A high ankle sprain, medically known as a syndesmotic sprain, involves damage to the robust ligaments directly above the ankle joint. Unlike the common lateral ankle sprain, which typically results from the foot rolling inward, a high ankle sprain impacts the stability of the lower leg bones. Because of this distinction in anatomy, recovery from a high ankle sprain is consistently longer and often more complex than recovery from a less severe lateral sprain.
Identifying a High Ankle Sprain
A high ankle sprain targets the syndesmosis, a collection of fibrous ligaments connecting the two long bones of the lower leg: the tibia and the fibula. These ligaments, including the anterior inferior tibiofibular ligament (AITFL) and the posterior inferior tibiofibular ligament (PITFL), maintain the crucial space just above the ankle joint. Damage to this area compromises the mortise, the bony structure essential for ankle stability and movement.
The injury mechanism involves a high-force movement where the foot is firmly planted on the ground. Trauma typically occurs when the foot is forcibly twisted outward (external rotation), often while the foot is flexed upward (dorsiflexion). This action forces the tibia and fibula apart, tearing the syndesmotic ligaments.
Grading the Severity and Expected Timelines
The length of recovery for a high ankle sprain is directly tied to the injury’s severity, which is categorized using a medical grading system. Diagnosis is confirmed through physical examination tests, such as the squeeze test, and is followed by imaging like X-rays or magnetic resonance imaging (MRI) to assess ligament damage and rule out fractures.
Grade I Sprain
A Grade I sprain represents a mild overstretching of the syndesmotic ligaments without any joint instability. Individuals with this mildest form can expect to return to regular activities within two to six weeks. Treatment is non-surgical, focusing on rest and controlled weight-bearing as symptoms allow.
Grade II Sprain
A Grade II injury involves a partial tear of the ligaments, resulting in moderate joint instability. Due to the significant structural damage, the recovery timeline lengthens considerably, often requiring six to twelve weeks. These cases necessitate a period of immobilization in a walking boot or cast to protect the healing ligaments.
Grade III Sprain
The most severe injury, a Grade III sprain, signifies a complete rupture of the syndesmotic ligaments and results in significant joint instability. This level of injury often requires surgical intervention to stabilize the tibia and fibula, sometimes involving the insertion of screws or a “tightrope” system. Recovery from a Grade III sprain is the longest, generally ranging from three to six months.
Essential Phases of Rehabilitation
Successful recovery follows a criterion-based progression through distinct phases, rather than a rigid timeline.
Acute or Protection Phase
This phase begins immediately after injury and focuses on reducing pain and swelling. This is achieved using the RICE principle (Rest, Ice, Compression, Elevation). It often involves a period of non-weight bearing or protected weight bearing with crutches or a boot to allow the damaged tissue to begin healing.
Subacute or Mobilization Phase
This stage begins once pain and swelling are significantly reduced and the individual can tolerate some weight-bearing. The primary goal is to restore the ankle’s range of motion, particularly dorsiflexion (the upward movement of the foot). Therapeutic exercises involve gentle joint mobility work, light stretching, and the introduction of isometric and resistance band exercises to begin rebuilding strength.
Functional or Strengthening Phase
This final stage concentrates on preparing the ankle for the demands of daily life and sport. This phase introduces challenging exercises aimed at improving proprioception and neuromuscular control, such as single-leg balance drills and exercises on unstable surfaces. Strengthening progresses from simple resistance to dynamic, weight-bearing activities like heel raises, calf presses, and eventually plyometrics.
Criteria for Returning to Activity
The decision to return to full activity is based on meeting specific, measurable physical benchmarks rather than simply the passage of time. A primary criterion is the achievement of full, pain-free range of motion in the injured ankle, especially in dorsiflexion, which is vital for walking and running mechanics. Strength symmetry is also measured, requiring the injured leg to demonstrate at least 90 to 95% of the strength of the uninjured leg in key movements. The final steps involve performing sport-specific functional testing without pain or instability, including high-demand activities like running, jumping, and controlled cutting maneuvers. Final clearance from a physician or physical therapist is necessary before returning to high-impact sports to ensure the syndesmosis is fully healed and to minimize the risk of re-injury.