Morton?s neuroma occurs as the nerve passes under the ligament connecting the toe bones (metatarsals) in the forefoot. Morton?s neuroma most frequently develops between the third and fourth toes, usually in response to irritation, trauma or excessive pressure. The incidence of Morton?s neuroma is 8 to 10 times greater in women than in men.
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.
The clinical symptoms should quickly lead your doctor to suspect a neuroma. When examined, the doctor may feel a “click” which is known as Mulder’s sign. There may be tenderness in the interspace. The metatarsal bones will also be examined both clinically (and often with an xray). Tenderness at one of the metatarsal bones can suggest an overstress reaction (pre-stress fracture or stress fracture) in the bone. An ultrasound scan can confirm the diagnosis and is a less expensive and at this time, at least as sensitive a test as an MRI. An x-ray does not show neuromas, but can be useful to “rule out” other causes of the pain.
Non Surgical Treatment
Rest. Continuing with normal training will increase pain and inflammation and prevent the injury from healing. Wear a metatarsal pad under the forefoot which will raise and spread the bones of the forefoot taking the pressure off the nerve. Wearing metatarsal pads in the shoes under the forefoot spreads the metatarsals creating more space for the nerve. See a sports injury professional who can advise on treatment and rehabilitation. Orthotic inserts may be required to correct any biomechanical dysfunction of the foot.
Should the problem have progressed beyond the point where these measures are sufficient, the podiatric professional may recommend surgery. This procedure involves excision of the involved nerve mass. This will relieve the pain. Many patients report permanent numbness in the spot formerly affected by the neuroma, but prefer it to the pain. Most surgeries are successful; unfortunately, there are cases where the patient suffers another neuroma, sometimes in or near the same spot as before. A podiatric professional can explain the statistics of recurrence in various cases. If you suspect a neuroma, don?t wait for it to get better on its own. The earlier the diagnosis, the higher the likelihood that it can be treated with conservative measures. Don?t think that foot pain of any kind is inevitable, either, even if it runs in your family.