Do you know what an os trigonum is? If you’re like most people, you probably don’t unless you have one and it’s causing you some pain or discomfort. At Edmond Norman Foot & Ankle we want our patients to be aware of this condition and its symptoms even though it is one that is not very common. Too often ankle problems are misdiagnosed or not fully rehabilitated which can lead to future problems such as chronic ankle instability, repeated strains or tendonitis. Below are some questions to help you indentify and understand os trigonum syndrome.
What is an os trigonum? An os trigonum is an accessory (meaning extra) bone that can form behind the ankle bone and is attached to the bone by a fibrous band of tissue. The bone develops as a result of one part of the ankle bone not completely fusing with the rest of the bone. This condition is congenital but doesn’t become fully obvious until adolescence.
How do I know if I have an os trigonum? Chances are you won’t know that you do unless you develop the painful condition known as os trigonum syndrome or if you have an x-ray of the area which will show the bone.
What is os trigonum syndrome? If the tissue that connects the os trigonum to the ankle bone gets overly stretched or torn, pain and inflammation result and this is os trigonum syndrome. Besides pain that feels that it is deep inside the back part of the ankle, other symptoms of the disorder are swelling and tenderness at the back of the ankle.
Who is prone to os trigonum syndrome? The motion of pointing the toes downward exerts a nutcracker like force on the os trigonum and causes irritation. Ballet dancers, soccer players, gymnasts and those who participate in other sports or activities that require repeatedly bending or pointing the toes are more susceptible to this condition (if they have an os trigonum). Inflammation of this area can also be the result of an accident or injury such as an ankle sprain.
What is the treatment for this condition? Our foot and ankle surgeon, Dr. A. Bil Buksh, will determine the correct treatment after examining your ankle and confirming the diagnosis. In many cases anti-inflammatory medication will be prescribed along with icing to relieve pain and swelling. Immobilization with a walking boot and resting the foot for a period of time will be necessary for healing. In rare cases surgery may be recommended.