Neuroma: An enlargement of a portion of a nerve.
A neuroma is an often painful enlargement of one of the body’s nerves. Though neuromas can develop in any part of the body, they most commonly occur in the foot, usually in one of the intermetatarsal nerves. Interdigital neuroma is the name used to describe this nerve mass or enlargement. An interdigital neuroma is more likely to occur in women than men.
A neuroma can manifest between any of the long bones, or metatarsals, in the foot. Morton’s neuromas are neuromas that develop between the third and fourth metatarsal bones. If a neuroma develops between any of the other metatarsal bones, it is called an interdigital neuroma, not a Morton’s neuroma. Neuromas, though considered to be growths or masses, are benign, or noncancerous, and often respond to conservative care methods.
Signs & Symptoms
Some of the most common signs and symptoms associated with an interdigital neuroma include:
- Foot cramping
- Foot numbness
- The sensation of walking on a lump
- A tingling sensation between the toes
- Burning, stinging, stabbing, or shooting pain in the ball of the affected foot
Two unique forces are responsible for irritating nerve tissue and causing neuromas: Pinch and stretch. An interdigital neuroma occurs when one of the intermetatarsal nerves is pinched and stretched across the ball of the foot, which happens with great frequency in people who wear shoes that possess tapering toe boxes (which pinch the intermetatarsal nerves) and toe spring and heel elevation (which stretch the intermetatarsal nerves).
Other factors that may contribute to interdigital neuromas include:
- Flat feet
- High-heeled shoes
- Excessively high foot arches
Bunions, hammertoes, and other forefoot problems
Conservative treatment for an interdigital neuroma involves adopting footwear that places the foot on a completely level surface and allows the toes to splay the way nature intended. A shoe that possesses toe spring, heel elevation, and toe box taper will not only stretch and pinch the foot’s intermetatarsal nerves, it will also put focal pressure or stress on the ball of the foot; this is another factor that can inflame nerve tissue in this part of the foot and cause neuromas.
For those who already have a neuroma (or for anyone, really), it’s always wise to perform the Shoe Liner Test to assess a shoe’s appropriateness before buying. Select shoes that have a removable liner or insole and stand on the liner, noting the position of the foot. If the foot is wider than the liner, that particular shoe will no doubt further irritate the neuroma by squeezing the metatarsal bones together.
Correct Toes toe spacers are an extremely helpful foot health tool in eliminating the pinch forces that contribute to interdigital neuromas, especially when they are used in combination with men’s and women’s foot-healthy footwear. A metatarsal pad is another helpful tool for relieving (or reducing) interdigital neuroma symptoms. A metatarsal pad will help spread the metatarsal bones and reduce focal pressure on the affected intermetatarsal nerve as it travels through the ball of the foot. A metatarsal pad will also help restore the forefoot fat pad to a position that protects ball of foot structures, including the intermetatarsal nerves. The proper placement of each metatarsal pad is extremely important to ensure optimal comfort and foot health benefits.
Another conservative care remedy for neuromas is anti-inflammatory supplements.
If conservative care measures fail to resolve this problem, some foot care providers may recommend a cortisone injection around the involved nerve to help reduce the swelling and inflammation. Concentrated alcohol injections around the affected nerve have also shown good results and should be considered before undergoing neurectomy, a surgical procedure to remove the enlarged, traumatized portion of the involved nerve.