Sesamoids are two small, pea-shaped bones located in the ball beneath the big toe joint at the bottom of the foot. Sesamoid bones are connected to muscles and other bones by tendons that envelop these bones. Sesamoids help the big toe move normally and absorb the weight placed on the ball.
Sesamoiditis is inflammation of the sesamoid bones and the tendons in the foot. The condition occurs when the tendons attached to and surrounding the sesamoid bones become injured, irritated and inflamed. It is a form of tendinitis (inflammation of the tendon).
Sesamoiditis is caused by:
Sesamoiditis is common among runners, basketball, baseball or football players, and ballet dancers. People with high foot arches and older adults with osteoarthritis may also experience sesamoiditis. The condition can also be caused by sesamoid bone fractures or by another condition called osteonecrosis (death of bone tissue).
The main symptom of the condition is a gradual onset and build-up of pain in the forefoot at the bottom. The pain develops under the big toe and on the ball of the foot. Other signs include:
If sesamoiditis is not treated, it may lead to serious complications such as:
Diagnosis of sesamoiditis begins with a physical examination of the foot. The doctor is likely to check for tenderness and pain around the sesamoid bones and the ball of the foot. The doctor may try to bend and move the big toe in different directions to assess flexibility. An X-ray of the forefoot may be ordered to confirm the condition. The doctor may also recommend other tests such as an ultrasound or an MRI or even a bone scan to check for tendon injuries or a sesamoid bone fracture.
Typically, sesamoiditis does not require surgery and is generally treated conservatively. Your doctor decides on the precise treatment depending on the degree of severity and may include one or more of the following.
If symptoms persist, the doctor may recommend wearing a removable, short leg brace for 4 to 6 weeks. This can reduce pain and pressure. It may take up to 6 weeks for at-home treatments to relieve the pain associated with sesamoiditis.
Surgery If conservative measures fail, surgical removal of one sesamoid bone may be necessary. It is good to only remove one of the two sesamoids. If both are taken out, it can lead to big toe deformity.
During surgery, the surgeon makes an incision on the bottom of your foot and then separates the soft tissue around the sesamoid bone. Once the bone is removed, the soft tissue is put back in place, and the incision is closed.
Recovery from a sesamoid injury may take 3 to 6 months.