Morton's metatarsalgia is a condition associated with a painful neuroma* on the digital nerve causing pain in the foot. Charcterised by perineural fibrosis and nerve degeneration due to repetitive irritation, is thought to be due to irritation of the digital nerve caused by repeated trauma, ischemia or entrapment of the nerve, occurs most frequently in women aged 40-50 who wear high-heeled, pointed-toe shoes. The neuroma occurs at the level of the metatarsal necks. The common digital nerve to the third/fourth metatarsal spaces is most often affected, although other interspaces can be involved.
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.
A Morton's neuroma usually causes burning pain, numbness or tingling at the base of the third, fourth or second toes. Pain also can spread from the ball of the foot out to the tips of the toes. In some cases, there also is the sensation of a lump, a fold of sock or a "hot pebble" between the toes. Typically, the pain of a Morton's neuroma is relieved temporarily by taking off your shoes, flexing your toes and rubbing your feet. Symptoms may be aggravated by standing for prolonged periods or by wearing high heels or shoes with a narrow toe box.
Morton's neuroma is usually diagnosed by your doctor listening to your symptoms and examining your foot. Sometimes your doctor can feel the 'neuroma', or an area of thickening in your foot, which may be tender. Sometimes, your doctor may suggest an ultrasound scan or MRI scan to confirm the diagnosis but this is not always necessary. Some doctors inject a local anaesthetic into the area where you are experiencing pain. If this causes temporary relief of pain, burning and tingling, it can sometimes help to confirm the diagnosis and show the doctor where the problem is.
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 maybe 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 corticosteroid injections 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 from the nerve. 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 death of other important structures in the area.
Surgery for Morton's neuroma is usually a treatment of last resort. It may be recommended if you have severe pain in your foot or if non-surgical treatments haven't worked. Surgery is usually carried out under local anaesthetic, on an outpatient basis, which means you won't need to stay in hospital overnight. The operation can take up to 30 minutes. The surgeon will make a small incision, either on the top of your foot or on the sole. They may try to increase the space around the nerve (nerve decompression) by removing some of the surrounding tissue, or they may remove the nerve completely (nerve resection). If the nerve is removed, the area between your toes may be permanently numb. After the procedure you'll need to wear a special protective shoe until the affected area has healed sufficiently to wear normal footwear. It can take up to four weeks to make a full recovery. Most people (about 75%) who have surgery to treat Morton's neuroma have positive results and their painful symptoms are relieved.