3 i6 



INFERIOR EXTREMITY 



by areolar tissue to the deep surface of the posterior part of the capsule. 

 Define the attachments of the crucial ligaments by removing the synovial 

 membrane which is wrapped round them and the areolar tissue in connec- 

 tion with them. The menisci should also 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 crucial ligaments, and the change brought 

 about in the position of the menisci 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 



Adductor magn 



Popliteal art 

 Semimembranosus 



Medial head of 

 gastrocnemius 



Inferior medial 

 artery of knee 



Popliteal vein 



Popliteus 

 Popliteu 



Synovial bursa 



.Common tendon of 

 quadriceps 



ynovial membrane 

 Patella 



Femur 



Infra-patellar 

 pad of fat 



Deep infra-patellar bursa 



Ligamentum 



patellae 



.Tibia 



FIG. 117. Vertical antero-posterior section through the Knee-joint. 



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

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

 the posterior part of the capsule with the accessory 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. 



But the movements of flexion and extension at the knee-joint are by no 

 means so simple as at first sight they might appear to be, and to obtain 

 some appreciation of them it is necessary to subject the opposed articular 

 surfaces to a close scrutiny. Flex the joint acutely, and examine the 

 cartilage-covered surface of the distal end of the femur. It consists of an 

 anterior trochlear portion for the patella, and two condylar surfaces which 

 move on the tibia. The trochlea is separated from the surface of the 

 lateral condyle by a faintly marked groove, which takes a slightly curved 

 course, from the lateral border of the distal end of the femur, medially and 

 posteriorly to the fore part of the intercondylar fossa. At either extremity 



