A hallux abducto valgus deformity, commonly called a bunion, is a deformity characterized by medial deviation of the great toe, often erroneously described as an enlargement of bone or tissue around the joint at the head of the big toe. There is disagreement among medical professionals about the cause of bunions; some see them as primarily caused by the long-term use of shoes, particularly tight-fitting shoes with pointed toes, while others believe that the problem stems from genetic factors that are exacerbated by shoe use. Bunions occur when pressure is applied to the side of the big toe (hallux) 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 tender. In a survey of people from cultures that do not wear shoes, no cases of bunions were found, lending credence to the hypothesis that bunions are caused by ill-fitting shoes. 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 top.Causes
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. 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 big 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. Atop of the first metatarsal head either medially or dorso-medially, there can also arise a bursa that when inflamed (bursitis), can be the most painful aspect of the process.Symptoms
Bunions typically start out as a mild bump or outward bending of the big toe. Bunions at this stage are usually only a concern of appearance at this stage, and at this point they often don't hurt much. Over time, the ligaments that connect the bones of the toe stretch out, and the tendons attaching to the big toe gradually pull it farther and farther towards the second toe. Sometimes patients will find their first and second toes begin to press together too much, and they'll often get a painful corn between those toes. As the bunion progresses, the big toe may begin to ride on top of the second toe, or vice versa, creating a second deformity. Others will develop bump pain at the site of the bony enlargement on the side of the foot. A painful bursa may develop at that site. This is particularly true in tight shoes. Many patients also develop a painful callus beneath the foot. Capsulitis and other types of metatarsalgia may develop in the joints beneath these calluses, particularly in the second and third metatarsophalangeal joints (the joints in the ball of the foot). Over time, with the toe held in a crooked position for enough time, arthritis develops in the big toe joint. This will usually result in decreased range of motion of that joint (a condition known as "Hallux Limitis"), which as a result, often causes the patient to changes in the way a patient walks. Often the patient walks in an "out-toed", or duck-like, fashion, which very frequently causes secondary pain in the legs, knee, hip, and low back.Diagnosis
People with bunions may be concerned about the changing appearance of their feet, but it is usually the pain caused by the condition that leads them to consult their doctor. The doctor will evaluate any symptoms experienced and examine the affected foot for joint enlargement, tissue swelling and/or tenderness. They will also assess any risk factors for the condition and will ask about family history. An x-ray of the foot is usually recommended so that the alignment of big toe joint can be assessed. This would also allow any other conditions that may be affecting the joint, such as arthritis, to be seen.Non Surgical Treatment
Bunions may be treated with proper shoes and corrective inserts such as toe spacers, bunion or toe separators, as well as bunion cushions and splints. In extreme cases, surgery may be needed to remove the bony enlargement of the first metatarsal bone, realigning the bone, or straightening the big toe.Surgical Treatment
If the bunion symptoms does not respond to the conservative measures or if the bunion has progressed past a threshold where these measures are not effective, bunion surgery may be necessary to correct alignment and remove the bunion. A large range of types of surgical procedures for bunions are available and the choice will depend on things like what bone or bones are involved, the angular relationship between the different bones, the amount of damage to the joint and the presence of deformities other than the bunion.Prevention
If the diagnosis is made early on, such as in preadolescence, bunion development can be slowed and in some cases arrested with the proper supportive shoe gear and custom functional shoe inserts (orthotics). Avoidance of certain athletic activities with improper shoe fit and toe pressure can prevent the symptoms that occur with bunions.
- 2015/03/29(日) 20:37:57|
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- 2017/07/22(土) 10:55:25 |
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