Basal Joint

5 principal supporting ligaments of the thumb CMC joint viewed from the volar perspective (A), the radial aspect of the joint (B) and from the dorsal perspective (C).

AOL = anterior oblique ligament (red), DRL = dorsal radial ligament (green), DCL = dorsal central ligament (yellow), POL = posterior oblique ligament (blue). The intermetacarpal ligament (IML) is depicted in purple, bridging the thumb and index finger metacarpal bases.