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The three ankle sprain grades are the language physicians use to describe how badly a ligament was injured in your ankle. Knowing your ankle sprain grade can tell you a lot about how long you will be out.
Grade 1 means the ligament stretched. Grade 2 means it partly tore. Grade 3 means it tore all the way through.
I want to be straightforward with you about where this article is coming from. My surgical practice at the Bone and Joint Institute of Tennessee is hip and knee replacement, and it has been for more than twenty years. Ankle injuries belong to my fellowship-trained foot and ankle partners at BJIT.
What follows is the general orthopaedic explanation I give when a patient in clinic points at a swollen ankle and asks how bad it is. Use it to understand what you are dealing with, then have the ankle seen by someone who treats them every day.
What are the three ankle sprain grades?
Ankle sprain grades sort the injury into three levels based on how much of the ligament failed. A ligament is a strong band of tissue that holds two bones together; in the ankle, ligaments keep the leg bones locked over the foot bones so the joint does not roll.
The grade describes tissue damage, not pain level. Some Grade 1 sprains hurt more in the first hour than Grade 3 sprains do, because a complete tear can leave the ankle numb and oddly quiet at first.
What is a Grade 1 ankle sprain?
A Grade 1 ankle sprain is a stretch of the ligament with microscopic tearing and no loss of joint stability. There is mild swelling, tenderness over the outside of the ankle, and some stiffness.
You can usually walk on it, with a limp. The ankle feels sore rather than loose. This is the sprain most people treat at home with rest, ice, compression, and elevation, the approach the American Academy of Orthopaedic Surgeons describes for mild sprains.
What is a Grade 2 ankle sprain?
A Grade 2 ankle sprain is a partial tear: the ligament is torn part of the way through but is still in one piece. Swelling and bruising are obvious, motion is limited, and walking hurts.
The ankle may feel slightly unstable, like it could give way. Grade 2 is the grade most often underestimated. Patients tell me they assumed it was minor because they could still hobble to the car.
What is a Grade 3 ankle sprain?
A Grade 3 ankle sprain is a complete tear of one or more ligaments, also called a ligament rupture. The ankle is markedly swollen and bruised, it feels unstable when a physician tests it, and putting weight on it is usually not possible.
A Grade 3 injury deserves same-week evaluation. The symptoms overlap almost exactly with an ankle fracture, and only an exam plus imaging can separate the two.
Which ligaments are injured at each of the ankle sprain grades?
Most ankle sprains injure the lateral ligaments on the outside of the ankle, in a predictable order as force increases.
- Anterior talofibular ligament (ATFL): the front outside ligament, and the first one to go. Nearly every inversion sprain (the foot rolling inward) involves it.
- Calcaneofibular ligament (CFL): injured next, when the force continues past the ATFL. Involvement here usually pushes the injury into the Grade 2 range.
- Posterior talofibular ligament (PTFL): the strongest of the three and rarely torn unless the injury is severe.
- Deltoid ligament: the thick ligament on the inside of the ankle, injured when the foot turns outward. Less common and slower to settle.
What is a high ankle sprain, and does it get a grade?
A high ankle sprain injures the syndesmotic ligaments that bind the two lower leg bones together just above the joint, and it is graded on its own scale rather than the standard 1 to 3 system. The pain sits higher up the leg than a typical sprain.
High ankle sprains take considerably longer to heal than lateral sprains of the same apparent severity. They are also the group most likely to need surgical stabilization. If your pain is above the ankle bone rather than below it, say so at your visit.
How does a physician assign the grade?
Ankle sprain grades are assigned from the physical examination first: where the tenderness sits, how much swelling and bruising there is, whether you can bear weight, and how the joint responds to gentle stability testing. Imaging confirms and refines it.
An X-ray is used to rule out a fracture, not to see the sprain; ligaments do not appear on plain films. An MRI is reserved for injuries that are not improving on schedule, cases where instability persists, or when a high ankle sprain is suspected.
