Kandis Mitten

Foot Disorders Database

What Causes Mortons Neuroma

Overview

interdigital neuromaMorton neuromas are focal areas of symptomatic perineural fibrosis around a plantar digital nerve of the foot. The abnormality is non-neoplastic and does not represent a true neuroma. It may more correctly be known as Morton?s metatarsalgia. The condition is thought to be due to chronic entrapment of the nerve by the intermetatarsal ligament. It most often occurs in middle-aged individuals and is many times more common in women than men. Approximately 30% of asymptomatic middle-aged persons have the radiological pathologic findings of a Morton?s neuroma.

Causes

Morton's neuroma may be the result of irritation, pressure or injury. In some cases its cause is unknown. In the majority of cases only one nerve is affected. Having both feet affected is extremely rare. A high percentage of patients with Morton's neuroma are women who wear high-heeled or narrow shoes. Patients with Morton's neuroma may need to change their footwear, take painkillers or steroid injections, while others may require surgery to either remove the affected nerve or release the pressure on it.

Symptoms

Often, no outward signs (such as a lump or unusual swelling) appear from the condition. Neuroma pain is most often described as a burning discomfort in the forefoot. Aching or sudden shooting pain in the forefoot is also common. All running sports, especially distance running can leave an athlete vulnerable to Morton?s Neuroma, which may appear or flare up in the middle of a run or at the end. The sufferer often has the desire to remove his shoe and rub the afflicted foot. Should the Neuroma be of sufficient size, or if footwear is particularly tight or uncomfortable, the painful condition may be present during normal walking. Numbness in the foot may precede or accompany Neuroma pain.

Diagnosis

A GP (general practitioner, primary care physician) or a podiatrist (foot specialist doctor) will ask the patient to describe the pain as well as its intensity, when symptoms started, what types of shoes are worn, as well as some questions about their job, lifestyle and hobbies. The doctor will then examine the foot and try to locate the affected nerve. This may involve attempting to reproduce symptoms by manipulating the foot. In order to get a detailed image of the inside of the food, one of the following scans may be ordered. X-ray, this is a type of high-energy radiation. In low doses they are used to diagnose diseases and condition by making pictures of the inside of the body. In higher doses they are used to treat cancer. This procedure is non-invasive and painless. Ultrasound scan, high frequency sound waves are pointed at a specific part of the body, which in this case is the foot. The ultrasound waves bounce of tissues; their echoes are then converted into a picture, called a sonogram. This allows the doctor to get an inside view of the foot. This procedure is non-invasive and painless. MRI (magnetic resonance imagining) a device that uses a magnetic field and radio waves to create detailed images of the body. Unlike CT scanning or general x-ray studies, no ionizing radiation is involved with an MRI. This procedure is non-invasive and painless. The doctor will have to rule out other conditions which may have similar symptoms, including capsulitis, bursitis, or Freiberg's disease.

Non Surgical Treatment

The most important factor in the treatment of Morton's neuroma is changing footwear. Sometimes a cushioned dome pad can be worn inside the shoe and this helps spread the metatarsal heads and decrease pressure on the nerve. There are other products that can be worn between the toes with certain types of shoes or when the client is barefoot. These toe spacers will help reverse biomechanical patterns that aggravate the nerve compression. Massage can be helpful, but should not be performed with deep pressure between the metatarsal heads. Additional pressure in this region can aggravate the nerve compression and prolong the pathology.intermetatarsal neuroma

Surgical Treatment

Operative treatment of Morton?s neuroma should be entertained only after failure of nonoperative management. Standard operative treatment involves identifying the nerve and cutting (resecting) it proximal to the point where it is irritate/injured. This is usually done through an incision on the top (dorsal) aspect of the foot, although in rare instances, an incision on the sole (plantar) aspect of the foot maybe used. An incision on the sole of the foot works very well, unless an excessive scar forms in which case it can be problematic. Some physicians will attempt to treat Morton?s neuroma by releasing the intermetatarsal ligament and freeing the nerve of local scar tissue. This may also be beneficial.

Prevention

Although the exact causes of neuromas are not completely known, the following preventive steps may help. Make sure your exercise shoes have enough room in the front part of the shoe and that your toes are not excessively compressed. Wear shoes with adequate padding in the ball of the foot. Avoid prolonged time in shoes with a narrow toe box or excessive heel height (greater than two inches).