2009 Reduction of Finger Joint Dislocations eMedicine Procedures

Description: Dislocation of a joint occurs when traumatic forces cause complete loss of continuity between the joint’s 2 articulating surfaces. Subluxation, on the other hand, occurs when the loss of continuity between the joints is only partial. A dislocation may or may not involve a fracture. Dislocations of the finger joints involve either the interphalangeal (IP) joint or the metacarpophalangeal (MCP) joint.
Each IP and MCP joint has 2 collateral ligaments and a volar fibrocartilaginous plate. Joint support is facilitated by these structures as well as the surrounding tendons. Overall, the IP joints are much more secure than the MCP joints because of the IP joints’ bicondylar arrangement and the fact that the collateral ligaments are tight throughout the entire range of motion. The MCP joints, on the other hand, are condyloid joints with additional lateral motion; their collateral ligaments are most taut during flexion only. Dislocation of a digit dorsally necessitates failure of the volar plate. On the other hand, lateral dislocation violates at least one of the collateral ligaments and produces a partial or complete tear in the volar plate.
Robin E Polansky, MD, MPH & Nancy S Kwon, MD, MPA Updated: May 17, 2009