A high ankle sprain is significantly more serious than a typical ankle sprain. While a standard sprain heals in a few weeks, a high ankle sprain takes six to eight weeks on average, and athletes often need even longer before returning to competition. The injury affects a different set of ligaments higher up on the ankle, and it carries a greater risk of long-term complications if not treated properly.
What Makes It Different From a Regular Sprain
A regular ankle sprain damages the ligaments on the outer side of your ankle, usually from rolling your foot inward. A high ankle sprain injures a completely separate group of ligaments called the syndesmosis, which sits above the ankle joint and holds the two lower leg bones (the tibia and fibula) together. These ligaments include the front and back connective tissue between the bones, plus a tough membrane that runs between them along the length of the lower leg.
This distinction matters because the syndesmosis does something fundamentally different from lateral ankle ligaments. It keeps the two leg bones properly spaced and aligned every time you push off, land, or change direction. When that stability is compromised, the entire ankle joint mechanics change. High ankle sprains account for only 1% to 11% of all ankle injuries, but they’re disproportionately common in sports that involve cutting, planting, and external rotation of the foot.
Severity by Grade
Like other sprains, high ankle sprains are classified into three grades, and the difference between them is substantial.
A Grade I injury involves stretching with microscopic tearing of the ligament fibers. You’ll have tenderness and mild swelling above the ankle, but you can usually still put weight on it with some discomfort. There’s no real instability in the joint.
A Grade II sprain means a partial tear. Swelling and bruising are moderate, and walking becomes noticeably difficult. The joint feels somewhat loose compared to the other ankle, but there’s still a firm endpoint when a clinician stresses it. This is where recovery starts to extend significantly.
A Grade III sprain is a complete rupture of one or more of the syndesmotic ligaments. Pain and swelling are severe, often with widespread bruising. You typically can’t bear weight at all. The joint is clearly unstable, and this grade frequently requires surgical repair. Grade III injuries can also involve small bone chip fractures at the attachment points of the torn ligaments.
How It’s Diagnosed
High ankle sprains are notoriously difficult to diagnose because standard ankle X-rays can look normal, and the swelling pattern overlaps with other injuries. The key indicator is tenderness located above the ankle joint, over the space between the tibia and fibula, rather than below or around the bony bumps on either side.
Clinicians use several physical tests to narrow it down. In the squeeze test, a provider compresses the two lower leg bones together at mid-calf level. If this produces pain down at the ankle, it suggests syndesmotic injury. This test has the highest specificity of the common clinical exams, at 88%, meaning when it’s positive, the injury is very likely real. Another test involves stabilizing the leg and rotating the foot outward while the ankle is flexed upward. Pain during this maneuver makes a syndesmotic injury about four times more likely.
One of the most sensitive screening signs is simply whether you can hop on the injured leg. In a study of 87 patients with ankle sprains, inability to perform a single-leg hop correctly identified 89% of those who turned out to have syndesmotic damage on MRI. No single test is reliable enough on its own, so providers typically combine several tests along with imaging to confirm the diagnosis.
Recovery Timeline
The minimum recovery for a high ankle sprain is roughly six to eight weeks, which is already two to three times longer than most lateral ankle sprains. Severe cases, especially those requiring surgery, can take several months.
In the acute phase, most people cannot bear full weight and need crutches. Those with milder injuries might walk with weight as tolerated, but more severe sprains often require one to two weeks of restricted weight bearing. You progress to full weight bearing only when you can walk on different surfaces and handle stairs with minimal pain. That milestone, ditching the crutches, marks the transition into the next phase of rehab.
From there, rehabilitation focuses on restoring range of motion, rebuilding strength, and retraining balance. The ankle’s ability to flex upward (dorsiflexion) is often limited after a syndesmotic injury, and recovering it is critical. Clinicians measure this with a lunge test: if you can’t get your knee within 9 to 10 centimeters of a wall while keeping your heel on the ground, your motion is still restricted.
When Surgery Is Needed
Grade I and most Grade II high ankle sprains are treated without surgery using immobilization and structured rehab. Grade III injuries, where the ligaments are completely torn and the joint is unstable, typically require surgical stabilization.
The two main surgical approaches involve either a rigid screw placed across the two leg bones to hold them together, or a flexible cord-and-button device (often called a tightrope) that allows some natural movement between the bones. A randomized trial comparing the two methods found similar rates of proper joint alignment and no significant difference in functional outcomes or arthritis development after at least two years. The screw approach showed slightly more loosening of the reduction over time, while the flexible device maintained alignment more consistently, but the differences were not statistically significant.
Long-Term Risks
What makes a high ankle sprain particularly serious is the potential for lasting problems. Even after the ligaments heal, abnormal bone formation can develop in the space between the tibia and fibula. This extra bone can restrict motion and alter how the joint moves, potentially contributing to early-onset arthritis in the ankle.
Chronic instability is another concern. If the syndesmosis doesn’t heal with proper alignment, the slight widening between the two leg bones changes how forces distribute across the ankle with every step. Over time, this accelerates cartilage wear. This is why getting an accurate diagnosis early, rather than treating it like a simple sprain, matters so much for the long-term health of the joint.
Returning to Full Activity
Returning to sports or high-demand activity after a high ankle sprain requires more than just the absence of pain. Functional testing is used to measure whether the ankle has truly recovered. These tests evaluate balance on one leg using a star-shaped reaching pattern, agility through timed direction changes, and vertical jump height compared to the uninjured side.
Rushing back is one of the most common mistakes with this injury. Because the pain often improves before the ligaments have fully healed and the joint has regained its stability, people frequently return to activity too soon and either re-injure the syndesmosis or develop compensatory problems in the knee or hip. The six-to-eight-week timeline is a floor, not a ceiling, and athletes in cutting or contact sports should expect to be on the longer end of recovery.