Medical term:

bunion

Bunion

Definition

A bunion is an abnormal enlargement of the joint (the first metatarsophalangeal joint, or MTPJ) at the base of the great or big toe (hallux). It is caused by inflammation and usually results from chronic irritation and pressure from poorly fitting footwear.

Description

A displacement of two major bones of the foot (hallux valgus) causes bunions, although not everyone with this displacement will develop the joint swelling and bone overgrowth that characterize a bunion. One of the bones involved is called the first metatarsal bone. This bone is long and slender, with the big toe attached on one end and the other end connected to foot bones closer to the ankle. This foot bone is displaced in the direction of the four other metatarsals connected with the toes. The other bone involved is the big toe itself, which is displaced toward the smaller toes. As the big toe continues to move toward the smaller toes, it may become displaced under or over the second toe. The displacement of these two foot bones causes a projection of bone on the inside portion of the forefoot. The skin over this projection often becomes inflamed from rubbing against the shoe, and a callus may form.

The joint contains a small sac (bursa) filled with fluid that cushions the bones and helps the joint to move smoothly. When a bunion forms, this sac becomes inflamed and thickened. The swelling in the joint causes additional pain and pressure in the toe.

Causes and symptoms

Bunions may form as a result of abnormal motion of the foot during walking or running. One common example of an abnormal movement is an excessive amount of stress placed upon the inside of the foot. This leads to friction and irritation of the involved structures. Age has also been noted as a factor in developing bunions, in part because the underlying bone displacement worsens over time unless corrective measures are taken.

Wearing improperly fitting shoes, especially those with a narrow toe box and excessive heel height, often causes the formation of a bunion. This forefoot deformity is seen more often in women than men. The higher frequency in females may be related to the strong link between footwear fashion and bunions. In fact, in a recent survey of more than 350 women, nearly 90% wore shoes that were at least one size too small or too narrow.

Because genetic factors can predispose people to the hallux valgus bone displacement, a strong family history of bunions can increase the likelihood of developing this foot disorder. Various arthritic conditions and several genetic and neuromuscular diseases, such as Down syndrome and Marfan syndrome, cause muscle imbalances that can create bunions from displacement of the first metatarsal and big toe. Other possible causes of bunions are leg-length discrepancies, with the bunion present on the longer leg, and trauma occurring to the joint of the big toe.

Key terms

Orthopedics — A medical specialty concerned with treating diseases, injuries, and malformations of the bones and supporting structures, such as tendons, ligaments, and muscles.

Orthotic — A device or brace to control, correct, or compensate for a bone deformity.

Podiatry — A medical specialty concerned with treating diseases, injuries, and malformations of the feet.

Symptoms of bunions include the common signs of inflammation such as redness, swelling, and pain. The discomfort is primarily located along the inside of the foot just behind the big toe. Because of friction, a callus may develop over the bunion. If an overlapping of the toes is allowed, additional rubbing and pain occurs. Inflammation of this area causes a decrease in motion with associated discomfort in the joint between the big toe and the first metatarsal. If allowed to worsen, the skin over the bunion may break down causing an ulcer, which also presents a problem of potential infection. (Foot ulcers can be particularly dangerous for people with diabetes, who may have trouble feeling the ulcer forming and healing if it becomes infected.)

Diagnosis

A thorough medical history and physical exam by a physician is always necessary for the proper diagnosis of bunions and other foot conditions. X rays can help confirm the diagnosis by showing the bone displacement, joint swelling, and, in some cases, the overgrowth of bone that characterizes bunions. Doctors will also consider the possibility that the joint pain is caused by or complicated by arthritis (which causes destruction of the cartilage of the joint), gout (which causes the accumulation of uric acid crystals in the joint), tiny fractures of a bone in the foot (stress fractures), or infection and may order additional tests to rule out these possibilities.

Treatment

Conservative

The first step in treating a bunion is to remove as much pressure from the area as possible. People with bunions should wear shoes that have enough room in the toe box to accommodate the bunion and avoid high-heeled shoes and tight-fitting socks or stockings. Dressings and pads help protect the bunion from additional shoe pressure. The application of splints or customized shoe inserts (orthotics) to correct the alignment of the big toe joint is effective for many bunions. Most patients are instructed to rest or choose exercises that put less stress on their feet, at least until the misalignment is corrected. In some cases, physicians also use steroid injections with local anesthetic around the bunion to reduce inflammation.

