Morton?s neuroma is inflammation, thickening, or enlargement of the nerve between the bones of the toes (metatarsal bones). The condition is also called intermetatarsal neuroma. The thickening is usually found between bones of the third and fourth toes of the foot, but sometimes it may develop between the second and third toes. It occurs when the medial plantar nerve near the bones of those toes becomes compressed or irritated, possibly because the metatarsal bones press against the nerve in the narrow gap between the toes. If left untreated, Morton?s neuroma can cause a sharp, burning, or shooting pain that often gets worse over time. The pain becomes worse when a person walks or stands on the ball of the foot. Sometimes the pain reaches the toes next to the neuroma and a sensation of tingling or numbness is felt.
The cause of this problem is often due to impingement of the plantar nerve fibres between the metatarsal heads and the intermetatarsal ligament. It is entirely a biomechanical phenomenon. Differential diagnoses include stress fracture, capsulitis, bursitis or ligament injury at the metatarsal-phalangeal joint, a tendon sheath ganglion, foreign-body reaction and nerve-sheath tumour.
Patients will complain of numbness, a ?pins and needles? type of tingling and loss of sensation in the toes. Burning pain in the ball of the foot that may radiate into the toes. The pain generally intensifies with activity or wearing shoes. Night pain is rare. There may also be numbness in the toes, or an unpleasant feeling in the toes. Runners may feel pain as they push off from the starting block. High-heeled shoes, which put the foot in a similar position to the push-off, can also aggravate the condition. Tight, narrow shoes also aggravate this condition by compressing the toe bones and pinching the nerve.
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
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.
The ultimate success of a Morton?s neuroma treated surgically can be variable. In cases where the underlying problem is only an irritated nerve (a true Morton?s neuroma), then surgery will probably be curative (although it may take a few months for the foot to fully heal). But in many cases, forefoot pain is more complex. There may be an irritated nerve or two causing pain, but the real problem is often excessive loading of the lesser metatarsals. The generic term for this condition is metatarsalgia. When considering surgery, identifying and addressing these problems may lead to a better end result.