ABT1CVLATI0N8 OF THE ANTERIOR LIMBS. 151 



anatomist, start from tlie interstices which separate the median metacarpal 

 bone from the lateral metacarpals, and join the interosseous ligaments of the 

 second row ; they are thick and short. We have sometimes noted one or 

 other of them to be absent. 



Synovial membrane.— This communicates, as indicated above, with the 

 synovial capsule of the preceding articulation. It furnishes a superior cul- 

 de-sac which rests on the interosseous ligament interposed between the two 

 last carpal bones of the second row. Two inferior cuh-de-sac descend into 

 the intermetacarpal arthrodial articulations. 



Ligaments common to the theee peeceding Articulations. As 



before mentioned, these are foui- in number two lateral, 

 one anterior, and one posterior. 



a. The external lateral ligament (Figs. 86 and 87, 3) is a 

 thick funicular cord composed of two orders of fibres — a deep- 

 seated and a superficial order, slightly crossed. It leaves 

 the external and inferior tuberosity of the radius, descends 

 vertically to the side of the carpus, transmits a fasciculus 

 to the first bone of the upper row, gives off another fasci- 

 culus which stops at the external bone of the second row, 

 and terminates on the head of the corresponding metacar- 

 pal bone. Traversed obliquely by the lateral extensor of 

 the phalanges, this ligament covers the external carpal 

 bones. In front, it is united to the capsular ligament; 

 near its inferior extremity, it is confounded with the strong 

 ligament which joins the supercarpal bone to the first bone 

 of the inferior row and to the head of the external meta- 

 carpal bone. 



6. The internal lateral ligament (Fig. 86, 4), analogous 

 to the preceding and situated on the opposite side, is wider 

 and thicker than it. It commences on the internal tube- 

 rosity of the radius, and terminates on the upper extremity 

 of the middle and internal metacarpal bones, after being 

 attached, by two distinct fasciculi, to the third carpal bone 

 of the upper row, and the two last of the metacarpal row 

 In contact by its external face with the tendon of the 

 oblique extensor muscle of the metacarpus, this ligament 

 responds, by its deep face, to the synovial membranes of 

 the carpus and to the bones to which it is attached. By 

 its anterior border it is united to the capsular ligament , 

 the opposite border is intimately confounded with the pos- 

 terior ligament, from which it is impossible to distinguish 

 it. 



c. The anterior, or capsular ligament, is a membranous 

 band covering the anterior faj^e of the carpal articulations. 

 Its superior border is attached to the radius , the inferior 

 is inserted into the superior extremity of the principal 

 metacarpal hone. The two right and left borders are 

 united with the lateral ligaments. Its external face is in 

 contact with the tendons of the anterior extensor muscles 

 of the metacarpus and phalanges. The internal face is 

 lined at certain points by synovial membrane, and adheres 

 in others to the carpal bones and the anterior ligaments 

 binding these to one another. This ligament is composed of transverse 



LATERAL VIEW OF 

 THE CAEPAL AE- 

 TIOULATIONS. 



1, 1, Anterior liga- 

 ments uniting 

 the two rows ol 

 carpal bones ; 2, 

 2, Anterior liga- 

 ments proper to 

 the carpo-meta- 

 carpal articula- 

 tion j 3, Common 

 external liga- 

 ment ; 4, One ot 

 the ligaments 

 proper to the 

 articulation of 

 the two rows 

 (metacarpo - su- 

 pracarpal) ; 5, 

 One of the liga- 

 ments proper to 

 the radio-carpal 

 articulation (ra- 

 dio supracar- 

 pal)., — A, Groove 

 on the external 

 surface of the su- 

 pracarpal bone 

 for the passage 

 of the external 

 flexor of the me- 

 tacarpus. 



