During certain activities, particularly weight-bearing activities (e.g. walking or running) a compressive force, is sometimes placed on the interdigital nerves and surrounding soft tissue, between the metatarsal bones (this is often the case with tight fitting shoes or in patients with flat feet). If this force is repetitive enough and beyond what the nerve and soft tissue can withstand, swelling to the nerve and soft tissue may occur. This may result in pain, tenderness, pins and needles or numbness in the forefoot or toes. When this happens, the condition is known as a Morton's neuroma.
There are many reasons to develop a neuroma. Improper shoe gear is probably the most likely cause. Repetitive activity and excessive pressure on the ball of the foot are common. Heredity and genetic factors may also be involved. In many cases the structure of the foot may predispose the condition. Associated conditions that may cause neuroma include: bunion, hammer toes, ligament laxity, and/or a tight calf muscle. Some patients may have thinning of the fat pad on the ball of the foot, which may result in increased pressure of the nerves. Tight pointy shoes (and high heels) without padding may induce pain in the ball of the foot. Neuroma may occur suddenly, or develop over time.
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.
During the exam, your doctor will press on your foot to feel for a mass or tender spot. There may also be a feeling of "clicking" between the bones of your foot. Some imaging tests are more useful than others in the diagnosis of Morton's neuroma. Your doctor is likely to order X-rays of your foot, to rule out other causes of your pain such as a stress fracture. Ultrasound. This technology uses sound waves to create real-time images of internal structures. Ultrasound is particularly good at revealing soft tissue abnormalities, such as neuromas. Magnetic resonance imaging (MRI). Using radio waves and a strong magnetic field, an MRI also is good at visualizing soft tissues. But it's an expensive test and often indicates neuromas in people who have no symptoms.
Non Surgical Treatment
You may be able to treat this problem at home. Avoid wearing tight, pointy, or high-heeled shoes. Choose well-fitted shoes with plenty of room for your toes. Put ice or a cold pack on the area for 10 to 15 minutes at a time. Put a thin cloth between the ice and your skin. Take anti-inflammatory medicines to reduce pain and swelling. These include ibuprofen (such as Advil or Motrin) and naproxen (such as Aleve). Rest your feet when you can. Reduce activities that put pressure on the toes, such as racquet sports or running. Try massaging your foot to relax the muscles around the nerve. If these steps do not relieve your symptoms, your doctor may have you use special pads or devices that spread the toes to keep them from squeezing the nerve. In some cases, a doctor may give a steroid shot to reduce swelling and pain. If these treatments do not help, your doctor may suggest surgery.
If conservative treatments haven't helped, your doctor might suggest injections. Some people are helped by the injection of steroids into the painful area. In some cases, surgeons can relieve the pressure on the nerve by cutting nearby structures, such as the ligament that binds together some of the bones in the front of the foot. Surgical removal of the growth may be necessary if other treatments fail to provide pain relief. Although surgery is usually successful, the procedure can result in permanent numbness in the affected toes.