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.
The cause of this problem is often due to impingement of the plantar nerve fibres between the metatarsal heads and the intermetatarsal ligament. It is entirely a biomechanical phenomenon. Differential diagnoses include stress fracture, capsulitis, bursitis or ligament injury at the metatarsal-phalangeal joint, a tendon sheath ganglion, foreign-body reaction and nerve-sheath tumour.
Morton’s neuroma can cause a very painful burning or sharp pain in your foot that feels worse when you walk. It may feel like a small lump inside the ball of your foot. It is usually between the third and fourth toes, but it can also be between other toes.
Diagnosis of Morton?s Neuroma typically involves a physical examination of the affected foot. Your health care provider will ask you about your symptoms and examine your feet and toes. He will manipulate your toes, pushing them from side to side and squeezing on the spaces in between. This physical exam will allow your health care provider to feel for any lumps that may be present under the soft tissue of your feet. Your health care provider may also listen for any clicking sounds that your bones may be making. Known as Muldor?s Sign, this clicking is common amongst sufferers of foot neuroma. Occasionally, an x-ray or MRI (magnetic resonance imaging) is performed to help rule out any breaks, sprains, or fractures in your foot.
Non Surgical Treatment
Treatment for Morton?s Neuroma usually begins conservatively, with a change in lifestyle choices. People suffering from the condition may find pain relief by reducing activity levels, changing footwear, using orthopedic supports, reducing weight. Medications are also available to help relieve the pain of Morton?s Neuroma. Over-the-counter medications are sometimes very helpful in reducing pain and inflammation. Your health care provider can also provide you with anesthetic or corticosteroid injections. These help to numb the area affected by the neuroma, and reduce inflammation.
Surgery is occasionally required when the conservative treatment is not able to relieve your symptoms, particularly if you have had pain for more than 6 months. 80% of patients who require surgery report good results, with 71% of people becoming pain-free.