A neuroma is a thickening of nerve tissue that may develop in various parts of the body. The most common neuroma in the foot is a Morton?s neuroma, which occurs between the third and fourth toes. It is sometimes referred to as an intermetatarsal neuroma. ?Intermetatarsal? describes its location in the ball of the foot between the metatarsal bones. Neuromas may also occur in other locations in the foot. MortonThe thickening, or enlargement, of the nerve that defines a neuroma is the result of compression and irritation of the nerve. This compression creates enlargement of the nerve, eventually leading to permanent nerve damage.
The exact cause is unknown. Doctors believe the following may play a role in the development of this condition. Wearing tight shoes and high heels. Abnormal positioning of toes. Flat feet. Forefoot problems, including bunions and hammer toes. High foot arches. Morton neuroma is more common in women than in men.
Often, no outward signs (such as a lump or unusual swelling) appear from the condition. Neuroma pain is most often described as a burning discomfort in the forefoot. Aching or sudden shooting pain in the forefoot is also common. All running sports, especially distance running can leave an athlete vulnerable to Morton?s Neuroma, which may appear or flare up in the middle of a run or at the end. The sufferer often has the desire to remove his shoe and rub the afflicted foot. Should the Neuroma be of sufficient size, or if footwear is particularly tight or uncomfortable, the painful condition may be present during normal walking. Numbness in the foot may precede or accompany Neuroma pain.
You should visit a doctor or podiatrist (foot doctor) if you have pain or tingling that does not stop. Your health care provider will examine your feet and will apply pressure on the spaces between the bones of the toes to determine the location of the foot pain. The doctor may order X-rays to rule out other conditions associated with foot pain, such as a stress fracture or arthritis. X-rays alone will not show whether or not a neuroma is present, so an ultrasound scan or magnetic resonance imaging (MRI) test may be done to confirm the diagnosis. A diagnostic procedure called an electromyography is sometimes used to rule out nerve conditions that may cause symptoms like those of associated with Morton?s neuroma.
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.
Patients are commonly offered surgery known as neurectomy, which involves removing the affected piece of nerve tissue. Postoperative scar tissue formation (known as stump neuroma) can occur in approximately 20%-30% of cases, causing a return of neuroma symptoms. Neurectomy can be performed using one of two general methods. Making the incision from the dorsal side (the top of the foot) is the more common method but requires cutting the deep transverse metatarsal ligament that connects the 3rd and 4th metatarsals in order to access the nerve beneath it. This results in exaggerated postoperative splaying of the 3rd and 4th digits (toes) due to the loss of the supporting ligamentous structure. This has aesthetic concerns for some patients and possible though unquantified long-term implications for foot structure and health. Alternatively, making the incision from the ventral side (the sole of the foot) allows more direct access to the affected nerve without cutting other structures. However, this approach requires a greater post-operative recovery time where the patient must avoid weight bearing on the affected foot because the ventral aspect of the foot is more highly enervated and impacted by pressure when standing. It also has an increased risk that scar tissue will form in a location that causes ongoing pain.