Every time you stand or walk, the syndesmosis ligament of the ankle provides support. As long as you're healthy and strong, you won't even notice it. But when you have a syndesmosis injury, it's impossible to ignore.
Most ankle sprains and fractures do not affect this ligament. When they do, it can be more difficult to diagnose and take longer to heal than other ankle injuries. It is true that there are some syndesmosis joints in the spine, but in this article we will talk about those of the ankle.
What is the syndesmosis ligament?
The syndesmosis is a fibrous joint held together by ligaments. It is located near the ankle joint, between the tibia or shin bone and the distal fibula or outer leg bone. That is why it is also called distal tibiofibular syndesmosis.
The syndesmosis complex is crucial in ankle stability, with little understanding in current textbooks. To best treat injuries in this region, we must understand the anatomy. The main ligaments are:
anterior inferior tibiofibular ligament
This inserts from the anterior tubercle of the distal tibia to the anterior fibula at the lateral malleolus. The ligament is made up of 3-5 bands, depending on the anatomy of each person. Together, the bands form a trapezoid with short accessory bands proximally and long, dense primary bands distally. The anterior medial tibiofibular ligament runs obliquely from the tibia to the fibula.
posteroinferior tibiofibular ligament
This ligament is also trapezoidal, with superior fibers attaching along the distolateral margin of the posterolateral tibial tubercle and then fusing with the posterior tibial cortex. It is almost continuous in the interosseous membrane, located in the upper part of the ligament. It is made up of a superficial ligament and a deep ligament (often called the inferior transverse tibiofibular ligament). The superficial fibers lie 26,3 mm from the lower tip of the lateral malleolus, whereas the deeper fibers are denser and attach to an oval attachment on both the fibula and tibia.
interosseous ligament
The pyramidal network between the fibular notch on the tibia and the medial fibula is the interosseous tibiofiular ligament. The ligament consists of short, dense ligamentous fibers and adipose tissue, arising from the interosseous membrane proximal to the tibial plafond and the inferior tip of the lateral malleolus. The fibers descend laterodistally from the tibia to the fibula, ending 34,5 mm above the lower tip of the lateral malleolus.
Some say that this ligament is insignificant, while others claim that this ligament acts as a shock absorber, providing stability and support for the ankle. The main function is to align the tibia and fibula and prevent them from spreading too far apart.
What are the most common injuries?
The truth is that they are not very common, unless you are an athlete. Although injuries to this ligament in the ankle account for only 1 to 18 percent of all sprains to the joint, the incidence among athletes is 12 to 32 percent. The instability could be due to widening of the ankle mortise after stretching of the ligaments. A 1 mm widening of the ankle decreases the contact area of the tibiotalar joint by 42%, which causes instability, with consequent osteoarthritis. Since the 1-mm change in width is clinically significant, syndesmosis injuries are rarely reported. Possibly with the improved images of the tests available, the incidence could be higher than 11%.
A likely scenario for a syndesmosis injury is:
- Your foot is firmly planted.
- The leg rotates internally.
- There is external rotation of the talus, a bone at the bottom 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 ligaments of the syndesmosis, it is called upper ankle sprain. The severity of the sprain depends on the extent of the tear. This type of injury usually involves a lot of force, so it is often accompanied by injuries to other ligaments, tendons, or bones. It is not unusual to have a syndesmosis sprain with one or more bone fractures.
Symptoms of Syndesmosis Injury
Syndesmosis injuries usually do not bruise or swell as much as other ankle sprains. That could lead you to believe that you are not seriously injured. Although you are likely to have other symptoms, such as:
- tenderness to the touch
- Pain above the ankle, possibly radiating down the leg
- Pain that increases when walking
- Pain when turning or flexing the foot
- Problems raising the calf
- Inability to put all your weight on the ankle
However, remember that the symptoms may vary depending on the severity of the injury. It is advisable to go to a specialist or an emergency doctor to assess your case and perform the necessary tests.
What can cause these injuries?
You can injure your ankle by doing something as simple as tripping over a toy in your living room. Depending on how your accident was, it is possible to injure your syndesmosis in this way. But syndesmosis injuries tend to involve high-energy force with a sudden twisting motion.
This can be especially likely in sports where players wear cleats, which can lock the foot into place while the ankle is forced to rotate outward. It is also a risk in sports that can involve a blow to the outside of the ankle.
Syndesmosis injuries tend to involve sports such as:
- Soccer
- Rugby
- Alpine ski
Among athletes, the highest frequency of syndesmosis injuries occurs in the professional hockey.
How is syndesmosis diagnosed?
The diagnosis of ligament injuries is challenging. Explaining exactly how the injury occurred will help the doctor decide what to look for first.
If you injure the syndesmosis, the Physical exam it can 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 the physical exam, you may need an X-ray. This can determine if you have one or more broken bones.
In some cases, a radiography it is not enough to see the full extent of a syndesmosis ligament injury. Other imaging studies, such as a tomography by computer or a magnetic resonance, can help detect tears and injuries to ligaments and tendons.
How are these injuries treated?
Rest, Ice, Compression, and Elevation (RICE) are the first steps after an ankle injury.
After that, treatment depends on the specifics of the lesion. Recovery time after a syndesmosis sprain can take twice as long as recovery from other ankle sprains. Untreated severe syndesmotic lesions can lead to chronic instability and degenerative arthritis.
Before your doctor can recommend treatment, he or she must fully assess the extent of the syndesmosis injury. It is important to know if other ligaments, tendons, and bones are also injured.
RICE treatment for minor injuries
A relatively minor injury can leave the ankle stable enough to support some weight. A stable high ankle sprain may not need surgical repair. So this technique may be enough.
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 severe syndesmoses
Unstable ankle sprains usually need to be repaired surgically. May require insertion of a screw between the tibia and fibula. This will help keep the bones in place and take pressure off the ligaments. After surgery, you may need a walking boot or crutches while you recover.
Whether you need surgery or not, severe syndesmotic sprains are often followed by physiotherapy. The focus is on healing and regaining full range of motion and normal strength. Full recovery can take 2-6 months.
When should you go to a doctor?
A misdiagnosis or lack of proper treatment can lead to long-term ankle instability and degenerative arthritis. See a doctor if you have any of these conditions:
- You have severe pain and swelling
- There is a visible abnormality, such as an open wound or lump
- There are signs of infection, including fever and redness
- You can't put enough weight on your ankle to stand upright
- Symptoms keep getting worse
If you're an athlete with an ankle injury, playing sports through pain can make things worse. It is best for you to have your ankle checked before you return to training. Do not continue to stress the joint, as this could only lead to a tear or much more serious cases.