A neuroma is a thickening of nerve tissue that may develop in various parts of the body. The most common neuroma in the foot is a Morton?s neuroma, which occurs between the third and fourth toes. It is sometimes referred to as an intermetatarsal neuroma. ?Intermetatarsal? describes its location in the ball of the foot between the metatarsal bones. Neuromas may also occur in other locations in the foot. MortonThe thickening, or enlargement, of the nerve that defines a neuroma is the result of compression and irritation of the nerve. This compression creates enlargement of the nerve, eventually leading to permanent nerve damage.
A Morton's neuroma commonly occurs due to repetitive weight bearing activity (such as walking or running) particularly when combined with tight fitting shoes or excessive pronation of the feet (i.e. "flat-feet"). The condition is also more common in patients with an unstable forefoot allowing excessive movement between the metatarsal bones. A Morton's neuroma can also occur due to certain foot deformities, trauma to the foot, or the presence of a ganglion or inflamed bursa in the region which may place compressive forces on the nerve.
Symptoms include: pain on weight bearing, frequently after only a short time. The nature of the pain varies widely among individuals. Some people experience shooting pain affecting the contiguous halves of two toes. Others describe a feeling like having a pebble in their shoe or walking on razor blades. Burning, numbness, and paresthesia may also be experienced. Morton's neuroma lesions have been found using MRI in patients without symptoms.
The exact cause of Mortons neuroma can often vary between patients. An accurate diagnosis must be carefully made by the podiatrist through thorough history taking and direct questioning to ensure all possible causes are addressed. The podiatrist will also gather further information about the cause through a hands on assessment where they will try to reproduce your symptoms. A biomechanical and gait analysis will also be performed to assess whether poor foot alignment and function has contributed to your neuroma.
Non Surgical Treatment
Initial treatment for Morton?s Neuroma may include non-prescription anti-inflammatory medications to reduce pain and swelling. These may consist of standard analgesics such as aspirin and ibuprofen (Advil, Motrin, others). Massaging the painful region three times daily with ice. Change of footwear. Avoid tight shoes, high heels or any footwear that seems to irritate the condition. Low heeled shoes with softer soles are preferable. Arch supports and foot pads to help reduce pressure on the nerve. In some cases, a physician may prescribe a customized shoe insert, molded to fit the contours of the patient?s foot. Reducing activities causing stress to the foot, including jogging, dancing, aerobic activity or any high impact movements of the foot. Injections of a corticosteroid medication to reduce the swelling and inflammation of the nerve and reduce pain. Occasionally other substances may be injected in order to ?ablate? the Neuroma. (The overuse of injected steroids is to be avoided however, as side effects, including weight gain and high blood pressure can result.)
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.
While Morton?s Neuroma has been an ongoing topic of clinical investigation, the condition is in some cases difficult to either treat or prevent. Experimental efforts involving the injection of muscle or bone with chemicals such as alcohol, as well as suturing, and covering affected areas with silicone caps have been attempted, with varying success.