THE HIP-JOINT 



247 



On laying open the capsule, some of the deeper fibres are seen reflected upwards 

 along the neck of the femur, to be attached much nearer the head: these are the 

 retinacula. One corresponds to the upper, and another to the lower part of the 

 sinral line; a third is seen at the upper and back part of the neck. They form flat 

 bands, which lie on the femoral neck. 



Superadded to the capsule, and considerably strengthening it, are three auxi- 

 liary Ijands, whose fibres are intimately blended with, and in fact form part of, the 

 capsule, viz. tlie ilio-femoral, ischio-femoral, and pectineo-femoral bands. 



The ilio-femoral (fig. 237) is the longest, widest, and strongest of the bands. 

 It is of triangular shape, with the apex attached above to a curved line on the ilium 

 immediately below and behind the anterior inferior spine, and its base below to the 

 anterior edge of the greater trochanter and to the spiral line as far as the inner border 

 of the shaft. The highest or outermost fibres are coarse, almost straight, and shorter 

 tlian the rest; the innermost fibres are also thick and strong, but oblique. This 



Fig. 237. — Axteriok View of the Capsule of the Hip-joixt. 



TendoB of rectus pulled up 



Tendino-troelianterie band passing 

 between rectus and vastus externus 



Placed on the weak spot of capsule, 

 which is sometimes perforated to 

 allow the bursa under psoas to com- 

 municate with joint 



Ilio-femoral band 



Pectineo-femoral band 



varying obliquity of the fibres, and their accumulation at the borders, explain why 

 this band has been described as the Y-shaped ligament. About the centre of its base, 

 near the femoral attachment, is an aperture transmitting an articular twig from 

 the transverse branch of the external circumflex artery. 



The ischio-femoral band (fig. 238) is formed of very strong fibres attached all 

 along the upper border of the groove for the external obturator, and to the iscliial 

 margin of the aceta1)ulum above the groove. Tlie highest of these incline a little 

 upwards as tliey pass outwards to be fixed to the greater trochanter in front of the 

 insertion of the pyriformis tendon, while the other fibres curve more and more 

 upwards as they pass outwards to their insertion at the inner side of the digital 

 fossa, blending Avith the insertion of the external rotator tendons. "When the joint 

 is in flexion these fibres pass in nearly straight lines to their femoral attachment, 

 and spread out uniformly over the head of tlie fcnnn-; but in extension they wind 



