Morton neuromas are focal areas of symptomatic perineural fibrosis around a plantar digital nerve of the foot. The abnormality is non-neoplastic and does not represent a true neuroma. It may more correctly be known as Morton?s metatarsalgia. The condition is thought to be due to chronic entrapment of the nerve by the intermetatarsal ligament. It most often occurs in middle-aged individuals and is many times more common in women than men. Approximately 30% of asymptomatic middle-aged persons have the radiological pathologic findings of a Morton?s neuroma.
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.
Feelings of numbness, tingling or tenderness in the ball of the foot (the area just behind the base of the toes) are some of the first signs of a condition known as Morton?s Neuroma. However, the condition is somewhat unpredictable, and symptoms may vary from patient to patient. Generally, however, the discomfort gets worse rather than better, and the patient may feel pain or a burning sensation that radiates out to the toes. Eventually, wearing shoes becomes uncomfortable (or even unbearable), and the patient may complain that the feeling is similar to that of having a stone bruise, or walking on a marble or pebble constantly, even though no there is no trauma to the skin, and no visible bump or lump on the sole of the foot.
To diagnose Morton’s neuroma the podiatrist commonly palpates the area to elicit pain, squeezing the toes from the side. Next he or she may try to feel the neuroma by pressing a thumb into the third interspace. The podiatrist then tries to elicit Mulder’s sign, by palpating the affected interspace with one hand and squeezing the entire foot at the same time with the other hand. In many cases of Morton’s neuroma, this causes an audible click, known as Mulder’s sign. An x-ray should be taken to ensure that there is not a fracture. X-rays also can be used to examine the joints and bone density, ruling out arthritis (particularly rheumatoid arthritis and osteoarthritis).
Non Surgical Treatment
Most patients’ symptoms subside when they change footwear to a wide soft shoe with a metatarsal support inside to relieve the pressure on the involved area. If this treatment fails, a cortisone injection into the nerve is occasionally helpful.
When early treatments fail and the neuroma progresses past the threshold for such options, podiatric surgery may become necessary. The procedure, which removes the inflamed and enlarged nerve, can usually be conducted on an outpatient basis, with a recovery time that is often just a few weeks. Your podiatric physician will thoroughly describe the surgical procedures to be used and the results you can expect. Any pain following surgery is easily managed with medications prescribed by your podiatrist.