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.
A Morton's neuroma commonly occurs due to repetitive weight bearing activity (such as walking or running) particularly when combined with tight fitting shoes or excessive pronation of the feet (i.e. "flat-feet"). The condition is also more common in patients with an unstable forefoot allowing excessive movement between the metatarsal bones. A Morton's neuroma can also occur due to certain foot deformities, trauma to the foot, or the presence of a ganglion or inflamed bursa in the region which may place compressive forces on the nerve.
A Morton's neuroma usually causes burning pain, numbness or tingling at the base of the third, fourth or second toes. Pain also can spread from the ball of the foot out to the tips of the toes. In some cases, there also is the sensation of a lump, a fold of sock or a "hot pebble" between the toes. Typically, the pain of a Morton's neuroma is relieved temporarily by taking off your shoes, flexing your toes and rubbing your feet. Symptoms may be aggravated by standing for prolonged periods or by wearing high heels or shoes with a narrow toe box.
Morton's neuroma is usually diagnosed by your doctor listening to your symptoms and examining your foot. Sometimes your doctor can feel the 'neuroma', or an area of thickening in your foot, which may be tender. Sometimes, your doctor may suggest an ultrasound scan or MRI scan to confirm the diagnosis but this is not always necessary. Some doctors inject a local anaesthetic into the area where you are experiencing pain. If this causes temporary relief of pain, burning and tingling, it can sometimes help to confirm the diagnosis and show the doctor where the problem is.
Non Surgical Treatment
The best results are achieved with massage techniques that encourage spreading and mobilizing the metatarsal heads. Metatarsal spreading is one technique that can help reduce the detrimental effects of nerve compression. To perform this technique, pull the metatarsal heads (not just the toes) apart and hold them in this position to help stretch the intrinsic foot muscles and other soft-tissues. When this technique is combined with the use of toe spacers, it will be even more effective.
If these non-surgical measures do not work, surgery is sometimes needed. Surgery normally involves a small incision (cut) being made on either the top, or the sole, of the foot between the affected toes. Usually, the surgeon will then either create more space around the affected nerve (known as nerve decompression) or will cut out (resect) the affected nerve. If the nerve is resected, there will be some permanent numbness of the skin between the affected toes. This does not usually cause any problems. You will usually have to wear a special shoe for a short time after surgery until the wound has healed and normal footwear can be used again. Surgery is usually successful. However, as with any surgical operation, there is a risk of complications. For example, after this operation a small number of people can develop a wound infection. Another complication may be long-term thickening of the skin (callus formation) on the sole of the foot (known as plantar keratosis). This may require treatment by a specialist in care of the feet (chiropody).
Ensuring that shoes are well fitted, low-heeled and with a wide toe area may help to prevent Morton's neuroma.