The sesamoids are two small round bones that live in the tendons, beneath the 1st MTPJ (big toe joint). These bones allow the hallux (big toe) to move up and down correctly. The term sesamoiditis describes a condition in which one or both of the sesamoids become painful and inflamed. Sesamoiditis is caused by either a single moment of trauma or repetitive minor trauma to the ball of the foot. There are some foot shapes (forefoot valgus and plantar flexed first metatarsal) that are predisposed to the overloading of the sesamoids.
Symptoms: The main symptom associated with sesamoiditis is pain and swelling under the 1st MTPJ (big toe joint). This pain is usually worse during weight-bearing activities, especially on hard surfaces. Ladies can experience sesamoiditis when wearing high heels. Alteration in gait (walking) patterns can also occur to deflect the pressure of weight bearing away from the painful area.
Treatment: Your podiatrist will assess your foot and identify which of the sesamoids is injured. A treatment plan to deflect pressure away from the painful site will then be implemented. Orthotic therapy may also be indicated to further off-load the site. X-rays may be necessary to rule out any fractures of the sesamoids. If left untreated, sesamoiditis can lead to fracture of the sesamoid and degeneration of the 1st MTPJ (big toe joint).