Morton’s neuroma is a growth or benign tumor that affects the ball of your foot. It is commonly located in the space between your third and fourth toe, which is why it is also known as an intermetatarsal neuroma or intermetatarsal space neuroma. The neuroma entraps the affected nerve, which is what causes the symptoms that characterize this condition.
The exact mechanism that leads to Morton’s neuroma isn’t known. Experts believe that the most likely cause is compression of the plantar nerve by the transverse metatarsal ligament. Over time, this compression leads to an abnormal thickening of the nerve and permanent nerve damage.
Morton’s neuroma is more common amongst middle-aged patients. Women between the ages of 45 and 50 years old are more likely to develop this condition.
Certain risk factors can increase your likelihood of suffering from Morton’s neuroma. These risk factors include:
- Excessive calf tightness
- Flat feet
- Foot overload
- Tight, narrow shoes
- Hammer toes
- Activities that place pressure on the ball of the foot, such as running and tennis
- Activities that require tight shoes, such as ballet
The most common symptom of Morton’s neuroma is pain; however, different patients can experience different types of pain. Pain usually starts after weight bearing or walking, even for short periods of time. It can also be triggered by squeezing the ball of the foot.
Most patients will experience shooting or burning pain that radiates to several toes. Other patients experience numbness, or feeling like they are walking on razor blades or have a pebble inside their shoe. In many cases, pain from this neuroma can stop patients from walking properly, and it might cause a limp.
The first symptom of Morton’s neuroma that many patients experience is called Mulder’s sign, and it consists of a tingling sensation located in the ball of the foot. The symptoms are usually progressive, but some patients remain asymptomatic.
In order to diagnose Morton’s neuroma, your physician or podiatrist will take your history and physical examination into account. Most patients don’t exhibit swelling, redness, or other physical signs of inflammation. Your healthcare provider will squeeze the ball on both sides to elicit tingling sensations or pain.
It is important to highlight the fact that getting an early diagnosis of Morton’s neuroma can help reduce the likelihood that you’ll require more invasive treatments.
Imaging tests, such as an MRI or ultrasound, might be ordered to rule out other conditions. Stress fractures, capsulitis, osteochondritis, bursitis, and arthritis, amongst others, can cause similar symptoms. Your podiatrist will also examine your feet and legs looking for foot overload, calf tightness, or other anatomical or mechanical abnormalities.
The treatment for Morton’s neuroma is usually very simple. Many patients experience instant relief once they remove their shoes. Your podiatrist will probably start out with a more conservative treatment plan and only move onto more aggressive measures if needed.
Conservative measures include:
- Wearing supportive shoes that don’t feature a narrow toe box
- Over-the-counter anti-inflammatory medications, such as ibuprofen or naproxen
- Over-the-counter or custom orthotics or shoe inserts
- Massaging your foot
- Applying cold packs to the ball of your foot
- Exercises that help stretch and loosen the affected ligaments, muscles, and tendons
If these measures aren’t effective, your podiatrist could suggest trying steroid injections. Steroids can help reduce inflammation and relieve symptoms. However, steroid injections can’t be used indefinitely, since they can damage your ligaments and tendons.
Local anesthetics can also be injected into the area, and studies have found that alcohol sclerosing injections can provide long-term relief for some patients. Radiofrequency ablation can also be used.
Surgery might be required if other therapeutic options fail. There are different types of surgery for Morton’s neuroma, and your medical team will choose the best option for you depending on the specific characteristics of your case.
The most common types of surgery that are currently used to treat Morton’s neuroma include:
- Neurectomy: this procedure involves removing the affected nerve tissue. Scar tissue can form after the surgery, leading to a stump neuroma which can cause symptoms that mimic those of the original neuroma. This surgery can also result in excessive splaying of the third and fourth toes.
- Cryogenic neuroablation: during this surgery, neuronal axons are destroyed by freezing them. Destroying the axons stops them from carrying painful impulses. This surgery doesn't carry the risk of developing a stump neuroma.
Morton’s neuroma can be a very uncomfortable condition; however, an early diagnosis and simple measures can provide great relief. It is very important to avoid narrow, tight shoes if you wish to avoid this condition.
If you experience symptoms such as pain or tingling along several of your toes, it might be time to go to your podiatrist. They will be able to examine you and give you the right diagnosis so that you can start your treatment right away.