KNEE JOINT 411 



of the medial and lateral portions of the posterior part of the 

 capsule also, and from them it is prolonged anteriorly, along 

 the sides and round the front of the cruciate ligaments. In the 

 anterior part of the joint it is prolonged upwards, beyond 

 the articular surface of the distal end of the femur, in the 

 form of a great cul-de-sac, under cover of the tendon of the 

 quadriceps (Fig. 181). The proximal extremity of this cul-de-sac 

 usually communicates by an orifice of greater or less width 

 with the suprapatellar bursa. The synovial layer also invests 

 the menisci, and a pouch -like diverticulum is prolonged 

 posteriorly and distally, along the tendon of the popliteus, 

 which it partially ensheaths, across the posterior part of the 

 external border of the lateral meniscus to the posterior aspect 

 of the proximal end of the tibia. That prolongation lies in 

 close relation with the capsule of the tibio-fibular joint, and 

 in some cases a communication is established between the 

 cavity of the diverticulum and the cavity of the tibio-fibular 

 joint. 



Dissection. Divide the patellar synovial fold and remove 

 the infrapatellar pad of fat. Then open and examine the bursa 

 between the ligamentum patellae and the proximal part of the 

 tibia. Next dissect away the intermediate part of the posterior 

 portion of the capsule (oblique popliteal ligament) and trace the 

 middle genicular artery, which pierces it, forwards to the cruciate 

 ligaments. It will now be seen that the posterior surface of 

 the posterior cruciate ligament is not covered by the synovial 

 layer, and that it is connected by areolar tissue to the deep 

 surface of the posterior part of the fibrous stratum of the 

 capsule. Define the attachments of the cruciate ligaments by 

 removing the synovial layer which covers them at the sides and 

 in front, and the areolar tissue in connection with them. The 

 menisci also should receive the attention of the dissector, and the 

 manner in which their fibrous, pointed extremities are fixed to 

 the tibia must be studied. At this stage the changes produced in 

 the degree of tension of the cruciate ligaments, and the change 

 in the position of the menisci brought about by movements 

 of the joint, should be examined. 



Movements at the Knee Joint. The movements of the knee joint are 

 those of flexion and extension. The leg can be bent posteriorly until the 

 prominence of the calf comes into contact with the posterior aspect of the 

 thigh ; but in extension the movement is brought to a close when the leg 

 comes into a line with the thigh. In that position the joint is firmly locked, 

 and the anterior cruciate, the tibial and the fibular collateral ligaments, and 

 the posterior part of the capsule with the oblique popliteal ligament 

 being fully stretched, the leg and thigh are converted into a rigid column 

 of support. In flexion, however, the ligaments mentioned are relaxed, and 

 a certain amount of rotation of the tibia upon the femur is allowed. 



Flex the joint acutely, and examine the cartilage-covered surface of 

 the distal end of the femur. It consists of an anterior trochlear portion 



