REGION OF THE KNEE. 



533 



The position of the femoral artery will depend on the point at which the amputation 

 is made. It does not lie close to the bone until the popliteal space is reached. 

 Bleeding from the perforating arteries along the linea aspera should, however, be 

 looked for and the sciatic nerve should be isolated and cut short. 



REGION OF THE KNEE. 



SURFACE ANATOMY. 



The bony landmarks are the patella, the two condyles of the femur, the tibia, 

 and the fibula (Fig. 543). 



The patella is pointed below where the tendo patellae is attached, is slightly 

 convex on its upper border, and its lateral edges are prominent, especially the 

 outer. It usually has little tissue 

 over it. With the limb extended and 

 quadriceps relaxed the patella can 

 be moved laterally. There is a hol- 

 low above the patella. When the 

 muscle contracts this hollow is filled 

 up by the rectus, and the muscular 

 swells on each side produced by the 

 vastus internus and externus are 

 visible. When the quadriceps mus- 

 cle is contracted the tense tendo 

 patellae becomes evident, when re- 

 laxed the soft fatty pad beneath the 

 tendon can be felt. 



About midway between the 

 patella and tubercle of the tibia on 

 each side can be felt a groove which 

 indicates the line of the joint and 

 the location of the semilunar carti- 

 lages. On the outer side posteriorly 

 opposite the level of the tibial tuber- 

 cle can be felt the head of the fibula. 

 Running upward from it is the ten- 

 don of the biceps. In front of the 

 biceps can be seen and felt the ilio- 

 tibial band. It is difficult to distin- 

 guish the joint-line on the sides, 

 therefore it is better to locate it by 

 recognizing the sulci anteriorly on 

 each side of the tendo patellae; flex- 

 ing the knee makes these depres- 

 sions more distinct. The joint on 

 the outer side is about 2 cm. (^ in. ) 

 above the head of the fibula. 



Posteriorly, with the leg ex- 

 tended, the condyles of the femur can readily be outlined; the inner is the more 

 prominent. The upper edge of their articular surfaces can be felt on firm pressure 

 at the sides, and the inner leads to the adductor tubercle, into which the adductor 

 magnus tendon is inserted this tendon can likewise frequently be felt. The tubercle 

 of the tibia can best be seen and felt when the tendo patellae is relaxed. It is about 

 4 cm. (i^ in.) below the patella. Just above and to its outer side, about 4 cm. 

 (i^ in.) distant, is the external tuberosity of the tibia; into it is inserted the lower 

 end of the iliotibial band. To the outer side at a little lower level can be seen and 

 felt the head of the fibula. On the inner side is the flat rounded internal tuberosity 

 of the tibia. Posteriorly is seen the fulness of the popliteal space; on its outer side 

 the tendon of the biceps is readily felt and running with it is the external popliteal 



Head of fibula 



FIG. 543. -Surface anatomy of the knee. 



