What Is a Syndesmosis Injury?
A syndesmosis injury, often referred to as a high ankle sprain, involves damage to the ligaments that connect the tibia and fibula—specifically, the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), interosseous membrane, and interosseous ligament. These ligaments stabilize the ankle joint, particularly during weight-bearing and rotational movements.
Unlike a common ankle sprain, which usually affects the ligaments on the outside of the ankle, a syndesmosis injury is more complex and typically takes longer to heal.
Causes and Mechanism of Injury
Syndesmosis injuries are common in athletes, especially in sports involving cutting, pivoting, and sudden changes in direction (e.g., football, soccer, skiing, and rugby). The injury often occurs due to:
- External rotation of the foot relative to the leg
- Excessive dorsiflexion
- A direct blow to the lateral leg while the foot is planted
These forces stretch or tear the syndesmotic ligaments, leading to instability between the tibia and fibula.
Signs and Symptoms
Recognizing a syndesmosis injury can be tricky, as it may not present with classic signs of a typical ankle sprain. Common symptoms include:
- Pain above the ankle, especially over the distal tibiofibular joint
- Pain worsens with weight-bearing or external rotation of the foot
- Swelling and bruising higher up the leg than a lateral ankle sprain
- Difficulty or inability to walk
Special tests like the squeeze test or external rotation stress test can help clinically identify a syndesmosis injury, but diagnosis is often confirmed through imaging (X-ray, MRI, or CT scan).
Grades of Injury
Syndesmosis injuries are typically graded based on severity:
- Grade I (Mild): Ligaments are stretched but not torn. Stable joint.
- Grade II (Moderate): Partial ligament tears with some instability.
- Grade III (Severe): Complete ligament rupture with significant instability, often requiring surgical intervention.
Physiotherapy Management
Physiotherapy plays a critical role in the rehabilitation of syndesmosis injuries—especially in restoring function, preventing chronic instability, and ensuring a safe return to activity.
1. Acute Phase (0–7 days)
Goals:
- Control pain and inflammation
- Protect the injury
- Minimize further damage
Interventions:
- Rest, Ice, Compression, Elevation (RICE)
- Immobilization with taping, a boot or a brace
- Use of crutches to avoid weight-bearing if needed
- Gentle isometric exercises to maintain muscle activation (if pain-free)
2. Subacute Phase (1–4 weeks)
Goals:
- Gradually restore range of motion (ROM)
- Maintain strength without stressing the syndesmosis
- Begin controlled weight-bearing
Interventions:
- Gentle active ROM exercises (avoid forced dorsiflexion or external rotation)
- Aquatic therapy (if available) to reduce load during movement
- Strengthening of surrounding muscles (hip, knee, and core)
- Proprioception and balance training (progressing from stable to unstable surfaces)
3. Rehabilitation Phase (4–8 weeks)
Goals:
- Restore full ROM and strength
- Improve neuromuscular control
- Prepare for functional movement
Interventions:
- Closed-chain strengthening (e.g., squats, calf raises)
- Dynamic balance and proprioceptive exercises
- Gait re-training
- Gradual increase in weight-bearing exercises
4. Return-to-Sport Phase (8+ weeks)
Goals:
- Achieve sport-specific strength and agility
- Prevent recurrence
Interventions:
- Plyometrics (jumping, hopping drills)
- Agility drills (cutting, lateral movements)
- Sport-specific training
- Functional testing to assess readiness
When Is Surgery Needed?
In cases of Grade III injuries or where conservative treatment fails, surgical fixation of the syndesmosis may be required (e.g., screw or suture-button fixation). Post-operative rehab follows a similar physiotherapy timeline but may involve a more extended non-weight-bearing period.
Final Thoughts
Syndesmosis injuries can be more debilitating and longer-lasting than common ankle sprains. Accurate diagnosis and a structured physiotherapy program are crucial for a full recovery. With the proper care and a progressive rehab plan, most individuals can return to their normal activities or sports safely and confidently.
Need help with your recovery? Contact a licensed physiotherapist for a personalized assessment and treatment plan.