Morton?s Neuroma is a pathological condition of the common digital nerve in the foot, most frequently between the third and fourth metatarsals (third inter-metatarsal space). The nerve sheath becomes abnormally thickened with fibrous (scar) tissue and the nerve fibres eventually deteriorate.This condition is named for the American surgeon, Thomas George Morton (1835-1903), who first recognised the condition in 1876. Incidentally his father was the dentist who discovered the anaesthetics; initially Nitrous oxide, the very gas used today in cryosurgery for the condition his son lent his name to? Morton?s neuroma.
The exact cause is as yet unclear. However there are a number of theories. Some expert s believe problems with the design of the foot makes some people more prone to Morton?s neuroma. Having flat feet or a high arch for example encourages the foot to slide forwards which can put excess pressure on the metatarsals. Bunions and hammer toes also increase the likelihood of developing Morton?s. However simply wearing high heels or any form of tight shoes that put pressure on the bones in the feet can also lead to a Morton?s . Typically the condition comes on between the age of 40 and 50. It is far more common in women than men – three out of four sufferers are women.
Patients will often experience a clicking feeling in the forefoot followed by a sharp shooting pain or a sensation of numbness or pins and needles extending into ends of their toes. Tight narrow fitting shoes may often exacerbate these feelings which become worse after long periods of standing or walking. Once the Mortons nueroma progresses symptoms will become more frequent and often more intense.
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
Simple treatments may be all that are needed for some people with a Morton’s neuroma. They include the following. Footwear adjustments including avoidance of high-heeled and narrow shoes and having special orthotic pads and devices fitted into your shoes. Calf-stretching exercises may also be taught to help relieve the pressure on your foot. Steroid or local anaesthetic injections (or a combination of both) into the affected area of the foot may be needed if the simple footwear changes do not fully relieve symptoms. However, the footwear modification measures should still be continued. Sclerosant injections involve the injection of alcohol and local anaesthetic into the affected nerve under the guidance of an ultrasound scan. Some studies have shown this to be as effective as surgery.
Majority of publications including peer review journal articles, surgical technique description and textbooks promote surgical excision as a gold standard treatment. Surgical excision is described as the most definitive mode of treatment for symptomatic Morton?s neuroma with reported success rates varying between 79% and 93%. Various surgical techniques are described, essentially categorised as dorsal versus plantar incision approaches. Beyond this the commonest technical variation described as influencing the outcome of surgery involves burying and anchoring transacted nerve into soft tissue such as muscle.