An interdigital neuroma is a painful condition in the foot associated with sharp, tingling pain most commonly situated between the third and fourth toes. This condition is also known as a Morton's neuroma or Morton neuroma after a prominent physician who studied it, and technically speaking, it is not actually a neuroma, a swelling or growth in the nerve. More properly, it is what is known as a perineural fibrosis, a condition where abnormal growth around the nerve compresses it and causes it to start malfunctioning. Several treatments are available for interdigital neuroma and treatment can involve a neurologist, as well as a foot and ankle surgeon.
In patients with this condition, the nerve between the third and fourth toes becomes compressed and irritated. A swelling may be palpable, but most commonly, the first symptom is pain. When the patient puts weight on the ball of the foot, a sharp pain can shoot through the foot. This can make walking, running, and standing very uncomfortable. The pain can also be centered between the second and third toes in some cases.
Diagnosis of interdigital neuroma requires a patient history, where the patient discusses the pain and talks about any associated problems, along with a physical exam. A physician should be able to palpate the foot and cause pain, and may be able to feel the area of inflammation and swelling. In some cases, imaging studies may be requested to rule out other causes of the pain, like a broken bone in the foot, for the purpose of being thorough.
For immediate relief, an injection of local anesthetic should help temper the pain and will increase patient comfort. This can also be useful in ambiguous cases where it is difficult to narrow down the origins of the pain. In the long term, patients may be advised to change shoes, and special inserts may be used to relieve pressure on the interdigital neuroma and allow the patient to resume normal activities.
If changing footwear is not sufficient to address the problem, the next treatment for interdigital neuroma is surgery. A surgeon can excise the area of abnormal growth through a small incision on the foot. Once the patient heals from the surgery, the pain should be resolved. Surgical options are usually not offered first, in case more conservative measures are sufficient to resolve the problem. Patients considering surgery may want to meet with several surgeons to find a good fit.