Morton’s Neuroma

Symptoms:

Symptoms include: pain on weight bearing, frequently after only a short time; the pain is

felt as a shooting pain affecting the contiguous halves of two toes. Burning, numbness and paresthesia may also be experienced. The pain is caused by pressure on the enlarged section of nerve where it passes between the metatarsal heads, and is squeezed between them. Exhibits similar symptoms to metatarsalgia, but may also cause numbness, tingling and discoloration of the third and fourth (lesser) toes.

Causes:

Commonly associated with Metatarsalgia, Morton’s Neuroma is an enlargement and entrapment of the interdigital nerve lying between the 3rd and 4th metatarsals. The reasons the nerve enlarges may vary. Excess pronation can cause the nerve to be medially displaced leading to irritation, inflammation and possibly enlargement of the nerve. This condition is a lot more common in women than men, mainly because of tight fitting fashion footwear which tends to squeeze the metatarsals together, pinching the nerve.

Also, high heels cause more weight to be placed to the forefoot which means more force is being applied in this area squeezing the nerve compartment. Under these conditions, even a minimal enlargement in the nerve can elicit pain.

Other conditions to consider are capsulitis, which is an inflammation of ligaments that surrounds two bones, at the level of the joint. In this case it would be the ligaments that attach the phalanx to the metatarsal bone. Inflammation from this condition will put pressure on an otherwise healthy nerve and generate neuroma-type symptoms. Additionally, an inter-metatarsal bursitis between the 3rd and 4th metatarsals will also give neuroma-like symptoms because it too puts pressure on the nerve. Freiberg’s disease, which is an Osteochondritis of the metatarsal head, causes pain on weight bearing or compression.

Treatment:

Orthotics and corticosteroid injections are widely used to treat Morton’s Neuroma. If such interventions fail, patients are commonly offered surgery known as neurectomy which involves removing the affected piece of nerve tissue. Post operative scar tissue formation known as stump neuroma can occur in approximately 20% of cases causing a return of neuroma symptoms. Orthotic treatment may greatly assist in the early stages of morton’s neuroma. Realigning the metatarsal shafts, redistributes the weight on the forefoot and prevents interdigital nerve impingement. Severe fibrosis of the interdigital nerve may require surgery. However, the use of orthotic devices may prevent further problems postoperatively.