LIGAMENTS BETWEEN SACRUM AND ISCHIUM 127 



verse process of the last lumbar vertebra, in front, passing 

 down and outward it is attached to the base of the sacrum; 

 blending with the anterior sacroiliac and iliolumbar ligaments. 



The iliolumbar ligament is attached to the tip of the trans- 

 verse process of the last lumbar vertebra and passes horizontally 

 outward to be inserted into the crest of the ilium, just in front 

 of the sacroiliac articulation. 



THE ARTICULATIONS OF THE PELVIS 



The ligaments connecting the bones of the pelvis with each 

 other are: (1) Those connecting the sacrum and ilium; (2) 

 the sacrum and ischium; (3) the sacrum and coccyx; and (4) 

 between the pubic bones (Gray). 



1. Articulation of the Sacrum and Ilium 



This is an amphiarthrodial joint, formed between the lateral 

 surfaces of the ilium and sacrum. The anterior portion of 

 each articular facet is covered by a thin plate of hyaline car- 

 tilage. These are in contact and partially united together by 

 irregular patches of 'softer fibrocartilage, and at the upper 

 and back portion by interosseous fibrous tissue. 



The ligaments are the anterior and posterior sacroiliac. 



The anterior sacroiliac ligament is attached to the front of 

 the sacrum and ilium. The posterior sacroiliac ligament 

 consists of an upper part (short sacroiliac) passing horizontally 

 from the first and second transverse tubercles on the posterior 

 surface of the sacrum, to the rough, uneven surface at the 

 posterior part of the inner surface of the ilium. The lower 

 part passes obliquely, and is attached to the third tubercle 

 on the posterior surface of the sacrum and the posterior superior 

 spine of the ilium ; it is sometimes called the oblique sacroiliac 

 ligament. 



2. The Ligaments Passing between the Sacrum and 



Ischium 



There is no joint. The ligaments are the great and small sacro- 

 sciatic. 



