Hallux Valgus and Bunion

Hallux valgus is an abnormally positioned big toe, in which the joint at the base of the toe bulges outward from the inner side of the foot and the big toe points inward (toward the smaller toes). A bunion is a painful swelling of the fluid-filled sac (bursa) at the base of the big toe that occurs because of the hallux valgus.

The cause of hallux valgus is usually ill-fitting footwear, but vulnerability to this disorder seems to run in families. Because women's fashions often dictate shoes that fit poorly, women are more prone to developing these deformities.

See the figure Hallux Valgus With a Bunion.

The hallux valgus actually creates a widening of the foot because the base of the big toe bulges outward from the foot. Deviation of the big toe also occurs, so that the big toe points toward the smaller toes. The result is a bump on the inside edge of the foot, where the metatarsal head meets the base of the big toe. Under this bump is a bursa (a fluid-filled sac). The bursa becomes irritated by friction with the shoe, resulting in swelling of the bursa underneath the bump, thus increasing the size of the bump--this is called a bunion. Continued irritation of the bunion by friction with the shoe leads to increased bone growth and further swelling of the bursa, enlarging the bunion and further widening the foot.

A doctor can usually make the diagnosis of hallux valgus and bunion by directly examining the foot. X-rays may help to determine the degree of the hallux valgus.

Pain can be treated by injecting a corticosteroid mixed with a local anesthetic into the bunion. Bunion shield pads or modified shoes may also help relieve painful pressure over the bunion. Severely painful bunions or a severe degree of hallux valgus may require surgical correction of the toe's position.