Toes are normally straight. A hammertoe is a common deformity in which one or more of the toes are held in a bent position at their joints.
The skin thickens where the deformed toe hits the shoe. Painful corns and calluses often develop where the deformed toe hits the shoe.
Some people are born with toe deformities. Under and overlapping toes are a common congenital deformity. But most people develop them over time.
In adults, the most common causes of hammertoes are mechanical imbalances in the foot and leg. Poorly fitted shoes make matters worse. They hurt existing problems and accelerate the the rate at which the deformity develops.
Toes are held straight by tendons attached to each toe (tendons connect muscle to bone). These are present on all sides of the toe and counterbalance each other. If one tendon pulls harder than its counterpart, the toe buckles.
At first, the toe deformity is flexible (it can be manually manipulated into a straight position). But the deformity eventually becomes fixed into the hammered, deformed position.
Some foot types, like high arched feet, are more prone to developing hammertoes than others. Neurological (nerve) problems that cause muscular imbalances may also cause hammertoes to develop. Some kinds of arthritis can cause hammertoes to develop too.
Interestingly, shoes probably play a somewhat smaller role than formerly thought. Certainly they irritate existing problems and seem to accelerate how quickly the deformity develops. But studies of people who have never worn shoes show that they also develop toe deformities—though to a lesser degree. And, of course, many people wear very tight shoes for years and have perfectly normal toes.
Apparently there is a hereditary predisposition in some people to develop hammertoes. Tight shoes and high-heeled shoes may hurry the process along in those people who are already predisposed to the condition.
For most people, the hammertoe itself is not usually a problem except, of course, for the fact that we wear shoes. With the curling of the toe, pressure is exerted on the skin where the toe hits the shoe. This causes the skin to thicken as a means of protection. But this thickened, callused skin itself causes additional pressure, irritation and pain.
Treatment varies. If the toe does not hurt it can be left alone.
If there is only a small callus or corn, or, if the patient has poor circulation, only occasional removal of the corn or callus is appropriate. This can be done by a podiatrist. Cutting it yourself or using over-the-counter acids can lead to severe infections. Diabetics and those with poor circulation should not do this themselves.
Padding around the painful area and wearing a shoe with a deeper toe box both help a lot. If a sore has already developed, a shoe can be cut to provide pressure relief.
Surgery is appropriate if conservative care has been tried and is failing—the problem keeps coming back and it is interfering with daily activities.
If the toe is still very flexible, sometimes the tendon alone can be released. More often, the procedure includes removing a small piece of bone from the toe to allow it to straighten. This is usually done on an outpatient basis (no overnight stay in the hospital is needed) and using a combination of a local anesthetic and sedation. The goal is a straight, pain-free toe.