During certain activities, particularly weight-bearing activities (e.g. walking or running) a compressive force, is sometimes placed on the interdigital nerves and surrounding soft tissue, between the metatarsal bones (this is often the case with tight fitting shoes or in patients with flat feet). If this force is repetitive enough and beyond what the nerve and soft tissue can withstand, swelling to the nerve and soft tissue may occur. This may result in pain, tenderness, pins and needles or numbness in the forefoot or toes. When this happens, the condition is known as a Morton’s neuroma.
Experts are not sure what exactly causes Morton’s neuroma. It seems to develop as a result of irritation, pressure or injury to one of the digital nerves that lead to the toes, which triggers a body response, resulting in thickened nerve tissue (neuroma). Feet conditions/situations that can cause the bones to rub against a nerve include high-heeled shoes, especially those over 2 inches (5cm), or a pointed or tight toe box which squash the toes together. This is probably why the condition is much more common in females than in males. High-arched foot, people whose feet have high arches are much more likely to suffer from Morton’s neuroma than others. Flat feet, the arch of the foot collapses. The entire sole of the foot comes into complete or near-complete contact with the ground. A bunion, a localized painful swelling at the base of the big toe, which enlarges the joint. Hammer toe, a deformity of the proximal interphalangeal joint of the second, third, or fourth toe causing it to be permanently bent. Some high-impact sporting activities including running, karate, and court sports. Any sport that places undue pressure on the feet. Injuries, an injury or other type of trauma to the foot may lead to a neuroma.
Typically, there’s no outward sign of this condition, such as a lump. Instead, you may experience the following symptoms. A feeling as if you’re standing on a pebble in your shoe. A burning pain in the ball of your foot that may radiate into your toes. Tingling or numbness in your toes. It’s best not to ignore any foot pain that lasts longer than a few days. See your doctor if you experience a burning pain in the ball of your foot that’s not improving, despite changing your footwear and modifying activities that may cause stress to your foot.
Your health care provider can usually diagnose this problem by examining your foot. A foot x-ray may be done to rule out bone problems. MRI or ultrasound can successfully diagnose the condition. Nerve testing (electromyography) cannot diagnose Morton neuroma. But it may be used to rule out conditions that cause similar symptoms. Blood tests may be done to check for inflammation-related conditions, including certain forms of arthritis.
Non Surgical Treatment
Symptoms of a Morton’s neuroma can completely resolve with simple treatments, such as resting the foot, better-fitting shoes, anti-inflammation medications, and ice packs. More rapid relief of symptoms can follow a local cortisone injection. Symptoms can progressively worsen with time. For those with persistent symptoms, the swollen nerve tissue is removed with a surgical operation.
Interdigital neurectomy (removal of the diseased nerve) in right hands, should give satisfactory results almost all the time. Some of the reasons behind failure is when not enough nerve is dissected, mistakes in initial diagnosis, or bad handling of adjacent nerves, tendons and joint capsules during the operation. It is very common and acceptable to have some numbness in the area where the nerve used to be. This never causes any discomfort and often gets better in few years. It is crucial to address the biomechanical pathologies underlying the impingement of the nerve during and after the surgery.
Ensuring that shoes are well fitted, low-heeled and with a wide toe area may help to prevent Morton’s neuroma.