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04 May 2022

Sprained vs. broken ankle: how to tell if you sprained your ankle

symptoms 3 minutes reading time

At some point, most of us have caught our ankle at an awkward angle while running, playing a sport, or simply walking down the stairs. The question that naturally follows is: is it broken, or just sprained?

What is a sprained ankle?

“Sprain” is a popular catch-all phrase for an injury of the non-broken bone variety, but it's not an entirely accurate description. Medically speaking, a sprain is defined as an inversion (or sometimes a supination) injury in which the foot rolls inward, underneath the leg or ankle.1 A sprained ankle will often swell and bruise and may be painful to bear weight on. Sprains are diagnosed as Grade 1, 2, or 3 (mild, moderate, or severe, respectively).

Ankle anatomy

Most ankle sprains are lateral, which means there’s a tear in one or more of the three ligaments that connect the ankle bones to each other. Here are the most commonly torn ankle ligaments:

  1. The anterior talofibular ligament (ATFL), which connects the front of the talus (a middle ankle bone) to the bottom of the fibula (the outermost ankle bone).
  2. The calcaneofibular ligament (CFL), which connects the bottom of the fibula (the outermost ankle bone) to the calcaneus (the heel bone).
  3. The posterior talofibular ligament (PTFL), which connects the back of the talus (a middle ankle bone) to the fibula (the outermost ankle bone).

The ATFL and CFL are the most commonly sprained ligaments in the ankle; a PTFL sprain is not nearly as common.

Lateral sprains should be distinguished from high ankle sprains, which are less common, but more severe. A high ankle sprain involves the ligaments that connect the bottom of the fibula (the outermost ankle bone) to the tibia (the shin bone). This is a more debilitating injury and can take longer to heal than a lateral sprain.

What is the difference between a sprained ankle and a broken ankle?

Sprained and broken ankles share a lot of key similarities. They both cause localized bruising, swelling, and pain.

However, in addition to those symptoms, people with ankle fractures (breaks) may also experience:

  • Swelling that goes up the leg.
  • Pain that radiates from the ankle up to the knee.
  • Difficulty bearing weight on the affected ankle and foot (though some people with broken ankles can tolerate weight bearing, so do not rely on this to self-diagnose one way or the other).
  • Blisters.
  • Bone protrusion, otherwise known as an open ankle fracture. (Seek medical treatment immediately if you can see bones protruding through your skin.)

How is a sprained ankle diagnosed?

Sprained ankles can be diagnosed with physical exams and X-rays. Doctors can safely diagnose an ankle injury as a sprain when ankle pain, swelling, and tenderness result from an inversion injury and the X-ray is clear of broken bones.

MRIs are used in severe cases where cartilage damage is suspected or the sprain-healing process is going slower than expected.

If an X-ray does reveal an ankle fracture, being able to see the fracture in detail on a medical imaging scan helps doctors determine the best course of treatment moving forward (splint, cast, surgery, bone-setting, etc.).

Treating and recovering from a sprained ankle

How long it takes to heal from a sprained ankle depends on the severity of the injury.

For a Grade 1 sprain, the RICE (rest, ice, compression, elevation) directive should be closely followed. A Grade 1 sprained ankle should be fairly quick to heal, especially if you can bear weight on the ankle after the injury.

For a Grade 2 sprain, RICE should be followed, with a bigger emphasis on the rest period. Your doctor may opt to give your ankle some extra protection by immobilizing it with a splint. You should be able to return to normal activity after an extended period of rest and stabilization.

For a Grade 3 sprain, RICE with a long period of rest should be observed, and a longer healing process should be expected. A tall walking boot or cast may be needed to stabilize your injury and encourage proper alignment during the recovery process. Physical rehabilitation is often recommended and can be super helpful in strengthening the muscles and ligaments around your ankle as it heals. In rare cases, surgery for ligament reconstruction may be indicated.

Where to get an ankle scan near you

If you think you may have sprained or broken your ankle, getting the correct diagnosis quickly is the first step to recovery. Head over to scan.com`s easy-to-use scan search tool and find a scan provider near you today.


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