What are bunions and is there a way to prevent them?

A. A bunion is an enlargement on the outside of the large joint of the big toe. In some cases bunions are merely unsightly, but in others they can cause much pain, making it difficult to wear shoes. Adam Landsman, chief of podiatry at Cambridge Health Alliance, says that bunions are the result of a misalignment of the first metatarsal, the bone in the ball of the foot below the big toe.

“The first metatarsal has to lock into position to keep the foot stable,’’ he explains. “In many people, it doesn’t lock for a variety of reasons, and it can drift outward.’’ The result is a painful enlargement at the toe joint, and the big toe itself often points inward, sometimes overlapping the next toe. The skin on the bunion may become irritated or calloused from rubbing against footwear.

Bunions are common and develop more frequently in women than in men. Landsman says that bunions tend to run in families. How you treat your feet can also make a difference. Wearing shoes with very narrow toes, or heels higher than three inches can exacerbate bunions in people susceptible to them. But Landsman says it’s a misconception that shoes are the only cause of bunions; a study in the 1960s found that bunions occurred in a small percentage of people in New Guinea who wore no shoes.

At the early stages, the development of bunions can sometimes be prevented or slowed by wearing comfortable footwear with arch support or corrective splints. But Landsman says that often the only way to fix the problem once it’s developed is to correct the alignment of the bones with surgery, which varies depending on the degree of misalignment. The simplest procedure may involve a cut to the bone, while more extreme cases require joint replacement or fusion. Landsman says many people put off seeing a doctor unnecessarily because they’re afraid of surgery. “The implants, screws and pins, and artificial joints that we use have improved dramatically over the past 10 or 15 years,’’ he says. He recommends seeing a doctor if your bunions are causing pain and making it difficult to walk.