708 LIGAMENTS OF THE METACARPUS. 



wrist it is called ligamentum carpi dorsale, and extends from 

 the styloid edge of the radius to the styloid edge of the ulna. 



The lower head of the ulna is received into the sigmoid 

 cavity of the radius, constituting the lower radio-ulnar 

 articulation, and is retained there by a loose synovial mem- 

 brane termed the sacciform ligament. 



The synovial membrane covers the articular surface of the 

 bones and the inter-articular fibro-cartilage, and is reflected 

 upon the inner surface of the capsular ligament. 



The first and second rows of the carpal bones, except the 

 pisiforme, are united by a capsular ligament, extending 

 from one row to the other, and seeming to be a continua- 

 tion of the radio-carpal ; it is also thickened laterally by 

 external and internal lateral ligaments, the former extending 

 from the scaphoides to the trapezium, the latter from the 

 cuneiform to the unciform. 



The pisiform bone articulates with the cuneiform by a 

 separate cartilage, synovial membrane and proper capsular 

 ligament. Interosseous ligaments are found connecting 

 also the several carpal bones, and ligamentous fibres, run- 

 ning transversely, called from their position palmar and 

 dorsal ligaments. 



The synovial membrane extends from the first carpal row 

 to the second and down to the metacarpal bones ; it also 

 dips down between the bones of the carpus and lines the 

 inner surface of the capsular ligament, and is thus common 

 to all the carpal and metacarpal articulations, except the 

 cuneiform and pisiforme, the trapezium and metacarpal 

 bone of the thumb, and the space between the third and 

 fourth metacarpal bones, all of which have distinct synovial 

 membranes. 



LIGAMENTS OF THE METACARPUS, (Fig. 223.) 



These belong to the carpo-metacarpal articulation, and 

 include the dorsal and the palmar ligaments. 



The dorsal pass directly from the carpal to the base of 

 the metacarpal bones, the latter being also connected by 

 transverse fibres. 



