- INTERTARSAL JOINTS. 301 
of the same bones. When there is an extension of the scapho-cuneiform joint 
backwards between the scaphoid and cuboid, it is situated in front of the last- 
mentioned ligament, and is called the articulatio scapho-cuboidea. Around this 
joint the preceding ligaments are grouped. Since, however, the joint is inconstant 
while the igaments are always present, it is preferable to consider them as above 
indicated. 
Scapho-cuneiform Articulation (articulatio cuneonavicularis)—This joint is 
situated between the scaphoid and the three cuneiform bones. The anterior surface 
of the secaphoid presents facets for each of the cuneiform bones, but its articular surface 
is not interrupted. These facets form a somewhat convex anterior surface which fits 
into the shallow articular concavity presented by the proximal ends of the three 
cuneiform bones. This joint may be extended by the occasional scapho-cuboid 
articulation already referred to. 
The capsule is composed of short strong bands which are distinctly visible 
on all sides except towards the cuboid bone, where the joint may communicate 
with the cuneo-cuboid and scapho-cuboid joints. Anteriorly the joint communi- 
cates with the intercuneiform articulations. The dorsal parts of the capsule are 
short longitudinal bands termed dorsal scapho-cuneiform ligaments (Figs. 228 and 
229). These extend without interruption to the inner aspect of the joint. 
Inferiorly there are similar bands, known as plantar scapho-cuneiform ligaments 
(Fig. 230), also longitudinal in direction, but intimately associated with offsets 
from the tendon of the tibialis posticus muscle. 
The synovial membrane which lines the capsule sends prolongations forwards on 
each side of the middle cuneiform bone, and in addition it often communicates 
with the cuneo-cuboid joint-cavity, and it always communicates with the scapho- 
cuboid cavity when that joint exists. 
Intercuneiform Articulations.—These are two in number, and exist between 
adjacent contiguous surfaces of the three cuneiform bones. These surfaces are partly 
articular and partly non-articular. The small size of the middle cuneiform bone 
allows the internal cuneiform as well as the external cuneiform to project forwards 
beyond it on both sides, and therefore the articular surfaces turned towards the middle 
cuneiform are not entirely occupied by that bone. They form a recess towards 
the metatarsus, into which the base of the second metatarsal bone is thrust. 
Dorsal intercuneiform ligaments (Figs. 228 and 229) constitute fairly strong 
transverse bands which extend between adjacent dorsal surfaces and invest the joint 
cavities in this direction. 
The plantar or interosseous intercuneiform ligaments (Fig. 250) are two strong 
bands which pass from the rough non-articulur areas on opposite sides of the 
middle cuneiform to the opposing surfaces of the inner and outer cuneiform bones, 
These hgaments shut in the joint-cavities inferiorly, and also anteriorly in the case 
of the outer of the two joints. 
The synovial membrane is an extension of that which lines the scapho-cuneiform 
joint ; but while it is restricted to the outer of the two joints,in the case of the 
inner one it is prolonged still further forward to the tarso-metatarsal series of joints. 
Cubo-cuneiform Articulation.—This occurs between the rounded or oval facets 
on the opposing surfaces of the cuboid and external cuneiform. 
The dorsal cubo-cuneiform ligament (Fig. 229) is a flat, somewhat transverse, 
band which closes the joint on its superior aspect, and extends between the dorsal 
surfaces of the two bones. 
The plantar cubo-cuneiform ligament is difficult to determine. It is situated sub- 
jacent to the long plantar ligament, and extends between adjacent rough surfaces 
of the two bones. 
The interosseous cubo-cuneiform ligament is the strongest. It closes the joint 
cavity anteriorly, and is attached to the contiguous non-articular surfaces of the 
two bones. 
The synovial membrane is frequently distinct, but at other times the joint cavity 
communicates with those of the scapho- cuneiform and scapho-cuboid articulations. 
Synovial Membranes of the Intertarsal Joints——Four and sometimes five 
distinct and separate synovial membranes may thus be enumerated in connexion 
