i  ARTICULATIONS OF THE CARPUS. O77 
between the two rows or between any two carpal bones is extremely limited. 
For this reason, as well as because of the nature of the movement, these articula- 
tions are called gliding joints (arthrodia). 
It is advisable to consider, first, the articulations between individual bones of 
the proximal row; second, the articulations between the separate bones of the 
distal row; third, the articulation of the proximal and distal rows with each other ; 
fourth, the pisiform articulation. 
The proximal row of carpal articulations (Fig. 216) comprises the joints 
between the scaphoid, semilunar, and cuneiform bones. On their adjacent lateral 
aspects these bones are partly articular and partly non-articular. 
Three sets of simple but strong, although short ligamentous bands bind these 
three carpal bones together, and form an investment for three sides of their inter- 
carpal joints. These are—(1) the anterior or palmar ligaments, two in number, which 
consist of transverse fibres passing between the adjacent rough palmar surfaces of 
the bones ; (2) the posterior or dorsal ligaments, also two in number, and composed 
of similar short transverse fibres passing between the adjacent dorsal surtaces ; 
(3) the interosseous ligaments (Fig. 217), again two in number, and transverse in 
direction, situated on a level with the superior articular surfaces, and extending from 
the palmar to the dorsal aspect of the bones, while attached to non-articular areas of 
the opposing surfaces. The radio-carpal joint is entirely shut off from the inter- 
earpal joints, and also from the joint between the two rows of carpal bones, except in 
rare cases, when an interosseous ligament is wanting. 
The distal row of carpal articulations (Fig. 216) includes the joints between 
the trapezium, trapezoid, os magnum, and unciform bones. Articular facets occur 
on the opposing lateral faces of the individual bones. 
Associated with this row there are again simple bands of considerable strength, 
and presenting an arrangement similar to that seen in the proximal row. As in 
the former case, they invest the intercarpal articulations, except on the superior 
aspect, where they communicate with the transverse carpal joint, and on the inferior 
aspect, where they communicate with the carpo-metacarpal joint cavity. 
The anterior or palmar ligaments are three in number. They extend in a trans- 
verse direction between contiguous portions of the rough palmar surfaces of the 
bones. The posterior or dorsal ligaments, also three in number, are similarly dis- 
posed on the dorsal aspect. The interosseous ligaments (Fig. 217) are two or three 
in number. That which joins os magnum to unciform is the strongest; that 
between the trapezoid and os magnum is situated towards the dorsal parts of their 
opposing surfaces; the third, situated between contiguous non-articular surfaces 
of the trapezium and trapezoid, is always the feeblest, and is frequently absent. 
The transverse carpal articulation (Fig. 217) is situated between the proximal 
and distal rows of the carpus. The bones of the proximal row present the following 
_ characters on their inferior or distal aspect. The outer part of the articular surface 
is deeply concave, both in the antero-posterior and in the transverse directions, but 
the inner part of the same surface is concavo-convex, more especially in the trans- 
verse direction. 
Superiorly, the articular surfaces of the distal row of carpal bones present an 
irregular outline. That part pertaining to the trapezium and trapezoid is concave 
in the antero-posterior and transverse directions, and lies at a considerably lower 
level than the portion belonging to the os magnum and unciform, which is, more- 
over, markedly convex in the antero-posterior and transverse directions, with the 
exception of the innermost part of the unciform, where it is concavo-convex in 
_ both of these directions. 
This articulation is invested by a complete short capsule (Fig. 216) which binds 
the two rows of the carpus together, and sends prolongations to the investing 
capsules of the proximal and distal articulations. The ligament as a whole is very 
strong, and individual bands are not readily defined, although certain special bands 
-tnay be described. The palmar ligaments radiate from the os magnum to the scaphoid, 
cuneiform, and pisiform. The interval between the os magnum and semilunar is 
occupied by oblique fibres, some of which pass from scaphoid to cuneiform, while 
these are joined by others, prolonged obliquely downwards and inwards, from the 
