The term bunion as it is popularly used describes a variety of deformities involving a painful prominence and swelling at the base of the big toe. Orthopaedists use additional terms to describe the different deformities. The condition in which the big toe deviates from the normal position toward the direction of the second toe is referred to as hallux valgus.
The word bunion refers specifically to the prominence made of bone and at times an inflamed bursa. This bursa develops on the first metatarsal head at the base of the big toe because of this bony prominence. Although a bunion may develop without hallux valgus, for the purposes of this discussion, the term bunion will include both. Dorsal bunions, are a separate entity, in which the prominence appears on the top of the base of the toe—often the result of an arthritic joint.
No single cause or set of causes for bunions has been identified, although gender—women develop them more frequently than men—and heredity play a role. In addition, the foot gradually widens with age as the ligaments that connect the bones in the forefoot become more lax. Contrary to what many people believe, ill-fitting footwear is not the cause of bunions. In fact, bunions are found in populations all over the world, including among those who never wear shoes. Shoes that are too tight can, however, contribute to the progression of the condition. Bunions are often bilateral, that is, appearing in both feet. Although bunions are usually seen in people who are middle-aged or older, there are adolescents who are diagnosed with the condition, usually the result of a congenital problem.
Orthopaedic surgeons diagnose bunions on the basis of physical examination and weight bearing X-rays. Two angles are assessed:
While bunions may be considered cosmetically undesirable, they are not necessarily painful. In cases where the individual has minor discomfort that can be eased by wearing wider shoes made of soft leather and/or with the aid of spacers—padding placed between the toes to correct alignment—further treatment may not be necessary. (Anti-inflammatory agents can be used to alleviate temporary discomfort at the site of the bursa.) For those who continue to experience pain on a daily basis and who cannot wear most types of shoe comfortably, surgical treatment may be the best choice.
"There are different reasons to consider surgery," says Jonathan T. Deland, MD, Chief of the Foot and Ankle Service. "If the patient has pain in reasonable shoes and has tried wearing wider shoes and this has been a long term problem which is worsening, surgery should be considered. Also, if the big toe is pushing against or overlapping the second toe and causing pain in that toe, the bunion must be addressed in order to take care of the painful second toe. Instability in the first ray with pain on the ball of the foot—the ball is the portion of the foot at the base of the toes under the metatarsals from the tip of the toe, back up to the mid-foot—may also be an indication for surgery." Cosmetic complaints alone are not considered a sufficient reason for surgery.
Surgical treatment for bunion deformities usually involves an osteotomy, a procedure in which a cut or cuts are made in the affected bone or bones to restore proper alignment. Different techniques are used depending on the type of deformity; selection is guided by the degree of deformity present and the goals of preventing recurrence and achieving the most rapid recovery possible. Some of the more common procedures are:
Patients undergoing bunion surgery are given an ankle block that anesthetizes the foot from the ankle down. Depending on individual preference, a sedative may be given as well and the patient can be as sedated as they wish. All bunion surgeries may be done on a same-day basis, eliminating the need for hospitalization.
"Bunion surgery has a reputation for being painful," says Dr. Deland. "But with appropriate pain management and elevation of the foot, this can be minimized." The ankle block administered as anesthesia provides pain relief for up to 12 hours following surgery. Strong pain relievers are provided and anti-inflammatories can be used as well.
Length of recovery from bunion surgery varies according to the nature of the procedure. Those who have had a distal chevron procedure are able to bear some weight on the foot on the day following surgery. Those who have had a scarf procedure can bear partial weight by 2 weeks. Crutches are used to assist in walking. Individuals who require a lapidus procedure must wear a cast and use crutches for a period of 8 weeks. Regardless of the procedure used, swelling will persist for some time with a gradual reduction over the course of the post-surgery year. Patients who undergo either a distal chevron, scarf or crescentic osteotomy should be able to wear some type of shoe or sneaker at 6-7 weeks; those undergoing the lapidus fusion will probably need to wait 10-12 weeks before they are able to wear shoes. Formal physical therapy is most often not necessary. Patients are given range of motion exercises for the toe. Therapy is used only if progress with the motion is slow.
Overall, outcomes for surgeries are quite good. At HSS more than 80% of patients express satisfaction with their results. However, orthopaedic surgeons on the Foot & Ankle Service also treat patients who have had an unsatisfactory outcome following surgery at another institution. While the problems resulting from these surgeries can be addressed, the success rate is better with a properly done initial surgery.
For individuals exploring the possibility of surgical correction of a bunion, Dr. Deland and members of the Foot and Ankle Service advise consultation with an orthopaedic surgeon who is experienced in a wide range of surgical techniques—from simple approaches to those that are more complex. A patient should feel confident that the correct procedure is being done and that the recovery and rehabilitation process will be appropriate and effective. In addition, Dr. Deland cautions against committing to a procedure in which the bunion is simply "shaved down" rather than addressing the metatarsal deformity, since this can set the stage for recurrence.
Orthopaedic foot and ankle specialists at HSS perform more than 400 bunion surgeries a year.
Summary prepared by Nancy Novick • Diagnostic imaging examinations provided by HSS Radiologists