THE FEMUR, OR THIGH BONE 



223 



at its base a deep depression, the 

 digital or trochanteric fossa (fossa 

 trochanterica), for the attachment 

 of the tendon of the Obturator 

 externus muscle; above and in 

 front of this an impression for 

 the attachment of the Obtura- 

 tor internus and Gemelli. The 

 superior border is free; it is thick 

 and irregular, and marked near 

 the centre by an impression, which 

 extends onto the internal surface, 

 for the attachment of the Pyri- 

 formis. The inferior border cor- 

 responds to the point of junction 

 of the base of the trochanter with 

 the outer surface of the shaft; it 

 is marked by a rough, prominent, 

 slightly curved ridge, which gives 

 origin to the upper part of the 

 Yastus externus muscle. The 

 anterior border is prominent, 

 somewhat irregular, as well as the 

 surface of bone immediately be- 

 low it; it affords attachment at its 

 outer part to the Gluteus mini- 

 mus. The posterior border is very 

 prominent, and appears as a free, 

 rounded edge, which forms the 

 .back part of the digital fossa. 



The lesser trochanter (trochan- 

 ter minor) is a conical eminence 

 which varies in size in different 

 subjects; it projects from the lower 

 and back parts of the base of the 

 neck. Its base is triangular, and 

 connected with the adjacent parts 

 of the bone by three well-marked 

 borders; two of these are above 

 the internal border, continuous 

 with the lower border of the neck, 

 the external border, with the pos- 

 terior intertrochanteric line - 

 while the inferior border is con- 

 tinuous with the middle division 

 of the linea aspera* Its summit, 

 which is directed inward and 

 backward, is rough and gives 

 insertion to the tendon of the 

 Iliopsoas. The Iliacus is also 

 inserted into the shaft below 

 the lesser trochanter between the 

 Yastus internus in front and the 

 Pectineus behind. 



Groove for tendon of 



POPLITEUS. 



Capsular 

 ** ligament 

 FIG. 177. Right femur. 



Posterior surface. 



