What is Sesamoiditis?

Sesamoiditis is the medical term used to describe painful inflammation of the sesamoid bones, or the tiny bones embedded in the tendon of the foot and surrounding areas. The sesamoid bones are located on the bottom of the foot beneath the big toe joint, and they aid in the movement of the toe. When they become inflamed, severe pain and swelling occur. The condition is common amongst dancers, runners, athletes who engage in strenuous physical activity, and women who frequently wear high-heeled shoes.

The most common symptom of sesamoiditis is pain around the ball of the foot that begins as a mild ache and gradually becomes worse. An intense throbbing sensation may develop if the condition is not treated and physical activity continues. Pain is often aggravated by movement, and the bottom of the forefoot may become swollen and tender. Bruising and redness are typically not present.

Repetitive, excessive pressure on the forefoot is the most common cause of sesamoiditis. Individuals with highly arched feet are more likely to develop the condition, as they naturally put more pressure on the balls of the feet when walking or running. This causes more stress on the sesamoid bones, resulting in a greater chance of irritation or inflammation. Poor calf flexibility and inappropriate footwear are also contributing factors.

A diagnosis of sesamoiditis begins with a physical examination of the big toe joint and surrounding areas. A physician will also evaluate a patient's walking patterns and the wear on the shoes. In some cases, an x-ray, bone scan or magnetic resonance imaging (MRI) scan may be required for a positive diagnosis.

Mild cases of sesamoiditis are treated by reducing the pressure on the sesamoid bones until inflammation subsides. Common treatments include resting the foot, binding the foot with athletic tape, wearing custom orthotics or arch supports, applying ice to the inflamed area, or taking anti-inflammatory medications. The foot may be placed in a walking cast, or crutches may be used to prevent the patient from placing weight on the affected foot. If sesamoiditis is left untreated and physical activity continues, stress fractures or complete fractures may develop.

In severe cases of sesamoiditis, surgery or steroid injections into the inflamed joint may be necessary. This is a rare last resort, and is reserved for patients who do not respond to other, less invasive treatments over long periods of time. Physical therapy may be required after surgery and immobilization to help the patient regain their previous range of motion.