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.
In many cases, a neuroma may develop as a result of excessive loading on the front of the foot. Sometimes, a patient?s anatomic alignment in the forefoot contributes to the overload. There may be some cases where the neuroma develops spontaneously, for no obvious reason. However, once the nerve is irritated, pressure from walking, and from the adjacent bony prominences (metatarsal heads), as well as from the intermetatarsal ligament that binds the heads together, all may contribute to persistent pain. Repetitive pressure on the nerve causes localized injury with resulting scarring and fibrosis of the nerve. This leads to symptoms in the distribution of the nerve.
Patients with a Morton's neuroma typically experience a sharp, shooting or burning pain, usually at the base of the forefoot or toes, which radiates into the two affected toes. Sometimes the pain may also radiate into the foot. The pain is often associated with the presence of pins and needles and numbness.
The physician will make the diagnosis of Morton's neuroma based upon the patient's symptoms as described above in an interview, or history, and a physical examination. The physical examination will reveal exceptional tenderness in the involved interspace when the nerve area is pressed on the bottom of the foot. As the interspace is palpated, and pressure is applied from the top to the bottom of the foot, a click can sometimes be felt which reproduces the patient's pain. This is known as a Mulder's sign. Because of inconsistent results, imaging studies such as MRI or ultrasound scanning are not useful diagnostic tools for Morton's neuroma. Thus the physician must rely exclusively on the patient's history and physical examination in order to make a diagnosis.
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.
Operative treatment of Morton?s neuroma should be entertained only after failure of nonoperative management. Standard operative treatment involves identifying the nerve and cutting (resecting) it proximal to the point where it is irritate/injured. This is usually done through an incision on the top (dorsal) aspect of the foot, although in rare instances, an incision on the sole (plantar) aspect of the foot maybe used. An incision on the sole of the foot works very well, unless an excessive scar forms in which case it can be problematic. Some physicians will attempt to treat Morton?s neuroma by releasing the intermetatarsal ligament and freeing the nerve of local scar tissue. This may also be beneficial.