One practical point patients rarely hear: swelling makes the first exam less reliable. A foot and ankle physician will often recheck the joint a few days later, once the stability test means something.
How long do the ankle sprain grades take to heal?
Recovery tracks the grade closely, and these are the ranges published by major academic centers.
- Grade 1: roughly 1 to 3 weeks to return to normal activity.
- Grade 2: roughly 3 to 6 weeks, often with a brace or walking boot for part of that time.
- Grade 3: several months, and formal physical therapy that can run up to 12 weeks.
- High ankle sprain: several months, sometimes longer than a Grade 3 lateral sprain.
I tell patients to expect swelling that comes and goes for months after the pain is gone, particularly at the end of a long day on their feet. That is normal and is not a sign the ligament is failing.
Which ankle sprain grades need physical therapy?
Grade 2 and Grade 3 sprains nearly always need supervised rehabilitation, and many Grade 1 sprains benefit from a short course of it. The reason is balance rather than strength.
A torn ligament also damages the position sensors inside it, so the ankle stops reporting its own position accurately. Rebuilding that sense, called proprioception, is what protects you from spraining the same ankle again. Rehabilitation exercises after an ankle sprain have been shown to reduce reinjury, and the National Institute of Arthritis and Musculoskeletal and Skin Diseases lists balance work as a core part of recovery.
How is each grade treated?
Early treatment is largely the same across all three ankle sprain grades: protection, rest, ice, compression, and elevation for the first 48 to 72 hours. What changes with the grade is how long the ankle is protected and how quickly you progress.
Grade 1 sprains are managed at home with a compression wrap and early gentle motion. Grade 2 sprains usually add a lace-up brace or walking boot and a structured therapy program. Grade 3 sprains may need a period of immobilization in a boot or short cast, crutches, and a longer rehabilitation runway.
Surgery is uncommon for acute ankle sprains. It is considered mainly for syndesmotic (high ankle) injuries, for competitive athletes with a complete lateral tear, and for people who develop chronic instability after conservative treatment has been given a fair trial.
What happens if an ankle sprain is not treated properly?
An undertreated sprain can leave the ankle chronically unstable, and repeated giving way over the years damages cartilage and raises the risk of post-traumatic ankle arthritis. The same wear pattern is why I write so often about how to prevent arthritis in every joint. This is the part of ankle sprain grades I care most about as a joint replacement surgeon.
Almost every arthritic joint I operate on has a history behind it. Ankles are no different: the sprain that never fully rehabilitated in your thirties is often the reason the joint is painful in your sixties.
The patients who do best are the ones who finish rehabilitation instead of stopping the day the pain does.
When should you see an orthopaedic specialist in Middle Tennessee?
See a physician within a day or two if you cannot put weight on the ankle, if there is significant deformity or numbness, or if pain and swelling are worse rather than better after 48 hours. Persistent joint swelling anywhere deserves attention, the same way it does when a knee fills with fluid. Also come in if a Grade 1 sprain has not improved after about a week.
Patients across Franklin, Nashville, Brentwood, Spring Hill, Columbia, and the rest of Middle Tennessee are seen at the Bone and Joint Institute of Tennessee at 3000 Edward Curd Lane, Franklin, TN 37067. Ankle injuries are evaluated by our fellowship-trained foot and ankle specialists; call (615) 791-2630 to arrange that visit.
If your question is about hip or knee pain rather than an ankle, you can read more about knee replacement and hip replacement, or schedule a consultation with Dr. Calendine directly.
Video: why some ankles keep rolling
This short covers the part patients ask about most: why an ankle that healed still gives way, and what that says about the ligament underneath.
Medical disclaimer: This article is general orthopaedic education and is not a substitute for an examination, diagnosis, or treatment plan from a qualified healthcare professional. Dr. Cory Calendine, MD, practices exclusively in hip and knee replacement; ankle injuries are managed by the fellowship-trained foot and ankle specialists at the Bone and Joint Institute of Tennessee. In a medical emergency, call 911.
