A syndesmosis ankle injury, commonly known as a high ankle sprain, can be a frustrating injury, particularly for athletes involved in sports such as AFL, rugby and netball.
Unlike a traditional rolled ankle, a high ankle sprain affects the ligaments connecting the two bones of the lower leg. Depending on the severity of the injury, recovery can involve anything from a period of immobilisation and physiotherapy to surgical reconstruction.
At Enhance Physio, we help patients understand their ankle injuries, identify potential instability and work towards a safe return to everyday activities and sport.
In this article, we explain what a syndesmosis injury is, how it occurs, when surgery may be necessary and what to expect during recovery.
What Is a Syndesmosis Ankle Injury?
The syndesmosis is a group of ligaments that connects the tibia (shinbone) and fibula (the smaller bone on the outside of your lower leg).
These two bones work together with the talus to form the ankle joint.
The syndesmosis plays an important role in maintaining ankle stability, particularly when the ankle bends upwards, such as when your knee moves forward over your toes.
A syndesmosis injury occurs when one or more of these connecting ligaments become stretched or torn.
In more serious cases, the tibia and fibula can begin to separate, creating instability within the ankle joint.
This is what makes a high ankle sprain potentially more complicated than a typical lateral ankle sprain.
What Causes a High Ankle Sprain?
Syndesmosis injuries commonly occur when the foot becomes trapped while the leg rotates, placing excessive force through the ligaments connecting the tibia and fibula.
There are several common ways this can happen.
1. External Rotation of the Foot
One of the most common mechanisms is when the foot becomes trapped and rotates outwards.
This rotational force can cause the tibia and fibula to separate, placing significant stress on the syndesmosis ligaments.
2. Tackles and Contact Sports
High ankle sprains are particularly relevant in contact sports such as AFL and NRL.
For example, an athlete’s foot may become trapped underneath another player during a tackle, causing the lower leg to rotate while the foot remains stationary.
Similarly, another player falling across a planted foot can create enough force to injure the syndesmosis.
3. Excessive Ankle Dorsiflexion
Dorsiflexion describes the movement that occurs when your knee travels forward over your toes.
If the ankle is forced too far into this position, particularly when combined with rotation, the syndesmosis ligaments can become injured.
4. A Severe Rolled Ankle
Although less common, a syndesmosis injury can also occur alongside a traditional lateral ankle sprain.
When the ankle rolls inwards with sufficient force, it may damage both the outer ankle ligaments and the syndesmosis.
This is particularly important because the syndesmosis component of the injury can sometimes be overlooked.
How Serious Is a Syndesmosis Ankle Injury?
Not all syndesmosis injuries are the same.
The severity depends on which ligaments have been damaged, whether they are partially or completely torn, and how much instability exists between the tibia and fibula.
Two important ligaments discussed when assessing these injuries are:
- Anterior Inferior Tibiofibular Ligament (AITFL): Located towards the front of the ankle syndesmosis.
- Posterior Inferior Tibiofibular Ligament (PITFL): Located towards the back of the ankle syndesmosis.
When both of these structures are torn, the ankle can become significantly unstable.
In these situations, the bones may separate excessively during movement, affecting the integrity of the ankle joint.
Identifying this instability is an important part of determining the most appropriate treatment.
Can a Syndesmosis Injury Heal Without Surgery?
Yes. Some syndesmosis ankle injuries can heal without surgery, particularly when the injury is relatively minor or appropriate immobilisation occurs early.
Conservative treatment may involve immobilising the ankle in a moon boot to allow the injured ligaments to heal and restore stability.
The objective is to protect the injured structures while they recover, before gradually progressing through rehabilitation.
However, not every syndesmosis injury will respond adequately to conservative treatment.
If the ankle remains unstable, further assessment and potentially surgical intervention may be necessary.
Why Early Assessment Matters
One challenge with syndesmosis injuries is that instability can sometimes be missed.
In certain cases, the injured ligaments may appear to heal but remain elongated, allowing excessive movement between the tibia and fibula.
This can leave the ankle unstable even after a period of immobilisation.
For this reason, identifying the extent of the injury and monitoring ankle stability are important parts of recovery.
How Is Syndesmosis Instability Diagnosed?
A physiotherapist or medical practitioner can assess the mechanism of injury, ankle function and signs of instability.
Where further investigation is required, imaging may help determine the extent of the injury.
One investigation discussed by Dave at Enhance Physio is a weight-bearing CT scan.
This can help assess the relationship between the tibia and fibula under load and identify abnormal separation that may indicate instability.
