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.
A Morton?s Neuroma are a result of complex biomechanical changes that occur in your feet. There are a number of theories as to the exact cause of the scarring and thickening, but it basically boils down to overload of the tissue structure. The body lays down scar tissue to try to protect the overloaded structure. Tight-fitting shoes may exacerbate a Morton?s Neuroma. Shoes such as high heels and shoes with tight toe boxes (eg womens fashion shoes and cowboy boots) are particularly damaging to the toes. These shoes have a sloping foot bed and a narrow toe box. The slope causes the front of the foot to bear your weight. The angle of the toe box then squeezes your toes together. Footwear is not the only cause of a Morton?s Neuroma. Injuries to the foot can also be a factor in developing the condition by changing your foot biomechanics. Poor foot arch control leading to flat feet or foot overpronation does make you biomechanically susceptible to a neuroma.
Morton's neuroma may cause Burning, pain, tingling, and numbness often shooting into the toes. Discomfort that is worse while walking. Feeling of a lump between the toes. Symptoms are usually temporarily relieved when taking off shoes, flexing toes or rubbing feet.
To diagnose Morton's neuroma the podiatrist commonly palpates the area to elicit pain, squeezing the toes from the side. Next he or she may try to feel the neuroma by pressing a thumb into the third interspace. The podiatrist then tries to elicit Mulder's sign, by palpating the affected interspace with one hand and squeezing the entire foot at the same time with the other hand. In many cases of Morton's neuroma, this causes an audible click, known as Mulder's sign. An x-ray should be taken to ensure that there is not a fracture. X-rays also can be used to examine the joints and bone density, ruling out arthritis (particularly rheumatoid arthritis and osteoarthritis).
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.
If conservative treatments haven't helped, your doctor might suggest injections. Some people are helped by the injection of steroids into the painful area. In some cases, surgeons can relieve the pressure on the nerve by cutting nearby structures, such as the ligament that binds together some of the bones in the front of the foot. Surgical removal of the growth may be necessary if other treatments fail to provide pain relief. Although surgery is usually successful, the procedure can result in permanent numbness in the affected toes.