THE FEMUR 



243 



on account of the greater breadth of the pelvis. The femur, like other long bones, 

 is divisible into a body and two extremities. 



The Upper Extremity (proximal extremity, Fig. 243). The upper extremity 

 presents for examination a head, a neck, a greater and a lesser trochanter. 



The Head (caput femoris) . The head which is globular and forms rather more 

 than a hemisphere, is directed upward, medialward, and a little forward, the greater 

 part of its convexity being above and in front. Its surface is smooth, coated with 

 cartilage in the fresh state, except over an ovoid depression, the fovea capitis 

 femoris, which is situated a little below and behind the center of the head, and gives 

 attachment to the ligamentum teres. 



The Neck (collum femoris) . The neck is a flattened pyramidal process of bone, 

 connecting the head with the body, and forming with the latter a wide angle open- 

 ing medialward. The angle is widest in infancy, and becomes lessened during 

 growth, so that at puberty it forms a gentle curve from the axis of the body of the 

 bone. In the adult, the neck forms an angle of about 125 with the body, but this 

 varies in inverse proportion to the development of the pelvis and the stature. In 



Obturator interims and Gemelli 

 Pirifomnis 



Insertion of Obturator 



externus 



Fovea capitis, 

 for lig. teres 



Lesser trochanter 



FIG. 243. Upper extremity of right femur viewed from behind and above. 



the female, in consequence of the increased width of the pelvis, the neck of the 

 f smur forms more nearly a right angle with the body than it does in the male. 

 The angle decreases during the period of growth, but after full growth has been 

 attained it does not usually undergo any change, even in old age; it varies con- 

 siderably in different persons of the same age. It is smaller in short than in long 

 bones, and when the pelvis is wide. In addition to projecting upward and medial- 

 vard from the body of the femur, the neck also projects somewhat forward; the 

 amount of this forward projection is extremely variable, but on an average is from 

 12 to 14. 



The neck is flattened from before backward, contracted in the middle, and 

 broader laterally than medially. The vertical diameter of the lateral half is in- 

 creased by the obliquity of the lower edge, which slopes downward to join the 

 body at the level of the lesser trochanter, so that it measures one-third more 

 than the antero-posterior diameter. The medial half is smaller and of a more 

 circular shape. The anterior surface of the neck is perforated by numerous vascular 

 foramina. Along the upper part of the line of junction of the anterior surface 

 with the head is a shallow groove, best marked in elderly subjects; this 





