Thumb Ligament Injuries

THUMB LIGAMENT INJURIES

INTRODUCTION The Metacarpophalangeal (MCP) joint of the thumb are stabilize by two major ligaments. The ulnar collateral ligament (UCL) and the Radial collateral ligament (RCL) . The UCL is more commonly injured, usually from forced radial deviation (abduction) of the thumb, while the RCL are rarely injuried. However, in severe type of injuries, both ligaments may be ruptured. Clinically Relevant Anatomy The thumb MCP is similar in anatomical appearance to those of the finger,but essentially functions as a hinge or ginglymus joints. the articular morphology found in this joint makes it the most varied motion of all joints, with range of motion of 6 to 86 degree in flexion-extension. Sesamoid bones are nearly always present at this joint and are embedded in the VP. The flexor pollicis brevis (FBP) and abductor pollicis brevis (APB) muscles insert partially on the sesamoids and provide stability against hyperextension forces. The ligamentous anatomy is analogous to that seen in the finger MCP joints, with extrinsic tendons providing additional support