THE KNEE 



1447 



fingers are insinuated beneath each border. (2) The pull of the extensor upon the patella, 

 ligamentum patellte, and tibia is somewhat laterally, as the tibia is directed a httle laterally 

 to the femur, to meet the medial direction of this bone; the femora being directed medially here, 

 to bring the knee-joints nearer the centre of gravity, and, so, counterbalance their wide separa- 

 tion above at the pelvis. The lateral pull of the quadriceps upon the patella is, in all normal 

 action of the muscle, counteracted by the space taken in the trochlear surface by the lateral 

 condyle, this being wider and creeping up higher, and having a more prominent and thus pro- 

 tective Up. In violent contraction, however, these counteracting points may be overcome. 



The condyles of the femur and tibia. — It should be noted that on the medial 

 side the prominence of the medial epicondyle of the femur is well marked, and that 



Fig. 1165. — Knee-joint as shown by the Rontgen-rays, Lateral View. 



of the tibia is less so, while on the lateral side this condition is reversed. Descend- 

 ing to the lateral condyle of the tibia, the iho-tibial band of the fascia lata can be 

 traced. The more distinct lateral condyle is a good landmark for opening the 

 joint in amputation and excision. It also indicates the lower level of the synovial 

 membrane of the knee-joint. 



Farther back are the biceps and fibular collateral (long external lateral) Ugament. The gap 

 on the medial side between the femoral and tibial condyles is the place for feeling for a displaced 

 medial fibro-cartilage in 'internal derangement' of the knee, and also for 'Upping' in suspected 

 osteoarthritis. On each femoral epicondyle, posteriorly, in a thin subject, can be felt its tubercle, 

 which gives attachment to the collateral ligament. Owing to their being placed behind the 

 centre of the bone, these Ugaments become tight in extension. On the upper and posterior 



