CAEPAL JOINTS. 



is restricted to the pisi-tri- 

 quetral articulation, and is 

 correspondingly simple, al- 

 though occasionally the joint 

 cavity may communicate 

 with that of the radio-carpal 

 joint. 



The other synovial stra- 

 tum is associated with the 

 transverse carpal joint which 

 extends transversely be- 

 tween the two rows of carpal 

 bones, with prolongations 

 into the intervals between 

 the adjoining bones of each 

 row, i.e. the intercarpal 

 articulations. It is, there- 

 fore, an elaborate cavity, 

 which may be still further 

 extended, by the absence of 

 interosseous ligaments, so as 

 to reach the radio-carpal and 

 carpo-metacarpal series of 

 joints. The first condition' is rare, but the second is not uncommon, and may 

 result from the absence of the interosseous ligament between the greater and lesser 

 multangular bones, or of that between the lesser multangular and the capitate 

 bone, but it may occur when all the interosseous ligaments are present. 



FIG. 311. FRONTAL SECTION through the radio-carpal, carpal, carpo- 

 metacarpal, and intermetacarpal joints, to show joint cavities and 

 interosseous ligaments (diagrammatic). 