These findings, alongside clinical assessment, can help determine whether the ankle is sufficiently stable to continue conservative rehabilitation or whether surgical assessment is required.
When Is Surgery Required for a High Ankle Sprain?
Surgery may be considered when the syndesmosis has been significantly damaged and the ankle joint cannot maintain adequate stability.
This may occur when multiple important ligaments have been completely torn or when instability persists despite immobilisation.
One surgical approach involves reconstructing or stabilising the syndesmosis using a device commonly known as a TightRope.
What Is TightRope Surgery?
TightRope fixation uses a strong suture-based device to help maintain the correct relationship between the tibia and fibula.
The device spans the two bones and helps prevent excessive separation while maintaining the stability required for the ankle to function.
The need for surgery depends on the individual injury, and the most appropriate treatment should be determined by the treating specialist.
Following surgery, physiotherapy plays an important role in restoring movement, strength and function.
How Long Does a Syndesmosis Ankle Injury Take to Heal?
One of the most common questions patients ask is:
How long will I be out with a high ankle sprain?
As Dave explains in the Enhance Physio video, recovery and rehabilitation may take approximately 4–6 weeks through to 10–12 weeks, depending on the severity of the injury and the treatment approach.
These are indicative rehabilitation timeframes rather than guaranteed dates for complete healing or return to sport. More complex injuries may require longer.
Several factors can influence recovery:
- The severity of the ligament damage.
- Whether the ankle joint remains stable.
- Whether treatment involves immobilisation or surgery.
- The rehabilitation protocol recommended by the physiotherapist or surgeon.
- The physical demands of the patient’s sport or daily activities.
Returning to AFL, Rugby and Other Sports
For athletes, particularly those playing competitive AFL or rugby, returning to sport is often a major priority.
In some circumstances, rehabilitation decisions may be influenced by important matches, finals or the demands of high-level competition.
However, there needs to be an appropriate balance between returning to sport quickly and restoring the stability and integrity of the ankle joint.
An accelerated return-to-sport approach may not be suitable for every injury.
Your physiotherapist and treating specialist can help determine the safest progression based on the severity of the injury, ankle function and sporting requirements.
Physiotherapy for Syndesmosis Ankle Injuries
Physiotherapy can play an important role in recovery from both surgically and conservatively managed syndesmosis injuries.
At Enhance Physio, we can assist patients at different stages of their recovery, including those who:
- Have recently injured their ankle and require assessment.
- Suspect their ankle sprain may involve the syndesmosis.
- Have completed a period of immobilisation in a moon boot.
- Are recovering from syndesmosis surgery.
- Need rehabilitation before returning to sport.
The rehabilitation approach will depend on the injury, the stability of the ankle and any instructions provided by the treating surgeon.
The overall aim is to support recovery, restore function and help patients return to their usual activities safely.
Frequently Asked Questions About Syndesmosis Injuries
Is a high ankle sprain worse than a normal ankle sprain?
A high ankle sprain can be more complicated than a traditional lateral ankle sprain because it affects the ligaments holding the tibia and fibula together.
More severe injuries can create instability within the ankle joint and may require immobilisation or surgery.
Can you walk with a syndesmosis injury?
The ability to walk depends on the severity of the injury. Being able to walk does not necessarily rule out syndesmosis damage.
If you suspect a high ankle sprain, seek an assessment rather than relying on your ability to bear weight as an indication of severity.
Do all syndesmosis injuries require surgery?
No. Minor or stable syndesmosis injuries may heal with appropriate immobilisation and rehabilitation.
Surgery may be required when significant instability is present.
Can a syndesmosis injury be missed?
Yes. Syndesmosis injuries can sometimes occur alongside a traditional rolled ankle and may not be immediately recognised.
Persistent symptoms or suspected instability following an ankle injury warrant further assessment.
How long before I can play AFL after a high ankle sprain?
Rehabilitation may take anywhere from several weeks to multiple months, depending on injury severity and treatment.
Returning to AFL requires consideration of ankle stability, function, rehabilitation progress and the demands of the sport, rather than time alone.
Concerned About a High Ankle Sprain? Speak to Enhance Physio
Whether you’ve recently injured your ankle playing sport, are recovering from surgery or have completed a period in a moon boot, understanding the extent of your injury is an important first step.
Syndesmosis injuries can vary considerably in severity, and identifying potential instability early can help guide the appropriate treatment.
At Enhance Physio, our team can assess your ankle, discuss your injury and help guide your rehabilitation and return to activity.
If you’re concerned about a possible syndesmosis injury or need assistance recovering from a high ankle sprain, contact Enhance Physio to arrange an appointment.