Sesamoiditis refers to an inflammation of the sesamoid bones and surrounding structures. The sesamoid bones are two small bones under the joint at the base of the big toe. The most common cause of this irritation is overuse, especially in athletes in side to side sports such as tennis and basketball. In these sports we use the base of the big to pivot on, so these two small sesamoid bones get subjected to a lot of stress during that process. The best treatment for sesamoiditis is foot orthotics or padding to have the bones get off the load. Sometimes a cortisone injection helps. Surgery is also indicative but it is rarely used.