By Victor 
Ankle sprain is defined as injury to the ligaments and sometimes tendons on the ankle joint. It can occur due to trauma in sports, or may be due to slip or taking wrong step on uneven surface.
Mechanism of injury is very important in determining what tests or image studies (e.g. X-ray or MRI) need to be done while severity on sprain determines type of treatment that’s appropriate. Home treatment of ankle sprain usually works for mild to moderate injuries, while severe injuries on the other side may require surgery.
Difference between Sprain and Strain
Sprain refers to injury on the ligaments or tendons of the joint while Strain refers to injury on the muscles usually due to overuse or over stretching. When you play sport or exercise and pull a muscle that is muscle strain but when you twist an ankle, the ligaments are overstretched and you suffer ankle sprain. Many people tend to confuse sprain with strain while they are two different conditions.
Ankle joint is made up of many ligaments that connect the bones of the foot with tibia and fibula bones. They also stabilize the joint while allowing many movements to be possible. Look at image below that demonstrate ankle ligaments that can tear in sprain.
Possible movements of ankle joint are inversion, eversion, plantarflexion and dorsiflexion. Look at the image below illustrating types of movements of ankle joint.
Common Mechanisms of injury
- Bad step while running
- Slipping and a fall
- Being tackled in sport
Some people are at greater risk of suffering from ankle sprain than others, these are:
- Elderly: Due to poor coordination when walking, old people can easily miss a step
- Arthritis: People who suffer from any type of arthritis are at increased risk because pain on other parts of their body may alter their gait.
- Obesity: Being obese or inactive is also a risk factor, ligaments may struggle to stabilize the joints due to large weight placed on them and lack of flexibility.
- Diabetes Mellitus: Neuropathy caused by diabetes mellitus complication can result in poor coordination and decreased sensation on the feet making the person prone to falls.
Symptoms and signs of Ankle Sprain
After twisting your ankle, you may experience one or more of the following signs and symptoms:
- Pain and swelling on the ankle
- Warmth
- Reduced active range of motion due to pain
- Redness
Physical Examination may reveal:
- Tenderness on the on the side affected
- Unstable joint indicate presence of third degree sprain
- Oedema and bruising on the side affected
Diagnosis and classification of Ankle Sprain
The diagnosis of ankle sprain is clinical, this means no tests or imaging is required in most cases. X-ray is done if bone fracture is suspected using Ottawa ankle rules.
Ottawa Ankle Rules
- Inability to bear weight without assistance immediately after injury AND unable to walk 4 steps without limping in Examination room
- Bone tenderness within 6cm above lateral or medial malleolus
If the person has one of the above, they should be done an X-ray of the ankle to rule out fracture. It applies to people that are 2 years and above.
MRI can be done as well to reveal clearly whether the ligaments are completely or partially torn but it’s rarely done.
Grades of Ankle sprain
First Degree (mild): The ligament is not torn but overstretched. The pain is usually mild with little or no swelling at all.
Second Degree (moderate): This is moderate injury where the ligament is partially torn. Joint is till stable but there is swelling and significant pain
Third Degree (severe): Here the ligament is completely torn with joint instability. This type of injury require surgical repair to prevent permanent disability and early Osteoarthritis.
Treatment
The best treatment for first and second degree ankle sprain is “PRICE” method. Each letter represent what you can do to shorten the duration of injury.
P-protection: You should apply protection of the ankle by using splints and crutches to limit weight bearing
R– rest: rest is very important to prevent further injury. It is important especially in the first week after injury.
I-ice: ice compression help to reduce inflammation and pain
C- compression: crepe bandage help in partially stabilizing the joint and reduce swelling
E- elevation: you should keep the leg high (i.e. put a stool underneath when sitting down) and pillow under it when on the bed to reduce swelling.
A cast may be needed as form of protection during the injury. Early mobilization should be started after at least a week following injury. For pain: Paracetamol (Acetaminophen) 1g oral 6 hourly helps in adults.
Use of NSAIDs such as Naproxen, Ibuprofen and Diclofenac among others can help if used for a short period of time. Longer duration is associated with Peptic Ulcer Disease.