What Causes Mortons Neuroma

Overview

Morton neuroma (interdigital neuroma), first described in 1876, is a perineural fibrosis and nerve degeneration of the common digital nerve. Morton neuroma, or Morton’s neuroma, is not a true neuroma, although it results in neuropathic pain in the distribution of the interdigital nerve secondary to repetitive irritation of the nerve. The most frequent location is between the third and fourth metatarsals (third webspace). Other, less common locations are between the second and third metatarsals (second webspace) and, rarely, between the first and second (first webspace) or fourth and fifth (fourth webspace) metatarsals.

Causes

Anything that causes compression or irritation of the nerve can lead to the development of a neuroma. One of the most common causes comes from wearing shoes that have a tapered toe box, or high-heeled shoes that cause the toes to be forced into the toe box and overload pressure onto the forefoot. An injury or trauma to the forefoot may also lead to a neuroma. People at a higher risk of developing a Neuroma include people with certain foot deformities, such as bunions or hammertoes. Certain foot types, such as flat feet (Pronation) More flexible feet, and woman after pregnancy.

Symptoms

Symptoms of interdigital neuroma typically manifest as a sharp, burning or tingling sensation in the forefoot. The pain radiates toward the lesser toes and is aggravated by shoe wear. The pain is relieved when the shoe is removed and the forefoot is massaged. Sometimes the symptoms involve specific toes.

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done. Initial diagnosis of Morton’s neuroma is based on your description of the type and location of pain and discomfort in the foot. The diagnosis will be confirmed by a physical exam of the foot, including checking for mechanical abnormalities in the foot, squeezing the side of the foot, which will usually cause pain when Morton’s neuroma is present. Examination of your shoes to check for excess wear in parts of the shoe, check to see whether the shoes are too tight. Imaging tests evaluate the foot and surrounding structures. This may be done with X-ray, MRI scan, Ultrasound. Injections of local anesthetic can also be used for diagnosis.

Non Surgical Treatment

In developing a treatment plan, your foot and ankle surgeon will first determine how long you?ve had the neuroma and evaluate its stage of development. Treatment approaches vary according to the severity of the problem. For mild to moderate neuromas, treatment options may include Padding techniques provide support for the metatarsal arch, thereby lessening the pressure on the nerve and decreasing the compression when walking. Placing an icepack on the affected area helps reduce swelling. Custom orthotic devices provided by your foot and ankle surgeon provide the support needed to reduce pressure and compression on the nerve. Activities that put repetitive pressure on the neuroma should be avoided until the condition improves. Wear shoes with a wide toe box and avoid narrow-toed shoes or shoes with high heels. Oral nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may be recommended to reduce pain and inflammation. Treatment may include injections of cortisone, local anesthetics or other agents.

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.

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