Overview
A bunion is enlargement of bone or tissue that develops at the joint that connects your big toe to your foot. The bones, muscles, ligaments and tendons of your feet normally are well-balanced to distribute your body's weight while standing, walking and running. When the joint, called the metatarsophalangeal joint, or MTP joint, experiences abnormal, prolonged stress in terms of weight distribution or squeezing of the toes within the shoe, the result can be the deformity called a bunion. Generally, a bunion develops when, as a response to prolonged stress, your big toe begins bending toward your foot's smaller toes and puts pressure on your MTP joint, forcing it to bulge outward (the term "bunion" comes from the Latin word for "enlargement"). There is no "standard" bunion, however, but rather a complex range of joint, bone and tendon abnormalities that can cause variation in each bunion's make-up.
Causes
A true bunion or hallux valgus results from a drifting inwards of the big toe metatarsal from its normal position closer to the second metatarsal. The bunion is the head of this first metatarsal which produces the prominence on the inner side of the now wider foot. Tendons run circumferentially around the metatarsal and toe. They both move and stabilise the toe under normal circumstances. In a bunion or hallux valgus, with the shift/displacement of the first metatarsal these tendons no longer lie in the correct axis and in fact act as a deforming force, contributing to the bunion condition.
Symptoms
Bunions are readily apparent, you can see the prominence at the base of the big toe or side of the foot. However, to fully evaluate your condition, the Podiatrist may take x-rays to determine the degree of the deformity and assess the changes that have occurred. Because bunions are progressive, they don't go away, and will usually get worse over time. But not all cases are alike, some bunions progress more rapidly than others. There is no clear-cut way to predict how fast a bunion will get worse. The severity of the bunion and the symptoms you have will help determine what treatment is recommended for you.
Diagnosis
Clinical findings are usually specific. Acute circumferential intense pain, warmth, swelling, and redness suggest gouty arthritis (see Gout) or infectious arthritis (see Acute Infectious Arthritis), sometimes mandating examination of synovial fluid. If multiple joints are affected, gout or another systemic rheumatic disease should be considered. If clinical diagnosis of osteoarthritic synovitis is equivocal, x-rays are taken. Suggestive findings include joint space narrowing and bony spurs extending from the metatarsal head or sometimes from the base of the proximal phalanx. Periarticular erosions (Martel sign) seen on imaging studies suggest gout.
Non Surgical Treatment
Custom orthoses or over-the-counter insoles to aid big toe joint function, help control over-pronation and maintain proper alignment of the bones in the feet. Properly sized, supportive footwear that are torsionally stable (can?t be folded or twisted easily) and that feature a good ?rocker profile? (curved from the ball to tips of the toes) help to reduce stress on the joint when walking. Footwear modifications to expand the area of the shoe surrounding the bunion to relieve pressure. Physical therapy modalities include rest, icing and massage. Injections, surgery and other treatment options, please consult your medical doctor for information and/or referral to a podiatrist or other foot and ankle specialist.
Surgical Treatment
Bunion surgery is most often done on an outpatient or day-surgery basis, usually with a local anesthetic technique called an ankle block. The surgery typically takes an hour or two to perform. Following your surgery, you will stay in the Recovery Room for several hours while the anesthetic wears off. For your safety, you will be required to have someone to drive you home. You should keep in mind that any surgery carries with it very small-but-possible risks of complications such as allergic reaction to anesthesia, bleeding and infection.
Prevention
Choosing footwear that fits correctly, especially low heeled shoes with plenty of space for the toes, is one of the main ways that bunions can be prevented. Always stand when trying on shoes to ensure they still fit comfortably when the foot expands under your body weight. Try shoes on both feet, and select the size appropriate for your larger foot. Use an extra insole if one shoe is looser than the other. Do not cramp the larger foot. People prone to flat-footedness should consider the use of arch supports, orthotic shoe inserts or special orthotic shoes to prevent or delay the development of bunions.
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