NEUROMA – MORTON’S NEUROMA

A  NEUROMA is a sometimes painful nerve enlargement of one of the nerves of the body.  When it occurs within the foot it usually happens in one of the nerves going to the toes in the forefoot.  The nerve that a neuroma most commonly forms within is called the intermetatarsal nerve and is one of the many branches within the foot that have traveled from the spine. A neuroma can occur between any of the long bones (metatarsals) in the forefoot, but is most commonly encountered in the intermetatarsal nerve between the 3rd and 4th metatarsals and toes.  This is a Morton’s neuroma as described Dr. Morton almost 100 years ago.  If a neuroma occurs between any of the other long bones, it is not called a Morton’s neuroma, but is just called a neuroma.

The nice thing about understanding medical terms is that often the words can be understood by breaking them apart and understanding their component parts.  Neuroma is no different.  "Neur" or "neuro" stands for nerve, and "oma" stands for swelling or tumor.  Simply stated a neuroma is a swelling or enlargement of a nerve.  The word tumor should be discouraged from being applied to a neuroma, since tumor could be construed to mean cancerous or malignant.  Neuromas are benign and often respond to conservative care.

Conservative treatment is first geared towards finding shoegear that allows the forefoot to spread and not be confined.  High heeled shoes aggravate neuromas on two counts.  They generally squeeze the intermetatarsal nerves and cause the wearer to bear weight directly on the nerve which is being stretched across the ball of the foot. This trauma is also encountered in shoes not considered high heeled by most of the population. A shoe with any heel and any lift in the front of the shoe (called toespring) will place more stress on the nerves and predispose to formation of a neuroma.

To find a shoe that has enough room in the forefoot, choose a shoe with a removal liner or insole and stand on it, to see if your foot is wider than the liner. If it is, the shoe will aggravate the neuroma by squeezing the metatarsal bones together. If you have a flexible foot, a footbed or orthotic will decrease the amount of spreading, and motion that your forefoot can undergo.  This is one of the reasons orthotics are prescribed for neuromas.  It is extremely important for those with neuromas to understand that by using an orthotic or footbed, they will automatically need a larger and often wider sized shoe, because the supportive device will take up some room in the shoe.  In this instance foot care providers should choose the thinnest device possible and possibly not use a full length device.  My favorite is the carbon graphite devices fabricated by Northwest Podiatric Labs of Blaine, Washington.  If choosing a footbed for a neuroma, it is possible to cut off the front of the footbed to give the forefoot more room within the shoe or boot.

If the wider shoe and supportive device do not help with your neuroma, you may seek out a metatarsal pad to be placed on your footbed or ask your foot care provider to put one on your orthotic.  This pad will spread the metatarsal bones and remove pressure from the nerve where it goes under the ball of the foot.  The placement of the metatarsal pad is of utmost importance and is best placed by a foot care provider with experience in the anatomy of the forefoot and the treatment of neuromas.

Other conservative remedies are ice therapy and anti-inflammatory medications.  If the above measures have not helped, foot care providers will sometimes inject cortisone around the nerve to decrease the size and inflammation from the trauma.  Injections of concentrated alcohol around the nerve have also shown good results and should be considered prior to undergoing surgery (neurectomy), which is a removal of the enlarged, traumatized portion of the nerve.  X – rays of the affected foot will not show a neuroma as nerve does not show up on x – ray studies, but they are helpful to determine if OSTEOARTHRITIS or STRESS FRACTURE are causing the symptoms.  ULTRASONOGRAPHY and MRI are sometimes used, but are not very helpful.  The clinical diagnosis by a foot care specialist with experience treating neuromas will be the best way to diagnose a neuroma.  The examiner will attempt to duplicate neuroma symptoms by pressing on the nerve at various locations and may try to produce a clicking of the nerve which will occur in skilled hands, if the nerve has enlarged.

Shoes are the main cause of neuromas, so professional fitting should be sought out by those struggling with the symptoms of a neuroma.

Those with a neuroma describe several different types of sensations. Burning, stinging, stabbing, shooting, tingling, cramping, numbness, fullness, walking on a lump, like their sock is wadded or bunched up in the front of their shoe.  Many will find near immediate relief of symptoms by removing their shoe/shoes.  This should be taken as confirmation that one should carefully assess the shoes they wear and their fit.

I  believe the toespring (toebox of shoe elevated above ground) and tapering (pointed in the front) toeboxes are the most common causes of neuromas, especially when they are part of the high heeled shoe.