ARTHROLOGY. 107 



The knee-joint, carpus, wrist of human subject, 



consists of four distinct joints, all synovial and having 

 distinct capsular ligaments. The radio-carpal joint is 

 between the inferior extremity of the radius and the sca- 

 phoid, lunar, and cuneiform bones and trapezium. These four 

 bones are united together by interosseous and connecting 

 ligaments, which it is unnecessary to specify. The carpal 

 joint is between the row thus formed, and the lower row 

 formed by trapezoides, magnum, and unciforme united 

 together in a corresponding manner, which by their under 

 surfaces come into connection with the upper surface 

 of the metacarpus, thus forming the carpo-metacarpal 

 joint. The last joint is arthrodial; the two former ginglymoid; 

 each has a synovial membrane, which in every case dips 

 down between the small facets presented by their small 

 bones for union with one another, which have been already 

 minutely described. The fourth capsular ligament is found 

 surrounding the synovial joint which trapezium makes 

 with the cuneiform bone. These different joints are con- 

 nected by lateral ligaments and the annular ligaments. The 

 outer lateral ligament may be divided into four, the inner 

 into three parts. The annular ligament is attached 

 anteriorly to the roughened anterior surfaces of all the 

 small bones of the knee, also to the roughened supero- 

 anterior part of the metacarpus. It anteriorhj presents 

 three channels running from above downwards with special 

 synovial thecse ; the inner one extends obliquely downwards 

 to the inner small metacarpal bone and gives passage to 

 extensor metacarpi obliquus. The outer one runs straight 

 downwards for passage of extensor pedis. The central is 

 broadest and terminates opposite the supero- anterior part 

 of metacarpi magnum, where the extensor metacarpi 

 magnus, to which it gives passage, is attached. A continu- 

 ation of the annular ligament surrounds extensor suffra- 

 ginis in the major portion of its course from the elbow 

 to the knee, and after it has passed through a sheath 

 formed by the outer part of this ligament, from which it 

 receives a reinforcing land, it is termed ligamentum exten- 

 sorum. On the surface of trapezium it forms a groove 

 with a theca for the lower tendon of flexor metacarpi 

 externus. The arrangement of the posterior part of the 

 annular ligament with its synovial membranes, and its 



