What Is Morton’s Neuroma?
Morton’s neuroma is a swollen, inflamed nerve at the ball of the foot, usually between the base of the third and fourth toes. The word “neuroma” usually refers to a benign (noncancerous) tumor, but Morton’s neuroma is not a tumor. Rather, it is caused by chronic compression of a branch of the plantar nerve between the ends of the metatarsal bones.
Causes and Risk Factors
The exact cause or causes of Morton’s neuroma are unknown, but risk factors have been identified. Women are much more likely than men to have the condition. Possible risk factors include:
- Foot deformities such as bunions and hammertoes
- High-heeled shoes
- High-impact sports like running, or sports with restrictive footwear such as skiing or ice skating
- Tight shoes, such as dress shoes
Symptoms
Because Morton’s neuroma is not a true tumor, there is generally no outward sign of the condition, such as a bump or growth under the foot. Symptoms of Morton’s neuroma include:
- Burning sensation or pain in affected toes
- Numbness or tingling in the affected toes
- Pain that gets worse when wearing shoes or with activity
The pain of Morton’s neuroma is sometimes described as having a pebble in the shoe.
Diagnosis
Diagnosis of Morton’s neuroma can be difficult because its symptoms are general and are shared by many other conditions. It is sometimes mistaken for:
- Bursitis
- Infection
- Lumbar radiculopathy
- Metatarsalgia
- Peripheral neuropathy
- Stress fracture
- Tarsal tunnel syndrome
Diagnosis will start with a physical exam and a medical history. During the physical exam, the doctor will often press on the typical site of a neuroma, looking for signs of pain and other symptoms.
Morton’s neuroma can often be diagnosed by ruling out other conditions. This is known as a diagnosis of exclusion or differential diagnosis. X-rays can be helpful in ruling out fractures as a source of foot pain, and other imaging tests such as magnetic resonance imaging (MRI) or computed tomography (CT) scans can help rule out soft tissue or other nerve conditions like tarsal tunnel syndrome.
Treatment
Surgery is sometimes necessary to treat Morton’s neuroma, but often more conservative treatment methods are attempted first. A change in footwear may bring some relief, such as a shoe with a low heel and wide toe box. Some evidence suggests that custom orthotics—shoe inserts made specifically for a person’s foot—may be helpful.
Injections are another possible treatment for Morton’s neuroma. Corticosteroid injections may reduce pain and inflammation. An injection of alcohol has been shown to provide short-term relief as well. Physical therapy can also be helpful.
There are a number of surgical procedures to treat Morton’s neuroma that can be used in isolation or in combination with each other, such as:
- Ligament release: In this procedure, one or more ligaments near the affected nerve are cut, with the goal of relieving pressure on the nerve.
- Nerve excision: The growth on the nerve is surgically removed.
- Osteotomy: Like ligament release, the goal of an osteotomy is to remove pressure on the nerve. In an osteotomy, this is accomplished by shortening one of the metatarsal bones.
If you have pain at the ball of your foot, schedule an appointment with one of our foot and ankle specialists. We can tell you if Morton’s neuroma or another condition is causing your foot pain as well as come up with a treatment plan that’s right for you.