Operative correction of swan-neck and boutonniere deformities in the rheumatoid hand.

A swan-neck or boutonniere deformity occurs in approximately half of patients with rheumatoid arthritis. The cause of boutonniere deformity is chronic synovitis of the proximal interphalangeal joint. Swan-neck deformity may be caused by synovitis of the metacarpophalangeal, proximal interphalangeal, or distal interphalangeal joints. Numerous procedures are available for the operative correction of these finger deformities. The choice of surgical procedure is dependent on accurate staging of the deformity, which is based on the flexibility of the proximal interphalangeal joint and the state of the articular cartilage. The patient's overall medical status and corticosteroid use, the condition of the cervical spine, the need for operative treatment of large joints, and the presence of deformities of the wrist and metacarpophalangeal joints must also be considered when planning treatment. In the later stages of both deformities, soft-tissue procedures alone may not result in lasting operative correction.