Health condition · Clinically reviewed
Syndesmosis injury, high ankle sprain — from bracing to TightRope / screw fixation.
Injury of the distal tibiofibular syndesmosis — the "high ankle sprain". Prolonged recovery and high missed-injury rate. Modern stratified care: boot immobilisation for stable injuries; TightRope / suture-button or screw fixation for unstable ones.
Why trust this guide
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Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
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Sourced from guidance
Every claim is checked against BOFAS, NICE or peer-reviewed sources you can see at the end.
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Current for 2026
Reflects current UK guidance on stratified care, TightRope / suture-button and screw fixation.
Key facts
Syndesmosis injury at a glance.
The essentials, in plain English — what the syndesmosis is, why a high ankle sprain behaves differently, and how modern stratified care decides who needs surgery.
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Definition
A syndesmosis injury is damage to the distal tibiofibular syndesmosis — the strong ligament complex that binds the tibia and fibula just above the ankle.
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The high ankle sprain
Classically seen in football, rugby and skiing — a twisting or external rotation force at the ankle, often mistaken for an ordinary lateral sprain.
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Key clinical signs
The squeeze test and external rotation stress test are the two examination findings that most reliably raise suspicion.
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Imaging tier
Weight-bearing X-ray with stress views plus MRI is the modern workup — plain films alone miss unstable injuries.
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Stratified by stability
The West Point classification separates stable from unstable syndesmosis injuries — and drives whether surgery is needed.
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Modern fixation
TightRope / suture-button flexible fixation is now the leading operative option for unstable injuries; screw fixation remains an alternative.
Why this guide matters
Not just an ankle sprain.
The high ankle sprain is the classic missed injury — often mistaken for a routine sprain, but with a much longer recovery and a real risk of chronic instability if under-treated.
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Stability decides the plan
Stable injuries settle in a boot and rehab; unstable ones need surgical fixation — the West Point classification separates the two.
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Reduction beats fixation type
Whether TightRope or screw, the single strongest predictor of a good outcome is anatomical reduction of the mortise.
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Don’t miss the Maisonneuve
Always palpate the proximal fibula in an "ankle sprain" that seems too painful — a Maisonneuve fracture completely changes management.
How the diagnosis is made
From twisted ankle to a clear plan.
The steps a UK GP, ED or sports clinician will normally follow, in order — so you know what to expect and why.
Phase 1 · Recognising
Mechanism, squeeze and external rotation tests
Phase 2 · Confirming
Weight-bearing X-ray, MRI and fracture screen
Phase 3 · Managing
Foot and ankle surgical opinion
- 01
Recognising
Mechanism of injury
A twisting or external rotation force at the ankle — a football tackle, a rugby ruck or a ski binding failing to release — is the classic story.
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Recognising
Squeeze test
Compressing the tibia and fibula at mid-calf reproduces pain at the distal syndesmosis — a simple but useful bedside sign.
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Recognising
External rotation stress test
The knee is flexed and the foot externally rotated — pain at the anterior syndesmosis strongly suggests injury.
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Confirming
Weight-bearing X-ray + comparison
Standing views of both ankles side-by-side reveal subtle widening of the tibiofibular clear space that supine films will miss.
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Confirming
MRI ankle for occult instability
MRI is the reference standard for grading ligament injury and picking up subtle instability not seen on plain films.
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Confirming
Assess coexisting fracture
Always palpate the proximal fibula — a Maisonneuve fracture pattern completely changes management and needs urgent orthopaedic review.
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Managing
Foot & ankle surgery consultation
Unstable injuries need timely specialist review — surgical fixation is time-sensitive and outcomes depend on anatomical reduction.
Typical timeline: 1–2 weeks from injury to a stability-based plan.
Symptoms
What a high ankle sprain actually feels like.
The pattern is more telling than any single symptom — pain higher up than a routine sprain, pain on external rotation and a slow, stuttering recovery.
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Anterior distal tibiofibular pain
Pain and tenderness just above the ankle at the front — the anterolateral syndesmosis is where symptoms concentrate.
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Lateral ankle pain
A more diffuse lateral ankle ache that overlaps with — and is often misdiagnosed as — a routine lateral sprain.
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Local swelling
Swelling above the level of the lateral malleolus, rather than around it, is a helpful pointer to the syndesmosis.
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Difficulty weight-bearing
Sharp pain on push-off and an inability to fully weight-bear — often more disabling than the swelling would suggest.
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Pain on external rotation
Rotating the foot outwards reproduces the pain — a classic mechanism-specific symptom.
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Limping
A protective limp that persists well beyond the timescale expected for a low ankle sprain.
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Recurrent symptoms
A prior "ankle sprain" that never fully settled and keeps flaring — a common presentation of missed syndesmosis injury.
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Red flag
Syndesmosis injury with a proximal fibula fracture — the Maisonneuve pattern — needs urgent surgical review, not conservative care.
Treatment
How syndesmosis injuries are treated in the UK.
A stratified approach — boot immobilisation and rehab for stable injuries; TightRope, suture-button or screw fixation for unstable ones, with combined ORIF when the fibula is also fractured.
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Non-weight-bearing boot immobilisation
A period of protected non-weight-bearing in a walker boot is first-line for stable syndesmosis injuries — often 6 weeks before progressive loading.
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Structured rehab and return-to-sport
A staged rehab programme with objective return-to-sport criteria — the key to avoiding chronic instability after conservative care.
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Peroneal strengthening
Targeted peroneal and dynamic stabiliser work to restore active control of the mortise as the ligaments heal.
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Ankle brace
A functional brace for the return-to-sport phase — mechanical support while proprioception and strength catch up.
