If you’re asking “Os what?” you’re not alone. At Gentle Professional Foot Care we find that many patients have never heard of an os trigonum, never mind realize that they have one. An os trigonum is an extra bone (also known as an accessory bone) that develops behind the talus or ankle bone. This congenital condition occurs when one part of the talus does not fuse with the rest of the bone and the small os trigonum bone forms instead. This bone exists in a small part of the population and most people who have it don’t even know it unless it becomes a problem.
Little Bone/Big Pain
People who frequently participate in an activity that requires pointing your toes—ballet dancers, soccer players and other athletes—may cause a “nutcracker injury.” The os trigonum bone gets repeatedly crunched between the ankle and heel bone causing pain and inflammation. An os trigonum injury can also occur as the result of an ankle sprain.
Part of the difficulty in diagnosing an os trigonum injury is that the symptoms can mimic other conditions such as Achilles tendonitis, a talon fracture or an ankle sprain. Os trigonum syndrome symptoms include:
·An aching pain deep in the back of the ankle that is particularly noticeable during the pushing off part of walking or running or when you point your toes down
·Swelling at the back of the ankle
·Tender to the touch
Our foot and ankle surgeon, Dr. Charles A. Suleskey, will first do a complete examination of your ankle and foot. The podiatrist will also ask questions about when you first noticed the symptoms and how they have progressed over time. X-rays and other imaging tests may be ordered which will reveal the presence of the os trigonum (if the patient is not already aware of its existence) and confirm the diagnosis.
For most patients symptoms will diminish or be eliminated through non-invasive treatment methods such as rest, icing and medication. In some cases, however, surgery is recommended. If you are consistently experiencing pain in the back of your ankle, contact our Venice office and set up an appointment for the podiatrist to evaluate your ankle by calling: 941-493-7999.