Injuries to the Collateral Ligaments of the Metacarpophalangeal and Interphalangeal Joints: Sonographic Appearance.

Injuries to the collateral ligaments of the metacarpophalangeal (MCP) and interphalangeal (IP) joints are commonly encountered in both athletes and nonathletes. They require prompt evaluation to ensure proper management and prevent loss of joint motion and permanent disability. Imaging is often required to confirm the diagnosis and assess injury severity. This review article aims to provide physicians with guidelines for sonographic assessment of the collateral ligaments of the MCP and IP and related injuries. Sonographic features of ligament injuries ranging from sprains and partial-thickness tears to full-thickness tears are described. Specific lesions of the ulnar collateral ligament of the thumb MCP joint, such as gamekeeper's thumb, skier's thumb, and Stener lesions, are also included. In conclusion, sonography is effective in evaluating the collateral ligaments of the MCP and IP joints and related injuries and represents a valuable tool for diagnosis.