Morton's neuroma (also known as Morton neuroma, Morton's metatarsalgia, Morton's neuralgia, plantar neuroma, intermetatarsal neuroma, and interdigital neuroma) is a benign neuroma of an intermetatarsal plantar nerve, most commonly of the second and third intermetatarsal spaces (between 2nd-3rd and 3rd-4th metatarsal heads), which results in the entrapment of the affected nerve. The main symptoms are pain and/or numbness, sometimes relieved by removing footwear.
The exact cause of Morton?s neuroma is not known, but the choice of footwear seems be a factor. Wearing high heels (shoes with heels over 2 inches) can put extra pressure on the balls of the feet. Wearing tight or pointed toed shoes may squeeze the toes together or otherwise constrict their movement. For that reason, women are about 8 to 10 times more likely to develop Morton?s neuroma compared with men. People who are born with flat feet, high arches, or an abnormal position of the toes are more prone to developing Morton?s neuroma. This may be due to instability around the toe joints. Certain conditions that develop over time, such as bunions or hammer toes, are also associated with Morton?s neuroma. Some sports that involve running, including tennis and other racquet sports, can also increase the chance of developing Morton?s neuroma due to trauma or injury to the foot.
People with Morton's neuroma usually complain of pain that can start in the ball of the foot and shoot into the affected toes. However, some people just have toe pain. There may also be burning and tingling of the toes. The symptoms are usually felt up the sides of the space between two toes. For example, if the nerve between the third and fourth long bones (metatarsals) of the right foot is affected, the symptoms will usually be felt up the right-hand side of the fourth toe and up the left-hand side of the third toe. Some people describe the pain that they feel as being like walking on a stone or a marble. Symptoms can be made worse if you wear high-heeled shoes. The pain is relieved by taking your shoe off, resting your foot and massaging the area. You may also experience some numbness between the affected toes. Your affected toes may also appear to be spread apart, which doctors refer to as the 'V sign'. The symptoms can vary and may come and go over a number of years. For example, some people may experience two attacks of pain in a week and then nothing for a year. Others may have regular and persistent (chronic) pain.
Morton?s neuroma can be identified during a physical exam, after pressing on the bottom of the foot. This maneuver usually reproduces the patient?s pain. MRI and ultrasound are imaging studiesthat can demonstrate the presence of the neuroma. An x-ray may also be ordered to make sure no other issues exist in the foot. A local anesthetic injection along the neuroma may temporarily abolish the pain, and help confirm the diagnosis.
Non Surgical Treatment
If symptoms are severe or persistent and self-help measures did not help, the doctor may recommend corticosteroid injections, a steroid medication that reduces inflammation and pain is injected into the area of the neuroma. Only a limited number of injections are advised, otherwise the risk of undesirable side effects increases, including hypertension (high blood pressure) and weight gain. Alcohol sclerosing injections, studies have shown that alcohol injections reduce the size of Morton's neuromas as well as alleviating pain. This is a fairly new therapy and may not be available everywhere. The doctor injects alcohol in the area of the neuroma to help sclerose (harden) the nerve and relieve pain. Injections are typically administered every 7 to 10 days. For maximum relief 4 to 7 injections are usually needed.
If pain persists with conservative care, surgery may be an appropriate option. The common digitial nerve is cut and the Mortons neuroma removed. This will result is numbness along the inside of the toes affected, and there is a small chance the end of the nerve will form a Stump Neuroma. Approximately 75% of people receive symptom resolution for Mortons Neuroma with conservative care.
To help reduce your chance of developing 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.