. SYMPHYSIS PUBIS. 283 
A proportion of these fibres is attached to the inner rough surface of the ilium 
between the iliac crest and the auricular impression. To these the name of the 
lig. ilio-lumbale inferius is applied (Fig. 219). 
The great or posterior sacro-sciatic ligament (lig. sacro-tuberosum, Fig. 220) 
is somewhat triangular in outline. It occupies the interval between the sacrum 
and the innominate bone, and is attached mesially, to the posterior inferior spine 
of the ilium; to the posterior aspect of the transverse tubercles and lateral 
margins of the third, 
fourth, and fifth seg-. 
ments of thesacrum, 
as well as to the 
side of the first seg- 
ment of the coccyx. 
It passes down- 
wards and outwards, 
becoming narrower Posterior sacro- 
as it approaches the “ssa! list 
c ‘ _ Smnall sacro- 
ischiu m, near to sciatic ligament 
Short posterior 
sacro-iliae ligament 
llio-lumbar ligament 
Oblique 
posterior 
sacro-iliac 
ligament 
Tschio-capsular 
which, however, it fi eee 
again expands, to be fs 
attached to the \ & 
inner side of the \i 
ischial tuberosity, 
immediately below 
the groove for the 
tendon of the ob- 
turator internus Fic. 220.—PELvic LIGAMENTS AS SEEN FROM BEHIND. 
muscle,7.e. the lesser 
sciatic notch. A continuation of the inner border of the hgament—the processus 
falciformis (Fig. 220)—runs upwards and forwards on the inner aspect of the 
ramus of the ischium. 
The great sacro-sciatic ligament is believed by many to represent the original 
or proximal end of the long or ischial head of the biceps flexor cruris muscle. 
The small or anterior sacro-sciatic ligament (lig. sacro-spinosum, Figs. 219 and 
220) is situated in front, and in a measure under cover of the great sacro-sciatic 
ligament. Triangular in form, it is attached by its base to the last two segments of 
the sacrum and the first seement of the coccyx, and by its pointed apex to the tip 
and upper aspect of the ischial spine. This ligament is intimately associated 
with the coceygeus muscle, and by some it is regarded as being derived from it by 
fibrous transformation of the muscle fasciculi. 
By the great and small sacro-sciatic ligaments the two sciatic notches of the 
innominate bone are converted into foramina. Thus the small sacro-sciatic lga- 
ment completes the boundaries of the great sciatic foramen (foramen ischiadicum 
majus); while the great sacro-sciatic ligament, assisted by the small sacro-sciatic 
ligament, closes the small sciatic foramen (foramen ischiadicum minus). 
Sub-pubic ligament 
Falciform process 
SYMPHYSIS PUBIS. 
The anterior wall of the osseous pelvis is completed by the articulation of the 
bodies of the two pubic bones constituting the symphysis pubis. This joint con- 
forms in its construction to the general plan of an amphiarthrosis. Thus it is 
mesial in position; each pubic bone is covered by a layer of hyaline cartilage, 
which closely adapts itself to the rough tuberculated surface of the pubic bone; 
while between these two hyaline plates there is an interposed fibro-cartilage 
(lamina fibro-cartilaginea interpubica), in the interior of which there is usually 
a vertical antero-posterior cleft. This cavity, which is placed nearer the posterior 
than the anterior aspect of the joint, does not appear until between the seventh 
and tenth years, and as it is not lined by a synovial membrane, it is supposed to 
result from the breaking down of the interpubic lamina. 
