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.
Some experts believe that other foot conditions may also be associated with Morton's neuroma. This is because other conditions may cause the metatarsal bones to rub against the nerve in your foot. Foot problems that may increase your risk of developing Morton's neuroma include abnormally positioned toes, high arches, where the arch or instep of your foot is raised more than normal, flat feet, low arches or no arches at all, bunions a bony swelling at the base of the toe. Hammer toe, where the toe is bent at the middle joint. Being active and playing sport can make the painful symptoms of Morton's neuroma worse. In particular, running or sports that involve running, such as racquet sports, can place extra pressure on the nerve in your foot, which can aggravate the problem.
The primary symptoms include sharp, shooting pain, numbness or paresthesia in the forefoot and extending distally into the toes, typically in the region of the third and fourth toes. Symptoms are aggravated with narrow toe box shoes or those with high heels. There is usually a reduction of symptoms when walking barefoot or wearing shoes with an appropriately wide toe box. Symptoms are also aggravated with shoes that are tied too tight.
To diagnose Morton's neuroma the podiatrist commonly palpates the area to elicit pain, squeezing the toes from the side. Next he or she may try to feel the neuroma by pressing a thumb into the third interspace. The podiatrist then tries to elicit Mulder's sign, by palpating the affected interspace with one hand and squeezing the entire foot at the same time with the other hand. In many cases of Morton's neuroma, this causes an audible click, known as Mulder's sign. An x-ray should be taken to ensure that there is not a fracture. X-rays also can be used to examine the joints and bone density, ruling out arthritis (particularly rheumatoid arthritis and osteoarthritis).
Non Surgical Treatment
You may need a metatarsal pad if wider shoes do not help relieve your Morton?s neuroma symptoms. A metatarsal pad will help spread your metatarsal bones and reduce pressure on your affected nerve as it travels under the ball of your foot. The placement of your metatarsal pad is important, and it is best placed by a foot care professional who has experience in the anatomy of the forefoot and Morton?s neuroma treatment.
If other therapies have not worked it may be necessary to perform surgery. As surgery may result in permanent numbness in the affected toe, doctors ten to use this procedure as a last resort. However, in most cases surgery is extremely effective. The patient usually receives a local anesthetic. Surgery involves either removing the nerve, or removing the pressure on the nerve. Two surgical approaches are possible. The dorsal approach, the surgeon makes an incision on the top of the foot, allowing the patient to walk soon after surgery, because the stitches are not on the weight-bearing side of the foot. The plantar approach, the surgeon makes an incision on the sole of the foot. In most cases the patient will be in crutches for about three weeks. The resulting scar may make walking uncomfortable. However, with this approach the neuroma can be reached easily and resected without cutting any structures. There is a small risk of infection around the toes after surgery.