Morton's neuroma is a swollen or thickened nerve in the ball of your foot. When your toes are squeezed together too often and for too long, the nerve that runs between your toes can swell and get thicker. This swelling can make it painful when you walk on that foot. High-heeled, tight, or narrow shoes can make pain worse. Sometimes, changing to shoes that give your toes more room can help.
The cause of this problem is often due to impingement of the plantar nerve fibres between the metatarsal heads and the intermetatarsal ligament. It is entirely a biomechanical phenomenon. Differential diagnoses include stress fracture, capsulitis, bursitis or ligament injury at the metatarsal-phalangeal joint, a tendon sheath ganglion, foreign-body reaction and nerve-sheath tumour.
Morton?s neuroma is a progressive condition which means the symptoms typically get worse over time. Initially people often complain of a tingling or numbness at the base of their toes, typically in the space between the third and fourth toes, or, less commonly , between the second and third toes, which feels a bit like pins and needles. Over time the pain progresses and can feel like a stabbing or burning sensation in the ball of the foot under the toes. Some describe it as feeling as if they are standing on a stone. Normally the pain will get worse when you wear tight fitting shoes. Doing exercise that impacts on the foot such as jogging can also make the symptoms worse. The extent of the pain varies from person to person but in some cases it can be so intense that every step can feel acutely painful.
Morton?s neuroma can be identified during a physical exam, after pressing on the bottom of the foot. This maneuver usually reproduces the patient?s pain. MRI and ultrasound are imaging studiesthat can demonstrate the presence of the neuroma. An x-ray may also be ordered to make sure no other issues exist in the foot. A local anesthetic injection along the neuroma may temporarily abolish the pain, and help confirm the diagnosis.
Non Surgical Treatment
In most cases, initial treatment for this condition consists of padding and taping to disperse weight away from the neuroma. If the patient has flatfeet, an arch support is incorporated into footwear. The patient is instructed to wear shoes with wide toe boxes and avoid shoes with high heels. An injection of local anesthetic to relieve pain and a corticosteroid to reduce inflammation may be administered. The patient is advised to return in a week or 2 to monitor progress. If the pain has been relieved, the neuroma is probably small and caused by the structure of the patient's foot and the type of shoes the patient wears. It can be relieved by a custom-fitted orthotic that helps maintain the foot in a better position. Another type of therapy that may be used is alcohol sclerosing injections. In this treatment, the doctor injects a small amount of alcohol in the area of the neuroma area to help harden (sclerose) the nerve and relieve the pain. Injections are given every 7-10 days and, in many cases, 4-7 injections are needed for maximum relief. Please ask your physician for more information regarding this type of treatment.
The ultimate success of a Morton?s neuroma treated surgically can be variable. In cases where the underlying problem is only an irritated nerve (a true Morton?s neuroma), then surgery will probably be curative (although it may take a few months for the foot to fully heal). But in many cases, forefoot pain is more complex. There may be an irritated nerve or two causing pain, but the real problem is often excessive loading of the lesser metatarsals. The generic term for this condition is metatarsalgia. When considering surgery, identifying and addressing these problems may lead to a better end result.