ARTICULATIONS OF THE CARPUS OR KNEE-JOINT 



271 



ARTICULATIONS OF THE CARPUS OR KNEE-JOINT 



As we have elsewhere pointed out, the 

 knee is not one joint but several; the chief 

 of which are : 1 , the radio-carpal ; 2, the car- 

 pal; 3, the carpo-metacarpal. In addition, 

 other small articulations exist on the sides 

 of the bones forming the two rows (fig. 354). 



The Radio -carpal articulation is 

 formed by the inferior extremity of the 

 radius or lower arm and the superior sur- 

 face of the upper row of carpal bones, the 

 two parts being suitably modelled to each 

 other. This joint enjoys and imparts to 

 the knee the greatest range of movement. 



The Carpal joint is that between the 

 two rows of small bones, and its action, 



Fig. 354. The Carpus or Knee-joint 



1, Radius. 2, Large metacarpal or canon 

 bone. 3, Small metacarpal or splint bone. 

 4, Pisiform bone. 5, Common external liga- 

 ment. 6, Radio-carpal ligament. 7, Carpo- 

 metacarpal ligament. 8, Anterior liga- 

 ments uniting the two rows of carpal bones. 

 9, Anterior ligaments proper to the carpo- 

 metacarpal articulation. 



although considerable, is less exten- 

 sive than that of the radio-carpal. 



The Carpo-metacarpal articu- 

 lation is formed by the inferior sur- 

 face of the lower row of bones and 

 the superior extremities of the three 

 metacarpal bones. In the movement 

 of the knee this joint contributes 

 nothing to flexion and extension, but 

 allows a gliding movement favourable 

 to the action of the joints above. 



The articulations by which the 

 bones composing each row are united 

 together laterally are small, and only 



Fig. 355. Anterior View of Knee-joint 



1, Radius. 2, Scaphoid. 3, Lunare. 4, Cunei- 

 form. 5, Os magnum. 6, Unciform. 7, Canon. 

 8, Transverse connecting ligaments. 9, Oblique 

 connecting ligaments. 



