[Swan-neck and buttonhole deformities on rheumatic long fingers].

Patients suffering from rheumatoid arthritis in many cases develop typical swan-neck and buttonhole deformities. In the further course of the disease we observe several stages. In the beginning active and later passive correction are still possible, while ultimately a fixed contracture is present. The activities of daily life may be severely reduced. The pathology of the swan-neck deformity is initiated at the level of the metacarpophalangeal joint, while at the origin of the buttonhole deformity the synovitis of the proximal interphalangeal joint is obvious. In the early stages, synovectomy and balancing of the soft tissues are surgically indicated. In advanced stages, complicated soft tissue reconstruction in combination with alloarthroplasty or arthrodeses may become necessary to allow for sufficient finger function.