This is a painful condition affecting a small nerve in the foot. It occurs when the five long bones that run the length of the foot get pushed together, pinching the nerve in between. This friction on the nerve causes it to thicken and inflame causing pain. The condition gets its name from an American surgeon, George Morton.
The exact cause is as yet unclear. However there are a number of theories. Some expert s believe problems with the design of the foot makes some people more prone to Morton?s neuroma. Having flat feet or a high arch for example encourages the foot to slide forwards which can put excess pressure on the metatarsals. Bunions and hammer toes also increase the likelihood of developing Morton?s. However simply wearing high heels or any form of tight shoes that put pressure on the bones in the feet can also lead to a Morton?s . Typically the condition comes on between the age of 40 and 50. It is far more common in women than men - three out of four sufferers are women.
If you have a Morton's neuroma, you will probably have one or more of these symptoms. Tingling, burning, or numbness. A feeling that something is inside the ball of the foot, or your sock is bunched up. Pain that is relieved by removing your shoes. A Morton's Neuroma often develops gradually. At first the symptoms may occur only occasionally, when wearing narrower shoes or performing certain activities. The symptoms may go away temporarily by massaging the foot or by avoiding aggravating shoes or activities. Over time the symptoms progressively worsen and may persist for several days or weeks. The symptoms become more intense as the neuroma enlarges and the temporary changes in the nerve become permanent.
Morton?s neuroma can be identified during a physical exam, after pressing on the bottom of the foot. This maneuver usually reproduces the patient?s pain. MRI and ultrasound are imaging studiesthat can demonstrate the presence of the neuroma. An x-ray may also be ordered to make sure no other issues exist in the foot. A local anesthetic injection along the neuroma may temporarily abolish the pain, and help confirm the diagnosis.
Non Surgical Treatment
Initial therapies are nonsurgical and can involve one or more of the following treatments Changes in footwear. Avoid high heels or tight shoes, and wear wider shoes with lower heels and a soft sole. This enables the bones to spread out and may reduce pressure on the nerve, giving it time to heal. Custom shoe inserts and pads also help relieve irritation by lifting and separating the bones, reducing the pressure on the nerve. One or more injections of a corticosteroid medication can reduce the swelling and inflammation of the nerve, bringing some relief. Massaging the affected area can provide some momentary relief. Several studies have shown that a combination of roomier, more comfortable shoes, nonsteroidal anti-inflammatory medication, custom foot orthoses and cortisone injections provide relief in over 80 percent of people with Morton?s Neuroma. If conservative treatment does not relieve your symptoms, your physician may discuss surgical treatment options with you.
Patients are commonly offered surgery known as neurectomy, which involves removing the affected piece of nerve tissue. Postoperative scar tissue formation (known as stump neuroma) can occur in approximately 20%-30% of cases, causing a return of neuroma symptoms. Neurectomy can be performed using one of two general methods. Making the incision from the dorsal side (the top of the foot) is the more common method but requires cutting the deep transverse metatarsal ligament that connects the 3rd and 4th metatarsals in order to access the nerve beneath it. This results in exaggerated postoperative splaying of the 3rd and 4th digits (toes) due to the loss of the supporting ligamentous structure. This has aesthetic concerns for some patients and possible though unquantified long-term implications for foot structure and health. Alternatively, making the incision from the ventral side (the sole of the foot) allows more direct access to the affected nerve without cutting other structures. However, this approach requires a greater post-operative recovery time where the patient must avoid weight bearing on the affected foot because the ventral aspect of the foot is more highly enervated and impacted by pressure when standing. It also has an increased risk that scar tissue will form in a location that causes ongoing pain.