CHAPTER XXXV. 

 THE REGION OF THE KNEE JOINT. 



MOVEMENTS. TUBERCULOSIS. 



LANDMARKS. MOVABLE BODIES. 



ANTERIOR BURS^ PATELLA. 

 SYNOVITIS. DISLOCATION. 



OPERATIONS. 



One would be led to think, on examining the skeleton, 

 that dislocation at the knee joint would be very common, 

 since this joint is formed by the large, lower extremity of 

 the femur resting upon the tibia, and is not protected, in 

 the same manner, as is the 'hip or elbow joint; but the 

 great strength imparted to the articulation by the powerful 

 ligaments connected with it, causes displacement to be, re- 

 latively, very rare. The space left between the ligamen- 

 tum patellae and the lateral ligaments, in front of 

 the joint, is filled up with the capsular ligament, 

 strengthened by lateral prolongations, or accessory bands, 

 from the extensor tendons, while, behind, the posterior 

 ligament is augmented by a number of fasciculi from the 

 semi-membranosus tendon, and, further, the two crucial 

 ligaments in the interior of the joint give additional 

 strength to the articulation and are important factors in 

 preventing dislocation. 



The Movements permitted at the knee joint are 

 flexion and extension, accompanied by a slight amount of 

 rotation. Flexion and extension result from the gliding 

 of the tibia beneath the femoral condyles, but the charac- 

 .ter of these movements causes them to differ from the 

 movements permitted in a pure hinge joint, like the hume- 

 ro-ulnar articulation. In the latter joint, the ulna moves 

 on a stationary axis, passing through the trochlear surface 



