Patient Education

Morton’s Neuroma

Description

It seems inevitable that on any hike (particularly when you’re wearing lace-up boots that take about an hour to put on or take off) you wind up with a rock in your shoe. It may be tiny, but as you continue to step on it, it begins to feel like a boulder that has somehow defied the laws of physics to fit inside your footwear. Now, imagine that the rock is not inside your shoe, but inside your foot. And imagine that it’s not a rock, but instead a swelling up of nerve tissue in the ball of your foot. Friend, you have now imagined up a foot neuroma. (Well, to be honest, not all foot neuromas show up in the ball of the foot, and not all feel like you’ve got a rock in your shoe. But many do.)

Neuromas are swellings of nerve tissue that may occur anywhere, although in the foot they most commonly show up between the toes. About 80% of the time they form between the third and fourth toe (Morton’s Neuroma), although neuromas between the second and third toe may also occur in about 15% of cases.

Imagine, for a moment, the inside of your foot. (You’ve already proved you’re adept at imagining, so let’s carry it a bit further, shall we?) Nerves enter your foot and then branch out. The ones that carry impulses to your toes run along between your metatarsals (the long bones that connect your toes to the rest of your foot). When they reach your toes, these nerves branch again into a Y shape, and one end goes into one toe, and one end goes into another toe. Neuromas usually show up at the base of that Y branch.

Now, despite the name (medical terms ending with -oma usually mean ‘tumor’), foot neuromas are not actually tumors, but swellings in the nerve tissue of your foot in response to some irritation or pressure. (Remember that the body tends to respond to irritation by swelling up to protect itself. And, well, we tend to swell up when we’re irritated ourselves, like the time when your son crashed the car for the fourth time this month, or when your coworker wouldn’t stop talking about her fabulous vacation in Fiji.)

This irritation or pressure can come from a variety of sources. Your foot may, unfortunately, be naturally disposed to develop neuromas if you have such conditions or deformities as flat feet, abnormally high arches, bunions, hammertoes, or toes that are in unusual positions. Such conditions tend to put stress or pressure on the nerves between the toes, making them swell up. However, irritation can also be caused (or exacerbated by) wearing shoes that pinch the toes or put pressure on the ball of the foot, such as shoes with pointed toe boxes or high heels. Trauma or repetitive stress (such as puncture wounds, injuries to the foot, surgery, or sports or work environments that involve stress on the ball of the foot) can also prompt the formation of a neuroma.

Symptoms

Because the condition involves a nerve, it’s perhaps unsurprising that many people experience burning, tingling sensations, or numbness in the ball of the foot or the toes. Some may also have sharp or shooting pain in the ball of the foot (that shoots up the leg or into the ends of the toes) that may be triggered by putting weight on the foot or by pressing on the area between the toes. You may feel as though your sock is bunched up, or that you have something in your shoe, or even something stuck inside the ball of your foot. The area around the base of your toes may become swollen. You may also find (much to your relief) that if you pause to take your shoe off and massage the ball of your foot that the pain goes away, at least temporarily.

As the condition progresses, the temporary damage to the nerve becomes permanent. The pain or other symptoms may persist for several days or weeks (as opposed to disappearing when you step out of your too-tight shoes). And the symptoms you have been experiencing may increase in intensity.

Diagnosis

Diagnosing a neuroma can be kind of a tricky business, since there are numerous conditions that have the same symptoms, such as stress fractures of the metatarsals, tendonitis in the tendons between your toes, arthritis or other joint problems, or nerve compression in another area of your body such as in your foot, ankle, knee or back. Fortunately, your podiatrist is skilled at detective work involving the foot, and is trained to get to the root of your pain. However, because this condition is progressive, it’s important to go in to see your podiatrist as soon as you begin experiencing symptoms. If you seek treatment early, you’re much more likely to be able to treat your condition conservatively rather than with surgery.

When you see your podiatrist, he or she will likely take a thorough history of your symptoms and do a physical examination of your foot. Your foot may get squeezed or pressed, which may result in the same type of shooting pain you’ve experienced before. Please understand that your podiatrist is not doing this to make you squirm, but to discover what exactly the problem is. Your podiatrist may be seeking to reproduce your symptoms, or may be able to feel the neuroma itself.

Neuromas won’t really show up on X-rays, but your doctor may request one anyway to rule out possible bone problems that could be causing your symptoms. Nerve testing, while also not able to diagnose neuromas, may be used to determine if you have other nerve problems. MRIs or high-frequency ultrasounds may be helpful in some cases.

Treatment

Your podiatrist is likely to treat your neuroma by attempting to reduce the irritation to your nerve. This may include padding the ball of the foot (also known as the metatarsal arch) to reduce pressure on the nerve, or possibly taping the foot. Orthotics may be prescribed to correct abnormal function of the foot, offer additional support, and will likely be used along with changes in footwear. You’ll probably have to give up high heels over two inches and shoes with pointed or cramped toe boxes.

Ice and anti-inflammatory medications (such as ibuprofen, or sometimes cortisone injections) may be recommended to reduce swelling in the area (and relieve pain). And your doctor may suggest changes in your activities to reduce stress on the area.

If these conservative treatments fail to adequately reduce the pain and other symptoms you’re experiencing, you may need to consider chemical destruction of the nerve or surgery. Both will (if successful) get rid of symptoms, but with a dead or removed nerve, you will have an area of your foot with little or no sensation. But, on the plus side, the next time you feel like you’ve got a rock in your shoe, you can be pretty sure it’s one you can take out and throw at the back of your hiking partner.