THE FEMUR. 221 
minent point to the fibres of the internal lateral ligament of the knee-joint. The 
external tuberosity (epicondylus lateralis), less pronounced and lying more in line 
with the outer surface of the shaft, is channelled behind by i 
| a curved groove—the lower rounded lip of which serves to ie 
separate it from the inferior articular surface. This eroove | 
ends in front in a pit which is placed just below the most 
| salient point of the tuberosity ; hereto is attached the tendon 
of the popliteus muscle, which overlies the lower lip of the 
groove in the extended position of the joint, but slips into 
and occupies the groove when the joint is flexed. Behind 
the most prominent part of the external 
tuberosity, and just above the pit for the 
attachment of the popliteus, the external 
lateral ligament of the knee-joint is 
attached, whilst superior to that there 
is a circumscribed area for the origin of — Gastroenemius 
the tendinous part of the outer head of — surface for the 
attachment of. ff 
the gastrocnemius muscle. jiteenie: ie 
The articular surface on the lower ex- ; ; _- hy 
e 5 . oo. . zroove Tor : 
tremity is divisible into three parts— tendo gee 
popliteus 
Plantaris — 
that which corresponds to the inferior 
| surface of the shaft and which is formed 
Popliteus 
Fic. 163.—LowkER END oF RicHT FEMUR (Outer Side). 
by the coalescence of the two condyles 
in front, and those which overlie the 
under and hinder aspects of each of those processes. The former is separated from 
the latter by two shallow oblique grooves which traverse the articular surface 
from before backwards, on either side, in the direction of the anterior part of the 
intercondylic notch. These furrows are the impressions in which fit the fore-parts 
of the internal and external semilunar cartilages of the knee-joint respectively when 
the knee-joint is extended. The anterior articular area or trochlea (facies patellaris) 
is adapted for articulation with the patella. Convex from above downwards, it 
displays a broad and shallow central groove, bounded on either side by two slightly 
convex surfaces. Of the two sides, the external is the wider and more prominent 
and rises on the front of the bone to a higher level than the internal. The 
condyloid or tibial surfaces are convex from side to side, and convex from 
before backwards. Sweeping round the under surface and posterior extremities of 
PATELLAR SURFACE the condy les, they descr be 
Impression ofa, spiral curve more open 
lunar cartilage jn front than behind. 
The inner condyloid arti- 
Sie oe cular surface 18 narrower 
FATELEAR FACET than the outer, and when 
viewed from below is also 
seen to describe a curve 
ee around a vertical axis. 
TipraL surFAcE The articular surface of 
the external condyle is 
inclined obliquely from 
before backwards and 
eel Sughtly ‘outwardsyiiihe 
surfaces of the condyles 
above the articular area 
posteriorly are confluent superiorly with the popliteal surface of the shaft; from 
these areas the heads of the gastrocnemius muscles arise. ‘The bone from which the 
inner head of the muscle springs is often elevated in the form of a tubercle placed on 
the lower part of the popliteal surface of the shaft, just above the internal condyle. 
The proportionate length of the femur to the body height is as 1 is to 3°55—3°92. 
Impression of 
external semi- 
lunar cartilage 
EXTERNAL 
TUBEROSITY 
POPLITEAL 
GROOVE 
EXTERNAL 
TIBIAL SURFACE INT. CONDYLE 
EXT. CONDYLE 
INTERCONDYLIC NOTCH 
Fic. 164.—Lowrr Enp oF RIGHT FEMUR AS SEEN FROM BELOW. 
Arterial Foramina.— Numerous vascular canals are seen in the region of the neck, at the 
bottom of the digital fossa, on the posterior intercondylic ridge and on the external surface of 
