Lateral Ankle Sprains, Chronic Instability and Ligament Reconstruction
Overview
Most lateral ankle sprains recover without surgery through early protection followed by progressive movement, strength and balance rehabilitation. Some people develop recurrent giving-way or persistent ligament looseness. Chronic instability should be assessed for associated tendon, cartilage, ‘high ankle’ ligament, nerve or foot-alignment problems. Ligament repair or reconstruction is considered only when instability remains functionally important despite a well-performed rehabilitation program.
Acute ankle sprain
The usual injury is an inward roll of the foot that stretches or tears one or both ligaments on the outer side of the ankle. Swelling, bruising and difficulty bearing weight vary with severity. A fracture, ‘high ankle’ ligament injury, tendon injury or cartilage damage can cause a similar presentation.
Early care usually includes protection, compression, elevation and pain relief, followed by weight-bearing and movement as tolerated or advised. Prolonged immobilisation is not needed for most uncomplicated sprains. A short period in a brace or Moonboot may be appropriate for a severe injury before functional rehabilitation begins.
When are X-rays or scans needed?
The injury pattern and examination help determine whether X-rays are needed to exclude a fracture. Persistent pain, locking, recurrent swelling, tenderness away from the outer ankle ligaments or failure to improve may prompt weight-bearing X-rays, ultrasound, MRI or CT.
MRI can show ligament injury, but a torn-looking ligament on a scan is not, by itself, an indication for surgery. Examination of stability, foot shape, peroneal tendons, the ligaments between the two lower-leg bones (the ‘high ankle’ ligaments), cartilage and nerves remains essential.
Rehabilitation
- Restore ankle movement without repeatedly provoking swelling.
- Progress calf, peroneal and whole-limb strength.
- Balance, joint-position control, landing and change-of-direction training.
- A brace or taping during higher-risk activity while control is rebuilt.
- Gradual sport- and work-specific loading rather than return based on time alone.
Chronic ankle instability
Mechanical instability means the ligaments remain lax on examination. Functional instability describes recurrent giving-way or lack of confidence and may persist because of strength, balance, pain or altered movement even when laxity is limited. Both can coexist.
Contributing problems include a high-arched foot that tilts inwards, peroneal tendon tears, ankle impingement, injury to cartilage and the underlying bone, loose bodies, a ‘high ankle’ ligament injury and nerve symptoms. These may need treatment in addition to the outer ankle ligaments.
When may surgery be considered?
Surgery may be discussed when recurrent instability continues to interfere with daily activity, work or sport after a well-performed rehabilitation program and examination confirms a correctable mechanical problem. Smoking, poor skin, nerve damage or reduced sensation, arthritis and major foot deformity influence the plan and risk.
A direct repair, often called a Broström repair, tightens and reattaches the person’s own ligaments. Poor tissue quality, generally flexible or loose ligaments, revision surgery or selected high-demand situations may require reconstruction with a tendon graft. Arthroscopy may be added when there is a separate problem inside the joint that can be treated.
Recovery
The ankle is initially protected in a splint, cast or Moonboot. Weight-bearing and movement progress according to the repair, associated procedures and tissue quality. Physiotherapy restores range, strength, balance, running and direction change in stages.
Return to work, driving and sport is individual. Cutting and pivoting sport generally requires more time and testing than straight-line walking. Swelling and reduced confidence can continue for several months.
Risks and limitations
- Infection, wound problems, blood clots or anaesthetic complications.
- Numbness or painful irritation of superficial sensory nerves.
- Stiffness, swelling, persistent pain or reduced ankle movement.
- Recurrent instability, over-tightening or failure of graft or repair.
- Unrecognised or progressive cartilage, tendon or alignment problems.
- Complex regional pain syndrome or need for further surgery.
Seek prompt review
Seek assessment after a sprain if there is marked deformity, inability to bear weight, pain over bone, numbness, colour change, severe pain above the ankle suggesting a ‘high ankle’ injury, or worsening symptoms. After surgery, fever, wound drainage, new calf swelling, chest pain or shortness of breath requires urgent care.
Frequently asked questions
Do all torn ankle ligaments need surgery?
No. Most acute lateral ligament injuries heal sufficiently with functional rehabilitation.
Why does my ankle still give way after the swelling has settled?
Persistent weakness, impaired balance, pain, ligament laxity or another injury may contribute. Reassessment and targeted rehabilitation are appropriate.
Does an MRI prove I need reconstruction?
No. Surgery is based on symptoms, examination, rehabilitation response, alignment and associated pathology—not MRI appearance alone.
Is arthroscopy always performed with ligament repair?
No. It is added when symptoms or imaging suggest a problem inside the joint that is likely to affect treatment.
Can instability return after surgery?
Yes. Re-injury, tissue quality, alignment, generalised laxity and rehabilitation can influence recurrence.
General information
This page provides general information only. It cannot diagnose your condition or replace advice from a clinician who has assessed you. Your treatment and recovery plan may differ from the examples described here. Follow the instructions from your treating team. In an emergency, call 000 or attend the nearest emergency department.