What is a Sesamoid?
A sesamoid is a bone embedded in a tendon. Sesamoids are found in several joints in the body. In the normal foot, the sesamoids are two pea-shaped bones located in the ball of the foot, beneath the big toe joint.
Acting as a pulley for tendons, the sesamoids help the big toe move normally and provide leverage when the big toe “pushes off” during walking and running. The sesamoids also serve as a weight-bearing surface for the first metatarsal bone (the long bone connected to the big toe), absorbing the weight placed on the ball of the foot when walking, running, and jumping.
Sesamoid injuries can involve the bones, tendons, and/or surrounding tissue in the joint. They are often associated with activities requiring increased pressure on the ball of the foot, such as running, basketball, football, golf, tennis, and ballet. In addition, people with high arches are at risk for developing sesamoid problems. Frequent wearing of high-heeled shoes can also be a contributing factor.
Types of Sesamoid Injuries in the Foot
There are three types of sesamoid injuries in the foot:
In diagnosing a sesamoid injury, the foot and ankle surgeon will examine the foot, focusing on the big toe joint. The surgeon will press on the big toe, move it up and down, and may assess the patient’s walking and evaluate the wear pattern on the patient’s shoes. X-rays are ordered, and in some cases, advanced imaging studies may be ordered.
Non-surgical treatment for sesamoid injuries of the foot may include one or more of the following options, depending on the type of injury and degree of severity:
When is Surgery Needed?
When sesamoid injuries fail to respond to non-surgical treatment, surgery may be required. The foot and ankle surgeon will determine the type of procedure that is best suited to the individual patient.