222 



SPECIAL ANATOMY OF THE SKELETON 



axis of the shaft. In the adult it forms an angle of about 125 degrees with the 

 shaft, but varies in inverse proportion to the development of the pelvis and the 

 stature. In consequence of the prominence of the hips and widening of the pelvis 

 in the female, the neck of the thigh bone forms more nearly a right angle with the 

 shaft than it does in the male. The neck is flattened from before backward, 

 contracted in the middle, and broader at its outer extremity, where it is connected 

 with the shaft, than at its summit, where it is continuous with the head. The 

 vertical diameter of the outer half is increased by the thickening of the lower edge, 

 which slopes downward to join the shaft at the lesser trochanter; as a result of 

 this the outer half of the neck is flattened from before backward, and its vertical 

 diameter measures one-third more than the antero-posterior. The inner half 

 is smaller and of a more circular shape. The anterior surface of the neck is per- 

 forated by numerous vascular foramina. The posterior surface is smooth, and is 

 broader and more concave than the anterior; it gives attachment to the posterior 

 part of the capsular ligament of the hip-joint, about half an inch above the 

 posterior intertrochanteric line. The superior border is short and thick, and ter- 

 minates externally at the great trochanter; its surface is perforated by large 

 foramina. The inferior border, long and narrow, curves a little backward, to 

 terminate at the lesser trochanter. 



Obturator Internus and Gemelli 

 Pyriformis 



Insertion of Obturator 

 externus 



Fovea capitis, 

 for lig. teres 



-Great trochanter 



Small trochanter. 



FIG. 176. Upper extremity of the femur viewed from behind and above. 



The trochanters are prominent processes of bone which afford leverage to the 

 muscles which rotate the thigh on its axis. They are two in number, the greater 

 and the lesser. 



The greater trochanter (trochanter major} is a large, irregular, quadrilateral emi- 

 nence, situated at the outer side of the neck, at its junction with the upper part of 

 the shaft. It is directed a little outward and backward, and in the adult is about 

 three-quarters of an inch lower than the head. It presents for examination 

 two surfaces and four borders. The external surface, quadrilateral in form, is 

 broad, rough, convex, and marked by a prominent diagonal impression, which 

 extends from the posterior superior to the anterior inferior angle, and serves for 

 the attachment of the tendon of the Gluteus medius. Above the impression is 

 a triangular surface, sometimes rough for part of the tendon of the same muscle, 

 sometimes smooth for the interposition of a bursa between that tendon and the 

 bone. Below and behind the diagonal line is a smooth, triangular surface, 

 over which the tendon of the Gluteus maximus muscle plays, a bursa being inter- 

 posed. The internal surface is of much less extent than the external, and presents 



