An ankle sprain refers to the tearing of the ligaments of the ankle and account for approximately 40% of all athletic injuries. 85% of ankle sprains occur on the outside (lateral side) of the ankle and are known as an inversion sprain. This is the type of injury that most runners experience when they sprain their ankles. Medial ankle sprains (along the inside of the ankle) occur less frequently and are usually caused by fractures or other traumatic events.
So, why is an inversion sprain so common? You can put it down to our lopsided anatomy! The bone on the lower outside of the ankle (the lateral malleolus – distal fibula) extends further down than the bone on the inside of the ankle (medial malleolus – fibula). This difference gives the inside of the ankle (medial side) more stability than the outside of the ankle (lateral side).
At a symptomatic level, most ankle sprains appear to resolve completely without rehabilitation. In reality, ankle sprains that have not been rehabilitated correctly are usually susceptible to further injury.
Anatomy of an Ankle Sprain
The outside (lateral side) of the ankle achieves its stability from a three-ligament complex. These three ligaments are the:
Anterior Talofibular ligament (ATFL)
Calcaneofibular ligament (CFL)
Posterior Talofibular ligament (PTFL)
In an inversion sprain, the Anterior Talofibular ligament (ATFL) is the most commonly injured. Ligaments in the ankle are named according to the bones to which they connect. In this case, the Anterior Talofibular ligament connects to the talus bone of the ankle as well as to a long bone of the lower leg – the fibula. The function of the ATFL is to prevent forward (anterior) displacement of the ankle (the talus).
In a severe ankle sprain another ligament called the calcaneofibular ligament (CFL) may also be damaged. This ligament connects your heel bone (calcaneous) with the fibula. This is a stronger ligament than the ATFL, and is not damaged as easily.
Both the ATFL and the CFL are usually damaged in motions where the foot is both pointed down (plantar flexed) and rolled out (inverted). Considerable instability in the ankle can occur when both these ligaments are injured.
The posterior talofibular ligament (PTFL) is not injured very often, except when there is a complete dislocation of the ankle (talus). The PTFL is the strongest ligament in the lateral complex.
Another sprain injury that is becoming more prevalent is called a “High Ankle Sprain” (syndesmotic ligament complex). In this injury, the ligament and connective tissue between your shin bones (tibia and fibula) are torn. This is a serious injury that may require surgery to resolve.
Not Just Ligaments
An ankle sprain may also result in damage to other structures. You may also experience damage to connective tissue, tendons, muscles further up the ankle, and even to the bones (possible fractures). This is why, with a severe ankle sprain, it is important to see a medical professional who can determine exactly which structures have been injured, and then provide treatment recommendations.
Grading the Severity of an Ankle Sprain
Ankle sprains are graded in increasing severity from grade 1 to 3. The following grading system should give you an indication of the severity of your ankle sprain.
Grade 1: Sprain
The injured person can still walk, although with some degree of difficulty.
There may be some swelling, stiffness, and pain.
There is only minor tearing of the ligaments. A common analogy is comparing a ligament to a piece of tissue paper. In a Grade 1 injury there are only minor tears in the tissue.
The ankle joint remains quite stable. This stability will be evident with stress testing (Anterior Drawer Test, and Anterior Tilt Test).
Grade 2: Sprain
The injured person may experience considerable difficulty when walking and could be in severe pain. There may be swelling and some degree of bruising.
There is a moderate amount of tearing of the ligaments. To use the tissue analogy, there will be a significant amount of tears in the tissue.
The ankle will become somewhat unstable. This instability is evident on stress testing (with increased anterior motion showing on the Anterior Drawer Test and indicating an ATFL tear).
Grade 3: Sprain
A Grade 3 Sprain is a complete tearing of the ligament. To use the tissue analogy, the tissue is now torn into two pieces. This type of sprain may require surgical intervention to reattach the ligament. In most cases a conservative period of therapy will be tried for about six weeks before surgery is considered.
The ankle is completely unstable, and the patient cannot walk or place weight on the ankle. (Increased motion on the Anterior Drawer and Talar Tilt Tests indicates a complete tear of the ATFL and at least a partial tear of CFL).
There will be severe pain at the initial event, followed by a compete lack of pain, as long as there is no weight placed on the joint.
Treatment of Ankle Sprains
There are a number of things you can do to treat ankle injuries.
Just After the Injury
Immediately after spraining your ankle, it is important to do everything you can to reduce the swelling in the ankle. The faster you can implement treatment, the faster you will recover. An ankle sprain injury that is addressed quickly will often resolve in short period of time. If the injury is ignored, the ankle sprain could be prolonged for extensive periods of time.
So, immediately after the injury, while still in the acute stage – use RICE – rest, ice, compress, and elevate!
R = Rest: During this stage, it may be necessary to take all weight off of the injured ankle. In such cases, crutches are commonly used. In my opinion, it is important to quickly return to weight-bearing as soon as possible to improve healing. I have found that reintroduction of weight-bearing stresses tends to decrease recovery time. When should you do this? As soon as possible, but not too soon! Rest is also essential.
I = ICE : See our page about Cold Therapy and Icing. Ice for at least 20 to 30, minutes 4 to 5 times per day to reduce swelling.
C = Compression: Compression (with an ACE wrap) reduces both swelling and bleeding. With a Grade 3 sprain, wear a brace at all times until you are able to bear weight on your ankle.
E = Elevation: Elevating the injured area acts to reduce swelling and bleeding.
Once you have used “RICE”, it is very important to introduce motion into the ankle as soon as possible. Depending on the degree of injury, the patient could be asked to perform gentle ankle circles, or if able to do so, write the alphabet with their feet. Light calf stretching and using a stationary bicycle may also be beneficial.
If you are going to use medication (NSAID’s) to reduce inflammation, be sure not to use them for more than seven days. Using anti-inflammatory medications for long periods of time inhibits tissue remodeling. See our Blog about Recommendations to Reduce Inflammation without Medication.