Bunions (Hallux Valgus)

A bunion causes a bony protrusion on the joint of the big toes. Image Source: Photo courtesy of Evelyn Taylor

The common bunion is a localized area of enlargement or prominence of the inner portion of the joint at the base of the big toe. The enlargement actually represents a misalignment of the big toe joint (metatarsal phalangeal joint) and, in some cases, additional bone formation. The misalignment causes the big toe to point outward and rotate (medically termed hallux abducto valgus deformity) toward the smaller toes. This deformity is progressive and will increase with time although the symptoms may or may not be present.

The enlarged joint at the base of the big toe (the first metatarsophalangeal joint, or MTP joint) can become inflamed with redness, tenderness, and pain. A small fluid-filled sac (bursa) adjacent to the joint can also become inflamed (bursitis), leading to additional swelling, redness, and pain. A deeper joint pain may occur as localized arthritis develops in later stages of the deformity.

A less common bunion is located at the joint at the base of the fifth (pinky) toe. This bunion is sometimes referred to as a tailor's bunion or bunionette. The misalignment at the fifth MTP joint causes the pinky toe to point inward and create an enlargement of the joint.

While the precise cause is not known, it is believed that bunions are caused by multiple factors including abnormal foot function and mechanics, such as overpronation, abnormal anatomy at first MTP joint, and genetic factors. Overpronation is a common cause of bunion in younger individuals. Abnormal biomechanics can lead to instability of the metatarsal phalangeal joint and muscle imbalance, resulting in the deformity. Abnormal anatomy at the first MTP joint can predispose an individual to develop a bunion deformity. A study has found a significant genetic heritability of bunion deformity among people of European descent.

Although shoe gear doesn't directly cause a bunion, it can certainly make the condition painful and swollen. Other less common causes of bunion deformities include trauma (sprains, fractures, and nerve injuries), neuromuscular disorders (polio or Charcot-Marie-Tooth disease), and limb-length discrepancies (one leg shorter than the other) where the longer leg develops the bunion. The longer limb will tend to cause the foot to overpronate.

Various arthritic conditions can cause or exacerbate bunion deformity. Gout, a painful joint condition, very commonly involves the first MTP joint, which can progress to arthritic bunion deformity. Rheumatoid arthritis often causes severe bunions to develop along with other toe deformities.

Bunions most commonly affect women. Some studies report that bunion symptoms occur nearly 10 times more frequently in women. It has been suggested that tight-fitting shoes, especially high-heel and narrow-toed shoes, might increase the risk for bunion formation. Tight footwear certainly is a factor in precipitating the pain and swelling of bunions. Complaints of bunions are reported to be more prevalent in people who wear closed shoes than in barefoot people.

Other risk factors for the development of bunions include abnormal formation of the bones of the foot at birth (congenital) and arthritic diseases such as rheumatoid arthritis. In some cases, repetitive stresses to the foot can lead to bunion formation. Bunions are common in ballet dancers.

Bunions may or may not cause symptoms. Early symptoms may be foot pain in the involved area when walking or wearing shoes; rest and/or change to a wider shoe relieves this pain. Shoe pressure in this area can cause intermittent pain while the development of arthritis in more severe bunions can lead to chronic, constant pain. For arthritis sufferers, removing shoes or resting does not always provide relief. Besides ill-fitting shoes, unsupportive flimsy soled shoes can add stress to the bunion joint and increase pain and instability to the area.

Skin changes such as blisters and calluses may also develop as a result of repeated friction and pressure on the prominence by ill-fitting shoes or from the deformity caused by arthritis.

Bunions that cause marked pain are often associated with swelling of the soft tissues, redness, joint stiffness, and local tenderness. It is important to note that, in post-pubertal men and postmenopausal women, pain at the base of the big toe can be caused by gout and gouty arthritis that is similar to the pain caused by bunions.

A physician will consider a bunion as a possible diagnosis when noting the symptoms described above. The anatomy of the foot, including joint and foot function, is assessed during the examination. Radiographs (X-ray films) of the foot can be helpful to determine the integrity of the joints of the foot and to screen for underlying conditions, such as arthritis or gout. X-ray films are an excellent method of calculating the alignment of the toes when taken in a standing position (weight-bearing).

Nonsurgical treatments such as rest and wearing loose (wider) shoes or sandals (preferably with a supportive sole) can often relieve the irritating pain of bunions. Walking shoes may have some advantages, for example, over high-heeled styles that pressure the sides of the foot.

Anti-inflammatory medications, such as acetylsalicylic acid (aspirin, Ecotrin), ibuprofen (Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever), and naproxen (Anaprox, Naprelan, Naprosyn, Aleve), can help to ease inflammation and provide pain relief. Local cold-pack application is sometimes helpful, as well.

Bunion shields or pads can reduce pressure on the bunion caused by closed shoes. A bunion splint may also help if the condition is still in its early stage with minimal deformity. Splints help to place the toe in a corrected position, while stretching tight soft tissue structures. Night splints are used while sleeping and splint booties can be worn inside a shoe. Taping and toe separators can also be used to achieve the same goal.

Stretches and manipulation of first MTP joint structures can help preserve joint mobility. This can delay onset of arthritis at the joint -- a common late-stage finding of long-term bunion deformity.

Custom orthotics are used to improve foot mechanics and address overpronation. Orthotics can prevent progression of bunion and relieve pain by improving joint function. In addition, orthotics need to be worn in stable, well-fitting, laced shoes. These shoes can positively influence joint position and reduce discomfort that is commonly encountered in ill-fitting, tight shoes.

Inflammation of the joint at the base of the big toe can often be relieved by a local injection of cortisone.

Constant pressure or friction can lead to skin breakdown and infection that may require antibiotic therapy.

When the measures above are effective in relieving symptoms, patients should avoid irritating the bunion again by optimizing footwear and foot care. Many treatments without surgery can provide pain relief. However, the only way to change the bunion structure is by performing surgery.

For those whose bunions cause persisting pain despite conservative care, a surgical operation is considered for correction of the bunion. The surgical operation to cure a bunion is referred to as a bunionectomy. Surgical procedures can correct deformity and relieve pain, leading to improved foot function. These procedures typically involve removing bony growth of the bunion while realigning the big toe joint. Surgery is often, but not always, successful; failure to relieve pain can result from the big toe moving back to its previous deviated position even after surgery since bunion surgery does not always address mechanical problems. However, proper footwear and orthotics can reduce the chances of surgical failure.

The treatments described above are very effective in treating bunion deformities, and the prognosis can be excellent. However, the correct diagnosis is essential to define any underlying associated deformities as well as the bunion severity. Also, a bunion is a progressive deformity and will get worse with time. It can cause instability to the rest of the foot and sometimes lead to arthritis in the joint at the base of the big toe. It is, therefore, advised to consult with a foot specialist to fully evaluate a bunion. Early recognition, diagnosis, and bunion care can prevent debilitating aftereffects.

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). Physical therapy involving stretch can also be beneficial. Avoidance of certain athletic activities with improper shoe fit and toe pressure can prevent the symptoms that occur with bunions. Early examination by a podiatrist is recommended.