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Home  »  Anatomy of the Human Body  »  pages 331

Henry Gray (1825–1861). Anatomy of the Human Body. 1918.

pages 331


Articulations of the Other Four Metacarpal Bones with the Carpus (articulationes carpometacarpeæ).—The joints between the carpus and the second, third, fourth, and fifth metacarpal bones are arthrodial. The bones are united by dorsal, volar, and interosseous ligaments.

The Dorsal Ligaments (ligamenta carpometacarpea dorsalia).—The dorsalligaments, the strongest and most distinct, connect the carpal and metacarpal bones on their dorsal surfaces. The second metacarpal bone receives two fasciculi, one from the greater, the other from the lesser multangular; the third metacarpal receives two, one each from the lesser multangular and capitate; the fourth two, one each from the capitate and hamate; the fifth receives a single fasciculus from the hamate, and this is continuous with a similar ligament on the volar surface, forming an incomplete capsule.

The Volar Ligaments (ligamenta carpometacarpea volaria; palmar ligaments).—The volar ligaments have a somewhat similar arrangement, with the exception of those of the third metacarpal, which are three in number: a lateral one from the greater multangular, situated superficial to the sheath of the tendon of the Flexor carpi radialis; and intermediate one from the capitate; and a medial one from the hamate.

The Interosseous Ligaments.—The interosseous ligaments consist of short, thick fibers, and are limited to one part of the carpometacarpal articulation; they connect the contiguous inferior angles of the capitate and hamate with the adjacent surfaces of the third and fourth metacarpal bones.

Synovial Membrane.—The synovial membrane is a continuation of that of the intercarpal joints. Occasionally, the joint between the hamate and the fourth and fifth metacarpal bones has a separate synovial membrane.
  The synovial membranes of the wrist and carpus (Fig. 336) are thus seen to be five in number. The first passes from the lower end of the ulnar to the ulnar notch of the radius, and lines the upper surface of the articular disk. The second passes from the articular disk and the lower end of the radius above, to the bones of the first row below. The third, the most extensive, passes between the contiguous margins of the two rows of carpal bones, and sometimes, in the event of one of the interosseous ligaments being absent, between the bones of the second row to the carpal extremities of the second, third, fourth, and fifth metacarpal bones. The fourth extends from the margin of the greater multangular to the metacarpal bone of the thumb. The fifth runs between the adjacent margins of the triangular and pisiform bones. Occasionally the fourth and fifth carpometacarpal joints have a separate synovial membrane.

Movements.—The movements permitted in the carpometacarpal articulations of the fingers are limited to slight gliding of the articular surfaces upon each other, the extent of which varies in the different joints. The metacarpal bone of the little finger is most movable, then that of the ring finger; the metacarpal bones of the index and middle fingers are almost immovable.
 
6i. Intermetacarpal Articulations
 
  
(Articulationes Intermetacarpeæ; Articulations of the Metacarpal Bones with Each Other)


The bases of the second, third, fourth and fifth metacarpal bones articulate with one another by small surfaces covered with cartilage, and are connected together by dorsal, volar, and interosseous ligaments.
  The dorsal (ligamenta basium oss. metacarp. dorsalia) and volar ligaments (ligamenta basium oss. metacarp. volaria; palmar ligaments) pass transversely from one bone to another on the dorsal and volar surfaces. The interosseous ligaments (ligamenta basium oss. metacarp. interossea) connect their contiguous surfaces, just distal to their collateral articular facets.
  The synovial membrane for these joints is continuous with that of the carpometacarpal articulations.

The Transverse Metacarpal Ligament (ligamentum capitulorum [oss. metacarpalium] transversum) (Fig. 337).—This ligament is a narrow fibrous band, which runs across the volar surfaces of the heads of the second, third, fourth and fifth metacarpal bones, connecting them together. It is blended with the volar (glenoid)