THE FEMUR 51 



THE FEMUR 



This is a long bone which extends obKquely downwards and 

 forwards from the hip joint above to the stifle joint below. It is 

 the most massive bone in the whole body. It possesses a shaft and two 

 expanded extremities. 



The shaft may be said to present for description four surfaces. 

 The anterior and lateral surfaces are blended with one another, are 

 markedly convex in the transverse direction, and almost straight from 

 above to below. These three surfaces are clothed by the vastus 

 externus, vastus internus, rectus femoris, and rectus parvus muscles, 

 which are collectively called the quadriceps extensor cruris. 



The posterior surface is widest superiorly where it presents a four- 

 sided, somewhat flattened area. This area extends outwardly into a 

 well-marked depression, which is placed to the inner side of the 

 trochanteric ridge, and hence receives the name trochanteric fossa. 

 In the fossa the obturator externus, obturator internus, pyriformis, 

 and gemelli muscles are inserted. Inferiorly and towards the outer 

 side of the bone, the above-mentioned area extends on to the back 

 of the external or third trochanter. Here is found a roughened 

 elevation with a somewhat circular base, which gives attachment to 

 the femoral slip from the biceps femoris or triceps abductor femoris 

 muscle. Almost in line with this elevation and towards the inner side 

 of the bone is a roughened area to which the quadratus femoris muscle is 

 attached. Below the tubercle to which the biceps femoris is attached, 

 and where the shaft of the bone becomes very much narrowed down, 

 are two or three roughened ridges. These give attachment to the great 

 and small adductor muscles of the thigh. 



The nutrient foramen is placed in the middle third of the bone and 

 towards its inner edge. The canal into which the nutrient artery 

 passes is disposed at right angles to the surface of the bone. Quite 



