A bunion is the common name for a structural deformity called hallux valgus. It develops when the big toe gradually moves towards the second toe while the first metatarsal bone moves in the opposite direction. This change in alignment creates the visible prominence on the inner side of the forefoot.
The prominence is not simply an extra piece of bone that has appeared. It is part of a broader change in the position of the bones, joint and supporting soft tissues. The big-toe joint may become irritated by footwear, the small fluid-filled sac over the joint can become inflamed, and the altered alignment may affect the way the foot bears weight during walking.
Some bunions remain relatively small and cause few symptoms. Others become painful, make shoes difficult to fit, reduce movement in the big-toe joint or contribute to pressure beneath the forefoot. The second toe may also begin to crowd, lift or overlap as the deformity progresses.
Bunions are often influenced by inherited foot shape and joint mechanics. Footwear does not necessarily create the underlying deformity on its own, but narrow or restrictive shoes can aggravate symptoms and may contribute to progression in a susceptible foot.
Treatment depends on the symptoms, severity and effect on daily life. Wider footwear, padding, activity modification, medication where appropriate and orthotic therapy may reduce pressure and discomfort. These measures can be valuable, but they do not usually realign an established structural deformity.
Surgery is generally considered when a bunion is painful or functionally limiting despite appropriate non-surgical care. The operation should be chosen for the individual deformity rather than treating every bunion in the same way. For many appropriately selected mild-to-moderate bunions, an Austin or Chevron osteotomy may be considered. This procedure corrects the alignment of the first metatarsal rather than merely shaving off the visible prominence.
An accurate assessment is therefore more important than the size of the bump alone. The decision-making process considers symptoms, clinical examination, weight-bearing X-rays, joint condition, foot mechanics, medical history and the patient’s goals.