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.
There are a number of common causes for Morton?s Neuroma, (though the condition can arise spontaneously for reasons still unknown). The Neuroma often occurs in response to irritation, pressure or traumatic injury to one of the digital nerves leading to the toes. A thickening of nerve tissue results as part of the body?s response to the irritation or injury. Abnormal foot movement used to compensate for bunions, hammertoes, flatfeet and other conditions can lead to irritation and development of Morton?s Neuroma. Pronation of the foot may cause the heads of the metatarsal bones to rotate slightly, thereby pinching the nerve running between the metatarsal heads. Chronic pressure or pinching causes the nerve sheath to enlarge, becoming increasingly squeezed, producing worsening pain over time, if not addressed. Morton?s Neuroma can be exacerbated when tight shoes providing little room for the forefoot are worn. Activities which over-pronate the foot (such as walking barefoot in sand) may increase the pain associated with Morton?s Neuroma, as will any high-impact activity, such as jogging.
Normally, there are no outward signs, such as a lump, because this is not really a tumor. Burning pain in the ball of the foot that may radiate into the toes. The pain generally intensifies with activity or wearing shoes. Night pain is rare. There may also be numbness in the toes, or an unpleasant feeling in the toes. Runners may feel pain as they push off from the starting block. High-heeled shoes, which put the foot in a similar position to the push-off, can also aggravate the condition. Tight, narrow shoes also aggravate this condition by compressing the toe bones and pinching the nerve.
During the exam, your doctor will press on your foot to feel for a mass or tender spot. There may also be a feeling of "clicking" between the bones of your foot. Some imaging tests are more useful than others in the diagnosis of Morton's neuroma. Your doctor is likely to order X-rays of your foot, to rule out other causes of your pain such as a stress fracture. Ultrasound. This technology uses sound waves to create real-time images of internal structures. Ultrasound is particularly good at revealing soft tissue abnormalities, such as neuromas. Magnetic resonance imaging (MRI). Using radio waves and a strong magnetic field, an MRI also is good at visualizing soft tissues. But it's an expensive test and often indicates neuromas in people who have no symptoms.
Non Surgical Treatment
In most cases, initial treatment for this condition consists of padding and taping to disperse weight away from the neuroma. If the patient has flatfeet, an arch support is incorporated into footwear. The patient is instructed to wear shoes with wide toe boxes and avoid shoes with high heels. An injection of local anesthetic to relieve pain and a corticosteroid to reduce inflammation may be administered. The patient is advised to return in a week or 2 to monitor progress. If the pain has been relieved, the neuroma is probably small and caused by the structure of the patient's foot and the type of shoes the patient wears. It can be relieved by a custom-fitted orthotic that helps maintain the foot in a better position. Another type of therapy that may be used is alcohol sclerosing injections. In this treatment, the doctor injects a small amount of alcohol in the area of the neuroma area to help harden (sclerose) the nerve and relieve the pain. Injections are given every 7-10 days and, in many cases, 4-7 injections are needed for maximum relief. Please ask your physician for more information regarding this type of treatment.
When conservative measures are unsuccessful, surgery can be a good choice in the treatment of Morton's neuroma. The operation for Morton's neuroma does not require an overnight hospital stay. The anesthetic used is an ankle block, which completely numbs the foot during the surgery. The physician removes the neuroma from an incision made on the top of the foot between the involved metatarsal heads. The nerve to the interspace is exposed and cut next to the metatarsal heads.
Although the exact causes of neuromas are not completely known, the following preventive steps may help. Make sure your exercise shoes have enough room in the front part of the shoe and that your toes are not excessively compressed. Wear shoes with adequate padding in the ball of the foot. Avoid prolonged time in shoes with a narrow toe box or excessive heel height (greater than two inches).