Sesamoiditis is an inflammatory condition that involves the sesamoid bones. These two small, egg-shaped bones sit under the big toe joint. They fit within two shallow grooves formed on the bottom of the first metatarsal head, the long bone that forms the first part of that joint. The sesamoid bones take an incredible amount of pressure, stress, and force with every step one takes. This puts these bones at risk for developing injury and inflammation as a response to these forces.
The sesamoids can be injured by numerous events, including falling from a height onto the ball of the foot, repetitive pressure on the ball of the foot from activities such as dancing or stair climber use, or doing jumping sports like netball or basketball, even walking can cause sesamoiditis.
The pain may be constant, or it may occur with or be aggravated by, movement of the big toe joint. It may be accompanied by swelling throughout the bottom of the forefoot.
Damage to the sesamoid bone may also result in sesamoiditis. Stress fractures (fine cracks in the bone structure due to repetitive abuse) can occur if the condition is untreated, and in more severe cases can turn into a true bone fracture.
Treatment for Sesamoiditis
Treatment is usually non-invasive. Minor cases require a strict period of rest and the use of a modified shoe or a shoe pad with a cut-out to reduce pressure on the affected area. A metatarsal pad can be placed away from the joint to redistribute the pressure of weight bearing to other parts of the forefoot. In addition, the big toe may be bound with tape or athletic strapping to immobilise the joint as much as possible and allow healing to occur. Oral anti-inflammatory drugs can be used to reduce swelling.
Severe cases may require a below-the-knee walking cast for 2 to 4 weeks and the injection of steroids. Often foot orthoses are used to correct any anatomical or functional foot issues that have contributed to the problem, in order to prevent a recurrence.
When chronic pain is unable to be managed by these conservative methods, or if avascular necrosis has occurred, a surgical procedure called a ‘sesamoidectomy’ may be indicated. This is removal of all or part of the painful sesamoid bone.
Most people recover uneventfully and don’t need surgery or prolonged immobilisation. Dancers and athletes can return to activity once the condition resolves, but with the knowledge the condition may return if stress to the big toe joint continues.