THE HIP-JOINT. 



369 



and upward across the back of the neck to the top of the greater trochanter (Fig. 

 387). Moreover, beneath the longitudinal layer there is a sling of circular fibres, 

 the zona orbicularis , starting from the anterior inferior spine of the ilium and pass- 

 ing behind the neck to return to the same point. It lies near the head of the 

 femur, completely concealed by the longitudinal fibres. It is isolated only by a 

 rather artificial dissection. 



The capsule varies much in thickness in different places ; thus, it is very weak 

 behind and very strong in front. It is strengthened by three collections of accessory 



Fig. 3S5. 



Ilio-femoral ligament 



Pubo- 

 femoral ii 

 liga- A 



merit . ,\1 



V,"' """^ 



Right hip-joint, anterior aspect. 



fibres. Much the most important is the ilio-femoral ligament ' (Fig. 385). a thick 

 triangular expansion, intimately fused with the capsule, arising by its apex from the 

 lower part of the anterior inferior spine of the ilium and from the bone below and 

 behind it above the lip of the acetabulum, and extending by its base from the 

 superior cervical tubercle to the level of the lesser trochanter. The borders of this 

 are often particularly strong, and are spoken of as the order and inner limbs of the 

 ligament. A weak space is sometimes seen between them near the insertion, whence 

 it has been called by Bigelow the Y-ligament from a resemblance to an inverted Y. 



^ Lig. illofemorale. 

 24 



