Patients › Ankle

Syndesmotic injury

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What you're feeling¶

A syndesmotic injury affects the ligaments that hold the two bones of your lower leg together just above your ankle. The pain is usually spread around the ankle rather than in one spot, and it often sits at the front and outer side, just above the outer ankle ligaments. You may also have tenderness near the inner side of the ankle.

Certain movements make it worse. Walking up hills, pivoting or twisting, and rising onto the ball of one foot all commonly cause pain. Turning your foot outward, or bending it up towards your shin, can also bring the pain on. Swelling and bruising are common, and the bruising may extend well up the leg or across the inner ankle. If the ankle is unstable, putting weight on it is usually too painful.

Some flare patterns point towards this injury rather than a simple sprain. Pain that keeps going despite rest is a typical sign. By contrast, a sprain that settles completely between episodes suggests a different problem with the outer ankle ligaments. Swelling and stiffness that linger, weakness when pushing off the foot, and a feeling that the ankle might give way can all continue long after the original injury, even when standard testing seems normal.

Everyday tasks can become difficult. Climbing stairs or hills, getting out of a chair, and standing on one leg to dress may all hurt. You might find you cannot push off properly when walking, so you favour the other leg.

A few early warning signs matter. If you cannot bear weight at all, if swelling comes on quickly and heavily, or if bruising is extensive on the inner or upper part of the leg, the syndesmosis is more likely involved. These injuries are easy to miss, and they are sometimes mistaken for a straightforward sprain at first. If any of this sounds like your ankle, it is worth having it assessed properly rather than waiting for it to settle on its own.

What's actually happening¶

Your lower leg has two bones, the tibia and the fibula, that sit side by side just above your ankle. They are held together by a bundle of strong ligaments called the syndesmosis. Think of it as a firm strap that keeps the two bones from spreading apart when you walk. It also helps carry your body weight down through the leg, so it does real work every time you stand.

The injury happens when your foot is bent up towards your shin and twisted outward at the same time. That twisting force can pry the two bones apart and tear the strap. If the injury is severe, other structures can be damaged too, such as the ligament on the inner side of the ankle or the fibula bone itself. For the bones to actually separate, several strong ligaments and a tough membrane between them all have to tear.

When the strap is damaged, the ankle joint loses some of its stability. The small bone under your ankle, the talus, can then shift slightly out of place as you move. That shifting is what causes the pain, swelling and giving-way feeling described above. The torn ligament can also become inflamed and scarred, which can pinch tissues at the front of the ankle and keep the pain going.

If the bones stay apart and it is not treated, the joint can wear unevenly over time and develop wear-and-tear arthritis. This is why getting the right diagnosis matters. Some injuries are stable, meaning the strap is strained but still holding the bones in place. These usually settle without surgery, with protected weight bearing. Others are unstable, meaning the bones can drift apart, and these need an operation to hold them together while they heal. Getting this sorted early matters, because delays past six months are linked with worse function later on.

What we can do about it¶

Dr Kieran Hirpara, an orthopaedic surgeon at Mater Private Hospital Rockhampton, matches the treatment to your specific injury. Patients are generally referred to our clinic by their GP; if a physiotherapist has suggested you see us, you will still need a referral from your GP in order to be eligible for the Medicare rebate. At the clinic visit we take a history, examine your ankle, and arrange imaging where it is needed. Because this injury can be missed, we sometimes use scans that show the ligaments clearly before deciding what to do.

If your injury is stable, meaning the strap of ligaments is strained but still holding the bones in place, surgery is not needed. We protect the ankle while it heals and let you put weight on it gradually. Physiotherapy helps you regain movement, strength and confidence in the ankle. Some people find a soft dressing is enough support early on, while others need a cast for up to three weeks. The right amount of rest from weight bearing varies, and we will guide you through it.

If the injury is unstable, meaning the bones can drift apart, surgery is usually recommended. Waiting more than six months makes the result worse, so we aim to sort it out early. The operation holds the two bones together while the ligaments heal. This can be done with a screw, a strong stitch and a small button, or by repairing the torn ligaments directly. We will talk through which option suits your injury and agree on a plan together.

After surgery, physiotherapy helps speed your recovery. Most people return to normal activity, including sport, around four months after the operation.

What to expect¶

The outlook depends on whether your injury is stable or unstable. A stable injury, where the strap of ligaments still holds the bones in place, usually settles without surgery. You protect the ankle, put weight on it gradually, and rebuild strength with physiotherapy. People treated this way report good function in the long run, and few go on to hurt the ankle again.

An unstable injury needs an operation to hold the bones together while the ligaments heal. When that is done well, with the bones lined up accurately and held firmly, most people get back to normal activity. Around four months after surgery, most people are back to their usual activities, including sport. Many people keep good ankle function decades later, even though scans sometimes show wear-and-tear arthritis in the joint. In one long-term study, everyone who had the ligaments repaired directly said they would do it again if needed.

Recovery is rarely a straight line. Early on, putting weight on the foot is the hard part, and getting the ankle moving again takes steady work with physiotherapy. Starting weight bearing and movement early helps your ankle work better in the first weeks, though it does not necessarily get you back to work sooner. How quickly people return to activity varies a lot from person to person, so try not to measure yourself against anyone else.

If an unstable injury is left alone, the problems tend to persist rather than settle. The bones can drift apart, the joint can wear unevenly, and long-term instability can leave you with ongoing pain and a weaker ankle. Waiting more than six months for surgery is linked with worse function later on, which is why early assessment matters. Sometimes the ligaments heal loosely even after treatment, and a loose or unstable joint is linked with poorer results.

Some injuries also involve damage inside the ankle joint itself. This happens in up to half of unstable injuries, and it needs extra treatment in about one in five cases. Your surgeon will look for this when planning your care.

When to see someone¶

Get your ankle assessed promptly if you cannot put weight on it at all, if swelling comes on quickly and heavily, or if bruising is extensive on the inner or upper part of the leg. These are the early signs that this injury involves more than a simple sprain. Ask for a specialist review if pain keeps going despite rest, if the ankle feels unstable or gives way, or if swelling and stiffness linger well after the injury. This injury is easy to miss, and it is sometimes mistaken for a straightforward sprain at first. If it is left too long, waiting past six months before surgery is linked with worse function later on. If you have already been told it is a sprain but your ankle is not settling, it is worth asking whether the syndesmosis has been checked.

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