FEACTUEES OF THE FEMUE. 93 



an unexpected strain upon the bone forming the neck, the muscles 

 not contracting sufficiently quickly to relieve the osseous tissue 

 of the brunt of the violence. The neck, therefore, breaks well 

 within the capsule of the joint. 



The amount of separation in these cases is but little, and must 

 necessarily be so on account of the anatomy of the part. In the 

 first place, the amount of violence which has occasioned the frac- 

 ture may be so slight that the cervical reflection of the capsular 

 ligament remains wholly or partially untorn. This reflection is 

 seen in the form of fairly strong bands passing up from the 

 lower attachment of the capsule along the neck to the margin of 

 the articular surface of the head. Secondly, even if these 

 retinacula are torn through, the amount of separation will still 

 be limited by the untorn true capsule itself, and its strengthening 

 bands. Thus it comes about that the shortening in an intra- 

 capsular fracture of the neck by slight indirect violence hardly, 

 if ever, amounts to more than one inch in an adult. 



Often although the violence has been so slight, the constitu- 

 tional disturbance is great, owing to the injury being generally in 

 an aged patient, and attention may not, therefore, be directed 

 specifically to the seat of fracture. Bruising about the hip is 

 but seldom seen, all the blood effused being within the untorn cap- 

 sule of the joint. The eversion of the foot, however, should draw 

 attention to the possibility of fracture. This eversion is brought 

 about chiefly by the natural weight of the limb, which is greater 

 externally than internally, and partly by the action of the 

 irritated external rotators. 



This fracture seldom, if ever, unites by bony tissue, and this 

 probably from three reasons : first, there is great difficulty in 

 obtaining and maintaining approximation, should the fragments 

 have become separated, owing to the inability to manipulate the 

 upper one ; secondly, owing to the limited blood supply of the 

 acetabular fragment, which receives only a small vessel from the 

 obturator along the ligamentum teres ; thirdly, owing to the 

 osteoporosis, that is, the thinning of the bony tissue and the fatty 

 degeneration of the medullary substance, found in persons of 



