242 SURGICAL ANATOMY OF 



The capsular ligament is the thickest and strongest in 

 the body, and particularly that anterior portion known 

 variously as the ilio-femoral band, or the inverted Y- 

 shaped ligament of Bigelow, of which the tail of the Y 

 is attached to the anterior inferior spinous process of the 

 ilium, and the fork to the root of the great trochanter 

 and intertrochanteric line. It has been shown by Bige- 

 low that this thickened portion of the capsule is the chief 

 agent in producing the characters of the regular varieties 

 of luxation. When it is ruptured in dislocation, it is 

 almost always at its base, and so strong is it in some 

 instances, that the margins of the cotyloid cavity have 

 given way. 



The neck of the femur varies as regards its obliquity to 

 the shaft with the age of the individual. Before puberty 

 it is very oblique, and almost in a continuous axis with 

 the shaft ; in the adult male it is at an obtuse angle with 

 it, and directed upwards, inwards, and forwards, whilst 

 in old persons it becomes horizontal. 



The head of the femur presents a smooth ball, of very 

 regular form, somewhat more than hemispherical, di- 

 rected upward, inward, and a little forward, for articula- 

 tion with the acetabulum. It has a separate point of 

 ossification, becoming united to the shaft at the eighteenth 

 year. 



The synovial membrane covers all that portion of the 

 neck within the joint, and is reflected on to the internal 

 surface of the capsule, ensheathing the ligamentum teres, 

 and often communicating anteriorly with the bursa be- 

 neath the psoas and iliacus. 



The cotyloid cavity is deepened by the cotyloid liga- 

 ment, rendered continuous below by the transverse liga- 

 ment, beneath which the nutrient vessels pass to the joint. 



