Most bones in the human body are connected to each other at joints. But there are a few bones that are not connected to any other bone. Instead, they are connected only to tendons or are embedded in muscle. These are known as sesamoids. The kneecap is the largest sesamoid in the body. Two other very small sesamoids bones which are about the size of a small frozen pea are found in the underside of the forefoot near the great toe, one on the outer side of the foot and the other closer to the middle of the foot.
The sesamoid bones are embedded in the flexor tendon of the big toe and have an articulation with the adjacent metatarsal bone. During movement the sesamoid actually glides with the tendon Sesamoids act like pulleys and help stabilize the flexor tendon stopping it from deviating. They provide a smooth surface over which the tendons slide, thus increasing the ability of the tendons to transmit muscle forces.
The sesamoids in the forefoot also assist with weight bearing and help elevate the bones of the big toe. Like other bones, sesamoids can fracture. Additionally, the tendons surrounding the sesamoids can become irritated or inflamed. This is called sesamoiditis and is a form of tendinitis. It is common among ballet dancers, runners.
- Pain is focused under the big toe joint on the ball of the foot. With sesamoiditis, pain may develop gradually; with a fracture, pain will be immediate
- Swelling and bruising may or may not be present
- You may experience difficulty and pain in bending and straightening the great toe
During the examination, the Podiatrist will look for point tenderness at the sesamoid bones this may involve slight manipulation the bone, you might be asked to bend and straighten the toe. Intensifying pain with bending the big toe is a diagnostic feature.
Your Podiatrist will often request X-rays of the forefoot to ensure a proper diagnosis. In some cases an MRI scan may also be required.
Treatment s usually none operative and is generally guided towards offloading the sesamoid bones with the use functional foot orthoses and shock absorbing padding. If symptoms persist, you may need to wear a removable air cast foot brace for four to six weeks.
On occasions and only after accurate diagnosis your podiatrist may also recommend a theraputic corticosteroid injection.
Self Management Should Include
- Stop the activity causing the pain
- Take aspirin or ibuprofen to relieve the pain (always seek the advice of your GP or pharmacist prior to taking such drugs for the first time)
- Rest and ice the sole of your feet. Do not apply ice directly to the skin, but use an ice pack or wrap the ice in a tea towel
- Wear soft-soled, low-heeled shoes. Stiff-soled shoes like clogs may also be comfortable
- Return to activity gradually, and continue to wear a cushioning pad of dense foam rubber under the sesamoids to support them. Avoid activities that put your weight on the balls of the feet
In a small percentage of patients, non-operative treatment will fail. At podiatry clinics we have a sound knowledge of available surgical techniques and sound working relationship with all local foot surgeons. So if the need arises we can direct you to the most appropriate surgical specialist.
- Ingrowing Toenails
- Achilles Tendinopathy
- Ankle Joint Arthritis
- Heel Pain / Plantar Fasciitis
- Back Pain
- Bunions (Hallux Valgus)
- Hip Pain
- Shin Splints and Medial Tibilal Stress (MTSS)
- Metatarsal Stress Fracture
- Morton’s Neuroma
- Runners Knee
- Tibialis Posterior Dysfunction
- Toe Deformities