Morton's neuroma is named after Dr Morton who first described this condition in 1876. It is sometimes called Morton's metatarsalgia or interdigital neuroma. It is a condition that affects one of the common plantar digital nerves that run between the long bones (metatarsals) in the foot. It most commonly affects the nerve between the third and fourth metatarsal bones, causing pain and numbness in the third and fourth toes. It can also affect the nerve between the second and third metatarsal bones, causing symptoms in the second and third toes. Morton's neuroma rarely affects the nerve between the first and second, or between the fourth and fifth, metatarsal bones. It tends to affect only one foot. It is rare to get two neuromas at the same time in the same foot.
Poorly fitted footwear can be a cause. Shoes that have a tight and narrow toe box can cause the never to become entrapped causing the pain. High heeled shoes abnormally place the metatarsals under extreme pressure which can cause Morton?s Neuroma. In cases of abnormal pronation, there can be significant motion between the 3rd and 4th metatarsals which can cause an irritation to the nerve that runs between them. This inflammation causes the pain.
Patients will often experience a clicking feeling in the forefoot followed by a sharp shooting pain or a sensation of numbness or pins and needles extending into ends of their toes. Tight narrow fitting shoes may often exacerbate these feelings which become worse after long periods of standing or walking. Once the Mortons nueroma progresses symptoms will become more frequent and often more intense.
Negative signs include no obvious deformities, erythema, signs of inflammation, or limitation of movement. Direct pressure between the metatarsal heads will replicate the symptoms, as will compression of the forefoot between the finger and thumb so as to compress the transverse arch of the foot. This is referred to as Mulder?s Sign. There are other causes of pain in the forefoot. Too often all forefoot pain is categorized as neuroma. Other conditions to consider are capsulitis, which is an inflammation of ligaments that surrounds two bones, at the level of the joint. In this case, it would be the ligaments that attach the phalanx (bone of the toe) to the metatarsal bone. Inflammation from this condition will put pressure on an otherwise healthy nerve and give neuroma-type symptoms. Additionally, an intermetatarsal bursitis between the third and fourth metatarsal bones will also give neuroma-type symptoms because it too puts pressure on the nerve. Freiberg's disease, which is an osteochondritis of the metatarsal head, causes pain on weight bearing or compression.
Non Surgical Treatment
If symptoms are severe or persistent and self-help measures did not help, the doctor may recommend corticosteroid injections, a steroid medication that reduces inflammation and pain is injected into the area of the neuroma. Only a limited number of injections are advised, otherwise the risk of undesirable side effects increases, including hypertension (high blood pressure) and weight gain. Alcohol sclerosing injections, studies have shown that alcohol injections reduce the size of Morton's neuromas as well as alleviating pain. This is a fairly new therapy and may not be available everywhere. The doctor injects alcohol in the area of the neuroma to help sclerose (harden) the nerve and relieve pain. Injections are typically administered every 7 to 10 days. For maximum relief 4 to 7 injections are usually needed.
Should the problem have progressed beyond the point where these measures are sufficient, the podiatric professional may recommend surgery. This procedure involves excision of the involved nerve mass. This will relieve the pain. Many patients report permanent numbness in the spot formerly affected by the neuroma, but prefer it to the pain. Most surgeries are successful; unfortunately, there are cases where the patient suffers another neuroma, sometimes in or near the same spot as before. A podiatric professional can explain the statistics of recurrence in various cases. If you suspect a neuroma, don?t wait for it to get better on its own. The earlier the diagnosis, the higher the likelihood that it can be treated with conservative measures. Don?t think that foot pain of any kind is inevitable, either, even if it runs in your family.
The best way to prevent a neuroma is by avoiding the things that cause them. Review your risk factors. If relatives have had similar problems, or if you know that you pronate or have any problem with the mechanics of your foot, talk with a podiatric physician about the correct types of shoes and/or orthoses for you. If you are not sure whether you have such a problem, the podiatric professional can analyze your foot, your stride and the wear pattern of your shoes, and give you an honest evaluation. Remember, though, that sometimes neuromas, like other conditions, can develop for no discernible reason. With this in mind, be good to your feet, and be aware of any changes or problems. Don?t wait to report them.