|Henry Gray (18251861). Anatomy of the Human Body. 1918.|
Articulations.The navicular articulates with five bones: the radius proximally, greater and lesser multangulars distally, and capitate and lunate medially.
The Lunate Bone (os lunatum; semilunar bone) (Fig. 222).The lunate bone may be distinguished by its deep concavity and crescentic outline. It is situated in the center of the proximal row of the carpus, between the navicular and triangular. The superior surface, convex and smooth, articulates with the radius. The inferior surface is deeply concave, and of greater extent from before backward than transversely: it articulates with the head of the capitate, and, by a long, narrow facet (separated by a ridge from the general surface), with the hamate. The dorsal and volar surfaces are rough, for the attachment of ligaments, the former being the broader, and of a somewhat rounded form. The lateral surface presents a narrow, flattened, semilunar facet for articulation with the navicular. The medial surface is marked by a smooth, quadrilateral facet, for articulation with the triangular.
FIG. 221 The left navicular bone. (See enlarged image)
FIG. 222 The left lunate bone. (See enlarged image)
Articulations.The lunate articulates with five bones: the radius proximally, capitate and hamate distally, navicular laterally, and triangular medially.
FIG. 223 The left triangular bone. (See enlarged image)
FIG. 224 The left pisiform bone. (See enlarged image)
The Triangular Bone (os triquetum; cuneiform bone) (Fig. 223).The triangular bone may be distinguished by its pyramidal shape, and by an oval isolated facet for articulation with the pisiform bone. It is situated at the upper and ulnar side of the carpus. The superior surface presents a medial, rough, non-articular portion, and a lateral convex articular portion which articulates with the triangular articular disk of the wrist. The inferior surface, directed lateralward, is concave, sinuously curved, and smooth for articulation with the hamate. The dorsal surface is rough for the attachment of ligaments. The volar surface presents, on its medial part,