What is the Accessory Bone of the Ankle? at Foot and Ankle Centers

An accessory bone of the ankle is an extra bone or bony prominence that some people naturally have. These bones are considered anatomical variations, meaning they are present at birth and not due to injury or disease. The most common accessory bone in the ankle is the "os trigonum," found at the back of the ankle, near the heel.

While many people with an accessory bone in the ankle experience no symptoms, others may develop pain, swelling, or discomfort, especially during activities that stress the ankle, like running or jumping. This condition, known as "os trigonum syndrome," occurs when the accessory bone rubs against surrounding tissues.

If you're experiencing persistent ankle pain or suspect an accessory bone, it’s important to see a specialist. At Foot & Ankle Centers, our team can accurately diagnose the condition and offer treatment options, including physical therapy or, in some cases, surgery, to alleviate pain and restore mobility.