The sesamoid bones are two small bone embedded in the tendon under the big toe joint. The function of these bones is similar to that of our knee caps (patella) in that that help create a better lever for the tendon to help the joint to move. The very location of these bone under the big toe joint mean that they do get subjected to a lot of force and pressure. This could be so high that the bones and structures around them become inflamed. This is commonly called sesamoiditis.
Sesamoiditis is probably not the best term as the sesamoid bones do not really become inflamed. It more of an inflammation of the structures around the sesamoiditis bones, so perhaps it should be called a ‘peri-sesamoiditis’.
The cause of sesamoiditis is simply an overload – the forces acting on the bones becomes too great and the structures become inflamed. This could be related to wearing high heel shoes; it could be related to standing all day at work on hard surfaces; it could be related to sporting activities. Sports, such as tennis, that involve pivoting on the ball of the foot really does put a lot of force through these bones. There could also be some atrophy of the fat pad under the ball of the foot that would normally protect these bones.
The treatment of sesamoiditis usually involved limiting activity and the use of padding materials to get force and load of the bones so that they can heal.
