Morton's Neuroma is the most common neuroma in the foot. It occurs in the forefoot area (the ball of the foot) at the base of the third and fourth toes. It is sometimes referred to as an intermetatarsal neuroma. "Intermetatarsal" describes its location in the ball of the foot between the metatarsal bones (the bones extending from the toes to the midfoot). A neuroma is a thickening, or enlargement, of the nerve as a result of compression or irritation of the nerve. Compression and irritation creates swelling of the nerve, which can eventually lead to permanent nerve damage.
A Morton's Neuroma is not a true neuroma, which is a tumor that is generally benign. Rather, it is an enlargement of the nerve where it goes between the metatarsal bones of the foot. Because the nerve no longer fits between the gap, the pressure causes pain and sometimes numbness. This enlargement of the nerve is often an inflammation due to irritation. If the forefoot becomes compressed due to shoes that are too narrow, the nerve becomes damaged and inflamed. This inflammation means the nerve no longer fits in the space between the bones, creating further irritation and more inflammation. If this vicious circle can be broken, the problem may be resolved. However, in some situations the nerve can have fibrous tissues formed around it, which may require the destruction of the nerve or surgical removal.
Symptoms of interdigital neuroma typically manifest as a sharp, burning or tingling sensation in the forefoot. The pain radiates toward the lesser toes and is aggravated by shoe wear. The pain is relieved when the shoe is removed and the forefoot is massaged. Sometimes the symptoms involve specific toes.
In some cases your doctor will be able to feel the Morton's as a swelling in the middle of your foot. However they may also suggest an X-ray or a blood test - this is normally to rule our other causes of the pain such as arthritis. The most accurate way to diagnose Morton?s itself is with magnetic resonance imaging (MRI) or ultrasound.
Non Surgical Treatment
Once a diagnosis is obtained, it is essential to begin treatment immediately. Your podiatric physician will advise you on the most effective means. If caught early enough, good foot care, shoes that fit properly, and/or orthoses may eliminate the need for any further intervention. Other conservative measures might include oral non-steroidal anti-inflammatory medication (NSAIDS), physical therapy, ultrasound or other non-invasive measures. If that doesn?t work, your podiatric physician might use injectable steroids, and/or a local anesthetic around the neuroma to reduce inflammation and pain. Many patients report relief after these measures are taken.
If these non-surgical measures do not work, surgery is sometimes needed. Surgery normally involves a small incision (cut) being made on either the top, or the sole, of the foot between the affected toes. Usually, the surgeon will then either create more space around the affected nerve (known as nerve decompression) or will cut out (resect) the affected nerve. If the nerve is resected, there will be some permanent numbness of the skin between the affected toes. This does not usually cause any problems. You will usually have to wear a special shoe for a short time after surgery until the wound has healed and normal footwear can be used again. Surgery is usually successful. However, as with any surgical operation, there is a risk of complications. For example, after this operation a small number of people can develop a wound infection. Another complication may be long-term thickening of the skin (callus formation) on the sole of the foot (known as plantar keratosis). This may require treatment by a specialist in care of the feet (chiropody).
Women, particularly those who wear tight shoes, are at greatest risk for Morton?s neuroma. The best way to prevent the condition is to wear shoes with wide toe boxes. Tight, pointed shoes squeeze bones, ligaments, muscles and nerves. High heels may worsen the problem by shifting your weight forward. Over time, this combination can cause the nerves to swell and become painful.