Sesamoiditis is a general term used to describe an inflammation of the sesamoids bones. Each human foot has two sesamoids bones. They are located on the underside of the forefoot or ball of foot specifically under the big toe joint and are about the size and shape of peanuts. They are embedded in the soft tissues under the first metatarsal phalangel joint or big toe joint.
Someone with sesamoiditis will generally experience a gradual onset of pain under the ball of the foot at the big toe joint, which may be accompanied by swelling. A fractured sesamoid will however result in a sudden onset of pain. Sesamoiditis is usually found in people with high arched rigid feet or in people that pronate excessively or are flatfooted. It is very common in dancers and athletes but also occurs in the general population.
An X-ray will generally be used to diagnose a fractured sesamoid but direct pressure on the irritated sesamoid will cause significant pain and is often used as a simple diagnosis.
Treatment of sesamoiditis starts with rest and decreased weight bearing, icing to reduce inflammation and the wearing of cushioned supportive low heeled shoes like athletic shoes. Generally pressure on the sesamoids must be removed to allow the sesamoids to heal so podiatrists will often adhere felt padding to the foot to remove pressure. Many patients require a custom foot orthotic to control the imbalances within the foot along with forefoot modifications to remove any pressure on the sesamoids when walking or running. More persistent cases can benefit from oral anti inflammatories or cortisone injections. Surgery is rarely indicated for sesamoiditis.