Hammertoe describes one shape the toe may take when the joints are contracted and deformed. The other shapes of deformed toes are claw toes and mallet toes. A corn is the thickened skin that forms where the shoe rubs on the toe. A hard corn forms where the skin is dry and a soft corn forms when it is moist, as between the toes.
Corns are always caused by shoes; shoes may also cause hammertoes. Shoes with high heels and narrow pointed toe boxes bunch up the toes, causing contracted joints and pressure areas in the skin. Some contracted toes are due to muscle weakness, arthritis or congenital problems but most are due to tight shoes. Beneath every corn there is a prominence of the bone. Pressure and friction from the shoe causes the skin to thicken at this point. Corns in the foot are like calluses in the hand – the skin thickens to resist pressure or friction. Unrelieved pressure on the toes can cause complications. With time, a flexible hammertoe deformity becomes a stiff hammertoe, which is more difficult to treat. The second toe may cross over the first and eventually dislocation may occur at the base of the second toe. Corns may eventually lose their ability to protect the toe and breakdown, forming skin ulcers. This may lead to infection.
The treatment is to either modify the shoes or modify the toes. The choice should be simple, but it is not, because fashion, not common sense, dictates the shape of the toe. To eliminate pressure on the toes, the shoes should have a deep toe box that is shaped like the toes and made from soft material. The heel should be low. Sandals or running shoes are the best, but even dress shoes may be found that meet these requirements. Corns that become too large can be shaved down. Sponge pads can be used on tender areas. The object of surgery is to reduce the prominence of the toe where the corn is formed. Part of the bone is removed to allow the toe to lay flat in the shoe.