During certain activities, particularly weight-bearing activities (e.g. walking or running) a compressive force, is sometimes placed on the interdigital nerves and surrounding soft tissue, between the metatarsal bones (this is often the case with tight fitting shoes or in patients with flat feet). If this force is repetitive enough and beyond what the nerve and soft tissue can withstand, swelling to the nerve and soft tissue may occur. This may result in pain, tenderness, pins and needles or numbness in the forefoot or toes. When this happens, the condition is known as a Morton's neuroma.
Morton's neuroma is an inflammation caused by a buildup of fibrous tissue on the outer coating of nerves. This fibrous buildup is a reaction to the irritation resulting from nearby bones and ligaments rubbing against the nerves. Irritation can be caused by wearing shoes that are too tight, wearing shoes that place the foot in an awkward position, such as high heels, a foot that is mechanically unstable, repetitive trauma to the foot such as from sports activities like tennis, basketball, and running. Trauma to the foot caused by an injury such as a sprain or fracture. It is unusual for more than one Morton's neuroma to occur on one foot at the same time. It is rare for Morton's neuroma to occur on both feet at the same time.
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
Treatment options vary with the severity of each neuroma, and identifying the neuroma early in its development is important to avoid surgical correction. For simple, undeveloped neuromas, a pair of thick-soled shoes with a wide toe box is often adequate treatment to relieve symptoms, allowing the condition to diminish on its own. For more severe conditions, however, additional treatment or surgery may be necessary to remove the tumor. The primary goal of most early treatment regimens is to relieve pressure on areas where a neuroma develops. Your podiatric physician will examine and likely X-ray the affected area and suggest a treatment plan that best suits your individual case. Padding and Taping. Special padding at the ball of the foot may change the abnormal foot function and relieve the symptoms caused by the neuroma. Medication. Anti-inflammatory drugs and cortisone injections can be prescribed to ease acute pain and inflammation caused by the neuroma. Orthotics. Custom shoe inserts made by your podiatrist may be useful in controlling foot function. Orthotics may reduce symptoms and prevent the worsening of the condition.
Surgery may be considered in patients who have not responded adequately to non-surgical treatments. Your foot and ankle surgeon will determine the approach that is best for your condition. The length of the recovery period will vary, depending on the procedure performed. Regardless of whether you?ve undergone surgical or nonsurgical treatment, your surgeon will recommend long-term measures to help keep your symptoms from returning. These include appropriate footwear and modification of activities to reduce the repetitive pressure on the foot.