A Morton?s Neuroma is actually incorrectly termed, with the name suggesting it is a tumour or growth. Rather than a true neuroma it is actually what is called a perineural fibrosis, which means that over time the sheath surrounding the nerve becomes irritated, inflamed, and forms a thickened scar tissue.
When a nerve is pinched between bones, the result is swelling of the nerve. It is this swelling which is referred to as a Neuroma. When the condition occurs in the foot, it is known as a Morton?s Neuroma. Morton?s Neuroma is technically not a tumor. Rather, it is a thickening of the tissue that surrounds the digital nerves leading to the toes. These nerves allow for physical sensation on the skin of the toes. The region of inflammation is found where the digital nerve passes under the ligament connecting the toe bones (metatarsals) in the forefoot. Morton?s Neuroma commonly develops between the third and fourth toes, generally as a result of ongoing irritation, trauma or excessive pressure. In some cases, the second and third toes are involved. Morton?s Neuroma is confined to one foot in most cases, though it can occur in both, particularly in athletes such as runners.
People with Morton's neuroma usually complain of pain that can start in the ball of the foot and shoot into the affected toes. However, some people just have toe pain. There may also be burning and tingling of the toes. The symptoms are usually felt up the sides of the space between two toes. For example, if the nerve between the third and fourth long bones (metatarsals) of the right foot is affected, the symptoms will usually be felt up the right-hand side of the fourth toe and up the left-hand side of the third toe. Some people describe the pain that they feel as being like walking on a stone or a marble. Symptoms can be made worse if you wear high-heeled shoes. The pain is relieved by taking your shoe off, resting your foot and massaging the area. You may also experience some numbness between the affected toes. Your affected toes may also appear to be spread apart, which doctors refer to as the 'V sign'. The symptoms can vary and may come and go over a number of years. For example, some people may experience two attacks of pain in a week and then nothing for a year. Others may have regular and persistent (chronic) pain.
The doctor will ask about your symptoms and medical history. A physical exam will be done. Initial diagnosis of Morton's neuroma is based on your description of the type and location of pain and discomfort in the foot. The diagnosis will be confirmed by a physical exam of the foot, including checking for mechanical abnormalities in the foot, squeezing the side of the foot, which will usually cause pain when Morton's neuroma is present. Examination of your shoes to check for excess wear in parts of the shoe, check to see whether the shoes are too tight. Imaging tests evaluate the foot and surrounding structures. This may be done with X-ray, MRI scan, Ultrasound. Injections of local anesthetic can also be used for diagnosis.
Non Surgical Treatment
Conservative treatment for Morton?s neuroma involves footwear that allows your forefoot to spread. High-heeled shoes cause neuromas by squeezing and stretching your involved intermetatarsal nerve across the ball of your foot and should be avoided as often as possible. A shoe that possesses any toe spring will also place more stress on your foot nerves and increase your likelihood of developing a neuroma. Test shoes before you buy them to see if they are appropriate for your feet. Select shoes that have a removable liner or insole, and stand on the liner, noting the position of your foot. If your foot is wider than your liner, that shoe will irritate your neuroma by squeezing your metatarsal bones together.
If pain persists with conservative care, surgery may be an appropriate option. The common digitial nerve is cut and the Mortons neuroma removed. This will result is numbness along the inside of the toes affected, and there is a small chance the end of the nerve will form a Stump Neuroma. Approximately 75% of people receive symptom resolution for Mortons Neuroma with conservative care.