220 OSTEOLOGY. 
the neck from the shaft anteriorly (see ante). The whole constitutes what is known 
as the spiral line, and extends from the fore and upper part of the trochanter minor 
above to the linea aspera below. Intermediate in position between the spiral line 
in front and internally, and the gluteal ridge externally, there is a third line, 
the pectineal line (linea pectinea), which passes down from the trochanter minor 
and fades away inferiorly into the surface between the two lips of the linea aspera. 
Into this the pectineus muscle is inserted. About the junction of the middle with 
the lower third of the shaft the two lips of the linea aspera separate from one 
another, each passing in the direction of the condyle of the corresponding side. 
The lines so formed are called the inner and outer epicondy lic lines respectively, and 
enclose between them a smooth triangular area corresponding to the back of the 
lower third of the shaft; this, called the popliteal surface (planum popliteum), forms 
the floor of the upper part of the popliteal space. The continuity of the upper part 
of the internal epicondylic line is but faintly marked, being interrupted by a wide 
and faint groove along which the popliteal artery passes to ‘enter the space of that 
name. Below, where the line ends on the upper and inner surface of the internal 
condyle, there is a little spur of bone called the adductor tubercle, to which the 
tendon of the adductor magnus is attached, and behind which the inner head of the 
gastrocnemius muscle takes origin. 
The linea aspera affords extensive linear attachments to many of the muscles of the thigh. 
The vastus internus arises from the spiral line above and the inner lip of the linea aspera below. 
The adductor longus is inserted into the inner lip about the middle third of the length of the shaft 
The adductor magnus is inserted into the intermediate part of the line, extending as high as the 
level of the trochanter minor, where it lies internal to the insertion of the gluteus maximus. 
Below, its insertion passes on the internal epicondylic ridge, reaching as low as the adductor 
tubercle. The adductor brevis muscle is inserted into the linea aspera above, between the pec- 
tineus and adductor longus muscles internally and the adductor magnus externally. Below the 
insertion of the gluteus maximus the short head of the biceps arises from the outer lip as well as froin 
the external epicondy] ic line ; in front these also serve for the origin of the vastus externus muscle. 
The canals for the nutrient arteries of the shaft, which have an upward direction, are usually 
two in number, and are placed on or near the linea aspera—the upper one about the level of the 
junction of the middle and upper third of the bone, the lower some three or four inches below— 
usually on the inner side of the shaft, immediately in front of the inner lip of the linea aspera. 
The front and lateral aspects of the shaft are covered by, and furnish surfaces 
for, the origins of the vasti and crureus muscles. 
The lower extremity of the femur comprises the two condyles. ‘These are two 
recurved processes of bone, each provided with an articular surface, and separated 
behind by a deep intercondylic notch. United in front, where their combined 
articular surfaces form an area on which the patella rests, the two condyles differ 
from each other in the following respects: If the shaft of the bone be held vertically, 
the internal condyle is seen to reach a lower level than the external; but, as the 
femur lies obliquely in the thigh, the condyles are so placed that their inferior sur- 
faces he in the same horizontal plane. Viewed from below, the internal condyle is 
seen to be the narrower and shorter of the two. The external condyle is broader, 
and advances further forward and higher up on the anterior surface of the shaft. 
The intercondylic notch (fossa intercondyloidea) reaches forwards as far as a trans- 
verse line drawn through the centre of the external condyle. Its sides are formed 
by the inner and outer surfaces of the outer and inner condyles respectively, the 
latter being more deeply excavated, and displaying an oval surface near its lower 
and anterior part for the attachment of the posterior crucial ligament of the knee- 
joint. Placed high up, on the posterior part of the inner surface of the external 
condyle, there is a corresponding surface for the attachment of the anterior crucial 
ligament. The floor of the notch, which is pierced by numerous vascular canals, 
slopes upwards and backwards towards the popliteal surface on the back of the 
shaft, from which it is separated by a slight ridge (linea intercondyloidea) to which 
the posterior part of the capsule of the knee-joint is attached. 
The cutaneous aspect of each condyle (i.e. the outer surface of the external 
condyle and the inner surface of the internal condyle) presents an elevated rough 
surface, called the tuberosity (epicondylus), that of the internal (epicondylus 
medialis) being the more pronounced and outstanding from the line of the shaft ; 
capped above by the adductor tubercle, it affords attachment near its most pro- 
