A neuroma is a thickening of nerve tissue. Morton’s neuroma refers to a lump of nerve tissue that forms on the branches of the plantar nerve on the sole of the foot. It is most commonly found in the webspace between the third and fourth toes (metatarsals), but can also occur between the other toes. The nerve most commonly involved is the third interdigital nerve.
Though the term ‘neuroma’ is used in other contexts to mean tumour, Morton’s neuroma is completely benign. For this reason, it is also known as ‘Morton’s metatarsalgia’ .
Morton’s neuroma presents as an increasingly painful lump in the ball of the foot, as though a pebble has become stuck in the skin. Irritation of the nerve can cause numbness and tingling through the foot.
Women are more likely to develop Morton’s neuroma than men, and it is believed that this is due to footwear. Morton’s neuroma can be treated through wearing appropriate footwear, through analgesic medication, and if necessary through surgery.
Symptoms
Symptoms of Morton’s neuroma include:
- Tingling in the space between the third and fourth toes
- Toe cramping
- Sharp, shooting, or burning pains in the ball of your foot (and sometimes toes)
- Pain that increases when wearing shoes or pressing on the area
- Pain that gets worse over time
In rare cases, nerve pain occurs in the space between the second and third toes. This is not a common form of Morton’s neuroma, but treatment is similar.
Causes
The exact cause of Morton’s Neuroma is unknown. Some experts believe the following may play a role in the development of this condition:
- Abnormal positioning of toes
- Flat feet
- Forefoot problems, including bunions and hammer toes
- High foot arches
- Tight shoes and high heels
Risk Factors
It’s not clear what causes Morton’s Neuroma, but some factors that may increase risk:
- Women are more likely to develop morton’s neuromas than men
- Deformities of the foot including flatfoot
Investigations
Your doctor will often be able to diagnose a neuroma from listening to your symptoms and examining your foot, however an x-ray may be done to rule out subtle stress fractures that can cause similar symptoms.
Other investigations that can be used include MRI or high-resolution ultrasound can confirm the diagnosis.
Nerve testing (electromyography) cannot definitely diagnose Morton’s neuroma, but may be used to rule out conditions that cause similar symptoms.
Your doctor may also order blood tests to check for inflammation-related conditions, including certain forms of arthritis.
Complications
Morton’s neuroma can make walking difficult. Persons with this foot condition may also have trouble performing activities that put pressure on the foot, such as pressing the gas pedal of a car. It may hurt to wear certain types of shoes, such as high-heels.
Treatment
Nonsurgical treatment is tried first. Your doctor may recommend any of the following:
- Padding and taping the toe area
- Shoe inserts
- Changes to footwear (for example, shoes with wider toe boxes)
- Anti-inflammatory medicines taken by mouth or injected into the toe area.
- Nerve blocking medicines injected into the toe area
- Other painkillers
- Physical therapy
Anti-inflammatories and painkillers are not recommended for long-term treatment.
Surgery in Morton’s Neuroma
In some cases, surgery may be needed to remove the thickened tissue. This is often a very successful method of relieving pain and improving foot function.
Before surgery is attempted, your doctor will suggest trying some of the methods above. If symptoms persist, your surgeon may trial an injection of anaesthetic into the affected nerve. A response of numbness and a reduction in pain confirms the diagnosis of neuroma and surgery can be planned. If, however, the injection causes numbness but does not relieve the pain, then it is possible that there is a subtle fracture that is causing the symptoms.
The procedure involved in treating Morton’s neuroma is fairly minimal. A regional anaesthetic is injected into nerves around the ankle to numb the foot. A small incision is then made on either the top or sole of the foot so that the nerve can be exposed and cut away. The wound is then washed carefully and resown.
After the operation, you may be required to wear a bandage around your foot for a few weeks to prevent swelling and allow the tendons and soft tissues to heal. Your stitches will need to be removed after 1-2 weeks, and you may not be able to put weight through the sole of your feet for a short time.
You should expect a gradual recovery from surgery, with near-complete recovery taking between 3-12 months. Despite this, you should be able to return to all your normal activities in the first few months. Keep in mind that numbness in the area of the cut nerve after surgery is permanent, but should not be painful.
As with any surgery, there are a number of risks. You should discuss these with your surgeon.
Seeking Advice
Your Family Doctor (GP)
Your Family Doctor will be able to diagnose and help treat your problem. He or she will be able to
- tell you about your problem
- advise you of the best treatment methods
- prescribe you medications
- and if necessary, refer you to Specialists (Consultants) for further treatment
When to Contact a Medical Professional
Call your health care provider if you have persistent pain or tingling in your foot or toe area.
Prevention
Some preventative measures include avoiding ill-fitting shoes and wearing shores that are comfortable and supportive.
F.A.Q. | Frequently Asked Questions
What are the long term outcomes for surgery?
Surgery is often very successful at reducing pain and improving walking. However, recovery may be longer than expected (taking months rather than weeks).
There are a number of negative outcomes from surgery which are rare but should be kept in mind. A number of different types of pain syndromes can affect the foot. In addition there are small risks of bleeding and infection.
Can the neuroma come back?
Yes, unfortunately neuroma’s do recur. There can be a number of reasons for this. Depending on your response to your original surgery, you may be considered for revision surgery. This will have to be discussed with your surgeon.
Is Morton’s neuroma a tumour?
Morton’s neuroma is not cancer, and does not progress to become cancerous. You can think of the neuroma as a lump of scar tissue in your foot.
References
Title, C. I., Schon, L. C., ‘Morton Neuroma: Primary and Secondary Neurectomy’, Journal of the American Academy of Orthopaedic Surgeons, Vol. 16, No. 9, Sept 2008, pp 550-557.
Villas C., et al., ‘Neurectomy versus Neurolysis for Morton’s Neuroma’, Foot and Ankle International, Vol. 29., No. 6, June 2008, pp 578-580.
Wu, K. K., ‘Morton’s Interdigital Neuroma: A Clinical Review of Its Etiology, Treatment, and Results’, The Journal of Foot and Ankle Surgery, Vol. 35, No. 2, 1996, pp 112-119.