(Interdigital Neuroma; Intermetatarsal Neuroma)
Definition
Definition
Morton’s neuroma is painful thickening of the tissue around one of the nerves in the foot. It can affect any of the toes in the foot. However, it most often affects the nerves that run between the third and fourth, or second and third toes.
Nerves of the FootCopyright © Nucleus Medical Media, Inc.
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Causes
Causes
The thickening of the nerve caused by inflammation and the build up of fibrous tissue on the nerve’s outer coating. This fibrous build-up is a reaction to the irritation resulting from nearby bones and ligaments rubbing against the nerves.
Irritation can be caused by:
- Wearing shoes that are too tight
- Wearing shoes that place the foot in an awkward position, such as with high heels
- A foot that is mechanically unstable
- Repetitive trauma to the foot such as from sports activities like tennis, basketball, and running
- Trauma to the foot caused by an injury such as a sprain or fracture
It is unusual for more than one Morton’s neuroma to occur on one foot at the same time. It is rare for Morton’s neuroma to occur on both feet at the same time.
Risk Factors
Risk Factors
Morton’s neuroma is more common in women. Other factors that may increase your chance of Morton’s neuroma include:
- Wearing narrow and/or high-heeled shoes
- Obesity
- Injuries to the foot
- Activities that cause repetitive trauma to the foot such as sports-related activities
Symptoms
Symptoms
Morton’s neuroma may cause:
- Burning, pain, tingling, and numbness often shooting into the toes
- Discomfort that is worse while walking
- Feeling of a lump between the toes
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Symptoms are usually temporarily relieved when:
- Taking off the shoes
- Flexing the toes
- Rubbing the feet
Diagnosis
Diagnosis
The doctor will ask about your symptoms and medical history. A physical exam will be done. Initial diagnosis of Morton’s neuroma is based on your description of the type and location of pain and discomfort in the foot. The diagnosis will be confirmed by:
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Physical exam of the foot, including:
- Checking for mechanical abnormalities in the foot
- Squeezing the side of the foot, which will usually cause pain when Morton’s neuroma is present
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Examination of your shoes to:
- Check for excess wear in parts of the shoe
- Check to see whether the shoes are too tight
Imaging tests evaluate the foot and surrounding structures. This may be done with:
Injections of local anesthetic can also be used for diagnosis
Treatment
Treatment
Treatments may include:
Rehabilitation Measures to Reduce Nerve Irritation
- Switching to low-heeled, wide-toed shoes with good arch support
- Wearing padding in the shoes and/or between the toes
- Wearing shoe inserts to correct a mechanical abnormality of the foot
- Having ultrasound, electrical stimulation, whirlpool, and massage done on the foot
Injection of Medication
The foot may be injected with corticosteroids mixed with a local anesthetic in order to reduce pain. Relief may be only temporary however, if the mechanical irritation is not corrected. Injections with other types of medications such as alcohol, phenol, or vitamin B12 are sometimes used.
Surgery
Surgery to remove the neuroma may be recommended if more conservative treatment does not solve the problem. While surgery usually relieves or completely removes the symptoms, it often leaves a permanent numb feeling at the site of the neuroma.
Prevention
Prevention
To help reduce your chance of Morton’s neuroma:
- Avoid wearing tight and/or high-heeled shoes.
- Maintain or achieve ideal body weight.
- If you play sports, wear roomy, properly fitting athletic footwear.
RESOURCES:
National Institute of Arthritis and Musculoskeletal and Skin Diseases http://www.niams.nih.gov
CANADIAN RESOURCES:
When it Hurts to Move—Canadian Orthopaedic Foundation http://whenithurtstomove.org
References:
Morton neuroma. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated April 16, 2014. Accessed August 20, 2014.
Morton’s neuroma (intermetatatarsal neuroma). American College of Foot and Ankle Surgeons’ Foot Health Facts website. Available at:
http://www.foothealthfacts.org/footankleinfo/mortons-neuroma.htm?terms=morton%27s%20neuroma
Accessed September 17, 2015.
Thomson CE, Gibson JN, Martin D. Interventions for the treatment of Morton’s neuroma. Cochrane Database of Sys Rev. 2004;(3):CD003118.
Last Updated: 9/17/2015