328 THE INFERIOR EXTREMITY 



trochanteric band. The more medial and longer band is 

 almost vertical, and its distal end is attached to the lower 

 part of the intertrochanteric line. The interval between the 

 two diverging bands is occupied by a thinner portion of the 

 capsule which is perforated by an articular twig from the 

 ascending branch of the lateral femoral circumflex artery. 

 The ilio-femoral ligament is sometimes called the Y-shaped 

 ligament^ but, in making use of this term, remember that 

 the shape it presents is that of an inverted Y. 



Ligamentum Pubocapsulare (O.T. Pubo-femoral Ligament). 

 The pubo-capsular ligament is the name applied to fasciculi 

 which spring from the pubic bone and the obturator mem- 

 brane, and join the lower and anterior aspect of the capsule. 

 In cases where the bursa under the ilio-psoas is continuous 

 with the cavity of the joint, the aperture of communication 

 is placed between this band and the ilio-femoral ligament. 



Ligamentum Ischiocapsulare (O.T. Ischio-femoral Ligament). 

 The ischio-capsular ligament is a comparatively weak band 

 which springs from the ischium, below the acetabulum, and 

 passes upwards and laterally, anterior to the tendon of the 

 obturator externus. It terminates in the capsule. 



Zona Orfa'cu/aris(O.T. Orbicular Ligament}. The zonaorbi- 

 cularis is composed of circular fibres, which are most distinct 

 on the posterior aspect of the capsule. It encircles the neck of 

 the femur posteriorly and below, but is lost as it is traced an- 

 teriorly towards the upper and anterior parts of the capsule. 



The dissector has already noted the close connection 

 which is exhibited between the capsule of the hip joint and 

 the tendons of the glutaeus minimus, and the reflected head of 

 the rectus femoris. Reinforcing fibres are contributed to the 

 capsule by both of those tendons. 



Movements permitted at the Hip Joint. Before the capsule of the 

 joint is opened the range of movement which is permitted at the hip joint 

 should be tested. Flexion, or forward movement, is very free, and is 

 checked by the anterior surface of the thigh coming into contact with the 

 abdominal wall. Extension, or backward movement, is limited by the 

 ilio-femoral ligament. That powerful ligament has a most important part to 

 play in preserving the upright attitude with the least possible expenditure 

 of muscular exertion. In the erect posture the line of gravity falls slightly 

 behind the line joining the central points of the two hip joints. In the 

 upright attitude the ilio-femoral ligaments are tense, and prevent the pelvis 

 from rolling backwards on the heads of the femora. Abduction, or lateral 

 movement of the limb, is checked by the pubo-capsular ligament. Adduction, 

 or medial movement (e.g. as in crossing one thigh over the other), is limited 



