What is os trigonum syndrome?

Fact Checked

The os trigonum is an extra bone that oftentimes forms at the back part of the ankle bone. It is linked to the ankle bone by a fibrous band and usually present at birth in one or both feet.

https://www.youtube.com/watch?v=97ojOUyyg4o

The extra bone becomes evident during the teenage years when one region of the ankle bone does not fuse with the entire bone, resulting to a small extra bone. Only a few individuals develop this accessory bone.

Oftentimes, many individuals are not aware that they have the condition if it does not trigger any issues. Nevertheless, some with the extra bone experience pain which is called os trigonum syndrome.

os-trigonum-syndrome
Deep, aching pain or discomfort in the back part of the ankle, usually when pushing off on the big toe or when the toes are pointed downward.

What is the cause?

Os trigonum syndrome is generally brought about by an injury such as an ankle sprain. It can also be caused by repetitive downward pointing of the toes which is common in ballet, soccer and other athletes.

What are the indications?

The usual indications of os trigonum syndrome might include the following:

  • Deep, aching pain or discomfort in the back part of the ankle, usually when pushing off on the big toe or when the toes are pointed downward
  • Swelling in the back region of the ankle
  • Tenderness of the area when touched

Management of os trigonum syndrome

The management of os trigonum syndrome is aimed on relieving the symptoms that is often achieved using treatment options such as:

  • Adequate rest by staying off the damaged foot to allow the inflammation to settle
  • Immobilization using a walking boot can help limit movement of the ankle as well as allow healing.
  • Application of an ice pack can help reduce the swelling.
  • Oral medications such as non-steroidal anti-inflammatory drugs (NSAIDs) can help reduce the inflammation and pain
  • Cortisone injections are administered directly into the area to reduce the pain and inflammation

In most cases, the symptoms generally settle with conservative measures. Nevertheless, surgery is needed to alleviate the symptoms. Surgery involves the removal of the os trigonum since it is not required for normal functioning of the foot.

Leave a Comment

Your email address will not be published. Required fields are marked *

The information posted on this page is for educational purposes only.
If you need medical advice or help with a diagnosis contact a medical professional

  • All firstaidcprottawa.ca content is reviewed by a medical professional and / sourced to ensure as much factual accuracy as possible.

  • We have strict sourcing guidelines and only link to reputable websites, academic research institutions and medical articles.

  • If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please contact us through our contact us page.