Morton's neuroma

Morton's neuroma is a thickening of the sheath around the nerve that runs between the long bones of the forefoot and supplies sensation to the toes. The name is misleading: it is not a tumour but scar tissue that has built up around the nerve after being squashed for long enough. Once thickened, the nerve is trapped even more tightly in that narrow space between the bones, and the cycle keeps feeding itself. The space between the third and fourth toes is affected most often, the one between the second and third less so. Women get it several times more often than men, and the explanation is fairly mundane: footwear. The good news is that in most people the pain can be settled without ever coming to surgery.

What it feels like

The pain sits in the front part of the foot, near the base of the toes, and people usually reach for words like shooting, burning or electric shock. It runs into the two neighbouring toes — precisely the ones the trapped nerve supplies. Between attacks the foot may not bother you at all.

The second giveaway is recognised by almost everyone who has it: the feeling of a rucked-up sock or a small pebble under the ball of the foot that you can never shake out. Some of the toes go numb or tingle alongside it, like a leg that has gone to sleep.

There is a pattern too. It is worst in narrow shoes, in heels and after a long walk; the first steps after sitting still can also hurt. It eases when you take the shoe off and rub the foot with your hands — many people do this automatically long before they know what is going on. Left alone, the picture usually worsens slowly over years: attacks come more often, the quiet spells get shorter, and walking barefoot at home is only bearable on something soft.

Why the nerve starts to suffer

The main cause is constant pressure across the forefoot. A narrow toe box pushes the long bones together and a heel shifts body weight onto them, so the nerve is pinched between bone and ligament with every step. Hence the imbalance between the sexes: the combination of a pointed toe and a raised heel is far commoner in women's shoes.

The second contribution is load. Running, especially on hard surfaces and in worn-out trainers, jumping sports, dancing, a long working day on your feet — all of it strikes the same spot over and over. Shoes with no cushioning deserve a mention of their own: a thin sole passes the impact straight to the forefoot.

The third is the shape of the foot itself. Flat feet or, conversely, a high arch, a bunion, hammer toes, or simply a long second toe change how weight is shared out and raise the pressure in the spaces between the bones. Excess weight plays its part as well, since every step costs the foot more.

What you can do yourself

First and most effective is the footwear. You need a wide toe box so the toes lie loose rather than being squeezed into a wedge, a low heel and a thick, soft sole. Sometimes that alone settles the pain within a few weeks. The reverse is equally true: narrow pointed shoes, stiletto heels and thin-soled pumps will undo every other treatment you try.

Second is a metatarsal pad. This is a small raised pad placed inside the shoe, and everything depends on where it goes: it should sit just behind the ball of the foot rather than under it, because that spreads the heads of the long bones apart and frees the nerve. Pads are sold in pharmacies, cost very little and often make a noticeable difference. Plain soft insoles without that raised part do considerably less.

The rest is about load and time. For a few weeks it is worth cutting back running and jumping and swapping them for swimming or cycling; after activity, a cold pack wrapped in a cloth for ten to fifteen minutes helps. If you are carrying extra weight, losing some eases the pain in its own right. Paracetamol is a reasonable painkiller here; non-steroidal anti-inflammatories are taken in short courses and with an eye on the stomach, the kidneys and blood pressure, and in pregnancy, with a peptic ulcer or while taking blood-thinning medicines they should not be used without medical advice. If two or three weeks of this brings no improvement, there is no point waiting longer.

When it is not Morton's neuroma

Pain in the forefoot comes from more than one condition, and they are treated differently. Think of another diagnosis if the pain sits directly over a bone rather than in the space between bones, started after a sudden increase in activity and worsens the moment you put weight on it — that is how a stress fracture of a metatarsal behaves. If both feet go numb at once, symmetrically, in a stocking pattern, nerve damage from diabetes or another polyneuropathy is more likely. If several joints in both feet swell and hurt and the foot is stiff in the mornings, an inflammatory arthritis is looked for. And pain travelling from the lower back through the buttock and calf down to the foot comes from the spine, so treating the foot achieves nothing.

