A deformity seen in patients with rheumatoid arthritis consisting of proximal interphalangeal (PIP) joint hyperextension and distal interphalangeal (DIP) joint flexion. The deformity may originate at the metacarpophalangeal (MCP), PIP, or DIP joint. It is seen in approximately 28% of rheumatoid arthritis fingers and has a predilection for the long and ring fingers. The deformity is caused by disruption of the extensor tendon at the DIP joint or volar herniation of the PIP joint capsule secondary to chronic synovitis. Treatment with ring splints to correct PIP joint hyperextension may be all that is required in patients with preserved PIP joint flexion. However, surgical intervention including joint fusion, arthroplasty or arthrodesis may be required in more advanced deformities.