Peroneal Tendon Rupture

Peroneal tendon rupture is a complete tear in one or both of the two peroneal tendons that are on the outside of the ankle. These tendons attach two muscles (peroneus longus and peroneus brevis) to the bones of the ankle.

These two muscles are used to straighten the foot, such as when standing on tiptoes or pushing off of the foot during walking, running, or jumping. These muscles are also used to turn the foot to the outside. A rupture of one or both of these tendons decreases the ankle’s ability to do these motions.

What are the causes?

This condition is often due to long-term (chronic) injury, but it may also occur suddenly. These types of injuries can happen if:

• Repeated ankle movements cause the peroneal tendons to rub forcefully against the bony groove in which they sit.
• A sudden stress on the peroneal tendons stretches them farther or faster than they are meant to stretch.
• A person has certain medical problems.
• A person has taken certain medicines for a long time.

What increases the risk?

This condition is more likely to develop in:

• People who play sports that require sudden, explosive lower leg muscle contraction, as with jumping or quick starts.
• People who play sports that involve kicking with the outer part of the foot, such as martial arts.
• People who have a misshapen groove in the bottom of the heel bone (calcaneus) where the peroneal tendons sit.
• People who have poor foot strength and flexibility.
• People who do not warm up properly before activities.
• People who have had a previous or recent ankle sprain.
• People who have had a previous or untreated peroneal tendon injury.
• People who have a corticosteroid injection in or near the peroneal tendon, especially where it inserts into the bone.
• People who have medical problems that decrease blood supply to the peroneal tendons.
• People who use certain antibiotics.

What are the signs or symptoms?

Symptoms of this condition include:

• A “pop” or tearing feeling behind the outer part of the ankle.
• Pain when moving the foot up and down.
• A clicking feeling when moving the foot up and down.
• Inability to stand on the toes or the ball of the foot or weakness when trying to stand on the toes or the ball of the foot.
• Pain when the injured area is pressed.
• Swelling around the injured area.
• Bruising around the injured area.

How is this diagnosed?

This condition is diagnosed with a medical history and physical exam. Your health care provider will ask about your symptoms and ask for details about your injury, if your condition was caused by an injury. Imaging studies are often used to confirm the diagnosis. These may include:

• X-ray.
• MRI.
• Ultrasound.

How is this treated?

Treatment may start with the use of icing and medicines to reduce your pain. You may also be advised to limit the movement of your ankle. This may include wearing a splint or a brace, or using crutches to avoid using your injured ankle to support your body weight. In severe cases, surgery may be needed to repair the rupture.

Follow these instructions at home:

If you have a splint or brace:

• Wear it as told by your health care provider. Remove it only as told by your health care provider.
• Loosen the splint or brace if your toes become numb and tingle, or if they turn cold and blue.
• Keep the splint or brace clean and dry.

Managing pain, stiffness, and swelling

• If directed, apply ice to the injured area.
  • Put ice in a plastic bag.
  • Place a towel between your skin and the bag.
  • Leave the ice on for 20 minutes, 2–3 times per day.
• Move your toes often to avoid stiffness and to lessen swelling.
• Raise (elevate) the injured area above the level of your heart while you are sitting or lying down.

Driving

• Do not drive or operate heavy machinery while taking prescription pain medicine.
• Ask your health care provider when it is safe to drive if you have a cast, splint, or brace on your ankle.

General instructions

• Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
• Take over-the-counter and prescription medicines only as told by your health care provider.
• Keep all follow-up visits as told by your health care provider. This is important.
• Do not use the injured limb to support your body weight until your health care provider says that you can. Use crutches as told by your health care provider.

Contact a health care provider if:

• Your pain gets worse even if you have had treatment.
• Your foot or ankle feels numb or cold, or looks blue.