A Morton's neuroma is a benign (noncancerous) swelling along a nerve in the foot that carries sensations from the toes. The reason the nerve starts to swell is unknown. But once swelling begins, the nearby bones and ligaments put pressure on the nerve, causing more irritation and inflammation. This produces burning pain, numbness, tingling and other abnormal sensations in the toes. A Morton's neuroma also is called an interdigital neuroma, intermetatarsal neuroma or a forefoot neuroma.
Morton's neuroma may be the result of irritation, pressure or injury. In some cases its cause is unknown. In the majority of cases only one nerve is affected. Having both feet affected is extremely rare. A high percentage of patients with Morton's neuroma are women who wear high-heeled or narrow shoes. Patients with Morton's neuroma may need to change their footwear, take painkillers or steroid injections, while others may require surgery to either remove the affected nerve or release the pressure on it.
Symptoms typically include pain, often with pins and needles on one side of a toe and the adjacent side of the next toe. Pain is made worse by forefoot weight bearing and can also be reproduced by squeezing the forefoot to further compress the nerve. Pressing in between the third and forth metatarsals for example with a pen can also trigger symptoms.
In some cases your doctor will be able to feel the Morton's as a swelling in the middle of your foot. However they may also suggest an X-ray or a blood test - this is normally to rule our other causes of the pain such as arthritis. The most accurate way to diagnose Morton?s itself is with magnetic resonance imaging (MRI) or ultrasound.
Non Surgical Treatment
Relief of symptoms can often start by having a good pair of well fitting shoes fitted to your feet ensuring that the shoes don't squeeze your foot together. Once footwear is addressed patients may require a small pre-metatarsal pad to be positioned onto the insole of the shoe to help lift and separate the bones in the forefoot to alleviate the pressure on the nerve. If the patients foot structure and mechanics is found to be a contributing cause, a custom made orthotic is usually the most convenient and effective way to manage the problem. Sometimes an injection of local anaesthetic and steroid is recommended to assist in settling acute symptoms.
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.
Although the exact causes of neuromas are not completely known, the following preventive steps may help. Make sure your exercise shoes have enough room in the front part of the shoe and that your toes are not excessively compressed. Wear shoes with adequate padding in the ball of the foot. Avoid prolonged time in shoes with a narrow toe box or excessive heel height (greater than two inches).