Morton's Neuroma

By Burton J. Katzen, DPM

Metro Foot Care Centers

. http://www.marylandfootdoctor.com

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Morton's Neuroma

Neuromas are a thickening of the outer coating of a nerve in the foot. It is classified as a benign soft tissue tumor. Almost 90% of all neuromas are found in females between the ages of 18-85.

Single neuromas are most common, however, instances of multiple neuromas in the same foot have been reported. The area between the third and fourth toes is most commonly affected, however the area between the second and third toes is also commonly irritated.

Causing Factors

Neuromas are usually caused by irritation as the nerve is rubbed by the long bones of the forefoot (metatarsals). There are a number of precipitatory factors that can cause a localized irritation to the nerve and thus may contribute to the development of the neuroma

1. Metatarsal bones that are too close together or the same length. This causes a rubbing of the two bones against the nerve.

2. Biomechanical abnormalities – An unstable (pronated) foot can predispose the foot to excess motion and excess rubbing of the two bones on the nerve.

3. Footgear – Any shoe that is high-heeled or is constricting may place the individual at higher risk for developing a neuroma.

4. Occupation – Occupations that require high-heeled shoes, excessive stress of the forefoot such as kneeling or climbing ladders, or requirements of constricting shoe gear.

5. Trauma – Repetitive trauma that results from certain activities such as basketball, tennis, aerobics or running. Also, trauma resulting from an injury such as fractures, sprains, dislocations and crushing blows to the foot.

Symptoms

There are usually no visible signs of neuroma. The pain can be shooting or stabbing radiating to the two adjacent toes. The pain can also be described as burning, tingling, cramping, and numbing. Symptoms usually occur during or after walking or standing, and the patient may get relief by removing the shoe and rubbing the foot.

As the neuroma enlarges, the toes may separate creating a “peace sign.” This is referred to as Sullivan's sign and is due to the growing mass pressing on bone and soft tissue. Pressing the web space between the two toes or squeezing the entire foot while moving the bones up and down often produces pain.

Diagnosis

Neuromas are usually diagnosed clinically, but X-rays are taken to rule out other causes of the pain and to see the possible juxtaposition (closeness) and relative length of the metatarsal bones.

MRI's can also be helpful in confirminig a questionable neuroma. Its use, however, is not recommended as part of the routine workup, because of its expense. Normally diagnosis is quite reliable with a thorough history and examination.

Non-Surgical Treatment

1. Orthotics – A shoe insole with special padding designed to support your foot. The padding may help to spread your foot in front which prevents irritation to the nerve.

2. Shoe changes – Tight shoes can aggravate this, so shoe stretching can be of great benefit. Also, avoid high-heeled and other constrictive shoe gear.

3. Physical therapy – Usually involves ultrasoundfor mild cases only.

4. Medication – Cortisone injections or oral anti-inflammatories may give temporary relief of pain and swelling.

Surgical Treatment

Since chronic neuromas are soft tissue tumors, they often have to be removed surgically. This involves a twenty minute in-office soft tissue procedure performed under local anesthesia or local anesthesia with IV sedation.