If you sometimes feel that you are "walking on a marble," and you have persistent pain in the ball of your foot, you may have a condition called Morton's neuroma. A neuroma is a benign tumor of a nerve. Morton's neuroma is not actually a tumor, but a thickening of the tissue that surrounds the digital nerve leading to the toes. 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 of interdigital neuroma typically manifest as a sharp, burning or tingling sensation in the forefoot. The pain radiates toward the lesser toes and is aggravated by shoe wear. The pain is relieved when the shoe is removed and the forefoot is massaged. Sometimes the symptoms involve specific toes.
To arrive at a diagnosis, the foot and ankle surgeon will obtain a thorough history of your symptoms and examine your foot. During the physical examination, the doctor attempts to reproduce your symptoms by manipulating your foot. Other tests or imaging studies may be performed. The best time to see your foot and ankle surgeon is early in the development of symptoms. Early diagnosis of a Morton?s neuroma greatly lessens the need for more invasive treatments and may avoid surgery.
Non Surgical Treatment
Treatments may include rehabilitation measures to reduce nerve Irritation. Switching to low-heeled, wide-toed shoes with good arch support. Wearing padding in the shoes and/or between the toes. Wearing shoe inserts to correct a mechanical abnormality of the foot. Having ultrasound, electrical stimulation, whirlpool, and massage done on the foot. The foot may be injected with corticosteroids mixed with a local anesthetic in order to reduce pain. Relief may be only temporary, however, if the mechanical irritation is not also corrected. Injections with other types of medications such as alcohol, phenol, or vitamin B12 are sometimes used.
Majority of publications including peer review journal articles, surgical technique description and textbooks promote surgical excision as a gold standard treatment. Surgical excision is described as the most definitive mode of treatment for symptomatic Morton?s neuroma with reported success rates varying between 79% and 93%. Various surgical techniques are described, essentially categorised as dorsal versus plantar incision approaches. Beyond this the commonest technical variation described as influencing the outcome of surgery involves burying and anchoring transacted nerve into soft tissue such as muscle.
Wearing proper footwear that minimizes compression of the forefoot can help to prevent the development of and aggravation of a Morton's neuroma.