The Lower Extremity and Pelvis 145 



further out here than the insertion of the tendon on the floor. The posterior inter - 

 trochantcric line is part of the trochanteric system and marks the pull of the Quadratus : 

 this is inserted by muscular fibre as a rule, so that its area is not linear and has not 

 any secondary markings : occasionally there are tendinous fibres, with corresponding 

 secondary roughnesses. The quadrate tubercle is that part of the trochanteric mass 

 on which the pull of the muscle is directly exerted, and it is thus of the nature of 

 a primary marking. 



FIG. 118. Upper end of right femur. The epiphysial line for the great trochanter is marked in green 

 round its base. The " retinacula of Weitbrecht," fibres running back toward the head under the 

 synovial membrane, are shown only where they are congregated into their three main groups ; they 

 are derived from the transverse capsular fibres, and the upper one obtains many fibres from Pyriformis 

 (see Fig. 117). I. Anterior aspect. Observe that the Gluteus minimus is attached only to the outer 

 ridge of the trochanter, but its tendon is continuous below with an aponeurotic sheet, the ilio-trochan- 

 teric band, which covers the bursa in front and reaches the bone internal to it. The upper part of the 

 origin of Crureus is mainly tendinous. The extension of the cartilage of the head on to the neck is 

 shown at x ; this lies under the ilio-femoral band or, if the opening for the sub-Psoas bursa is large, 

 under the tendon of the Psoas. 2. From the outer side. The oblique insertion of Gluteus medius is 

 continuous below and in front with that of Gluteus minimus, and frequently with that of Pyriformis 

 above and behind ; it divides this aspect of the trochanter into two areas, one, C, in front and above, 

 under cover of medius and therefore bevelled off in the direction of that muscle, the other, A , below 

 and behind, covered by Gluteus maximus and therefore moulded by that muscle so that it is more 

 vertically directed and curved from before backwards. The surface C carries a bursa, but A has only 

 occasionally an extension of the bursa situated below in relation with it. B, surface covered by Vastus 

 externus and more or less flattened by it. Crureus fuses with V. externus at a lower level. 3. Posterior 

 aspect. D, surface covered by Quadratus femoris ; deep to this muscle the Obturator externus lies 

 against the bone, moulding the back and lower part of the neck in the area F as it passes to the digital 

 fossa. 4. From the inner side. Observe the pointed area between the spiral line and pectineal line 

 which is occupied by Iliacus. E, inner surface, covered by Vastus internus but not affording origin 

 to it ; the Crureus does not transgress the inner border. 



The Small Trochanter is a traction epiphysis at the insertion of the tendon of the 

 Psoas (Fig. 118). The tendon is inserted into its inner rough aspect and, with the 

 Iliacus, into the front surface as well : the Iliacus is also inserted by muscular fibre into 

 the bone in front of and below its level, a triangular area bounded by the spiral 

 and pectineal lines. The back of the small trochanter gives attachment to no muscle, 

 but it is covered by a well-formed bursa which separates it from the top fibres of the 

 Adductor magnus,* into the substance of which it projects when the limb is inverted. 

 This projection can be felt in thin people when the limb is strongly inverted. The 

 plane of the shaft wall deep to the trochanter is strengthened, and forms a bony bar 

 or column visible on section (Fig. 116) and extending up into the neck : this is termed 

 the calcar femoralc, and is supposed to receive the weight transmitted through the head 

 and from thence by the cancellous arches to the shaft (see Fig. 125). Now articulate 

 the femur and the pelvis and see what the action of the Psoas would be in addition to 

 flexing the joint. Its tendon passes downwards over the front of the joint and turns 

 outwards and backwards to reach its insertion that is, it pulls on the femur outside 

 the position of the axis of rotation, which passes down through the joint nearly vertically. 

 It is therefore an internal rotator as well as flexor, but the rotating action is probably 

 very small. 



The Anterior Intertrochanteric Line (Fig. 118). 



The anterior intertrochanteric line marks the attachment of the ilio-femoral 

 band : the outer strong limb of the ligament goes to the tubercle at the upper end of the 

 line, the inner band to the lower end of the marking, and the intermediate thinner part 

 to the line in between. The line turns upwards and backwards for a little distance at 

 its lower end, this part of the marking being mostly made by pubo-femoral fibres, and 



* Occasionally also the lowest fibres of Quadratus femoris. 

 i A 10 



