Bunions
| Bunion | |
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| Synonyms | Hallux abducto valgus |
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| Specialty | Orthopedics |
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A bunion is a common deformity of the joint connecting the big toe to the foot. It is characterized by the first metatarsal bone deviating toward the midline of the body and the big toe deviating away from the midline of the body. This is often erroneously described as an enlargement of the metatarsal bone or tissue around the metatarsophalangeal joint. A similar condition of the little toe is referred to as a Tailor's bunion, or bunionette.
The cause is unclear. One proposed idea is that bunions are primarily due to the long-term wearing of particularly tight-fitting shoes with pointed toes. Others believe the problem stems from genetic factors, exacerbated by shoe use. Bunions occur when long-term pressure is applied to the side of the big toe forcing it inwards, towards – and sometimes under or over – the other toes (angulation). As pressure is applied, the tissues surrounding the joint may become swollen and painful. In a survey of people from cultures which do not wear shoes, no cases of bunions were found, lending credence to the first hypothesis.
The bump itself is partly due to the swollen bursal sac or an osseous (bony) anomaly on the metatarsophalangeal joint. The larger part of the bump is a normal part of the head of the first metatarsal bone that has tilted sideways to stick out at its distal (far) end.
The symptoms of bunions include irritated skin around the bunion, pain when walking, joint redness and pain, and possible shift of the big toe toward the other toes. Blisters may form more easily around the site of the bunion as well.
The presence of bunions can lead to difficulties finding properly fitted footwear and may force a person to buy a larger size shoe to accommodate the width the bunion creates. If the bunion deformity becomes severe enough, the foot can hurt in different places even without the constriction of shoes. It is then considered as being a mechanical function problem of the forefoot.
Bunions are sometimes genetic and consist of certain tendons, ligaments, and supportive structures of the first metatarsal that are positioned differently. This bio-mechanical anomaly may be caused by a variety of conditions intrinsic to the structure of the foot – such as flat feet, excessive flexibility of ligaments, 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, other sources concede that footwear only exacerbates the problem caused by the original genetic structure.
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Wikipedia