A high ankle sprain, technically called a syndesmotic sprain, is an injury to the ligaments connecting the tibia and the fibula just above the ankle joint. This injury is distinctly different from the more common lateral, or low, ankle sprain, which affects the ligaments on the outside of the ankle. A high ankle sprain compromises the stability of the entire ankle mortise, or joint structure. It is considered more severe and requires a careful and lengthy management approach. Given the structures involved, the ability to walk on a high ankle sprain is severely compromised, and attempting to do so can significantly worsen the injury.
Understanding the Syndesmosis and Severity
The syndesmosis holds the tibia and fibula together, preventing them from spreading apart under pressure. Stability is maintained primarily by the anterior inferior tibiofibular ligament (AITFL) and the posterior inferior tibiofibular ligament (PITFL). The interosseous membrane, a thick sheet of tissue running between the tibia and fibula, also contributes to this connection.
A high ankle sprain occurs when the foot is forcibly twisted outward while flexed upward, causing these ligaments to tear. This mechanism of injury is common in contact sports and puts extreme stress on the joint.
Damage to the syndesmosis is serious because these ligaments maintain the correct spacing between the tibia and fibula, allowing the talus bone to fit securely within the ankle joint. When torn, the joint becomes unstable, allowing the bones to separate, especially when bearing weight. This instability is why a high ankle sprain is associated with a greater risk of persistent pain and long-term dysfunction compared to a low ankle sprain.
Immediate Assessment and the Weight-Bearing Question
While some individuals with a milder injury may manage a painful limp, walking on a high ankle sprain is highly discouraged. The inability to bear weight is a major indicator of a severe sprain or possible fracture, necessitating immediate medical attention. Forcing weight onto an unstable syndesmosis can widen the gap between the tibia and fibula, potentially turning a partial tear into a complete ligament rupture.
The pain is typically localized higher up the leg, above the ankle joint, in the area between the two bones. Medical professionals identify this injury using specific tests, such as the squeeze test, where compressing the tibia and fibula causes significant pain at the syndesmosis. This distinct location of pain helps differentiate it from a common lateral sprain, where tenderness is focused on the outer side of the ankle.
Initial management should follow the RICE protocol: Rest, Ice, Compression, and Elevation. Rest is paramount, requiring the use of crutches to avoid putting pressure on the injured leg. Seeking a professional diagnosis is imperative, as X-rays are required to check for fractures and assess if the tibiofibular joint has widened, indicating severe instability.
Medical Treatment and Expected Recovery Journey
Treatment depends on the injury’s severity and whether the joint is stable or unstable. For stable injuries, typically Grade 1 or 2 sprains, non-surgical treatment is the standard approach. This involves a prolonged period of immobilization, often utilizing a walking boot, with a non-weight-bearing phase lasting two to six weeks.
Recovery is significantly longer than for a standard ankle sprain, often requiring eight to twelve weeks or more before returning to full activity. Physical therapy is a necessary component, beginning with gentle range of motion exercises after the initial non-weight-bearing period. The subsequent phase focuses on strengthening surrounding muscles and improving balance to restore the ankle’s function.
Severe, unstable high ankle sprains, sometimes classified as Grade 3, often require surgical intervention to restore proper bone alignment. Procedures may involve using a screw or a modern suture-button device, such as the TightRope system, to provide a strong connection between the tibia and fibula. Following surgery, patients face a recovery period of four months or longer, requiring a structured rehabilitation program for a successful return to activity.