What it is

A high ankle sprain, also known as a syndesmosis injury, is a more severe injury than a typical “rolled” ankle sprain, involving the ligaments that connect the tibia and fibula (the lower leg bones) above the ankle joint. These ligaments stabilise the ankle mortise during weight-bearing and turning, which is known as the “syndesmosis”. It is also known as a syndesmotic injury, referring to the syndesmosis, the fibrous joint formed by these ligaments.

Injury typically occurs when the foot is planted and the leg rotates outward, often due to forceful twisting or rotation of the leg. It typically occurs during impact sports such as football, basketball, and soccer. People feel pain higher up above the ankle joint line, particularly with turning, pushing off, or stepping downhill. Swelling may be modest compared with a lateral sprain, which can mislead early care.

High ankle sprains take longer to recover because these ligaments are loaded with every step, and potential recovery times can be as long as 6-8 weeks or more. Severe injuries can widen the joint and often require surgical stabilisation. In severe cases, a fracture of the tibia or fibula can accompany a high-ankle sprain. With timely diagnosis and a disciplined plan, most athletes regain full function.

What happens when it occurs

External rotation and dorsiflexion stress the syndesmosis.

Microscopic or macroscopic fibre disruption reduces the ability of the tibia and fibula to grip the talus.

Protection from rotation and dorsiflexion early allows healing; progressive loading then restores stability.

Common causes and risk factors

  • Cutting and tackling in field sports, as well as awkward landings and collisions. Occurs when the foot is planted and twists violently
  • Prior ankle injury, limited calf length, poor change-of-direction mechanics
  • Contact sports, where extreme upward bending of the ankle can lead to injury, are often seen in sports such as football or rugby, where tackling is a common technique.
  • Incorrect footwear with limited ankle support
  • Common in sports such as football, soccer, basketball, and ice skating due to the twisting motions and impacts that occur.

Who is most affected?

Field and court athletes, alpine and field-based running sports, and workers who carry loads on uneven ground.

Typical symptoms

  • Pain above the ankle that is worse with twisting or pushing off
  • Swelling and bruising higher up the leg, rather than around the ankle
  • Difficulty with walking or full weight bearing, especially with stairs and downhill walking
  • A sense that the ankle separates during rotation

When to seek care

Early assessment is crucial if pain is located above the ankle joint line, if walking with a normal pattern is not possible within a few days, or if there is any sensation of joint separation.

How we diagnose

A doctor or physiotherapist may recommend imaging tests to confirm the diagnosis and assess the extent of the ligament damage. Clinical tests include the external rotation test, squeeze test, and dorsiflexion-compression test. Weight-bearing X-rays are used when instability or an associated fracture is suspected; MRI defines the extent of ligament injury. Severe diastasis needs orthopaedic input.

Severity and Recovery

Grades: High ankle sprains are classified into three grades, from:

  • A stretched ligament (Grade I) to
  • A partially torn (Grade II) or
  • Completely torn (Grade III) ligament

Longer Recovery: These injuries typically have longer recovery times compared to typical low ankle sprains, often lasting 6-8 weeks or more.

Functional Impairment: Can lead to long-term functional instability if left untreated or not properly managed.

Imaging

X-rays are very important. A broken bone must be looked for. Three views of the ankle, including the whole leg, are needed. A fracture on the back portion of the tibia may indicate an injury to the high ankle ligaments. It is also important to look for increased space between the tibia and the fibula, as the high ankle ligaments keep these bones in place. Special imaging techniques, such as MRI or CT scans, may be used to assess the relationship between the tibia and the fibula. MRI provides excellent soft tissue contrast and direct visualisation of the syndesmotic ligaments

Management

Conservative treatment is generally preferred for stable syndesmosis injuries. Initially, it includes rest, ice, and immobilisation, followed by limited weight-bearing with the application of joint-protective devices, such as a walker boot or functional brace. As the patient improves, strengthening and agility exercises can aid in returning to normal activities and athletic competition.

