ARTICULATIONS OF THE POSTERIOR LIMBS. 161 



2. Coxo-femoral Articulation. 



(Preparation.— Remo'ie the muscles surrounding the articulation. To view the 

 interior, divide the capsular ligament by a circular incision.) 



This is an enarthrosis, formed by the reception of the head of the 

 femur into the cotyloid cavity of the coxa. 



Articular surfaces.— As already shown, the cotyloid cavity represents 

 the segment of a hollow sphere, deeply notched on the inner side, and 



Fi^. 90. 



SACEO-ILIAO AND OOXO-PEMOEAL ARTICULATIONS, WITH THE SMALL DEEP 

 MUSCLES SURKOUNDINS THE LATTER. 



1, Sacro-iliac ligament ; 2, Sacro-ischiatic ligament ; 3, Great ischiatic notch ; 4, 

 Anterior portion of the capsular ligament of the coxo-femoral articulation ; 5, 

 Internal band of cotyloid ligament ; 6, Coxo-femoral ligament ; 7, Pubio-femoral 

 ligament ; 8, Its insertion into the femur ; 9, Small gluteal muscle ; 10, Origin 

 of the straight anterior muscle of the thigh (rectus); 11, Anterior thin muscle 

 (rectus parvus); 12, Pyramidal muscle of the pelvis; 13, External obturator 

 muscle; 14, Square crural muscle (quadratus femoris); 15, Inferior sacro- 

 coccygeal muscle. 



provided at the bottom with a wide depression, the internal moiety of which 

 is destined for the insertion of one of the interosseous ligaments, while the 

 external half plays the part of a synovial fossa. This depression is not 

 covered by cartilage, and communicates by the internal notch with the 

 inferior furrow on the pubis. The lip of the cotyloid cavity is covered by 

 a complementary fibro-cartilage — the cotyloid ligament. This fibro-cartilage 

 is not interrupted at the notch just mentioned, but passes over it, forming a 

 remarkable band (Fig. 90, 5) that converts it into a foramen, through which 

 pass the pubio- or ilio-femoral ligament and the vessels of the articulation. 



