THE FEMUR, OR THIGH-BONE. 185 



intertrocbanteric line. The superior border is short and thick, and terminates 

 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. 



The Trochanters (rpo^dio, to run or roll) are prominent processes of bone 

 which afford leverage to the muscles which rotate the thigh on its axis. They 

 are two in number, the great and the lesser. 



The Great Trochanter is a large, irregular, quadrilateral eminence, 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 inter- 

 position 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 

 maxinms muscle plays, a bursa being interposed. The internal surface is of much 

 less extent than the external, and presents at its base a deep depression, the digital 

 or troclumtcric fossa, for the attachment of the tendon of the Obturator externus 

 muscle ; above and in front of this an impression for the attachment of the 

 Obturator internus and Gemelli. The superior border is free ; it is thick and 

 irregular, and marked near the centre by an impression for the attachment of 

 the Pyriformis. The inferior border corresponds 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 attachment to the upper 

 part of the Vastus externus muscle. The anterior border is prominent, somewhat 

 irregular, as well as the surface of bone immediately below it ; it affords attach- 

 ment at its outer part to the Gluteus minimus. 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 is a conical eminence which varies in size in different 

 subjects ; it projects from the lower and back part of the base of the neck. Its 

 base is triangular, and connected with the adjacent parts of the bone by three 

 Avell-marked borders : two of these are above the internal continuous with the 

 lower border of the neck, the external with the posterior intertrochanteric line 

 while the inferior border is continuous 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 Ilio-psoas. The Iliacus is also inserted into 

 the shaft below the lesser trochanter betAveen the Vastus internus in front and the 

 Pectineus behind. 



A well-marked prominence of variable size, which projects from the upper and 

 front part of the neck at its junction with the great trochanter, is called the tubercle 

 of tlie femur ; it is the point of meeting of five muscles : the Gluteus minimus 

 externally, the Vastus externus below, and the tendon of the Obturator internus 

 and Gemelli above. Running obliquely downward and inward from the tubercle is 

 the spiral line of the femur, or anterior intertrochanteric line ; it winds round the 

 inner side of the shaft, below the lesser trochanter, and terminates in the linea 

 aspera, about two inches below this eminence. Its upper half is rough, and affords 

 attachment to the ilio-femoral ligament of the hip-joint ; its lower half is less 

 prominent, and gives attachment to the upper part of the Vastus internus. Run- 

 ning obliquely downward and inward from the summit of the great trochanter on 

 the posterior surface of the neck is a very prominent, well-marked ridge, the pos- 

 terior intertrochanteric line. Its upper half forms the posterior border of the great 

 trochanter, and its lower half runs downward and imvard to the upper and back 

 part of the lesser trochanter. A slight ridge sometimes commences about the 



