A neuroma develops when a nerve is compressed, injured or pinched, causing swelling and pain. A neuroma in the area between the third and fourth toes, or between the second and third toes, is known as a Morton?s neuroma. Morton?s neuroma causes sharp, burning pain and numbness in the toes and foot. You may feel like you?ve stepped on a tiny hot coal and can?t get rid of it. At the same time, you?ll have the disconcerting experience of not being able to feel your toes. Sometimes the nerve tissue becomes so thickened you can feel or see a lump.
Various factors have been implicated in the precipitation of Morton's neuroma. Morton's neuroma is known to develop as a result of chronic nerve stress and irritation, particularly with excessive toe dorsiflexion. Poorly fitting and constricting shoes (ie, small toe box) or shoes with heel lifts often contribute to Morton's neuroma. Women who wear high-heeled shoes for a number of years or men who are required to wear constrictive shoe gear are at risk. A biomechanical theory of causation involves the mechanics of the foot and ankle. For instance, individuals with tight gastrocnemius-soleus muscles or who excessively pronate the foot may compensate by dorsiflexion of the metatarsals subsequently irritating of the interdigital nerve. Certain activities carry increased risk of excessive toe dorsiflexion, such as prolonged walking, running, squatting, and demi-pointe position in ballet.
Symptoms associated with a neuroma include a dull burning sensation radiating towards the toes, a cramping feeling, or even a stinging, tingling sensation that can be described as being similar to an electric shock. It is often worse when wearing shoes with most people finding the pain disappears when removing their shoes.
To diagnose Morton's neuroma the podiatrist commonly palpates the area to elicit pain, squeezing the toes from the side. Next he or she may try to feel the neuroma by pressing a thumb into the third interspace. The podiatrist then tries to elicit Mulder's sign, by palpating the affected interspace with one hand and squeezing the entire foot at the same time with the other hand. In many cases of Morton's neuroma, this causes an audible click, known as Mulder's sign. An x-ray should be taken to ensure that there is not a fracture. X-rays also can be used to examine the joints and bone density, ruling out arthritis (particularly rheumatoid arthritis and osteoarthritis).
Non Surgical Treatment
The first line of treatment is to try modifying footwear. Often simply wearing broader fitting shoes can reduce pressure on the neuroma and so reduce pain. Orthotic inserts can also help as they can again help reduce pressure on certain parts of the foot. Padding and taping the toe area is another option. In some cases a steroid injection into the foot may be suggested. This can be done as a day case without the need for anaesthesia and helps reduce inflation of the nerve. It can halt the pain in round 70 % of cases. Sometimes a combination of alcohol and local anaesthesia may be injected as this helps reduce pain.
If symptoms do not respond to any of the above measures then surgery may be suggested. This involves a short 30 minute operation to either remove tissue to take pressure off the nerve or to remove the nerve causing the pain. The surgery can be done as a day case but it will be two or three weeks before you can be fully active on your feet. There may be some lingering numbness afterwards if the nerve is removed. But surgery is successful in around 80% of cases. There is a small risk of complications such as infection and thickening of the skin on the soles of the feet.