The Popliteal Space. 347 



Landmarks. For the Popliteal Artery. To repre- 

 sent the upper part of the popliteal artery, draw 

 a line from the outer border of the semi-mem- 

 branosus at the junction of the middle and lower 

 thirds of the thigh, obliquely downwards to the 

 middle of the popliteal space opposite the line of the knee 

 joint. The lower part of the vessel would be represented 

 by a line joining the lower end of the above line with a 

 point opposite the lower border of the tubercle of the 

 tibia, since this is the landmark for the termination of the 

 vessel. Landmarks for the superior articular arteries. 

 A line passing transversely from the line of the artery, on 

 either side, immediately above the condyles of the femur. 

 For the inferior internal articular vessel. Draw a trans- 

 verse line inwards from the line of the artery and pass- 

 ing immediately below the inner tuberosity of the tibia, 

 while for the inferior external articular, draw a line out- 

 wards, from the line of the popliteal, immediately above 

 the head of the fibula. Landmarks for the internal popli- 

 teal nerve. Draw a line downwards in the course of the 

 continuation of the great sciatic nerve, already referred to, 

 and crossing the line for the popliteal artery opposite the 

 line of the joint. For the external popliteal nerve. Draw 

 a line from the preceding, starting about opposite the 

 junction of the middle and lower thirds of the thigh, and 

 continue it downwards and outwards to a point, a little in 

 front and outside of the styloid process of the fibula. The 

 lines for the nerve, artery and vein correspond in the mid- 

 dle of the popliteal space opposite the joint line, but, 

 above, the line for the nerve is a little over half an inch 

 external to the commencement of the artery, so that the 

 order of the chief structures found in the upper part of 

 the popliteal space is, both from behind forwards and from 

 without inwards nerve, vein and artery. 



