
• The pathology is impaired stability of the syndesmosis, which in turn leads to fibular problems.

Risk factors

• It is common in sports with high-speed collisions, artificial surfaces, uneven terrain, and high-torque cutting and jumping forces, forces that can drive dorsiflexion and external rotation of the foot relative to the ankle and tibia.
• Examples include football, American football, basketball, rugby, skiing, and ice hockey.

Commonly associated conditions

• Fibular or medial malleolar fracture
• Supination-external rotation or pronation-external rotation pattern fractures
• Anterior talar fracture or occult talar dome fracture

History

• A mechanism of ankle sprain, including a fixed foot with forced external rotation or dorsiflexion
• Symptoms may include:
  • Deep pain in the ankle, especially at the anterior tibiofibular ligament
  • Pain that worsens with walking, particularly during weight-bearing
  • Difficulty walking on stairs or uneven ground
  • A sense of chronic instability that may appear after the acute phase

Physical examination

• Palpation findings:
  • Localized tenderness at the anterior tibiofibular ligament and the interosseous membrane
• Specific tests:
  • Squeeze test: compressing the mid-shaft of the tibia and fibula provokes pain above the ankle
  • External rotation test: with the ankle held in dorsiflexion, applying an external rotation force to the foot may provoke pain
  • Dorsiflexion maneuver: pain worsens with dorsiflexion
• Be careful to distinguish it from other ligament injuries, such as an anterior talofibular ligament injury

Differential diagnosis

• Anterior talofibular or calcaneofibular ligament injury (a typical low ankle sprain)
• Ankle fracture (such as a medial, lateral, or posterior malleolar fracture)
• Deltoid ligament injury
• Talar dome injury or talar bone bruise
• Tibiofibular interosseous membrane injury or diastasis

Diagnostic tools

• Imaging studies:
  • Standard ankle radiographs to assess for a fracture or increased syndesmotic width
  • Stress radiographs: images under stress to assess syndesmotic stability
  • MRI: to detect soft-tissue injury, especially of the anterior tibiofibular ligament and interosseous membrane, and any associated injuries
  • Ultrasound: can quickly assess ligament integrity

Initial treatment

• Conservative therapy:
  • RICE principle: Rest, Ice, Compression, Elevation of the affected limb
  • Reduce activity and provide support, such as an air walking boot or an ankle brace
  • Use non-steroidal anti-inflammatory drugs (NSAIDs) to ease pain and inflammation
• Rehabilitation phases:
  • Days 1 to 4:
    • Non-weight-bearing, with crutches or a knee scooter; a removable walking boot to reduce swelling, pain, and inflammation
    • Gentle manual resistance exercises, active-assisted exercises, and passive exercises as tolerated
  • Days 4 to 7:
    • Protected weight-bearing with crutches, gradually reducing crutch use as ability allows
    • Continue exercise and resistance training along with swelling-reduction therapy, add weight-bearing exercises and seated heel raises, and add light proprioception training
  • Day 7 onward:
    • Weight-bearing as tolerated, continuing the second-phase approach
    • Begin functional exercises: double-leg heel raises and hopping, then single-leg heel raises and hopping; integrate position-specific training such as jogging, running, direction changes, jumping, and dynamic explosive movements
    • When first returning to sport, use an ankle brace and/or taping
• Further management:
  • Severe instability or an associated fracture may require considering surgical intervention, such as fixation of the syndesmosis

Medications

• Use anti-inflammatory drugs (NSAIDs) to ease acute pain and reduce inflammation
• During the acute pain phase, a short course of analgesics may be prescribed
• Some patients may need a local injection, such as a corticosteroid, to relieve stubborn pain, but this should be used with caution to avoid delaying ligament healing

Additional treatment

• Exercise training:
  • Early phase: the goal is to control swelling and pain and restore range of motion
  • Middle phase: focus on strengthening syndesmotic stability, especially the lower-leg muscles (gastrocnemius and tibialis anterior)
  • Late phase: sport-specific functional training to restore full-speed running, jumping, and cutting ability
• Bracing:
  • Use an ankle brace or walking boot for protection
  • Severe cases may require avoiding weight-bearing and walking with crutches

Surgery

• Indicated when conservative treatment fails or the syndesmosis is severely unstable
• Surgical options include:
  • Using screws or a suture-button device to repair and stabilize the syndesmosis
  • Severe injuries may require addressing other ligament or fracture injuries at the same time
• Recovery after surgery is usually longer, including delayed weight-bearing and supervised physical therapy

Follow-up

• Follow up every 1 to 2 weeks in the early phase to assess pain, range of motion, and stability
• Use imaging to confirm healing progress, especially in surgical cases
• Long-term follow-up may be needed to watch for chronic instability or dysfunction
• Regular assessment can help guide a gradual return to sport or daily activities

Prognosis

• The prognosis depends on the severity of the injury and the treatment approach:
  • Mild sprains return to normal activity within a few weeks
  • Moderate to severe injuries may take several months to fully recover, especially in surgical cases
• If not managed properly, it may lead to:
  • Chronic ankle instability
  • Reduced sports performance
  • An increased long-term risk of arthritis

References

• https://my.clevelandclinic.org/health/diseases/22249-high-ankle-sprains
• https://www.orthobullets.com/foot-and-ankle/7029/high-ankle-sprain-and-syndesmosis-injury
• J Am Acad Orthop Surg. 2015 Nov;23(11):661-73.
• Foot Ankle Spec. 2020 Oct;13(5):420-430.

Further reading

• Rehabilitation exercises
• Sports injury overview
• PRP prolotherapy
• Rehabilitation exercise prescription
• Pain management