254 SURGICAL ANATOMY OF THE 



belongs to the lower third of the thigh, the knee-joint, 

 and the upper portion of the leg, is conveniently associa- 

 ted with the surgical anatomy of the knee. 



Surface Markings. If the leg be extended on the thigh, 

 from above downwards, in front is the tendon of the 

 quadriceps extensor, in which lies subcutaneously the 

 patella, from the lower border of which descends the 

 ligamentum patellae passing to its insertion in the tuber- 

 cle of the tibia; on either side of the quadriceps extensor 

 tendon is a deep furrow, between it and the vasti muscles. 

 In cases of synovitis, this furrow is obliterated, owing to 

 the collection of fluid causing the synovia! membrane to 

 bulge beneath the tendon. If the leg be flexed^ the 

 condyles of the femur, and the interspace between them, 

 are very evident, and the patella fills up the interval 

 between the femur and the tibia, tuberosities of which are 

 readily seen. In front of the patella and ligameutum 

 patella? the integument is slightly raised at a spot corre- 

 sponding with the bursa patellae. 



Posteriorly , during complete extension the surface of 

 the popliteal space is convex, and the positions of the 

 muscles which bound it, although evident, are not so pro- 

 nounced as when flexion commences ; the most salient 

 tendon is that of the semi-tendinosus. The position of 

 the external and internal popliteal nerves lying in the 

 middle of the space is easily seen during extension, as, 

 being put on the stretch, they lie immediately beneath 

 the integument, and resemble tendons. Externally, the 

 knee presents a depression, formed by the obliquity of 

 the axes of the femur and tibia, the deepest part of 

 which corresponds with the position of the outer interar- 

 ticular fibro-cartilage. Above this is the external con- 

 dyle of the femur, below the external tuberosity of the 



