74 



TOPOGRAPHICAL ANATOMY OF 



The synovial lining of the joint capsule is divided into three parts 

 in agreement with the three articulations over which the capsule 

 extends. Its' radiocarpal part is most extensive, lubricates the radio- 

 carpal joint, and is continuous with the articulations of the accessory 

 carpal (pisiform) bone. It also lubricates the articulations between 

 the neighbouring bones of the proximal row above the interosseous 

 ligaments. The intercarpal part of the synovial lining lubricates the 



Radius. 



Radial carpal bone 

 (scaphoid). 

 Lis. collaterale mediate.. 



Third carpal bone 

 (magnum). 



Third metacarpal bone. _ 



Accessory carpal bone (pisiform). 



Second metacarpal bone. 



Fig. 52. — Medial Aspect of the Carpal Articulations. 



1. = Ligament from accessory carpal bone to radius. 

 2. = Ligament from accessory bone to fourth carpal and fourth metacarpal bones. 



articulations between the two rows of bones, and extends between the 

 individual bones of a row as far as the interosseous ligaments. The least 

 extensive part (carpometacarpal) of the synovial lining is that con- 

 nected with the carpometacarpal articulation, the intermetacarpal 

 articulations, and the small joints between the members of the lower 

 row of carpal bones distal to the interosseous ligaments. The interior 

 of the intercarpal and carpometacarpal sacs intercommunicate by a 

 small passage between the third (magnum) and fourth (unciform) 

 carpal bones. 



Lateral collateral ligament (ligamentum collaterale laterale). — The 

 fibres of the lateral collateral ligament spring from the projecting 

 lateral part of the end of the radius, and are attached to the ulnar 

 carpal bone (cuneiform), fourth carpal bone (unciform), and the base 

 of the fourth metacarpal bone. A few of the more superficial fibres 



