Overview
Morton's neuroma is an enlarged nerve that usually occurs in the third interspace, which is between the third and fourth toes. To understand Morton's neuroma further, it may be helpful to look at the anatomy of the foot. Problems often develop in the third interspace because part of the lateral plantar nerve combines with part of the medial plantar nerve here. When the two nerves combine, they are typically larger in diameter than those going to the other toes. Also, the nerve lies in subcutaneous tissue, just above the fat pad of the foot, close to an artery and vein. Above the nerve is a structure called the deep transverse metatarsal ligament. This ligament is very strong, holds the metatarsal bones together, and creates the ceiling of the nerve compartment. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament pushes down. This causes compression in a confined space.
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
Normally, there are no outward signs, such as a lump, because this is not really a tumor. Burning pain in the ball of the foot that may radiate into the toes. The pain generally intensifies with activity or wearing shoes. Night pain is rare. There may also be numbness in the toes, or an unpleasant feeling in the toes. Runners may feel pain as they push off from the starting block. High-heeled shoes, which put the foot in a similar position to the push-off, can also aggravate the condition. Tight, narrow shoes also aggravate this condition by compressing the toe bones and pinching the nerve.
Diagnosis
During the exam, your doctor will press on your foot to feel for a mass or tender spot. There may also be a feeling of "clicking" between the bones of your foot. Some imaging tests are more useful than others in the diagnosis of Morton's neuroma. Your doctor is likely to order X-rays of your foot, to rule out other causes of your pain such as a stress fracture. Ultrasound. This technology uses sound waves to create real-time images of internal structures. Ultrasound is particularly good at revealing soft tissue abnormalities, such as neuromas. Magnetic resonance imaging (MRI). Using radio waves and a strong magnetic field, an MRI also is good at visualizing soft tissues. But it's an expensive test and often indicates neuromas in people who have no symptoms.
Non Surgical Treatment
Initial therapies are nonsurgical and can involve one or more of the following treatments Changes in footwear. Avoid high heels or tight shoes, and wear wider shoes with lower heels and a soft sole. This enables the bones to spread out and may reduce pressure on the nerve, giving it time to heal. Custom shoe inserts and pads also help relieve irritation by lifting and separating the bones, reducing the pressure on the nerve. One or more injections of a corticosteroid medication can reduce the swelling and inflammation of the nerve, bringing some relief. Massaging the affected area can provide some momentary relief. Several studies have shown that a combination of roomier, more comfortable shoes, nonsteroidal anti-inflammatory medication, custom foot orthoses and cortisone injections provide relief in over 80 percent of people with Morton?s Neuroma. If conservative treatment does not relieve your symptoms, your physician may discuss surgical treatment options with you.
Surgical Treatment
The above measures are often sufficient to resolve Morton?s Neuroma. Should the condition persist or worsen despite these efforts, surgery may be recommended to remove the Neuroma. The surgery requires only a short recovery period, though permanent numbness in the affected toes can result, so such surgery is generally used as a last resort.
Morton's neuroma is an enlarged nerve that usually occurs in the third interspace, which is between the third and fourth toes. To understand Morton's neuroma further, it may be helpful to look at the anatomy of the foot. Problems often develop in the third interspace because part of the lateral plantar nerve combines with part of the medial plantar nerve here. When the two nerves combine, they are typically larger in diameter than those going to the other toes. Also, the nerve lies in subcutaneous tissue, just above the fat pad of the foot, close to an artery and vein. Above the nerve is a structure called the deep transverse metatarsal ligament. This ligament is very strong, holds the metatarsal bones together, and creates the ceiling of the nerve compartment. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament pushes down. This causes compression in a confined space.
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
Normally, there are no outward signs, such as a lump, because this is not really a tumor. Burning pain in the ball of the foot that may radiate into the toes. The pain generally intensifies with activity or wearing shoes. Night pain is rare. There may also be numbness in the toes, or an unpleasant feeling in the toes. Runners may feel pain as they push off from the starting block. High-heeled shoes, which put the foot in a similar position to the push-off, can also aggravate the condition. Tight, narrow shoes also aggravate this condition by compressing the toe bones and pinching the nerve.
Diagnosis
During the exam, your doctor will press on your foot to feel for a mass or tender spot. There may also be a feeling of "clicking" between the bones of your foot. Some imaging tests are more useful than others in the diagnosis of Morton's neuroma. Your doctor is likely to order X-rays of your foot, to rule out other causes of your pain such as a stress fracture. Ultrasound. This technology uses sound waves to create real-time images of internal structures. Ultrasound is particularly good at revealing soft tissue abnormalities, such as neuromas. Magnetic resonance imaging (MRI). Using radio waves and a strong magnetic field, an MRI also is good at visualizing soft tissues. But it's an expensive test and often indicates neuromas in people who have no symptoms.
Non Surgical Treatment
Initial therapies are nonsurgical and can involve one or more of the following treatments Changes in footwear. Avoid high heels or tight shoes, and wear wider shoes with lower heels and a soft sole. This enables the bones to spread out and may reduce pressure on the nerve, giving it time to heal. Custom shoe inserts and pads also help relieve irritation by lifting and separating the bones, reducing the pressure on the nerve. One or more injections of a corticosteroid medication can reduce the swelling and inflammation of the nerve, bringing some relief. Massaging the affected area can provide some momentary relief. Several studies have shown that a combination of roomier, more comfortable shoes, nonsteroidal anti-inflammatory medication, custom foot orthoses and cortisone injections provide relief in over 80 percent of people with Morton?s Neuroma. If conservative treatment does not relieve your symptoms, your physician may discuss surgical treatment options with you.
Surgical Treatment
The above measures are often sufficient to resolve Morton?s Neuroma. Should the condition persist or worsen despite these efforts, surgery may be recommended to remove the Neuroma. The surgery requires only a short recovery period, though permanent numbness in the affected toes can result, so such surgery is generally used as a last resort.