220 



OSTEOLOGY. 



Capitate 



Greater 

 multangular 



Radius - 



Os lunatum 



Radius 



here also the transverse carpal ligament is attached. The ulnar artery and nerve 

 are in immediate relation with the lateral side of the bone. 



Os Multangulum Majus (O.T. 

 Trapezium). The greater mult- 

 angular is the most lateral bone of 

 the distal row of the carpus. It 

 may be readily recognised by the 

 oval saddle-shaped facet on its 

 distal surface for articulation with 

 the metacarpal bone of the thumb. 

 From its volar aspect there rises a 

 prominent ridge, medial to which is 

 a groove along which the tendon 

 of the flexor carpi radialis muscle 

 passes. The ridge furnishes an 

 attachment for the transverse 

 carpal ligament, as well as for some 

 of the short muscles of the thumb. 

 The proximal surface has a half- 

 oval facet for the navicular, lateral 



to which it is rough, and becomes 

 FIG. 213. THE RIGHT NAVICULAR BONE. , . .,, . 



. rr , , continuous with the non-articular 



NOTE. The bone is represented in the centre of the figure 7 7 , . , 



in the position which it occupies in the right hand viewed ^WTOl aspect, Which serves for 



_ from the volar aspect. The views on either side, and above the attachment of ligaments. On 



~and below, represent respectively the corresponding surfaces fa medial surface there are two 



of the bone turned towards the reader. P -\ *\ M> i 



facets ; the proximal is a half-oval, 



concave proximo-distally, and very slightly convex from volar to dorsal side, and 

 is for articulation with the lesser multangular; the distal, small and circular, 

 and not always present, is for articulation with the lateral side of the base of the 

 second metacarpal bone. The 

 dorsal surface, of irregular 

 outline, is rough for the attach- 

 ment of ligaments. The greater 

 multangular articulates with 

 four bones, the navicular, lesser 

 multangular, and the first and 

 second metacarpal bones. 



Os Multangulum Minus 

 (O.T.Trapezoid Bone). With 

 the exception of the pisiform, 

 the lesser multangular is the 

 smallest of the carpal bones. 

 Its rough volar surface is small 

 and pentagonal in outline. 

 By a small oblong area on its 

 proximal surface it articulates 

 with the navicular. Distally, 

 by a somewhat saddle-shaped 

 surface, it articulates with the 

 base of the second metacarpal. 



Separated from this by a rough NOTE. The bone is represented in the centre of the figure in the 



Os hamatum 



Os triquetrum Tj 



Os hamatum 



Capitate 



Radius 



Radius 

 Navicular 



FIG. 214. THE RIGHT Os LUNATUM. 



position which it occupies in the right hand viewed from the 

 volar aspect. The views on either side, and above and below, 

 represent respectively the corresponding surfaces of the bone 

 turned towards the reader. 



V-shaped impression prolonged 



from its volar aspect, is the 



area on the lateral surface for 



articulation with the greater 



multangular ; this is obliquely grooved from before backwards and distally. The 



medial facet, for articulation with the capitate, is narrow proximo-distally, and 



deeply curved from before backwards. The dorsal surface of the bone, which is rough 



and non-articular, is much larger than the volar aspect. The mass of the bone, 



