OF THE PELVIS. 



281 



The two proper ligaments connecting the pelvis with the spine are the lumbo- 

 sacral and lumbo-iliac. 



The Lumbo-sacral Ligament (Fig. 194) is a short, thick, triangular fasciculus, 

 which is connected above to the lower and front part of the transverse process 

 of the last lumbar vertebra, passes obliquely outwards, and is attached below 

 to the lateral surface of the base of the sacrum, becoming blended with the 

 anterior sacro-iliac ligament. This ligament is in relation in front with the 

 Psoas muscle. 



The Lumbo-iliac Ligament {Fig. 194) passes horizontally outwards from the 

 apex of the transverse process of the last lumbar vertebra, to the crest of the 

 ilium immediately in front of the sacro-iliac articulation. It is of a triangular 

 form, thick and narrow internally, broad and thinner externally. It is in rela- 

 tion, in front, with the Psoas muscle; behind, with the muscles occupying the 

 vertebral groove ; above, with the Quadratus Lumborum. 



X. ARTICULATIONS OF THE PELYIS. 



The ligaments connecting the bones of the pelvis with each jther may be 

 divided into four groups. 1. Those connecting the sacrum and ilium. 2. Those 



Fig. 195. Articulations of Pelvis and Hip. Posterior View. 



passing between the sacrum and ischium. 3. Those connecting the sacrum and 

 coccyx. 4. Those between the two pubic bones. 



1. ARTICULATION- OF THE SACRUM AND ILIUM. 



The sacro-iliac articulation is an amphiarthrodial joint, formed between the 

 lateral surfaces of the sacrum and ilium. The anterior or auricular portion of 

 each articular surface is covered with a thin plate of cartilage, thicker on the 

 sacrum than on the ilium. The surfaces of these cartilages in the adult are 

 rough and irregular, and separated from one another by a soft yellow pulpy 



