THE FEMUR. 



123 



that of the anterior ligament occupies the hindmost part of the inner surface of the 

 external condyle, while that of the posterior ligament is at the inner and fore part 

 of the fossa, above the curved portion of the internal tibial articular surface. 



The head and neck of the femur are deeply placed ; the great trochanter is 

 covered only by the aponeurosis of the gluteus maximus, and is readily felt, forming 

 the most prominent part of the hip. The shaft is thickly surrounded by muscles. 

 The condyles are subcutaneous on each side of the knee, the internal being especially 

 prominent ; the trochlear surface is concealed by the patella during extension, but 

 in the flexed limb its form can be traced pushing up the muscular covering. 



The arrangement of the cancellous tissue at the upper end of the femur is shown in 

 fig 1 . 136. A system of " pressure-lamellae," springing from the compact wall of the lower 

 side of the neck and the upper end of the shaft internally, ascends radiating inwards to the 

 head and outwards to the great tro- 

 chanter ; those passing to the head are 

 especially dense. These are crossed at 

 right-angles by a set of "tension-la- 

 mella?," which start from the outer side 

 of the shaft, and ai'ch upwards and 

 inwards to the head and inner side of 

 the neck. The concave side of the neck 

 is farther strengthened by a nearly 

 vertical plate of compact tissue (calcar 

 femorale 1 ), which projects upwards into 

 the spongy substance a little in front 

 of the small trochanter. At the lower 

 end of the bone the chief lamellas run 

 vertically from the compact wall of the 

 shaft to the tibial articular surfaces. 



The average length of the femur in 

 the European male is a little more than 



18 inches, in the female about 17 inches. Fi S- I^.-TRANSVERSE SECTION OF THE FEMUR 



It equals about -275 of the stature, and SWATJSLT ABOVE THE SMALL TROCHANTER. (G. D. T. ) 

 its proportion to the humerus is as 100 : 71. 



In the erect attitude the inclination of the femur is such that the shaft forms an angle of 

 about 9 with the sagittal plane, and 5 with the frontal plane ; the former angle is larger 

 in the female than in the male. The femur also exhibits a torsion similar to that of the 

 humerus, but usually in the opposite direction, the head being inclined forwards from the 

 transverse axis of the lower extremity : the angle of torsion varies within wide limits, but is 

 in the majority of cases between 5" and 20 (Mikulicz, Arch. f. Anat., 1878). 



The angle between the neck and shaft of the femur varies much in different individuals, 

 ranging in the adult from 110 to 140. It is as a rule smaller in short than in long thigh- 

 bones, and in women than in men. It is more open in the foetus and child, and decreases 

 during the period of growth under the influence of the weight of the body ; but it does not 

 appear to undergo any change after growth is completed (Humphry, Journ. Anat., xxiii, 

 273). 



Varieties. The upper part of the gluteal ridge is sometimes very prominent, forming a 

 third trochanter similar to the process so named in the horse and some other animals. In 

 some cases there is a hollow, fossa hypotrochanterica? in place of or in addition to the ridge. 

 A marked development of the linea aspera gives rise to the condition known as the pilastered 

 femur. The adductor tubercle may be of unusual size, and has been seen forming a projection 

 three-quarters of an inch in length. 



1 Merkel, Yirchow's Arehiv, lix. 



2 Houze, Bull. deJa Soc. d'Anthrop., Eruxelles, 1883. 



