Morton?s neuroma is a swollen nerve in the distal portion of the foot. The enlarged portion of the nerve represents scarring within the plantar nerve that occurs after chronic compression and/or repetitive injury. This may come about when the toes are squeezed together for too long, as can occur with the chronic use of high heels. The nerve that runs between your toes will swell and thicken. This can cause pain when walking. The symptoms of Morton?s neuroma can include burning pain in the foot, the feeling of a lump inside your foot, pain between the third and fourth toes typically but it can occur between other toes.
There are a number of common causes for Morton?s Neuroma, (though the condition can arise spontaneously for reasons still unknown). The Neuroma often occurs in response to irritation, pressure or traumatic injury to one of the digital nerves leading to the toes. A thickening of nerve tissue results as part of the body?s response to the irritation or injury. Abnormal foot movement used to compensate for bunions, hammertoes, flatfeet and other conditions can lead to irritation and development of Morton?s Neuroma. Pronation of the foot may cause the heads of the metatarsal bones to rotate slightly, thereby pinching the nerve running between the metatarsal heads. Chronic pressure or pinching causes the nerve sheath to enlarge, becoming increasingly squeezed, producing worsening pain over time, if not addressed. Morton?s Neuroma can be exacerbated when tight shoes providing little room for the forefoot are worn. Activities which over-pronate the foot (such as walking barefoot in sand) may increase the pain associated with Morton?s Neuroma, as will any high-impact activity, such as jogging.
Outward signs of Morton's neuroma, such as a lump, are extremely rare. Morton's neuroma signs and symptoms, which usually occur unexpectedly and tend to worsen over time, include, pain on weight bearing (while walking) - a shooting pain affecting the contiguous halves of two toes, which may be felt after only a short time (of weight bearing). Sometimes there may be a dull pain rather than a sharp one. Most commonly, pain is felt between the third and fourth toes. Typically, a patient will suddenly experience pain while walking and will have to stop and remove their shoe. Burning. Numbness. Parasthesia, tingling, pricking, or numbness with no apparent long-term physical effect. Commonly known as pins-and-needles. A sensation that something is inside the ball of the foot.
Metatarsal bones will be examined clinically, and often an x-ray will be taken to assess the particular case and ensure against other conditions, including fracture. When the foot is examined by a doctor, he may feel a characteristic ?click,? referred to as Mulder?s sign, and the interspaces between toe bones will often be tender. The doctor may put pressure on these areas to localize the site of pain and test for other conditions, including calluses or stress fractures. Range of motion tests will also be applied to rule out arthritis or joint inflammations. X-rays may be required to ensure there are no stress fractures or arthritis within the joints that join the toes to the foot. Tenderness in one or more metatarsal bones may imply a pre-stress fracture or stress-fracture. An ultrasound scan may be used to confirm diagnosis of Morton?s Neuroma, as x-ray will not detect the condition, (but can confirm that the bones are uninjured).
Non Surgical Treatment
Orthotics and corticosteroid injections are widely used conservative treatments for Morton?s neuroma. In addition to traditional orthotic arch supports, a small foam or fabric pad may be positioned under the space between the two affected metatarsals, immediately behind the bone ends. This pad helps to splay the metatarsal bones and create more space for the nerve so as to relieve pressure and irritation. It may however also elicit mild uncomfortable sensations of its own, such as the feeling of having an awkward object under one's foot. Corticosteroid injections can relieve inflammation in some patients and help to end the symptoms. For some patients, however, the inflammation and pain recur after some weeks or months, and corticosteroids can only be used a limited number of times because they cause progressive degeneration of ligamentous and tendinous tissues.
When conservative measures are unsuccessful, surgery can be a good choice in the treatment of Morton's neuroma. The operation for Morton's neuroma does not require an overnight hospital stay. The anesthetic used is an ankle block, which completely numbs the foot during the surgery. The physician removes the neuroma from an incision made on the top of the foot between the involved metatarsal heads. The nerve to the interspace is exposed and cut next to the metatarsal heads.