THE WRIST-JOINT AND ARTICULATIONS OF THE CARPUS. 



173 



The posterior ligament extends obliquely downwards and inwards, from the 

 extremity of the radius to the posterior surface of the first row of the carpal bones, 

 especially the pyramidal bone ; its fibres are prolonged some distance on the surface 

 of the carpal bones. 



The synovial membrane is simple and lines the ligaments between the articular 

 surfaces. 



THE CARPAL ARTICULATIONS. The bones of the carpus, the pisiform excepted, 

 are so arranged in two rows, that while only slight movement can take place between 

 the members of each row, a considerable amount of movement is possible between 

 the two rows. The surface presented by the first row to the second is concave both 

 transversely and from before backwards in the greater part of its extent, but in its 

 outer part it is formed by the convex part of the scaphoid bone. The opposing 

 surface of the second row is concavo-convex from without inwards, the concavity 



Fig. 200, A. DORSAL VIEW OP THE LIGAMENTS OF THE WRIST- JOINT, AND OF THE CARPAL AND 

 CARPO-METACARPAL ARTICULATIONS. (Allen Thomson, after Arnold. ) ^ 



1, lower part of the ulna ; 2, external lateral ligament of the wrist-joint ; 3, internal ; near it 

 descending obliquely to 6, from the radius, the dorsal radio-carpal ligament ; 4 to 5, dorsal ligaments of 

 the first row ; 4, is on the scaphoid, 5, on the lunar bone ; 6, pyramidal bone ; 7, trapezium ; 8, 

 trapezoid ; 9, os magnum ; 10, unciform ; 11 to 15, metacarpal bones ; 7 to 8, 8 to 9, and 9 to 10, 

 dorsal ligaments of the second row of carpal bones ; 4 to 8, 4 to 9, 5 to 9, and others, dorsal ligaments 

 between the first and second row ; 8 to 12, 9 to 13, and others, dorsal ligaments from the second row 

 to the metacarpal bones ; between the metacarpal bones, from 12 to 15, the dorsal intermetacarpal 

 ligaments. 



Fig. 200, B. PALMAR VIEW OF THE LIGAMENTS OF THE WRIST- JOINT, AND OF THE CARPAL AND 



CARPO-METACARPAL ARTICULATIONS. (Allen Thomson.) \ 



The anterior radio-carpal ligament has been removed : 1, anterior ligament of the lower radio-ulnar 

 articulation ; 2, external, and 3, internal lateral ligament of the wrist-joint ; 4, scaphoid bone ; 5, 

 lunar ; 6, pyramidal ; 7, pisiform, with the tendon of flexor carpi ulnaris attached ; 4 to 5, and 5 to 6, 

 palmar ligaments of the first row ; 8, external lateral ligament between the first and second rows of 

 carpal bones ; 9, trapezium (the trapezoid is not numbered) ; 10, os magnum ; 11, hook of the unciform 

 bone ; 9 to 10, 10 to 11, and others, palmar ligaments of the second row ; 4 to 10, and 6 to 10, some of 

 the palmar ligaments uniting the two rows, converging on the os magnum ; 7 to 11, pisi-uncinate 

 ligament ; 7 to 16, pisi-metacarpal ligament ; 12, external ligament of the first carpo-metacarpal 

 articulation ; 13, 14, 15, 16, the proximal ends of the second to the fifth metacarpal bones, on which 

 the palmar transverse ligaments are shown. 



being formed by the trapezium and trapezoid, the convexity by the os magnum and 

 unciform bone. 



In the transverse carpal articulation the two rows of carpal bones are 

 united by dorsal, palmar, and lateral ligaments. The lateral ligaments are placed 



