A high ankle sprain, medically known as a syndesmotic injury, is often more severe than a common lateral ankle sprain. This injury involves the ligaments connecting the tibia and the fibula, which are crucial for maintaining ankle joint stability. Recovery is highly variable and typically requires a much longer healing time, depending on the severity of the ligament damage and adherence to treatment.
Defining the High Ankle Sprain
A high ankle sprain affects the syndesmosis, the fibrous joint located just above the ankle joint. The syndesmotic ligaments, primarily the anterior inferior tibiofibular ligament (AITFL) and the posterior inferior tibiofibular ligament (PITFL), hold the tibia and fibula together. When these ligaments are stretched or torn, the stability of the ankle mortise—the socket where the talus bone fits—is compromised.
This injury typically occurs from a high-force mechanism, such as a planted foot being twisted outward (external rotation) combined with the foot flexing upward (dorsiflexion). This action forces the wider front part of the talus bone into the joint, separating the tibia and fibula. Because the syndesmosis is directly involved in ankle stability, its injury creates a much more unstable situation than a common lateral ankle sprain.
Standard Timelines for Recovery
Recovery timelines are directly tied to the extent of ligament damage, categorized into three grades of severity. These durations represent the time until functional recovery under non-operative management. The inherent instability caused by syndesmotic injury makes these timelines notably longer than those for common ankle sprains.
A Grade I high ankle sprain involves a mild stretch of the ligaments without joint instability. Recovery generally requires four to six weeks. Individuals can often begin gentle weight-bearing activities relatively quickly, but a measured return to activity is still necessary for full ligament healing.
For a Grade II sprain, there is a partial tear of the syndesmotic ligaments and potential instability. Patients can expect a healing duration of six to twelve weeks to safely regain strength and stability. This moderate injury often requires initial immobilization to protect the ligaments from further separation.
A Grade III injury involves a complete rupture of the syndesmotic ligaments, resulting in definite joint instability, often associated with a fracture. Non-surgical recovery for this severe sprain can take three to six months or longer. If significant instability requires surgical fixation, the recovery timeline is extended by the initial non-weight-bearing phase required for surgical healing.
Treatment Protocols That Impact Healing Duration
Healing duration is influenced by the treatment protocols and the patient’s adherence. Initial management for non-surgical sprains follows the RICE principle: rest, ice, compression, and elevation, focusing on reducing swelling. For most cases, crutches are necessary for non-weight-bearing to prevent the tibia and fibula from separating, which disrupts healing.
Immobilization, often using a walking boot or cast, continues until the patient can bear weight without pain. Once pain-free weight-bearing begins, physical therapy (PT) drives recovery. PT focuses on restoring range of motion while avoiding forceful dorsiflexion and external rotation initially to protect the repair.
A structured PT program gradually progresses to strengthening exercises and balance training to restore proprioception. Consistent participation in rehabilitation is the most important factor in meeting recovery timelines. If the injury is Grade III or a significantly unstable Grade II, surgery may be required, adding four to six weeks of strict non-weight-bearing before rehabilitation begins.
Recognizing Readiness for Return to Activity
Returning to high-impact activity or sport is determined by functional criteria demonstrating the ankle’s stability, strength, and pain-free motion. Readiness is confirmed when the individual can perform all required movements without pain or a feeling of instability.
Functional testing includes achieving symmetrical, pain-free range of motion, especially into dorsiflexion, compared to the uninjured ankle. Specific strength metrics must also be met, often involving the ability to perform a certain number of single-leg calf raises.
Dynamic tests simulate sport-specific movements, such as hopping for distance, vertical hopping, and performing cutting or pivoting maneuvers. Only after all functional milestones are achieved is the high ankle sprain considered fully healed and ready for the demands of full activity.