A Morton's neuroma, or interdigital neuroma, is a painful condition which involves a nerve on the plantar aspect (bottom) of the foot. Occasionally a neuroma develops following a bruising injury to the sole of the foot, such as might be caused by jumping onto a rock or other objects, but in general, the origin of the condition is unknown.
Morton's neuroma is an inflammation caused by a buildup of fibrous tissue on the outer coating of nerves. This fibrous buildup is a reaction to the irritation resulting from nearby bones and ligaments rubbing against the nerves. Irritation can be caused by wearing shoes that are too tight, wearing shoes that place the foot in an awkward position, such as high heels, a foot that is mechanically unstable, repetitive trauma to the foot such as from sports activities like tennis, basketball, and running. Trauma to the foot caused by an injury such as a sprain or fracture. It is unusual for more than one Morton's neuroma to occur on one foot at the same time. It is rare for Morton's neuroma to occur on both feet at the same time.
There may be pain at the end of the push-off phase when walking or running, and this pain is generally worse when the client is wearing shoes as opposed to being barefoot. Clients may also report a relief of symptoms by massaging the foot, which may spread the metatarsal heads and mobilize the entrapped nerve.
The physician will make the diagnosis of Morton's neuroma based upon the patient's symptoms as described above in an interview, or history, and a physical examination. The physical examination will reveal exceptional tenderness in the involved interspace when the nerve area is pressed on the bottom of the foot. As the interspace is palpated, and pressure is applied from the top to the bottom of the foot, a click can sometimes be felt which reproduces the patient's pain. This is known as a Mulder's sign. Because of inconsistent results, imaging studies such as MRI or ultrasound scanning are not useful diagnostic tools for Morton's neuroma. Thus the physician must rely exclusively on the patient's history and physical examination in order to make a diagnosis.
Non Surgical Treatment
Treatments may include rehabilitation measures to reduce nerve Irritation. Switching to low-heeled, wide-toed shoes with good arch support. Wearing padding in the shoes and/or between the toes. Wearing shoe inserts to correct a mechanical abnormality of the foot. Having ultrasound, electrical stimulation, whirlpool, and massage done on the foot. The foot may be injected with corticosteroids mixed with a local anesthetic in order to reduce pain. Relief may be only temporary, however, if the mechanical irritation is not also corrected. Injections with other types of medications such as alcohol, phenol, or vitamin B12 are sometimes used.
When early treatments fail and the neuroma progresses past the threshold for such options, podiatric surgery may become necessary. The procedure, which removes the inflamed and enlarged nerve, can usually be conducted on an outpatient basis, with a recovery time that is often just a few weeks. Your podiatric physician will thoroughly describe the surgical procedures to be used and the results you can expect. Any pain following surgery is easily managed with medications prescribed by your podiatrist.