Common deformities in rheumatoid arthritis

Common deformities in rheumatoid arthritis are the Boutonniere deformity (Hyperflexion at the proximal interphalangeal joint with hyperextension at the distal interphalangeal joint), swan neck deformity (Hyperextension at the proximal interphalangeal joint, hyperflexion at the distal interphalangeal joint). The thumb may develop a "Z-thumb" deformity with fixed flexion and subluxation at the metacarpophalangeal joint, and hyperextension at the IP joint.