|Henry Gray (18251861). Anatomy of the Human Body. 1918.|
| The ligaments connecting the pisiform bone are the articular capsule and the two volar ligaments.|
| The articular capsule is a thin membrane which connects the pisiform to the triangular; it is lined by synovial membrane.|
| The two volar ligaments are strong fibrous bands; one, the pisohamate ligament, connects the pisiform to the hamate, the other, the pisometacarpal ligament, joins the pisiform to the base of the fifth metacarpal bone (Fig. 334). These ligaments are, in reality, prolongations of the tendon of the Flexor carpi ulnaris.|
Articulations of the Distal Row of Carpal Bones.These also are arthrodial joints; the bones are connected by dorsal, volar, and interosseous ligaments.
The Dorsal Ligaments (ligamenta intercarpea dorsalia).The dorsal ligaments, three in number, extend transversely from one bone to another on the dorsal surface, connecting the greater with the lesser multangular, the lesser multangular with the capitate, and the capitate with the hamate.
The Volar Ligaments (ligamenta intercarpea volaria; palmar ligaments).The volar ligaments, also three, have a similar arrangement on the volar surface.
The Interosseous Ligaments (ligamenta intercarpea interossea).The three interosseous ligaments are much thicker than those of the first row; one is placed between the capitate and the hamate, a second between the capitate and the lesser multangular, and a third between the greater and lesser multangulars. The first is much the strongest, and the third is sometimes wanting.
Articulations of the Two Rows of Carpal Bones with Each Other.The joint between the navicular, lunate, and triangular on the one hand, and the second row of carpal bones on the other, is named the midcarpal joint, and is made up of three distinct portions: in the center the head of the capitate and the superior surface of the hamate articulate with the deep cup-shaped cavity formed by the navicular and lunate, and constitute a sort of ball-and-socket joint. On the radial side the greater and lesser multangulars articulate with the navicular, and on the ulnar side the hamate articulates with the triangular, forming gliding joints.
| The ligaments are: volar, dorsal, ulnar and radial collateral.|
The Volar Ligaments (ligamenta intercarpea volaria; anterior or palmar ligaments).The volar ligaments consist of short fibers, which pass, for the most part, from the volar surfaces of the bones of the first row to the front of the capitate.
The Dorsal Ligaments (ligamenta intercarpea dorsalia; posterior ligaments).The dorsal ligaments consist of short, irregular bundles passing between the dorsal surfaces of the bones of the first and second rows.
The Collateral Ligaments (lateral ligaments).The collateral ligaments are very short; one is placed on the radial, the other on the ulnar side of the carpus; the former, the stronger and more distinct, connects the navicular and greater multangular, the latter the triangular and hamate; they are continuous with the collateral ligaments of the wrist-joint. In addition to these ligaments, a slender interosseous band sometimes connects the capitate and the navicular.
Synovial Membrane.The synovial membrane of the carpus is very extensive (Fig. 336), 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 upwardbetween the navicular and lunate, and the lunate and triangularand 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.