48 THE ANATOMY OF THE HOUSE. 



radius ; and passing over the outside of the carpus, it furnishes slips to 

 the cuneiform and unciform bones, and termiiiates on the head of the 

 external small metacarpal bone. The ligament is perforated by a thecal 

 canal in which the tendon of the extensor sufFraginis plays. 



The Internal Lateual Ligament is fixed superiorly to the internal 

 tuberosity of the radius, and inferiorly to the heads of the large and 

 inner small metacarpal bones, furnishing slips, as it passes over the 

 carpus, to the scaphoid, magnum, and trapezoid bones. 



The Anteuior Common Ligament has a flattened, four-sided form. It 

 is fixed superiorly to the radius, and inferiorly to the large metacarpal 

 bone, while its lateral borders are united to the lateral ligaments. Its 

 deep fiice is partly adherent to the carpal bones or their anterior 

 ligaments, and partly it is lined by synovial membrane. The tendons 

 of the extensor pedis and the extensors of the metacai-pus play over its 

 superficial face, where they are provided with synovial bursee. The 

 ligament is somewhat loose when the joint is extended, and is put on 

 the stretch dui'ing flexion. 



The Posterior Common Ligament is a much stronger ligament than 

 the preceding. It is fixed above to the radius, and below to the large 

 metacarpal bone. Its internal border mixes its fibres with the internal 

 lateral ligament, while its outer border is blended in the same way with 

 the most external of the intercarpal ligaments. Its anterior or deep 

 face is very intimately united to the carpal bones, and its posterior fiice 

 is smooth and lined by the synovial membrane of the carpal sheath. 

 The suhcarjxd ligament, or fibrous band wliich reinforces the perforans 

 tendon below the carj^us, takes origin from the posterior common liga- 

 ment, or may be described as the downward continuation of that 

 ligament. 



Directions. — The anterior and lateral ligaments just described are to 

 be carefully dissected away, and in removing the first of these, care is 

 to be taken of the anterior bands connecting the bones in each row. 



Radio-carpal Ligaments. — There are three of these. The strongest 

 of them is a thick cord that stretches obliquely downwards and inwards 

 behind the carpus, and connects the radius and scaphoid. It will be 

 seen, without removing the posterior common ligament, which covers it, 

 by strongly flexing the joint and looking into it from the front. The 

 second is a very slender ligament which is fixed to the radius beneath 

 the preceding, and passes downwards to be attached to the pisiform and 

 the interosseous ligament luiiting the cuneiform and semilunar bones. 

 The third is situated at the outside of the carpus, where it connects 

 the radius and the upper border of the pisifoi*m bone, and is partly 

 covered by the lateral ligament. 



The Inter-carpal Ligaments are also three in number. Two of 

 them are situated behind the joint, under cover of the posterior common 