Do not put off seeing a doctor if:

• the foot is red, hot and swollen and you have a temperature;
• a sore or ulcer has appeared that will not heal, particularly if you have diabetes;
• after an injury you cannot put any weight on the foot;
• numbness or weakness is spreading quickly, moving up the leg, or comes with trouble passing urine;
• the foot has turned pale and cold and the pain will not settle even at rest.

The first two point to infection and the last to a blood supply problem; none of them has anything to do with a neuroma and none of them can wait.

How the diagnosis is confirmed

It starts with an examination, which is more informative than it looks. The doctor finds the tender spot in the space between the bones and squeezes the foot from the sides while pressing up into that space from below: in a neuroma this reproduces the familiar pain and is sometimes accompanied by a click as the thickened nerve slips out from under the ligament. Sensation on the facing sides of the two toes is checked at the same time.

The finding is confirmed with an ultrasound scan, which shows the thickening itself, its size and its exact position — quickly, cheaply and without radiation. An MRI scan is kept for cases where the picture is unclear, where there may be more than one neuroma, or where surgery is being considered.

X-rays deserve a separate word, because they are the test most often requested and the one that most often disappoints. An X-ray cannot show Morton's neuroma at all: the neuroma is soft tissue. It is done for a different reason — to rule out a stress fracture, arthritis or a bony deformity. So a normal X-ray does not mean there is no neuroma; it only means the bones are intact.

What the doctor can offer

If self-help has not worked, the next step is usually not an operation. It starts with custom-made orthotic insoles moulded to your foot: they take load off the forefoot and put the metatarsal pad exactly where it belongs. An assessment by a podiatrist is useful at this stage.

The next rung is a steroid injection into the space between the bones, usually guided by ultrasound so it lands accurately. In a good proportion of people it takes the pain away for a long time, but it is not repeated indefinitely: steroid thins the fat pad under the sole and lightens the skin where it goes in. There are other options that avoid an incision — sclerosing alcohol injections, or destroying the nerve with radiofrequency or cold; these are used less often, are not available everywhere, and the results behind them are more modest.

Surgery is discussed when nothing above has helped and the pain is stopping you walking. There are two approaches: cutting the ligament that is compressing the nerve while leaving the nerve in place, or removing the affected segment of nerve. The second is more reliable at abolishing the pain but leaves permanent numbness on the facing sides of the two toes; it does not affect walking, but it is something to know beforehand. Getting back into ordinary shoes takes several weeks, and in around one person in ten the pain returns in time.

Keeping it from coming back

Morton's neuroma responds well to changes in daily habits and comes back just as readily when those habits lapse. So a wide toe box and a modest heel are worth keeping even after the pain has gone; shoes for special occasions do not have to be thrown out, they simply stop being the everyday pair.

Running shoes are replaced when the cushioning gives out, and training volume is built up gradually rather than in a jump after a break. Stretching the calf muscles and Achilles tendon helps, because when they are tight more weight is thrown onto the forefoot. If you have flat feet, a high arch or a bunion, it makes sense to address that specifically: while the foot spreads load badly, the nerve will be squeezed again. And at the first familiar twinges it is cheaper to go back to insoles and soft shoes for a few weeks than to wait until the pain is daily again.

Online consultation

A remote conversation fits this problem better than it might seem, because half the job is working out what is actually hurting. From a description of the pain, where it sits, which shoes bring it on and after what, a doctor can say whether this sounds like Morton's neuroma, whether to start with an ultrasound scan, and whether there is reason to look for another cause — a fracture, a polyneuropathy, a problem in the lower back.

An online appointment is also useful later: choosing footwear and explaining exactly where the metatarsal pad goes, going through the scan report, weighing up whether an injection is worth it and what it will achieve, what surgery involves and how to build activity back up afterwards. The limits of the format are obvious: feeling the foot and squeezing it between the hands cannot be done through a screen, and if the foot is hot, swollen and red, if you cannot stand on it after an injury, or if a sore has appeared that will not heal, what is needed is a face-to-face examination rather than a call.

This material is for information only and does not replace medical advice.