What causes Morton’s neuroma?

Anything that causes compression or irritation of the nerve can lead to neuroma. One of the most common offenders is wearing shoes that have a tapered toe box. High-heeled shoes that cause the toes to be forced into the toe box could also cause Morton’s neuroma. People with certain foot deformities, such as bunions, hammertoes, flatfeet, or more flexible feet are at higher risk for developing Morton’s neuroma. Other potential causes are activities that involve repetitive irritation to the ball of the foot, such as running or racquet sports. An injury or other type of trauma to the area may also lead to Morton’s neuroma.

Diagnosing Morton’s neuroma

To diagnose Morton’s neuroma the podiatrist commonly palpates the area to elicit pain. He will try to diagnose you by squeezing the toes from the side. Next he or she may try to feel the neuroma by pressing a thumb into the third interspace of the foot. The podiatrist then tries to elicit Mulder’s sign. He or she will do this by holding the patient’s first, second, and third metatarsal heads with one hand and the fourth and fifth metatarsal heads in the other and pushing half the foot up and half the foot down slightly, where in many cases of Morton’s neuroma, this causes an audible click. This click is known as Mulder’s sign, which can help with Morton’s neuroma diagnosis. An x-ray should be taken to ensure that there is not a fracture of the foot. X-rays also can be used to examine the joints and bone density, ruling out arthritis and osteoarthritis. An MRI scan or magnetic resonance imaging is used to ensure that the compression is not caused by a tumor. An MRI also determines the size of the neuroma and how the syndrome should be treated - whether conservatively or aggressively. If surgery is indicated, the podiatrist can determine how much of nerve must be resected. This is important because there are different surgical techniques available, depending on the size and the position of the neuroma. However, MRIs are expensive, which is why some insurance companies are reluctant to pay for them. If the podiatrist believes an MRI is necessary, he or she can persuade the insurance company to pay for it. To establish a diagnosis, the foot and ankle surgeon will also need to obtain a thorough history of your symptoms and examine your foot. The best time to see a foot and ankle surgeon is early in the development of symptoms. This is because early diagnosis of a Morton’s neuroma greatly lessens the need for more invasive treatments and may avoid surgery.

Treatment of Morton’s neuroma

In most cases, initial treatment consists of padding and taping. The goal is to disperse weight away from the neuroma. If the patient has flat feet, an arch support is incorporated so the patient will be instructed to wear shoes with wide toe boxes and avoid shoes with high heels. The doctor could recommend an injection of a local anesthetic to relieve pain and a corticosteroid to reduce inflammation. The patient is advised to return in a week or two sothat the progress of the disease could be monitored. If the pain has been relieved, the neuroma is probably small and caused by the structure of the patient’s foot and the type of the patient’s shoes. It can be relieved by a custom-fitted orthotic that helps keep the foot in a better position to prevent further damage. Conservative treatment does not work for most of patients and minor surgery usually is necessary to treat Morton’s neuroma.

There are two surgical procedures available in Morton’s neuroma treatment. The dorsal approach involves making an incision on the top of the foot, which permits the patient to walk soon after surgery. This is because the stitches are not on the weight-bearing side of the foot. The podiatrist maneuvers the instruments carefully through many structures and cuts the deep transverse metatarsal ligament. This ligament typically causes most of the nerve compression. This procedure can lead to instability in the forefoot that may require attention after treatment. The second procedure involves a plantar approach. In this procedure the incision is made on the sole of the foot. The patient must use crutches for about three weeks and the scar that forms can make walking uncomfortable as a side effect of this approach.

The advantage of the plantar approach is that the neuroma can be reached easily and resected without cutting any structures in the foot. However, before surgery, while developing a treatment plan, the foot and ankle surgeon will first determine how long the patient has had the neuroma. He will also need to evaluate its stage of development, because treatment approaches vary according to the severity of the problem. For mild to moderate cases of neuroma, treatment options include padding, which are techniques that provide support for the metatarsal arch, thereby lessening the pressure on the nerve and decreasing the compression when walking. Icing mean placing an icepack on the affected area helps reduce swelling. Orthotic devices issued by a foot and ankle surgeon provide the support needed to reduce pressure and compression on the nerve. Activity modifications are important to reduce especially those that put repetitive pressure on the neuroma. You should avoid these activities until the condition improves.

Changes in shoe wear could help, because it is important to wear shoes with a wide toe box and avoid narrow-toed shoes or shoes with high heels. Non-steroidal anti-inflammatory drugs such as Ibuprofen help reduce the pain and inflammation. If there is no significant improvement after the initial treatment, injection therapy may be tried as a treatment option for Morton’s neuroma. Surgery may be considered in patients who have not received adequate relief from other treatment options. The foot and ankle surgeon will determine which approach is optimal for your condition. The length of the recovery period after surgery will vary depending on the procedure or procedures performed. Regardless of whether you've undergone surgical or non-surgical treatment, your foot and ankle surgeon will recommend long-term measures, since it is important to help keep your symptoms from returning.