Patients with Morton?s neuroma present with pain in the forefoot, particularly in the ?ball? of the foot. However, not all pain in the forefoot is a Morton?s neuroma. In fact, most chronic pain in the forefoot is NOT the result of a Morton?s neuroma, but rather is from metatarsalgia - inflammation (synovitis) of the ?toe/foot? joints. The symptoms from Morton?s neuroma are due to irritation to the small digital nerves, as they pass across the sole of the foot and into the toes. Therefore, with a true Morton?s neuroma, it is not uncommon to have nerve-type symptoms, which can include numbness or a burning sensation extending into the toes. There are several interdigital nerves in the forefoot. The most common nerve to develop into a neuroma is between the 3rd and 4th toes. With a true neuroma, the pain should be isolated to just one or two toes.
The source of this pain is an enlargment of the sheath of an intermetatarsal nerve in the foot. This usually occurs in the third intermetatarsal space, the space between the third and fourth toes and metatarsals. It occurs here, at the site third intermetatarsal nerve, since this intermetatarsal nerve is the thickest being comprised of the joining of two different nerves. It also may occur in the other intermetatarsal areas, with the second interspace being the next most common location.
Normally, there are no outward signs, such as a lump, because this is not really a tumor. Burning pain in the ball of the foot that may radiate into the toes. The pain generally intensifies with activity or wearing shoes. Night pain is rare. There may also be numbness in the toes, or an unpleasant feeling in the toes. Runners may feel pain as they push off from the starting block. High-heeled shoes, which put the foot in a similar position to the push-off, can also aggravate the condition. Tight, narrow shoes also aggravate this condition by compressing the toe bones and pinching the nerve.
A thorough subjective and objective examination from a physiotherapist is usually sufficient to diagnose a Morton's neuroma. Investigations such as an X-ray, ultrasound, MRI, CT scan or bone scan may sometimes be used to assist with diagnosis, assess the severity of the injury and rule out other conditions.
Non Surgical Treatment
Most non-operative treatment is usually successful, although it can take a while to figure out what combination of non-operative treatment works best for each individual patient. Non-operative treatment may include the use of comfort shoe wear. The use of a metatarsal pad to decrease the load through the involved area of the plantar forefoot. A period of activity modification to decrease or eliminate activities, which maybe exacerbating the patient?s symptoms. For example, avoiding long periods of standing or other activities that result in significant repetitive loading to the forefoot can be very helpful. Wearing high heels should be avoided. Local corticosteroid injections can help decrease inflammation associated with the nerve. However, this does not necessarily address the underlying loading forces that maybe causing the injury to the nerve in the first place. It has been proposed that an alcohol injection in and around the nerve will cause a controlled death to the nerve and subsequently eliminate symptoms from the nerve. In theory, this may be helpful. In practice, adequate prospective studies have not demonstrated the benefit of this procedure above and beyond the other standard non-operative treatments available. In addition there is the concern that the alcohol will cause excessive scarring and death of other important structures in the area.
Surgical treatment has provided relief in some cases while poor results and surgical complications have resulted in other cases. It is believed that ligament weakness, as opposed to the pinching of nerves in the foot, may be to blame for recurrent pain in these situations. For reasons which are not fully understood, the incidence of Morton?s Neuroma is 8 to 10 times greater in women than in men.