Put simply - Morton's neuroma is a swollen (inflamed) nerve in the ball of the foot, commonly between the base of the second and third toes. Patients experience numbness and pain in the affected area, which is relieved by removing footwear and/or massaging the foot. A neuroma is a tumor that arises in nerve cells, a benign growth of nerve tissue that can develop in various parts of the body. In Morton's neuroma the tissue around one of the nerves leading to the toes thickens, causing a sharp, burning pain in the ball of the foot. A sharp severe pain, often described as a red hot needle may come on suddenly while walking. There may also be numbness, burning and stinging in the toes. Although it is labeled a neuroma, many say it is not a true tumor, but rather a perineural fibroma (fibrous tissue formation around nerve tissue).
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.
Symptoms include tingling in the space between the third and fourth toes, toe cramping, a sharp, shooting, or burning pain in the ball of the foot and sometimes toes, pain that increases when wearing shoes or pressing on the area, pain that gets worse over time. In rare cases, nerve pain occurs in the space between the second and third toes. This is not a common form of Morton neuroma, but treatment is similar.
To diagnose Morton's neuroma the podiatrist commonly palpates the area to elicit pain, squeezing the toes from the side. Next he or she may try to feel the neuroma by pressing a thumb into the third interspace. The podiatrist then tries to elicit Mulder's sign, by palpating the affected interspace with one hand and squeezing the entire foot at the same time with the other hand. In many cases of Morton's neuroma, this causes an audible click, known as Mulder's sign. An x-ray should be taken to ensure that there is not a fracture. X-rays also can be used to examine the joints and bone density, ruling out arthritis (particularly rheumatoid arthritis and osteoarthritis).
Non Surgical Treatment
Wear shoes with plenty of room for the toes to move, low heels, and laces or buckles that allow for width adjustment. Wear shoes with thick, shock-absorbent soles, as well as proper insoles that are designed to keep excessive pressure off of the foot. High-heeled shoes over two inches tall should be avoided whenever possible because they place undue strain on the forefoot. Resting the foot and massaging the affected area can temporarily alleviate neuroma pain. Use an ice pack to help to dull the pain and improve comfort. Use over-the-counter shoe pads. These pads can relieve pressure around the affected area.
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.