  • Essential for rehabilitation to control pain, regain motion, strengthen muscles, improve balance, and gradually return to normal function.
  • High ankle sprains typically have longer recovery times than low ankle sprains, depending on the severity (grade) of the sprain.
  • Protection from rotation and dorsiflexion with a boot or brace in the early weeks in smaller grade tears
  • Graduated weight bearing, then calf and peroneal strength in neutral alignment
  • Balance and anti-rotation control progressing to cutting and acceleration.

In patients with unstable syndesmotic injury or frank diastasis of the syndesmosis, surgical reduction with placement of trans-syndesmotic screws (ORIF) or a tight-rope procedure may be indicated. This is usually followed by casting for 6 weeks and subsequent rehabilitation.

  • Early surgical intervention ensures adequate reduction of the ankle mortise and positions the injured ligaments for optimal healing.
  • Delayed surgery (due to initially missed diagnosis or loss of reduction in a conservatively treated patient) is generally associated with less robust healing.
  • Surgical treatment for chronic syndesmotic injuries has been reported to improve symptoms in the majority of patients, with residual pain and dysfunction in 14 to 20%.

Rehabilitation milestones

Phase 1, weeks 0-2: Boot protection, deload walking plan, and isometrics in neutral.

Phase 2, weeks 2 to 6: progressive weight bearing, calf and peroneal strength, balance drills.

Phase 3, weeks 6 to 10: anti-rotation strength, straight-line jog to run, careful change of direction.

Phase 4, weeks 10 to 16: full agility, contact progressions, return to play testing.

Readiness to progress

  • Pain-free jog and cut in a figure-of-eight
  • Symmetry in single-leg calf raise endurance and hop tests
  • No apprehension with anti-rotation drills

Prevention

  • Technique coaching for cutting and tackling
  • Calf and peroneal strength
  • Controlled exposure to rotation and dorsiflexion loads in training

Australia snapshot

  • High ankle sprains account for a minority of ankle sprains overall, commonly near one in ten.
  • Time away from sport is longer than a standard lateral sprain
  • Twisting and cutting sports dominate the local caseload

Latest insights

Do not be guided solely by swelling; modest swelling can conceal a significant syndesmotic injury.

Protect against rotation early, then build anti-rotation strength and balance before cutting.

Use imaging to confirm stability when clinical signs persist.

Frequently Asked Questions

Timeframes depend on the grade and your starting capacity. Mild injuries often settle within weeks when loading is matched to tolerance. Moderate injuries take longer to recover from, as strength and control are rebuilt after a period in a splint or boot. Severe injuries or those with instability need a longer block and closer supervision. Progress is criteria-based and relies on the patient attending treatment and remaining compliant with their rehabilitation plan.

Yes, if pain during activity stays at or below 3 out of 10 and does not worsen the next morning. Reduce volume and intensity, maintain a tidy technique, and avoid movements that exacerbate symptoms.

Imaging is based on a universal criterion, known as the “Ottawa rules’, which guide a clinician’s decision-making for imaging. Imaging helps when red flags are present, progress stalls after two weeks, or instability or a tear is suspected. Your clinician will advise on whether an X-ray, ultrasound, or MRI is most suitable for your condition based on your presentation.

Use a brace or tape during the early return or on uneven ground. Remove it for controlled strength and balance work so that muscles can relearn their job. A period of 3 months is usually indicated by research to protect the ankle ligaments during their initial phase of healing and ligament remodelling after injury.

Ice helps early when swelling and pain dominate. Heat helps later when stiffness is the main issue.

When next‑morning pain is 2 out of 10 or less, strength is within 90% of the other side, and you pass the functional test for this condition, such as single‑leg hops, figure‑of‑eight runs, or step‑downs. This depends on the severity or grade of the injury and the patient’s compliance in completing their rehabilitation.

Cut the next session’s volume by 20 to 30 per cent, keep strength work, and retest the following day. Progress again when baseline settles. Your clinician will guide you. 

They can unload sensitive tissue early. Keep them while strength and control improve, then review fit and need. These are typically not required.

Most people continue working on tasks and making standing adjustments. Drive when you can load and move the ankle safely and brake firmly without pain. Your clinician will guide you.