1214 SURFACE AND SURGICAL ANATOMY. 
intertrochanteric line. The ilio-psoas crosses the anterior and the inner part of the capsule ; 
between the two is a bursa, which frequently communicates with the joimt through the thin part 
of the capsule internal to the ilio-femoral band ; it is by way of this communication that a psoas 
abscess occasionally gives rise to secondary tubercular disease of the hip-joint. One of the 
commonest situations to meet with an abscess in hip-joint disease is in the cellular tissue and fat 
under the tensor fascize femoris ; or the pus may pass below and to the mner side of the neck of 
the femur, and thence along the course of the internal circumflex artery to the back of the 
thigh. Yo tap or explore the hip-joint, the puncture should be made in the interval between the 
sartorius and the tensor fasciee femoris, 2 to 3 in. below the anterior superior iliac spine; if 
the instrument is then pushed upwards, inwards, and backwards beneath the tendon of the rectus, 
it will pass through the capsule a little above the anterior intertrochanteric line. Regarded 
from the point of view of dislocation, the regions of the cotyloid notch and of the inferior part 
of the capsule are the weak points in the joint; it follows, therefore, that abduction favours 
dislocation by bringing the head of the femur into relation with these two weak areas. 
THE KNEE. 
With the knee extended and the quadriceps relaxed, the patella can be readily 
outlined and moved from side to side upon the femoral condyles. On contracting 
the quadriceps its tendon springs 
forwards and is felt as a tense band 
_ above the patella; while the patellar 
Wp. ligament, which has become tense 
Sand prominent, may be traced to 
®.the lower part of the tubercle of 
“= the stibia. In front of the lower 
part of the patella and of the upper 
Vastus internus part of the patellar hgament is the 
pre-patellar bursa, into which effusion 
takes place in the condition known 
Quadriceps extensor as housemald’s knee. Beneath and 
tendon 
/ 
Gracilis¥ 
Sartofrass “&™ 
~ Vastus externus 
- Upper border of On either side of the patellar lga- 
patella i c es — oy. 
ment is a well-circumscribed pad 
Patella of fat, palpation of which gives rise 
to a feeling closely resembling true 
jis) fluctuation. In extension, only the 
Internal condyle 3 > : 5 cos ‘ 
Internal semiiunar lower pair of articular facets of the 
Ticumectum patetie Patella are in contact with the 
BT pete trochlear surface of the femur. In 
Internal tuberosity semiflexion the middle pair of facets 
He see Baie rests upon the trochlea; in this 
position the imner margin of the 
Tubercle of tibia internal condyle, the upper border 
of the inner tuberosity of the tibia, 
and the lower part of the patella 
Inner border of tibia are all distinctly visible, and to- 
Chae oman vether bound a triangular depres- 
sion, which overlies the line of the 
joint and contains the anterior part 
of the internal semilunar cartilage : 
Soleus it is in this triangle that the surgeon 
searches for a displaced or thickened 
internal semilunar cartilage, for a 
loose body, and for “ lipping” of the 
edge of the articular cartilage in 
chronic osteo-arthritis. A sinilar, 
but less well defined, triangle may 
be felt immediately external to the 
lower edge of the patella. When 
the quadriceps is thrown into sudden or violent contraction, as in preventing 
oneself from falling backwards, the patella may be transversely fractured at the 
~ Tlio-tibial band 
Gastroenemius 
Fic. 818.—ANTERIOR ASPECT OF KNEE. 
