A sesamoid bone is a bone embedded within a tendon where the tendon passes over a joint. Tendons themselves are strong bands of tissue that attach the muscles to the bone.
Each foot contains two small sesamoid bones. They are about the size of a pea and are located in the ball of the foot just beneath the big toe joint. These bones act as pulleys for the tendons and help flex or curl your big toe. They help the big toe move normally and provide leverage when the big toe pushes off during walking, running and jumping. While doing these activities, the sesamoid bones carry much of your weight, which is why it is concerning when they become irritated or fractured.
There are three types of sesamoid injuries that can occur within the foot and each one is caused by different factors:
A sesamoid bone injury can be a very painful experience. An acute fracture produces an immediate pain and swelling at the site of the break but usually does not affect the entire big toe joint. On the other hand, a chronic sesamoid fracture produces long standing pain in the ball of the foot beneath the big toe joint. The pain tends to come and go, becoming aggravated during activity and relieved while resting.
Another sesamoid injury, turf toe, causes immediate, sharp pain and swelling. It usually affects the entire big toe joint and limits the motion of the toe. A patient with sesamoiditis shows symptoms like that of a chronic fracture.
In diagnosing a sesamoid injury, your doctor will ask you about your symptoms, medical history and activities. The foot and ankle surgeon will examine the foot focusing on the big toe joint. The surgeon will press on the big toe, move it up and down, and may assess the way you walk. He may also evaluate the wear pattern of your shoes. An x-ray will be ordered and in some cases advanced imaging studies may be required too.
If you need help in treating your sesamoid injury, contact us as soon as possible. Our medical team will be ready to help you anytime.