Synovial Membrane
The synovial membrane of the carpus is very extensive, and bounds a synovial cavity of very irregular shape.
The upper portion of the cavity intervenes between the under surfaces of the navicular, lunate, and triangular bones and the upper surfaces of the bones of the second row.
It sends two prolongations upward—between the navicular and lunate, and the lunate and triangular—and three prolongations downward between the four bones of the second row.
The prolongation between the greater and lesser multangulars, or that between the lesser multangular and capitate, is, owing to the absence of the interosseous ligament, often continuous with the cavity of the carpometacarpal joints, sometimes of the second, third, fourth, and fifth metacarpal bones, sometimes of the second and third only.
In the latter condition the joint between the hamate and the fourth and fifth metacarpal bones has a separate synovial membrane.
The synovial cavities of these joints are prolonged for a short distance between the bases of the metacarpal bones.
There is a separate synovial membrane between the pisiform and triangular.
Read more about this topic: Intercarpal Articulations