A high ankle sprain, known medically as a syndesmotic injury, is a severe injury requiring a distinct and often longer recovery period than a common ankle sprain. Unlike typical sprains affecting the outer ankle ligaments, this injury involves the structures holding the two lower leg bones together. A structured approach to rehabilitation is necessary to ensure the ankle regains full strength and stability, preventing long-term problems and managing a safe return to activity.
Understanding the Syndesmosis Injury
The syndesmosis is a fibrous joint located high above the ankle joint, where the tibia and fibula bones of the lower leg are connected. This connection is stabilized by a complex of ligaments, including the anterior inferior tibiofibular ligament (AITFL), the posterior inferior tibiofibular ligament (PITFL), and the interosseous ligament, which collectively provide a ring of support. The syndesmosis permits controlled movement between the two bones, which is necessary for normal ankle function.
A high ankle sprain typically results from a forceful external rotation and dorsiflexion of the foot, a movement common in contact sports. This mechanism causes a sequential rupture of the syndesmotic ligaments, separating the tibia and fibula. This injury is more serious than a standard lateral ankle sprain because it compromises the stability of the entire ankle mortise.
Diagnosis involves grading the injury to determine the appropriate rehabilitation protocol. A Grade I injury involves a stable joint with only partial ligament damage. Grade II injuries suggest a complete tear of the AITFL and interosseous ligament, but stability can vary. A Grade III injury represents a complete disruption of all syndesmotic ligaments, leading to an unstable joint that usually requires surgical stabilization.
Immediate Care and Immobilization
Initial management focuses on protection and managing swelling and pain using the P.O.L.I.C.E. principle: Protection, Optimal Loading, Ice, Compression, and Elevation. Protection involves using a walking boot or cast to limit movements that stress the healing ligaments, specifically avoiding external rotation and excessive dorsiflexion. Crutches are typically advised initially to remain non-weight-bearing, as placing full weight on the ankle can worsen the injury.
Optimal Loading encourages gentle movement of the injured area early in the process, which stimulates healing. For a high ankle sprain, this loading is highly restricted and must be pain-free, often starting with gentle, non-weight-bearing exercises. Ice should be applied for approximately 20 minutes every two hours to control pain and inflammation.
Compression with a wrap helps to minimize swelling, and the injured leg should be elevated above the level of the heart to assist fluid drainage. Seek immediate medical consultation if there is an inability to bear weight, signs of severe swelling, or suspicion of a fracture. The initial period of immobilization is often longer than a lateral sprain, sometimes lasting several weeks, depending on the injury grade.
Phased Rehabilitation Exercises
The rehabilitation for a high ankle sprain progresses through distinct phases, each building on the stability and pain tolerance achieved previously. The first phase focuses on restoring pain-free range of motion without stressing the syndesmosis. Gentle, non-weight-bearing exercises, such as tracing the alphabet with the toes, promote fluid movement and prevent stiffness.
Early mobility exercises should include gentle plantar flexion and inversion/eversion, but forceful dorsiflexion and external rotation must be avoided. Once pain and swelling subside and medical clearance is given, the next phase introduces strengthening. This progression begins with isometric exercises, followed by resistance band exercises.
Resistance band work targets the muscles that control inversion and eversion. Calf raises are gradually introduced to rebuild strength in the calf muscles, which are vital for walking and running. As strength improves, partial weight-bearing activities begin, progressing to full weight-bearing as tolerated.
The final phase focuses on proprioception, the body’s sense of its own position and movement. This neuromuscular control prevents re-injury. Exercises begin with simple single-leg stance drills on a stable surface, which challenges the ankle’s ability to maintain balance. Progression involves standing on unstable surfaces, such as a foam pad or balance board, to simulate unpredictable movements encountered in sport.
Criteria for Safe Return to Activity
A safe return to high-impact activities or sports is governed by objective criteria rather than the absence of pain. The healing timeline is highly variable, often ranging from six weeks to several months, and returning too early increases the risk of chronic instability. Before being cleared, the injured ankle must demonstrate a full, pain-free range of motion compared to the uninjured side.
Strength testing is essential, requiring the injured leg to achieve a near-equal level of strength (90% or more) compared to the uninjured leg. Functional tests are the final hurdle, ensuring the ankle can handle the dynamic demands of sport. These tests include performing a single-leg hop for distance, figure-eight running drills, and lateral shuffling, all executed without pain or hesitation.
The athlete must complete sport-specific drills at full speed and intensity without symptoms before full clearance is granted. Returning to play is a gradual process, starting with limited participation in low-impact activities and increasing intensity over time. Adherence to this criterion-based progression ensures the syndesmosis has healed sufficiently to withstand the stress of competition.