Morton's neuroma is an enlarged nerve that usually occurs in the third interspace, which is between the third and fourth toes. To understand Morton's neuroma further, it may be helpful to look at the anatomy of the foot. Problems often develop in the third interspace because part of the lateral plantar nerve combines with part of the medial plantar nerve here. When the two nerves combine, they are typically larger in diameter than those going to the other toes. Also, the nerve lies in subcutaneous tissue, just above the fat pad of the foot, close to an artery and vein. Above the nerve is a structure called the deep transverse metatarsal ligament. This ligament is very strong, holds the metatarsal bones together, and creates the ceiling of the nerve compartment. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament pushes down. This causes compression in a confined space.
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.
If you have a Morton?s neuroma, you may have one or more of these symptoms where the nerve damage is occurring, Tingling, burning, or numbness, pain, a feeling that something is inside the ball of the foot or a feeling that there?s something in the shoe or a sock is bunched up. The progression of a Morton?s neuroma often follows the following pattern. The symptoms begin gradually. At first they occur only occasionally, when wearing narrow-toed shoes or performing certain aggravating activities. The symptoms may go away temporarily by removing the shoe, 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.
To confirm the diagnosis, your doctor will examine your feet. He or she will look for areas of tenderness, swelling, calluses, numbness, muscle weakness and limited motion. To check for a Morton's neuroma, your doctor will squeeze the sides of your foot. Squeezing should compress the neuroma and trigger your typical pain. In some cases, your doctor will find numbness in the webbed area between the affected toes. Pain in two or more locations on one foot, such as between both the second and third toes and the third and fourth toes, more likely indicates that the toe joints are inflamed rather than a Morton' 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.)
When early treatments fail and the neuroma progresses past the threshold for such options, podiatric surgery may become necessary. The procedure, which removes the inflamed and enlarged nerve, can usually be conducted on an outpatient basis, with a recovery time that is often just a few weeks. Your podiatric physician will thoroughly describe the surgical procedures to be used and the results you can expect. Any pain following surgery is easily managed with medications prescribed by your podiatrist.
Wearing proper footwear that minimizes compression of the forefoot can help to prevent the development of and aggravation of a Morton's neuroma.