Limbs : Upper Limb 



107 



corresponding areas by a badly-marked ridge. Dorsal surface is encroached upon by 

 the lower and upper articular surfaces, so is only represented by a narrow rough strip 

 for dorsal ligaments of the wrist. 



Anterior surface presents a concavity or notch, below which is the prominent 

 tuberosity. The upper parts of the deeper fibres of the anterior annular ligament are 

 attached to the tuberosity, which may, as in the figure, show a ridge for this, with a 

 groove external to it for the tendon of F. carpi radialis : further in is a ligamentous 

 area d this may be enlarged in the angle between the trapezoid and os magnum 

 surfaces by the attachment here of an interosseous band connecting the bone with the 

 os magnum. 



Abductor pollicis gets some slight origin from the tuberosity outside the groove 

 for the radial flexor. 



Semilunar. Rather obliquely placed, in an upward and inward direction. A deep 

 concavity below for head of os magnum, a flattened four-sided facet on inner side for 

 cuneiform, and between these two, on the lower and inner angle, an elongated strip 



1 1 vL tendon of 

 ' ^ F.etrpt uliurit 



FIG. 87. Palmar aspect of pisiform. On the right the bone is 

 shown in position ; the Abductor minimi digiti is indicated 

 by interrupted lines in its position lying on the ligamentous 

 fibres connecting pisiform with bases of metacarpals. 

 Observe that the oblique and raised anterior ridge is directed 

 downwards and outwards ; this enables one to place the bone 

 on its proper side. 



of articular surface for unciform. Outer facet for scaphoid is elongated and crescentic, 

 with a roughened area above it for the interosseous ligament between the bones : a 

 similar band is on the ulnar side, connecting it with the cuneiform and attached above 

 the facet for that bone, on the edge that separates it from the upper articular surface, 

 but a definite marking is frequently wanting (see Fig. 86). 



Upper articular surface extends on to dorsal surface in its outer part : this is 

 for the radius ; but the inner part of the surface, more on the upper aspect of the bone, 

 is for the triangular nbro-cartilage, and the two areas, though continuous, are some- 

 times separately recognisable on the bone. As a result of this the dorsal surface is 

 diminished, particularly its outer part, and is a roughened and purely ligamentous 

 one. Anterior surface, larger than the dorsal, has only weak ligamentous bands 

 attached to it, and is not much roughened. 



Cuneiform. Three-sided pyramid with its base resting against the semilunar, its 

 apex directed downwards and inwards, an inferior surface concavo-convex and resting 



