Definition and Overview
Morton’s neuroma is a common foot problem that occurs when the nerve that supplies sensation to the web space between the toes is trapped. The nerve can thicken and compress surrounding nerve cells. When this happens, sufferers will experience sharp or burning pain, which can be so intense that they are forced to stop walking or limp from pain.
Also called Morton's metatarsalgia or interdigital neuroma, Morton’s neuroma usually affects the nerve found in between the third and fourth toes. However, it can also affect the one in between the second and third toes. The condition can develop in people from all age groups but is most common in middle-aged women who tend to wear high-heeled or tight shoes that put pressure on the feet.
Morton’s neuroma is rarely a medical emergency but when left untreated, the thickened nerve can further enlarge and become permanently damaged.
In the majority of cases, conservative treatments are often enough to experience symptoms relief. However, sufferers who experience chronic and severe symptoms may need to undergo surgery to have the thickened nerve removed.
Causes of Condition
The exact cause of foot neuroma is not known. However, it is believed that trauma or injury to the nerve plays a key role in the development of the condition.
Factors that can either increase the risk of Morton’s neuroma or make its symptoms worse include the following:
Foot deformities that can cause the toe joints to become unstable. These include flat or high-arched feet, hammertoes, and bunions.
Wearing constrictive or high heels shoes. The condition is common in women who habitually wear high-heeled shoes and men who wear tight sports shoes.
Certain sports or activities that cause trauma to the feet, such as running and jogging
The anatomy of the foot bones is also believed to increase the risk of Morton’s neuroma. The spaces between the third and second toes and between the fourth and third toes are narrower. This makes the nerves in between these metatarsals more prone to being compressed or irritated. Having a fatty lump (lipoma), inflamed joints near the digital nerves or a fluid-filled sac around a bursa can make this compression even worse.
The most common symptom of Morton’s neuroma is pain in the ball of the foot that extends to the affected toes. Some people describe the pain as similar to walking with a marble or stone inside their shoes. Others also experience tingling or burning sensation in the toes that is often relieved with a foot massage. The symptoms can vary in length and intensity. Some people suffer from excruciating pain on a daily basis while others experience attacks as seldom as once or twice a year.
Symptoms often begin gradually and intensify over time. If left untreated, symptoms will persist longer and become more intense as the nerve damage becomes permanent.
Who to See and Types of Treatments Available
Patients are encouraged to consult a general practitioner or their family doctor if they experience any of the symptoms mentioned above. Although Morton’s neuroma is not considered a medical emergency, seeking treatment during the early stages can help prevent serious complications and the need for a surgical treatment later on.
Doctors can diagnose Morton’s neuroma by evaluating the symptoms and performing a physical examination, which can reveal a tender spot or thickened nerve in the foot. Although not often necessary, some imaging tests can be carried out, including magnetic resonance imaging (MRI), ultrasound, and X-ray. These procedures can help provide an accurate diagnosis and rule out other conditions that share the same symptoms.
Treatment options range from simple home remedies to an outpatient surgical procedure. In the majority of cases, doctors initially advise conservative treatments, which include the following:
Footwear modification or wearing comfortable footwear as often as possible
Using orthotics that cushion the feet and minimise pressure while doing certain activities such as walking or running. These custom-made insoles can help control foot function as well as prevent the condition from worsening.
Resting and massaging the foot when symptoms start to appear
Physical therapy - The inflammation can be reduced through physical therapy that uses ultrasound technology. Patients are also taught how to stretch their foot and leg properly to optimise blood flow to the affected foot and toes.
Anti-inflammatory drugs and steroid injections
Sclerosing alcohol injection - This aims to prevent the affected nerve from transmitting pain signal to the brain to achieve permanent pain relief.
Morton's neuroma surgery (neurectomy)
Surgery is reserved as the last option for the treatment of foot neuroma. It is recommended when patients have tried all non-surgical treatments but still suffer from foot pain and other symptoms.
The procedure is performed on an outpatient basis using local anaesthetic. It can be performed in an ambulatory surgery centre, a hospital, or even in a doctor’s office as long as it is fully equipped for the procedure.
The surgery involves making an incision on top of the foot or near the location of the damaged nerve. The surgeon will then carefully remove the nerve or release the ligament that compresses it.
Many people who have undergone neurectomy are able to fully recover after a couple of weeks. They are provided with special post-surgical shoes that they must use until their surgical wound has fully healed.
Although the procedure is considered safe, it carries a small risk of complications, including:
Weakness in toe, which could be temporary or permanent
Adverse reaction to the anaesthetic used
American Podiatric Medical Association (APMS) http://www.apma.org/Learn/FootHealth.cfm?ItemNumber=987
Frontera WR. Morton neuroma. In: Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, Pain, and Rehabilitation. 3rd ed. Philadelphia, Pa.: Saunders Elsevier; 2015. http://www.clinicalkey.com.
Safran MR, et al. Morton neuroma (Interdigital plantar neuroma). In: Instructions for Sports Medicine Patients. 2nd ed. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.clinicalkey.com.