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Health condition · Clinically reviewed

Chronic ankle instability, structured rehab, Broström-Gould repair and InternalBrace augmentation.

Around 40 per cent of ankle sprains never fully recover. A proper rehab programme resolves most cases - and modern anatomical surgery handles the rest.

Jump to treatment
A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against BOFAS, NICE and peer-reviewed foot and ankle sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK practice including structured rehabilitation, Broström-Gould repair and InternalBrace augmentation.

Key facts

Chronic ankle instability at a glance.

The essentials, in plain English - what it is, why it happens, and how UK foot and ankle teams approach it today.

  • What it is

    Chronic ankle instability (CAI) - recurrent giving way and repeat inversion sprains after an initial ankle injury that never fully recovered.

  • How common

    Around 40 per cent of people who sustain an ankle sprain go on to develop chronic instability, usually because early rehab was inadequate.

  • Two overlapping types

    Mechanical instability (loose ATFL, CFL and PTFL ligaments) and functional instability (proprioceptive and neuromuscular deficits). Most patients have both.

  • First-line management

    A structured 8 to 12 week physiotherapy programme - balance, peroneal strengthening and neuromuscular retraining - resolves the majority of cases.

  • When surgery helps

    If conservative care fails at 3 to 6 months, anatomical Broström-Gould repair, often with InternalBrace augmentation, is the gold standard.

  • Return to sport

    Non-surgical: back to sport in 8 to 12 weeks. Post-Broström repair: typically 4 to 6 months with a graded return-to-sport programme.

Why this guide matters

A stepped plan, not a lifetime of taping.

Ankle instability is treatable, and the ladder is clear. The three points below shape everything else on this page.

  • Rehabilitation is first-line

    A structured 8 to 12 week programme of balance, peroneal strengthening and neuromuscular retraining resolves most cases - and the evidence is strong.

  • Mechanical and functional overlap

    Loose ligaments and poor proprioception usually coexist. Treating one without the other is why some patients keep spraining.

  • Modern surgery is anatomical

    Broström-Gould repair, often with InternalBrace augmentation, restores native anatomy and supports earlier, safer return to sport.

How the diagnosis is made

From recurrent sprains to a clear plan.

The steps a UK GP, physiotherapist or foot and ankle surgeon will normally follow, in order - so you know what to expect and why.

  1. 01

    Assessing

    Focused history

    Two or more ankle sprains, a real sensation of the ankle giving way, and confidence or performance dropping off - the diagnostic triad.

  2. 02

    Assessing

    Clinical examination

    Anterior drawer test and talar tilt test for ligament laxity, plus palpation over the ATFL, CFL and syndesmosis to localise tenderness.

  3. 03

    Assessing

    Functional testing

    Star Excursion Balance Test (SEBT), single-leg squat and hop tests give an objective measure of proprioceptive and neuromuscular deficit.

  4. 04

    Confirming

    Weight-bearing X-rays

    To exclude fracture, osteoarthritis and hindfoot varus alignment. Stress views are used selectively when mechanical laxity is unclear.

  5. 05

    Confirming

    MRI for the deep picture

    MRI shows cartilage lesions, osteochondral defects of the talus, tendon injury, ATFL/CFL/PTFL tears and any syndesmotic injury the X-ray misses.

  6. 06

    Confirming

    Dynamic ultrasound

    Ultrasound can visualise the lateral ligaments live under stress - useful where MRI is inconclusive or contraindicated.

  7. 07

    Planning

    Specialist foot and ankle opinion

    If instability persists after structured rehab, or if MRI shows a concurrent cartilage or tendon lesion, a foot and ankle surgeon guides next steps.

Typical timeline: a first assessment to a working plan in a single clinic visit.

Symptoms

What chronic ankle instability actually feels like.

The classic pattern of recurrent giving way, lateral pain and lost confidence - and the features that mean it is time to escalate.

  • Recurrent inversion sprains

    The ankle rolls outwards again and again, often on flat ground or awkward steps rather than sport.

  • Giving way sensation

    A distinct feeling that the ankle is about to buckle - even when it does not fully collapse.

  • Persistent lateral pain

    Dull ache over the outside of the ankle, often flaring after activity or long periods on your feet.

  • Swelling that keeps returning

    Recurrent low-grade swelling around the lateral malleolus, especially after sport or uneven terrain.

  • Reduced confidence

    Avoiding uneven ground, kerbs, hills or sport because you no longer trust the ankle to hold.

  • Reduced sport performance

    Cutting, pivoting and jumping feel tentative - times, jump heights and agility scores drop off.

  • Stiffness and weakness

    Peroneal muscles weaken with disuse, and dorsiflexion range can quietly shrink after months of guarding.

  • Red flag - locking or catching

    Locking, catching or sharp pain deep in the joint may signal an osteochondral defect and needs specialist review.

Treatment

How ankle instability is treated in the UK.

Structured rehabilitation first. Broström-Gould repair and modern augmentation when conservative care has genuinely been given its chance.

  • Structured physiotherapy

    The 8 to 12 week first-line programme - proprioceptive work, wobble board, BAPS, eyes-closed balance, peroneal strengthening and sport-specific drills.

  • Neuromuscular retraining

    Coordination, reaction and landing mechanics - retraining the ankle to react before it rolls, not just after.

  • Bracing and taping

    Lace-up braces or stirrup braces for high-demand sport - useful short-term protection while strength and balance rebuild.

  • Broström-Gould repair

    The gold-standard open anatomical repair of the ATFL and CFL, reinforced with the inferior extensor retinaculum (the Gould modification).

  • Modified Broström with anchors

    Suture-anchor augmentation of the Broström repair - stronger early fixation and faster protected rehab.

