Radial Collateral Ligament Injuries of the Thumb Metacarpophalangeal Joint.

PURPOSE OF REVIEW: Injuries to the radial collateral ligament (RCL) of the thumb are thought to be relatively uncommon, especially when compared to the ulnar collateral ligament. However, the radial collateral ligament is increasingly recognized as critical for the overall stability of the thumb metacarpophalangeal joint. This article sets out to provide a comprehensive review of RCL injuries of the thumb MCP joint, including epidemiology, biomechanics, diagnosis, and treatment. RECENT FINDINGS: Although traditionally thought to respond well to conservative management, especially when compared to injuries to the ulnar collateral ligament, there is mounting evidence that chronic RCL injury leads to thumb metacarpophalangeal joint instability and can accelerate post-traumatic joint degeneration. Thus, much of the recent literature details surgical treatment options for radial collateral ligament injury, including repair and reconstruction. While incomplete tears of the thumb RCL respond well to immobilization, complete tears should generally be treated with operative management, either direct repair or anatomic reconstruction, depending on tissue quality. Even subacute and chronic injuries may be amenable to direct repair, with good to excellent outcomes, including in high-demand patient populations, such as professional athletes.