A bunion is an enlargement of bone or tissue around the joint at the base of the big toe (metatarsophalangeal joint). The big toe may turn in toward the second toe (angulation), and the tissues surrounding the joint may be swollen and tender.

Today the term usually is used to refer to the pathological bump on the side of the great toe joint. The bump is the swollen bursal sac and/or an osseous (bony) deformity that has grown on the mesophalangeal joint (where the first metatarsal bone and hallux meet).

Medical terms

The term "hallux valgus" or "hallux abducto valgus" are the most commonly-used medical terms associated with a bunion deformity, where "hallux" refers to the great toe, "valgus" refers to the abnormal angulation of the great toe commonly associated with bunion deformities, and "abducto" refers to the abnormal drifting or inward leaning of the great toe towards the second toe, which is also commonly associated with bunion disorders.

Symptoms

The symptoms of bunions include irritated skin around the bunion, joint redness and pain, and possible shift of the big toe toward the other toes.

Formation/development

Bunions are caused by a biomechanical abnormality, where certain tendons, ligaments, and supportive structures of the first metatarsal are no longer functioning correctly. This biomechanical abnormality may be caused by a variety of conditions intrinsic to the structure of the foot--such as flat feet, excessive ligamentous flexibility, abnormal bone structure, and certain neurological conditions. These factors are often considered genetic. Although some experts are convinced that poor fitting footwear is the main cause of bunion formation 1, other sources concede only that footwear exacerbates the problem caused by the original genetic deformity. 2

Bunions are commonly associated with a deviated position of the big toe toward the second toe; and the deviation in the angle between the first and second metatarsal bones of the foot. The small sesamoid bones found beneath the first metatarsal (which help the flexor tendon bend the big toe downwards) may also become deviated over time as the first metatarsal bone drifts away from its normal position. Arthritis of the great toe joint, diminished and/or altered range of motion, and discomfort with pressure applied to the bump or with motion of the joint, may all accompany bunion development.

Treatment

Bunions may be treated conservatively with changes in shoe gear, different orthotics (accommodative padding and shielding), rest, ice, and medications. These sorts of treatments address symptoms more than they correct the actual deformity. Surgery, by a Podiatrist, may be necessary if discomfort is severe enough or when correction of the deformity is desired.