  • InternalBrace augmentation

    Arthrex InternalBrace - a collagen-coated tape that reinforces the repaired ligament and supports earlier weight-bearing and return to sport.

  • Ligament reconstruction

    Autograft or allograft reconstruction for revision surgery, connective tissue disease, or when native tissue is too poor to repair.

  • Calcaneal osteotomy

    For hindfoot varus alignment driving repeat sprains - realigns the heel so the ligament repair is not overloaded from day one.

Combined with arthroscopy

Where MRI shows a concurrent osteochondral lesion of the talus, anterior impingement or loose body, ligament repair is often combined with ankle arthroscopy in the same operation - see our guide to ankle arthroscopy for what that involves.

Post-op you can expect a CAM boot for 2 to 4 weeks with gradual weight-bearing, physiotherapy from around 4 to 6 weeks, and return to sport at 4 to 6 months guided by a graded programme.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and 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 surgeon knows your ankle and history and can tell you which parts apply to you. If in doubt, get seen.

  • British Orthopaedic Foot and Ankle Society (BOFAS). Patient information on chronic ankle instability.

  • NICE Clinical Knowledge Summary. Sprains and strains.

  • International Ankle Consortium. Position statements on chronic ankle instability.

  • Journal of Bone and Joint Surgery. Broström-Gould repair and InternalBrace outcome studies.

Red flags

When ankle instability needs urgent attention.

Most instability is managed in physiotherapy and outpatient orthopaedics. These are the situations that need a faster route.

  • Locking or catching

    Suggests an osteochondral lesion of the talus or a loose body - needs MRI and a foot and ankle opinion.

  • High ankle pain

    Pain above the joint line, worse on external rotation, points to syndesmotic injury and changes both imaging and treatment.

  • Complete peroneal weakness

    Inability to evert against resistance may mean a peroneal tendon tear or dislocation, not simple weakness.

  • Neurovascular symptoms

    Numbness, tingling or a cold foot after a sprain needs urgent assessment to exclude nerve or vascular injury.

  • Post-injury deformity

    Any visible deformity, especially with inability to weight-bear, needs same-day imaging to exclude fracture or dislocation.

  • Rapidly progressive giving way

    Instability worsening week on week, out of keeping with activity, deserves early specialist review.

  • Signs of infection after surgery

    Fever, spreading redness, wound discharge or worsening pain post-Broström needs urgent surgical review.

  • Bilateral generalised laxity

    Instability in multiple joints raises the question of a connective tissue disorder and changes the surgical plan.

  • Failed conservative care at 6 months

    Ongoing instability despite a proper rehab programme is the trigger for a formal surgical opinion, not more of the same.

Living with it

A treatable condition, with a clear ladder.

Four things that make the biggest difference day to day - finish your rehab, train balance daily, brace for high-risk sport and do not tolerate repeated giving way.

A quiet reminder

Every extra sprain adds cartilage damage.

Repeat giving way is not a nuisance to be lived with - it is what drives long-term ankle arthritis. Fix the instability, protect the joint.

  1. 01 Rehab

    Finish the rehab, properly

    Most instability starts with a sprain that was under-rehabbed. Twelve honest weeks of balance and strength work beats years of taping.

  2. 02 Balance

    Train balance every day

    Two minutes of single-leg balance while brushing your teeth is worth more than one weekly gym session. Small, daily, non-negotiable.

  3. 03 Kit

    Use a brace for high-risk sport

    Court sports, netball, basketball and trail running - a lace-up brace is not a defeat, it is sensible protection while you build.

  4. 04 Escalate

    Do not tolerate giving way

    Repeated giving way damages cartilage. If a structured programme has not worked, ask for a foot and ankle referral - do not wait it out.

Frequently asked

Everything we get asked about ankle instability.

Quick answers on rehab, imaging, Broström-Gould repair and return to sport.

  • What is chronic ankle instability?

    Chronic ankle instability (CAI) is recurrent giving way and repeat sprains of the ankle after an initial injury. It has two overlapping components - mechanical instability from lax lateral ligaments (ATFL, CFL, PTFL) and functional instability from proprioceptive and neuromuscular deficits. Most patients have both.

  • How common is it after an ankle sprain?

    Around 40 per cent of people who sustain a lateral ankle sprain develop chronic instability, most often because early rehabilitation was inadequate. A properly completed 8 to 12 week rehab programme after the first sprain is the single best way to prevent it.

  • Do I need an MRI?

    Not always. Diagnosis is largely clinical - based on history, anterior drawer and talar tilt testing, and functional tests. MRI is used when specialist review is planned, to look for cartilage lesions, osteochondral defects, tendon injury and ligament tears that change the surgical plan.

  • Will physiotherapy actually fix it?

    For the majority of patients, yes. A structured 8 to 12 week programme of proprioceptive training, wobble board, BAPS, eyes-closed balance, peroneal strengthening and sport-specific drills resolves symptoms in most cases. Surgery is reserved for those who fail this properly delivered programme at 3 to 6 months.

  • What is a Broström-Gould repair?

    The Broström-Gould procedure is the gold-standard open anatomical repair of the ATFL and often the CFL, reinforced with the inferior extensor retinaculum. Modern practice frequently adds suture anchors or an InternalBrace tape augmentation for stronger early fixation and faster protected rehab.

  • When can I get back to sport after surgery?

    A typical schedule is a CAM boot for 2 to 4 weeks with gradual weight-bearing, physiotherapy from around 4 to 6 weeks, running from around 3 months, and return to cutting, pivoting or contact sport at 4 to 6 months - guided by a graded return-to-sport programme rather than the calendar alone.

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