Every time you stand or walk, the syndesmosis ligament in your ankle lends its support. As long as it’s healthy and strong, you don’t even notice it. But when you have a syndesmosis injury, it’s impossible to ignore.

Most ankle sprains and fractures don’t affect the syndesmosis ligament. When they do, it can be harder to diagnose and take longer to heal than other ankle injuries.

You have a few syndesmosis joints in your spine, but this article is about the ankle syndesmosis. Let’s take a closer look at the anatomy of the syndesmosis ligament and what you need to know when you hurt your ankle.

The syndesmosis is a fibrous joint held together by ligaments. It’s located near the ankle joint, between the tibia, or shinbone, and the distal fibula, or outside leg bone. That’s why it’s also called the distal tibiofibular syndesmosis.

It’s actually made up of several ligaments. The primary ones are:

The syndesmosis ligament acts as a shock absorber, providing stability and support for your ankle. Its main job is to align the tibia and fibula and keep them from spreading too far apart.

Syndesmosis injuries aren’t very common, unless you’re an athlete. While syndesmosis injuries make up only about 1 to 18 percent of all ankle sprains, incidence among athletes is 12 to 32 percent.

A likely scenario for a syndesmosis injury is:

  1. Your foot is firmly planted.
  2. The leg rotates internally.
  3. There’s external rotation of the talus, a bone in the lower part of the ankle joint, above the heel bone.

This set of circumstances can tear the ligament, causing the tibia and fibula to separate.

When you injure the syndesmosis ligaments, it’s called a high ankle sprain. The seriousness of the sprain depends on the extent of the tear.

This type of injury usually involves a lot of force, so it’s often accompanied by injuries to other ligaments, tendons, or bones. It’s not unusual to have a syndesmosis sprain with one or more bone fractures.

Syndesmosis injuries don’t generally bruise or swell as much as other ankle sprains. That could lead you to believe you’re not seriously injured. You’re likely to have other symptoms, such as:

  • tenderness to the touch
  • pain above the ankle, possibly radiating up the leg
  • pain that increases when you walk
  • pain when you rotate or flex your foot
  • trouble raising your calf
  • inability to put your full weight on your ankle

Symptoms can vary depending on the severity of the injury.

You can injure your ankle doing something as simple as tripping over a toy in your living room. Depending on the mechanics of your accident, it’s possible to injure your syndesmosis this way. But syndesmosis injuries tend to involve high-energy force with a sudden twisting motion.

This may be especially likely in sports where players wear cleats, which can plant the foot in place while the ankle is forced to rotate outwardly. It’s also a risk in sports that can involve a blow to the outside of the ankle.

Injuries to the syndesmosis tend to involve sports such as:

  • football
  • rugby
  • downhill skiing

Among athletes, the highest frequency of syndesmosis injuries occurs in professional hockey.

Diagnosing syndesmosis ligament injuries is a challenge. Explaining exactly how the injury occurred will help a doctor decide what to look for first.

If the syndesmosis is injured, physical examination may be painful, or at least uncomfortable. Your doctor will squeeze and manipulate your leg and foot to see how well you can flex, rotate, and bear weight.

After physical examination, you might need an X-ray. This can determine if you have one or more broken bones.

In some cases, an X-ray isn’t enough to see the full extent of a syndesmosis ligament injury. Other imaging studies, such as CT scan or MRI can help detect tears and injuries to ligaments and tendons.

Rest, ice, compression, and elevation (RICE) are the first steps following an ankle injury.

After that, treatment depends on the specifics of the injury. Recovery time following syndesmosis sprain can take twice as long as recovery from other ankle sprains. Untreated, severe syndesmotic injuries can lead to chronic instability and degenerative arthritis.

Before your doctor can recommend treatment, they have to fully assess the degree of the syndesmosis injury. It’s important to know whether other ligaments, tendons, and bones are also injured.

RICE treatment for minor injuries

A relatively minor injury may leave the ankle stable enough to bear some weight. A stable high ankle sprain may not need surgical repair. RICE may be sufficient.

On the other hand, a major tear in the ligament allows the tibia and fibula to spread too far apart when you move. This makes your ankle unstable and less able to bear weight.

Surgical repair for more serious injuries

Unstable high ankle sprains typically need to be surgically repaired. It may require insertion of a screw between the tibia and fibula. This will help hold the bones in place and relieve pressure on the ligaments.

What to expect during recovery

Following surgery, you may need a walking boot or crutches while you heal.

Whether you need surgery or not, severe syndesmotic sprains are usually followed by physical therapy. The focus is on healing and regaining full range of motion and normal strength. Full recovery may take as long as 2 to 6 months.

Misdiagnosis or lack of the proper treatment can lead to long term instability of the ankle and degenerative arthritis. See a doctor if:

  • you have severe pain and swelling
  • there’s a visible abnormality such as an open wound or protrusion
  • there are signs of infection, including fever and redness
  • you can’t put enough weight on your ankle to stand
  • symptoms keep getting worse

If you’re an athlete with an ankle injury, playing through the pain can make matters worse. It’s in your best interest to have your ankle checked before getting back in the game.

The syndesmosis ligament helps support your ankle. A syndesmosis injury is generally more serious than other ankle injuries. Without proper treatment, it can lead to long-term problems.

There are effective treatments that can have you back on your feet within a few months, but the first step is getting the right diagnosis.

If your ankle injury isn’t healing as well as expected, ask your doctor to check your syndesmosis ligament.