Morton’s metatarsalgia is a condition associated with a painful neuroma* on the digital nerve causing pain in the foot. Charcterised by perineural fibrosis and nerve degeneration due to repetitive irritation, is thought to be due to irritation of the digital nerve caused by repeated trauma, ischemia or entrapment of the nerve, occurs most frequently in women aged 40-50 who wear high-heeled, pointed-toe shoes. The neuroma occurs at the level of the metatarsal necks. The common digital nerve to the third/fourth metatarsal spaces is most often affected, although other interspaces can be involved.
A Morton’s Neuroma is not a true neuroma, which is a tumor that is generally benign. Rather, it is an enlargement of the nerve where it goes between the metatarsal bones of the foot. Because the nerve no longer fits between the gap, the pressure causes pain and sometimes numbness. This enlargement of the nerve is often an inflammation due to irritation. If the forefoot becomes compressed due to shoes that are too narrow, the nerve becomes damaged and inflamed. This inflammation means the nerve no longer fits in the space between the bones, creating further irritation and more inflammation. If this vicious circle can be broken, the problem may be resolved. However, in some situations the nerve can have fibrous tissues formed around it, which may require the destruction of the nerve or surgical removal.
The symptoms of a Morton’s neuroma are classic in nature. The patient complains of a burning , tingling, slightly numb feeling (dysesthesias) which radiates out to the toes on either side of the interspace that is involved. For instance, a Morton’s neuroma of the third interspace will result in pain between the third and fourth toes, and a neuroma in the second interspace will cause pain between the second and third toes. The symptoms are usually aggravated by wearing shoes, particularly those with high heels. Symptoms are relieved by walking in flat, wide shoes or going barefoot. Rarely will the patient experience pain when sitting or laying down.
There is a special orthopedic test called the Morton’s test that is often used to evaluate the likelihood of plantar nerve compression. For this test, the client is supine on the treatment table. The practitioner grasps the client’s forefoot from both sides and applies moderate pressure, squeezing the metatarsal heads together. If this action reproduces the client’s symptoms (primarily sharp, shooting pain into the toes, especially the third and fourth), Morton’s neuroma may exist.
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.
Operative treatment of Morton?s neuroma should be entertained only after failure of non-operative management. Standard operative treatment involves identifying the nerve and cutting (resecting) it proximal to the point where it is irritated/injured. This is usually done through an incision on the top (dorsal) aspect of the foot, although an incision on the sole (plantar) aspect of the foot can be used. Some physicians will attempt to treat Morton?s neuroma by releasing the intermetatarsal ligament, and freeing the nerve of local scar tissue. This may also be beneficial.