COMMON CARPAL LIGAMENTS. 



139 



binds the unciform to the external splint bone. The two 

 posterior bind the magnum and trapezoid to the large and 

 inner metacarpal bones. The interossei unite the heads of the 

 splint bones to the large metacarpal and bones of the lower 



row. 



Common Ligaments. 



The Common Ligaments are the external and internal lateral, 

 and the anterior and posterior common, or capsular. 



The internal lateral ligament, stronger 

 than the external one, is slightly crucial, 

 consisting of two bundles of fibres which 

 cross each other ; both spring from the 

 internal side of the inferior extremity of 

 the radius ; the superficial bundle goes 

 to the os magnum and large metacarpal, 

 and the deep set to the scaphoid, trape- 

 zoid and inner splint bones. A part of 

 this ligament, deep-seated also, joins the 

 scaphoid and small metacarpal bones. 



TheesctemcU lateral ligament also con- 

 sists of two fasciculi, springing from the 

 external side of the distal end of the 

 radius ; the superficial fibres are attached 

 to the external splint, the deep to the 

 same, and also to the cuneiform and 

 unciform bones. 



The anterior common or capsular 

 ligament is membranous, covering the 

 anterior portion of the carpus. This 

 ligament is attached to the radius, the 

 head of the large metacarpal bone, the 

 lateral ligaments, and to the carpal 

 bones and their anterior ligaments. 



The annular ligaments are thickenings of this structure, which 

 bind down the extensor tendons. The inner surface is smooth, 

 and lined by synovial membrane. The posterior common 

 ligament is one of the strongest in the body, and covers the 

 posterior surface of the carpus, filling up the depressions. It 

 passes from the distal end of the radius to the head of the 

 large metacarpal bone, adhering to the internal lateral, median, 



FIG. 54. 



Ligaments of the carpus 

 postero-internal view, o b, Deep 

 portions of internal lateral liga- 

 ment ; , Oblique ligament ; d, 

 Interosseous metacarpal ligament ; 

 f, External interosseous ligameut 

 of the upper row. 