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TightRope / suture-button flexible fixation
The modern operative choice for unstable injuries — a strong flexible cord that permits micromotion and often avoids a second procedure.
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Syndesmotic screw fixation
The traditional operative option — one or two cortical screws hold the mortise while ligaments heal, with screw removal often planned.
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Combined syndesmotic + fibular ORIF
When syndesmosis injury coexists with an unstable fibula fracture, both are addressed together at a single operation.
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Delayed reconstruction (chronic instability)
For patients presenting late with chronic instability — reconstruction of the syndesmotic ligaments with graft or augmentation.
What this guide is based on
The sources behind every claim on this page.
UK and international specialist society standards, current at the time of last review.
Key references
Guidelines and standards we relied on.
A quiet reminder
This guide is for information, not medical advice.
Your GP, physiotherapist or foot and ankle team knows your history and can tell you which parts apply to you. If in doubt, get seen.
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British Orthopaedic Foot and Ankle Society (BOFAS). Standards for the management of ankle injuries.
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NICE MSK guidance on soft-tissue ankle injuries and referral pathways.
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American Orthopaedic Foot & Ankle Society (AOFAS). Position statements on syndesmotic fixation.
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Sports Medicine Australia. Consensus on the high ankle sprain — diagnosis and return to sport.
Red flags
When a high ankle sprain needs urgent review.
Most syndesmosis injuries progress predictably. These are the patterns that change the plan — and where a foot and ankle surgical opinion should not wait.
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Maisonneuve fracture
Syndesmosis injury with a proximal fibula fracture — an unstable pattern that needs urgent surgical review, not a boot alone.
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Chronic syndesmosis instability
Persistent pain, giving-way and mortise widening months after the original injury — often needs delayed reconstruction.
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Failed conservative therapy
Pain and dysfunction persisting beyond a well-conducted rehab programme — reconsider stability and imaging.
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Post-op malreduction
Poor anatomical reduction at fixation is the biggest single predictor of a bad outcome — a threshold for revision.
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Hardware failure
Broken screws, cut-out or loose suture-buttons — needs surgical review to protect the reduction.
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Post-op infection
Increasing pain, redness, wound discharge or fever after fixation — same-day contact with the surgical team.
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Recurrent injury
A repeat twisting injury on a previously reconstructed syndesmosis — image early to protect the fixation.
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Post-traumatic ankle arthritis
Longer-term joint pain, stiffness and swelling after syndesmosis injury — a well-recognised late complication needing specialist review.
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Concomitant osteochondral lesion
A talar dome cartilage injury sustained at the same time — often the reason for ongoing pain after a well-reduced syndesmosis.
Living with it
A slow injury, but a very treatable one.
Four things that make the biggest difference day to day — respect for the timeline, staged rehab, brace support and re-review if things stall.
A quiet reminder
Rushing back is how re-injury happens.
Objective, milestone-based progression through rehab beats an arbitrary calendar every time — especially in contact and cutting sports.
- 01 Rehab
Respect the timeline
Syndesmosis injuries take longer than a lateral sprain — six weeks in a boot and months of rehab is normal, not a setback.
- 02 Footwear
Support during return
A functional ankle brace during the return-to-sport phase adds mechanical support while strength and proprioception rebuild.
- 03 Load
Progress in steps, not leaps
Objective, milestone-based progression through jogging, cutting and contact — leapfrogging stages is how re-injury happens.
- 04 Reviews
Reassess if things stall
Persistent pain, giving-way or a feeling of instability warrants re-imaging and a foot and ankle surgical opinion.
Frequently asked
Everything we get asked about the high ankle sprain.
Quick answers on diagnosis, TightRope versus screw fixation, recovery timelines and when to seek help.
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What is a syndesmosis injury?
It is an injury to the distal tibiofibular syndesmosis — the ligament complex that holds the tibia and fibula together just above the ankle. It is commonly called a "high ankle sprain" and behaves very differently from a routine lateral ankle sprain.
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How is it different from a normal ankle sprain?
A lateral (low) ankle sprain injures the ligaments on the outside of the ankle after an inversion twist. A syndesmosis (high) sprain injures the ligaments above the ankle after an external rotation force, hurts higher up, takes much longer to settle and — if unstable — often needs surgery.
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Do I need surgery for a high ankle sprain?
Not always. Stable injuries are managed with a period of non-weight-bearing in a walker boot and structured rehab. Unstable injuries — including any with a Maisonneuve fracture pattern — typically need surgical fixation with a TightRope / suture-button or a syndesmotic screw.
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What is a TightRope fixation?
A TightRope or suture-button is a strong flexible cord that holds the tibia and fibula in the correct position while the ligaments heal. It permits small physiological micromotion and often avoids the second operation that a syndesmotic screw sometimes requires.
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How long is recovery?
Recovery is genuinely prolonged — typically six weeks in a boot followed by months of graded rehab, with return to contact sport often at four to six months. Rushing the timeline is a common cause of chronic instability.
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What is a Maisonneuve fracture?
It is a syndesmosis injury combined with a fracture of the proximal fibula, near the knee. It is an unstable pattern that must not be missed — always palpate the proximal fibula in anyone with an "ankle sprain" that seems too painful, and refer urgently for surgical review.
Related content
Keep reading.
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Ankle sprain
The routine lateral ankle sprain — and how it differs.
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Chronic ankle instability
When ankle sprains keep happening — assessment and care.
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Foot MRI
The reference-standard scan for occult ankle instability.
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All conditions
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Musculoskeletal MRI
Related diagnostic test.
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X Ray
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Cortisone Shots
Related treatment option.
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Chondroplasty
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