128 ARTHROLOGY, OR ANATOMY OF ARTICULATIONS 



The great sacrosciatic ligament (posterior) is triangular, and 

 attached to the posterior inferior spine of the ilium, by its 

 broad base, to the fourth and fifth transverse processes of the 

 sacrum, and to the lower part of the lateral margin of that 

 bone and the coccyx. Then passes obliquely downward, 

 outward, and forward to the inner margin of the tuberosity 

 of the ischium. Some of the fibers pass to the inner margin 

 of the pubic bone (falciform ligament) . 



This ligament is united to the small sacrosciatic ligament. 

 Its outer border forms the posterior boundary of the great 

 sacrosciatic foramen, and below, the posterior boundary of 

 the lesser sacrosciatic foramen. It gives attachment to some 

 of the fibers of origin of the gluteus maximus muscle. 



The small sacrosciatic ligament (anterior) is shorter and 

 smaller than the great sacrosciatic ligament. It is attached 

 by its apex to the spine of the ischium, then passes internally 

 to be inserted by its base into the lateral margin of the sacrum 

 and coccyx, anterior to the attachment of the great sacrosciatic 

 ligament, with which it blends. 



3. Articulation of the Sacrum and Coccyx 



This is an amphiarthrodial joint, formed by the oval surface 

 at the base of the sacrum and coccyx. The ligaments are 

 the anterior and posterior sacrococcygeal, lateral sacrococcygeal, 

 and interarticular fibrocartilage. 



The anterior sacrococcygeal ligament is attached to the 

 anterior surface of the sacrum and coccyx, blending with the 

 periosteum. It is a continuation of the anterior common 

 ligament. 



The posterior sacrococcygeal ligament is divided into a 

 deep and superficial portion. The deep is a continuation of 

 the posterior common ligament. It arises from the lower 

 orifice of the sacral canal, and passing downward is inserted 

 into the posterior surface of the coccyx. It completes the 

 lower, back part of the sacral canal. The superficial extends 

 from the middle sacral ridge to the posterior surface of the 

 coccyx; and encloses, partly, the sacral canal. The lateral sacro- 

 coccygeal ligament connects the transverse process of the coccyx 

 to the lower lateral angle of the sacrum. The interarticular fibre- 



