Ankle Instability and Ligament Reconstruction

An ankle that keeps rolling, or that you no longer trust on uneven ground, is a different problem from a single sprain. When the ligaments on the outside of the ankle heal stretched — or do not heal at all — the joint stays loose, and every further roll adds to the damage inside it. This page covers why an ankle keeps giving way, what can be done without an operation, and what ligament repair and reconstruction involve.

What ankle instability is

Most ankle sprains settle within a few weeks and cause no lasting trouble. Instability is what happens when they do not: the ankle keeps giving way months later, feels unreliable on uneven ground or in the dark, and often aches or swells after a long day.

Two things usually sit behind it, and most people have some of both. The ligaments themselves may be genuinely lax — the anterior talofibular ligament (ATFL) is the one that stretches first, and the calcaneofibular ligament (CFL) beneath it is frequently involved as well. Alongside that, the balance and muscle control that normally protect the ankle may never have been fully retrained after the first injury.

Why an ankle keeps giving way

Common contributors include:

• a first sprain that healed with the ligament longer than it started

• rehabilitation that stopped when the pain settled rather than when control returned

• weakness in the peroneal tendons, which are the ankle’s own stabilisers

• reduced proprioception — the sense of where the joint is without looking at it

• naturally lax ligaments, which some people simply have

• a high arch or an inward-turned heel, which leaves the ankle at a mechanical disadvantage

• an old fracture, or a cartilage injury sustained at the time of the sprain

What happens if it is left

Each episode of giving way is a small injury in its own right. Repeated episodes damage the cartilage on the dome of the talus, tear or fray the peroneal tendons, and leave scar tissue at the front of the joint that pinches when you squat or push off.

Left long enough, an unstable ankle wears out. Chronic instability is one of the recognised causes of ankle arthritis: the joint is repeatedly loaded off-centre, the cartilage gives way, and the ankle becomes stiff and painful in its own right. By that stage the ligaments are no longer the problem, and treatment means the larger operations — ankle fusion or ankle replacement. Stabilising an ankle that keeps rolling is, in part, about protecting the joint you will still be walking on in thirty years.

How your ankle is assessed

The history matters as much as the scan: how often the ankle gives way, on what surface, what you have stopped doing because of it, and what rehabilitation you have already had.

Examination assess the ankles directly — how far the talus shifts forward, how far it tilts, peroneal strength, the alignment of the heel, and how well you can balance on the leg. Weightbearing X-rays show the alignment and the state of the joint. Where the examination suggests significant laxity, an MRI adds what it cannot: the condition of the ligaments themselves, the cartilage surface, and the peroneal tendons behind the fibula. Between a careful examination and an MRI there is rarely a need for stress X-rays.

The joint immediately below the ankle, the subtalar joint, is checked as well. Subtalar instability can give the same sense of the ankle giving way, and it occasionally explains an ankle that has stayed unstable after a ligament repair. Where the examination points to it, it is addressed alongside the lateral ligaments.

Non-surgical treatment comes first

Most unstable ankles are treated without an operation, and many settle. A properly progressed programme runs for at least three months and works on peroneal strength, single-leg balance and reaction, and a graded return to the surfaces and movements that catch you out. A brace or strapping for sport, and a change of footwear or an orthotic where the foot shape is contributing, can carry you through that.

Surgery is considered when a fair trial of this has not restored a reliable ankle — not as the first step.

Ligament repair: the Broström-Gould procedure

The usual operation for an unstable ankle is a repair of your own ligament, known as a modified Brostrom-Gould repair. Dr Janan performs this as an open procedure through a small incision on the outside of the ankle. The stretched ATFL is tightened and reattached to the fibula, and in most cases the CFL is repaired at the same time, since the two work together and the deeper ligament is often stretched as well. The repair is then reinforced with a layer of the overlying retinaculum — the Gould modification, which is where the second half of the name comes from. Because your own ligament is repaired rather than replaced, the ankle keeps its normal anatomy and its normal range of movement.

An ankle arthroscopy is often done at the same time. A camera passed into the joint through two small openings allows the cartilage surface and the peroneal tendons to be assessed directly, and anything found — a cartilage injury, loose tissue, scarring at the front of the joint — to be dealt with in the same anaesthetic rather than at a second operation.

The commonest thing found on that look inside the joint is damage to the cartilage and the bone just beneath it on the top of the talus, known as an osteochondral lesion of the talus (OLT), and also written as an osteochondral lesion or defect (OCL, OCD). Where a lesion is small, the bone underneath it can be stimulated to heal, a step called microfracture or bone marrow stimulation. Where it is larger, or where it has already been treated once, the surface can be rebuilt by transferring cartilage and bone from elsewhere, an osteochondral autograft transfer (OATS).

Where the peroneal tendons behind the fibula are themselves part of the problem, they can be inspected inside their own sheath through a fine camera, a peroneal tendoscopy, so that a split or inflamed tendon is treated at the same time.

Where the ligament tissue will not hold a repair on its own, the repair is supported with a suture-tape augmentation, also sometimes called an internal brace: a strong tape fixed to the bone at each end, running alongside the repaired ligament and sharing the load while it heals. It is used selectively — for people whose ligaments are generally lax, and for those whose first repair has already failed — rather than routinely.

When a tendon graft reconstruction is needed instead

Occasionally there is too little ligament left to repair at all, usually after many years of instability or where a previous repair has not held. The ligament is then rebuilt with a tendon graft, passed through small tunnels in the bone to recreate the line of the original. This is rarely needed, but it is done here when it is, rather than being referred elsewhere.

Recovery

You stay in hospital overnight. The physiotherapist sees you the following morning to make sure you are safe on your feet before you go home.

The ankle is protected in a plaster for the first two weeks while the swelling settles and the repair takes. At the two-week review the plaster comes off, you move into a boot and start putting weight through the leg. The boot stays on for a further four weeks, and is then weaned over about two weeks as your own muscles take back the work and you ramp up physiotherapy.

As a guide:

• 0 to 2 weeks — plaster, no weight through the leg, foot elevated

• 2 weeks — into a boot, and weightbearing begins

• 6 to 8 weeks — weaning out of the boot over about two weeks

• Driving — around eight weeks for a right ankle, earlier for a left in an automatic

• Desk work — about two weeks, with the leg up where possible

• Physical work — around three months

• Running — around three months, in a straight line first

• Pivoting sport — around three to six months, once strength and balance are back

Some swelling at the end of the day is normal for several months. Your own timeline depends on what was found in the joint and what you are going back to.

Risks

Every operation carries risk. For ligament surgery the specific ones are numbness or irritation over the top or outside of the foot, where small nerves run close to the incision; stiffness, particularly turning the foot inward; wound problems and infection; blood clots; ongoing pain; and instability that returns despite a sound repair. These are gone through in detail at your consultation, weighed against what the ankle is doing now.

Dr Janan’s approach

Dr Janan Chandrananth is a foot and ankle orthopaedic surgeon who completed fellowship training in Bristol and in Tokyo, the latter under a past president of the Japanese Society for Surgery of the Foot. Unstable ankles are a routine part of his practice.

His approach is to treat the ankle rather than the ligament alone: to look for the cartilage injury, tendon problem or foot shape that so often sits alongside the instability, to deal with those in the same operation, and to make sure rehabilitation has had a fair run before an operation is put on the table.