What Causes Mortons Neuroma

Overview

Morton's neuroma is a condition that affects one of the nerves between the toes. It's also known as Morton's metatarsalgia or interdigital neuroma. In Morton's neuroma, fibrous tissue develops around the nerve, which becomes irritated and compressed. This causes severe pain on the ball of the foot and at the base of the toes. Morton's neuroma can occur on one foot or both feet. It usually affects the nerve between the third and fourth toes, but sometimes the second and third toes are affected.

Causes

Some say that this condition should not be called Morton's neuroma as, in fact, it is not actually a neuroma. A neuroma is a non-cancerous (benign) tumour that grows from the fibrous coverings of a nerve. There is no tumour formation in Morton's neuroma. The anatomy of the bones of the foot is also thought to contribute to the development of Morton's neuroma. For example, the space between the long bones (metatarsals) in the foot is narrower between the second and third, and between the third and fourth metatarsals. This means that the nerves that run between these metatarsals are more likely to be compressed and irritated. Wearing narrow shoes can make this compression worse.

Symptoms

Many patients describe the sensation as a burning pain in the ball of the foot that often radiates to the toes. Initially, the pain may become much more apparent when the person wears tight, narrow or high-heeled shoes, or engages in activities which place pressure on the foot. Eventually, symptoms may be continuous and last for days, and even weeks. MRI (magnetic resonance imaging) scans have revealed Morton's neuroma lesions in patients who had no symptoms at all. Symptoms can become so disrupting that many affected individuals become anxious about walking, or even placing their foot on the ground.

Diagnosis

Your podiatric physician will begin by taking a history of your problem. Assist him or her by describing your condition as well as you can. Keep track of when the symptoms started and how, any changes you?ve noted (whether the pain has gotten worse, or whether other symptoms have appeared as well, etc.). If you?ve noticed that certain activities or footwear make things worse or bring about additional symptoms, be sure to mention that. If you work in specific footwear, or if you participate in any certain sports, bring the shoes you use. Your doctor may be able to learn quite a lot about your condition that way!

Non Surgical Treatment

Treatments may include rehabilitation measures to reduce nerve Irritation. Switching to low-heeled, wide-toed shoes with good arch support. Wearing padding in the shoes and/or between the toes. Wearing shoe inserts to correct a mechanical abnormality of the foot. Having ultrasound, electrical stimulation, whirlpool, and massage done on the foot. The foot may be injected with corticosteroids mixed with a local anesthetic in order to reduce pain. Relief may be only temporary, however, if the mechanical irritation is not also corrected. Injections with other types of medications such as alcohol, phenol, or vitamin B12 are sometimes used.

Surgical Treatment

If other therapies have not worked it may be necessary to perform surgery. As surgery may result in permanent numbness in the affected toe, doctors ten to use this procedure as a last resort. However, in most cases surgery is extremely effective. The patient usually receives a local anesthetic. Surgery involves either removing the nerve, or removing the pressure on the nerve. Two surgical approaches are possible. The dorsal approach, the surgeon makes an incision on the top of the foot, allowing the patient to walk soon after surgery, because the stitches are not on the weight-bearing side of the foot. The plantar approach, the surgeon makes an incision on the sole of the foot. In most cases the patient will be in crutches for about three weeks. The resulting scar may make walking uncomfortable. However, with this approach the neuroma can be reached easily and resected without cutting any structures. There is a small risk of infection around the toes after surgery.

Prevention

How can Morton?s neuroma be prevented? Do not wear tight shoes or high-heeled shoes for prolonged periods. Do wear shoes with a wide toe box so that your toes are not squeezed or cramped. Do wear athletic footwear with enough padding to cushion the balls of the feet when exercising or participating in sports.