Sesamoiditis is an inflammation of two small bones, called sesamoids, situated below the first metatarsal joint of the big toe in the ball of the foot. Sesamoids, which are also located elsewhere in the body, are bones that, instead of being connected to other bones by joints, are connected only to tendons or are embedded in muscle. In the big toe, the sesamoids protect the tendons and help stabilize the foot during walking.

These two small bones are subjected to great pressure and are especially vulnerable to high-impact activities such as athletic pursuits or ballet dancing, and to occupational stress from repeated squatting or heavy lifting. They frequently suffer damage in the form of inflammation or stress fractures.

Risk Factors for Sesamoiditis

While traumatic injury and repeated stress are the most common causes of sesamoiditis in young to middle-aged adults, there are certain risk factors that make individuals of all ages more susceptible to this problem. These include:

  • Wearing high-heeled shoes
  • Having feet with very high arches
  • Having abnormally large sesamoid bones
  • Having osteoarthritis or bone spurs
  • Having osteoporosis

Diagnosis of Sesamoiditis

Sesamoiditis may be suspected because of the location of the inflammation and the pain experienced when walking or bearing weight. Because the surrounding tissues may also be tender, pain that increases when pressure is applied to the area may be a sign of the condition. Some swelling under the first metatarsal joint may also be an indicator.

While sesamoiditis usually presents as a pain that worsens over time, sudden severe pain is possible when the inflammation is the result of a traumatic injury or stress fracture. When the pain of sesamoiditis is progressive, it may begin as pain only during activity or applied pressure and become more constant. Since, due to the small size of the bones involved, diagnostic X-rays may be inconclusive, a bone scan may be necessary for a definitive diagnosis.

Treatment for Sesamoiditis

Typical treatments for sesamoiditis, designed to reduce swelling and pain, are similar to those for other inflammatory conditions. Immediate treatments include resting, icing the affected region and taking oral anti-inflammatory medication. Long-term methods of treatment, employed both to provide pain relief and to prevent recurrence, include wearing well-padded shoes or orthotic inserts and engaging in physical therapy. In more severe cases, surgical removal of the affected sesamoid may be necessary. If the inflammation is caused by a fracture, casting may be necessary for a period of up to 2 months.

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