Also known as Morton’s Interdigital Neuroma, Morton’s Metatarsalgia, Morton’s Neuralgia, Plantar Neuroma, Intermetatarsal Neuroma) What is a Morton’s neuroma? Morton’s neuroma is a condition characterized by localized swelling of the nerve and soft tissue located between two of the long bones of the foot (metatarsals – figure 1), which can result in pain, pins and needles, or numbness in the forefoot or toes.
Occupational hazards. Individuals whose jobs place undue stress on their forefeet (with or without wearing improper footwear) are among those who complain of neuromas. Podiatric physicians report that individuals who work on ladders, or who perform activities on their knees (such as doing landscaping, carpeting, flooring, or other work on the ground) are at risk for this problem, too, since these activities cause stress to the nerve near the ball of the foot. Those who engage in high-impact activities that bring repetitive trauma to the foot (running, aerobics, etc.) have a better than average chance of developing a neuroma at the site of a previous injury. To put it more simply, if you have sustained a previous injury to your foot (a sprain, stress fracture, etc.), that area of your foot will be more prone to neuroma development than an area that has not been injured. However, sports injuries aren?t automatically a ticket to neuromas. Trauma caused by other forms of injury to the foot (dropping heavy objects, for example) can also cause a neuroma to develop at the site of the previous injury. Much though we hate to say it, sometimes neuromas just develop and nobody knows why. The patient doesn?t have a previous injury, is wearing properly fitted shoes, and doesn?t stress his/her feet with any specific activity but the neuroma develops anyway. It is important to remember that some of the factors listed above can work alone, or in combination with each other, to contribute to the formation of neuroma.
It usually occurs in between the 3rd and 4th toes (about 65% of cases) as is pictured to the right. It is less commonly found in the 2nd webspace, and rarely at all in the 1st or 4th webspaces. You can also experience pins and needles and/or numbness as a result of the nerve being affected. The condition tends to occur predominantly in middle aged females.
The exact cause of Mortons neuroma can often vary between patients. An accurate diagnosis must be carefully made by the podiatrist through thorough history taking and direct questioning to ensure all possible causes are addressed. The podiatrist will also gather further information about the cause through a hands on assessment where they will try to reproduce your symptoms. A biomechanical and gait analysis will also be performed to assess whether poor foot alignment and function has contributed to your neuroma.
Non Surgical Treatment
Once a diagnosis is obtained, it is essential to begin treatment immediately. Your podiatric physician will advise you on the most effective means. If caught early enough, good foot care, shoes that fit properly, and/or orthoses may eliminate the need for any further intervention. Other conservative measures might include oral non-steroidal anti-inflammatory medication (NSAIDS), physical therapy, ultrasound or other non-invasive measures. If that doesn?t work, your podiatric physician might use injectable steroids, and/or a local anesthetic around the neuroma to reduce inflammation and pain. Many patients report relief after these measures are taken.
Operative treatment of Morton?s neuroma should be entertained only after failure of non-operative management. Standard operative treatment involves identifying the nerve and cutting (resecting) it proximal to the point where it is irritated/injured. This is usually done through an incision on the top (dorsal) aspect of the foot, although an incision on the sole (plantar) aspect of the foot can be used. Some physicians will attempt to treat Morton?s neuroma by releasing the intermetatarsal ligament, and freeing the nerve of local scar tissue. This may also be beneficial.