THE FEMUR. 



353 



between the neck and the overhanging trochanter is the trochanteric or digital fossa. ' 

 There is usually a round recess at its anterior end for the tendon of the obturator 

 externus. 



The lesser trochanter^ is a rounded knob at the inner side of the posterior 

 aspect of the shaft at its junction with the neck. The posterior side is triangular. 

 It is at the junction of three lines : the posterior intertrochantei'ic ridge, a line run- 

 ning down to the linea aspera, and an inconstant ridge on the neck. It receives on 

 its end the tendon of the ilio-psoas, and below some of the iliac fibres of that muscle 



Fig. 369. 



OREATER TROCHANTER 



Tubercle for 

 quadratus femoris 



Third trochanter. 



Gluteal ridge 



Fossa for round 

 ligament 



Upper extremity of left femur from behind. 



That part of the spiral line above the level of the lesser trochanter (the so- 

 called anterior intertrochanteric ridge) is generally a very distinct rough line. It 

 may be so faint as to be hardly distinguishable, and extremely rarely a hollow may 

 be found in its place. The posterior intertrochanteric ridge is a thick swell- 

 ing, broader above than below. Near its junction with the greater trochanter it has 

 a slightly rounded prominence, or occasionally a vertical line, linea quadratic for the 

 quadratus femoris. 



The shaft ' is very strong, and convex in front, except below the neck, where it 

 is slightly concave. In the middle it would be nearly cylindrical were it not for the 



* Fossa trochanterica. ^ Trochanter minor. ' Corpus femoris. 



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