Surgery

If conservative treatment is not successful, surgical removal of the bunion may be necessary to correct the deformity. This procedure is called a bunionectomy, and there are many variations on the operation, which is usually performed by a surgeon who specializes in treating bone conditions (orthopedics) or by one who specializes in treating the foot (podiatry). Surgeons consider the angle of the bone misalignment, the condition of the bursa, and the strength of the bones when they choose which procedure to use. Most bunionectomies involve the removal of a section of bone and the insertion of pins to rejoin the bone. Sometimes the surgeons may move ligaments (which connect bone to bone in the joint) or tendons (which connect bone to muscle) in order to realign the bones. After this procedure, the bones and other tissues are held in place while they heal by compression dressings or a short cast. The individual must refrain from vigorous exercise for six weeks.

Alternative treatment

Deep friction massage techniques by a physical or massage therapist can be helpful to increase circulation, reduce inflammation, and prevent soft tissue build up. Physical therapy also provides useful approaches such as ultrasound to help retard or reverse the formation of the bunion. Various taping techniques can be useful to realign the toe and decrease friction and rubbing that may be present. The homeopathic tissue salt Calcarea phosphorica can be useful in balancing the bone formation/remodeling.

Prognosis

Often modifications in footwear allow a good prognosis without surgery. If surgery is necessary, complete healing without complications requires approximately four to six weeks. Even after surgery corrects the bone misalignment, patients are usually instructed to continue wearing low-heeled, roomy shoes to prevent the bunion from reforming.

Prevention

Prevention begins with proper foot wear. Shoes with a wide and deep toe box are best. High-heeled shoes should not be worn for long periods of time. If a bunion is present and becomes inflamed, the foot should be elevated with the application of an ice pack over the painful area for not more than 20 minutes every other hour. If pain and swelling continue, a podiatrist or physician should be contacted.

Resources

Organizations

American Orthopedic Foot and Ankle Society. 222 South Prospect, Park Ridge, IL 60068.

American Podiatry Medical Association. 9312 Old Georgetown Road, Bethesda, MD 20814.

Other

Griffith, H. Winter. "Complete Guide to Symptoms, Illness & Surgery." ThriveOnline. http://thriveonline.oxygen.com.

bunion

[bun´yun]

an abnormal prominence on the inner aspect of the first metatarsal head, with bursal formation, and resulting in lateral or valgus displacement of the great toe. Bunions can be caused by congenital malformation of the bony structure of the foot or by joint disease such as rheumatoid arthritis, but they are most often caused by wearing shoes with pointed toes, especially ones that are high-heeled and too short. When the shoes do not fit properly they force the great toe toward the outer side of the foot. The result is continued pressure on the joint where the great toe articulates with the first metatarsal head. Chronic irritation causes a buildup of soft tissue and underlying bone in the area. Symptoms are swelling, redness, and pain.

Bunion. From Dorland's, 2000.

Mild cases can be relieved by changing to properly fitting shoes. If there is severe pain making ambulation difficult or impossible, antiinflammatory agents may be effective. Surgical correction (bunionectomy) is indicated when all other measures fail.

bun·ion

(bŭn'yŭn),

A localized swelling at either the medial or dorsal aspect of the first metatarsophalangeal joint, caused by an inflammatory bursa; a medial bunion is usually associated with hallux valgus.

[O.F. buigne, bump on the head]

bunion

(bŭn′yən)

A painful, inflamed swelling of the bursa at the first joint of the big toe, characterized by enlargement of the joint and lateral displacement of the toe.

bunion

A localised, often painful swelling or deformity at the first metatarsal head of the great toe, which may be associated with bursitis or degenerative joint disease (osteoarthritis).

bunion

Podiatry A localized, often painful swelling or deformity at the first metatarsal head of the great toe, which may be associated with bursitis or degenerative joint disease (osteoarthritis)

bun·ion

(bŭn'yŏn)

A localized swelling at either the medial or dorsal aspect of the first metatarsophalangeal joint, caused by bursal inflammation and fibrosis; a medial bunion is usually associated with hallux valgus.

[O.F. buigne, bump on the head]

bunion

Inflammation of the protective, fluid-filled tissue bag (BURSA) overlying the main joint of the big toe. This is due to wearing pointed shoes which lever the big toes outward and exert pressure on the prominent joint.

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