What Is Mortons Neuroma

Overview

A Morton's neuroma is a benign (noncancerous) swelling along a nerve in the foot that carries sensations from the toes. The reason the nerve starts to swell is unknown. But once swelling begins, the nearby bones and ligaments put pressure on the nerve, causing more irritation and inflammation. This produces burning pain, numbness, tingling and other abnormal sensations in the toes. A Morton's neuroma also is called an interdigital neuroma, intermetatarsal neuroma or a forefoot neuroma.

Causes

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.

Symptoms

Morton's neuroma can cause a very painful burning or sharp pain in your foot that feels worse when you walk. It may feel like a small lump inside the ball of your foot. It is usually between the third and fourth toes, but it can also be between other toes.

Diagnosis

The clinical symptoms should quickly lead your doctor to suspect a neuroma. When examined, the doctor may feel a "click" which is known as Mulder's sign. There may be tenderness in the interspace. The metatarsal bones will also be examined both clinically (and often with an xray). Tenderness at one of the metatarsal bones can suggest an overstress reaction (pre-stress fracture or stress fracture) in the bone. An ultrasound scan can confirm the diagnosis and is a less expensive and at this time, at least as sensitive a test as an MRI. An x-ray does not show neuromas, but can be useful to "rule out" other causes of the pain.

Non Surgical Treatment

Common treatments involve wearing different shoes or using arch supports. Resting the foot, massaging the toes and using an ice pack may work for some people. A GP or a podiatrist (foot specialist) may also recommend anti-inflammatory painkillers or a course of steroid injections. Numbing injections, in which alcohol and a local anaesthetic are injected into the affected area of the foot, may also be effective. In extreme cases, when the condition does not respond to treatment, day case surgery may be needed.

Surgical Treatment

Surgery for neuroma most often involves removing affected nerve in the ball of the foot. An incision is made on the top of the foot and the nerve is carefully removed. Surgeon must remove the nerve far enough back so that the nerve doesn?t continue to become impinged at the ball of the foot. Alternatitvely, another type of surgery involves releasing a tight ligament that encases the nerve. Recovery after Morton?s neuroma (neurectomy) surgery is generally quick. Typically patients are walking on the operated foot in a post-surgical shoe for 2 - 4 weeks, depending on healing. Return to shoes is 2-6 weeks after the surgery. Factors that may prolong healing are age, smoking, poor nutritional status, and some medical problems.

Prevention

The best way to prevent a neuroma is by avoiding the things that cause them. Review your risk factors. If relatives have had similar problems, or if you know that you pronate or have any problem with the mechanics of your foot, talk with a podiatric physician about the correct types of shoes and/or orthoses for you. If you are not sure whether you have such a problem, the podiatric professional can analyze your foot, your stride and the wear pattern of your shoes, and give you an honest evaluation. Remember, though, that sometimes neuromas, like other conditions, can develop for no discernible reason. With this in mind, be good to your feet, and be aware of any changes or problems. Don?t wait to report them.