Morton?s neuroma occurs as the nerve passes under the ligament connecting the toe bones (metatarsals) in the forefoot. Morton?s neuroma most frequently develops between the third and fourth toes, usually in response to irritation, trauma or excessive pressure. The incidence of Morton?s neuroma is 8 to 10 times greater in women than in men.
Experts are not sure what exactly causes Morton's neuroma. It seems to develop as a result of irritation, pressure or injury to one of the digital nerves that lead to the toes, which triggers a body response, resulting in thickened nerve tissue (neuroma). Feet conditions/situations that can cause the bones to rub against a nerve include high-heeled shoes, especially those over 2 inches (5cm), or a pointed or tight toe box which squash the toes together. This is probably why the condition is much more common in females than in males. High-arched foot, people whose feet have high arches are much more likely to suffer from Morton's neuroma than others. Flat feet, the arch of the foot collapses. The entire sole of the foot comes into complete or near-complete contact with the ground. A bunion, a localized painful swelling at the base of the big toe, which enlarges the joint. Hammer toe, a deformity of the proximal interphalangeal joint of the second, third, or fourth toe causing it to be permanently bent. Some high-impact sporting activities including running, karate, and court sports. Any sport that places undue pressure on the feet. Injuries, an injury or other type of trauma to the foot may lead to a neuroma.
Patients will feel pain that worsens with walking, particularly when walking in shoes with thin soles or high heels. Also, anything that squeezes the metatarsal heads together may aggravate symptoms, such as narrow shoes. A patient may feel the need to remove the shoe and rub the foot to soothe the pain.
Patients with classic Morton?s neuroma symptoms will have pain with pressure at the base of the involved toes (either between the 2nd and 3rd toes, or between the 3rd and 4th toes). In addition, squeezing the front of the foot together can exacerbate symptoms. As well, they may have numbness on the sides of one toe and the adjacent toe as this corresponds with the distribution of the involved nerve.
Non Surgical Treatment
Most non-operative treatment is usually successful, although it can take a while to figure out what combination of non-operative treatment works best for each individual patient. Non-operative treatment may include the use of comfort shoe wear. The use of a metatarsal pad to decrease the load through the involved area of the plantar forefoot. A period of activity modification to decrease or eliminate activities, which may be exacerbating the patient?s symptoms. For example, avoiding long periods of standing or other activities that result in significant repetitive loading to the forefoot can be very helpful. Wearing high heels should be avoided. Local can help decrease inflammation associated with the nerve. However, this does not necessarily address the underlying loading forces that maybe causing the injury to the nerve in the first place. It has been proposed that an alcohol injection in and around the nerve will cause a controlled death to the nerve and subsequently eliminate symptoms. In theory, this may be helpful. In practice, adequate prospective studies have not demonstrated the benefit of this procedure above and beyond the other standard, non-operative treatments available. In addition there is the concern that the alcohol will cause excessive scarring and damage to other important structures in the area.
If symptoms do not respond to any of the above measures then surgery may be suggested. This involves a short 30 minute operation to either remove tissue to take pressure off the nerve or to remove the nerve causing the pain. The surgery can be done as a day case but it will be two or three weeks before you can be fully active on your feet. There may be some lingering numbness afterwards if the nerve is removed. But surgery is successful in around 80% of cases. There is a small risk of complications such as infection and thickening of the skin on the soles of the feet.