Swan-Neck Deformity

Swan neck deformity is characterized by proximal interphalangeal (PIP) joint hyperextension and flexion of the distal interphalangeal (DIP) joint. There is also reciprocal flexion noted of the metacarpophalangeal (MCP) joint. This is a result of an imbalance of the extensor mechanism of the digit. The imbalance could be due to a significant laceration or stretching of the extrinsic tendon forces on the distal phalanx or from tightness and pulling of the extensor mechanism, both intrinsic and extrinsic, at the PIP joint.[1][2]