142 ARTHROLOGY, OR ANATOMY OF ARTICULATIONS 



The articular cartilage of the acetabulum is 2 mm. thick, 

 a little thinner toward the centre; that on the head of the 

 femur is thickest at the centre, i inch (4 mm.). The fossa 

 acetabuli contains a fat pad. 



FIG. 25 



Hip-joint, showing inverted Y -ligament. (Bigelow.) 



The ligamentum teres is misnamed, being neither ligamentous 

 nor round; it is somewhat triangular. It is planted by its 

 apex into the fossa on the posterior inferior quadrant of the 

 head of the femur, and rises from the notch and fossa acetabuli. 

 Unoccupied space around it is filled with synovia. A cross- 

 section of it discloses an outer firm and an inner loose part; 



