THE LOWER LIMB 



539 



two) articular branches, one with the superior internal articular 

 artery (inconstant), one with the central or azygos articular, and 

 one with the inferior internal articular. 



The anterior femoral nerve furnishes articular branches as follows: 

 (i) the nerve to the vastus externus furnishes one articular 

 branch ; (2) the most internal of the branches to the crureus 

 furnishes another articular branch, which in its course supplies 

 the subcrureus ; and (3) the nerve to the vastus internus furnishes 

 a third articular 



branch, which is 

 of large size, and 

 ultimately accom- 

 panies the deep 

 branch of the 

 anastomotica magna 

 artery. 



The obturator 

 nerve, by its deep 

 or posterior division, 

 furnishes an articular 

 branch called the 

 geniculate nerve. 

 This branch, how- 

 ever, may be absent. 



If the nerve-supply 

 of the knee-joint is 

 compared with that 

 of the hip-joint, it 

 will be evident that 

 there is a nervous 

 sympathy between 

 these two articula- 

 tions. 



Anastomotica Magna 

 (Deep Branch) 



Superior 

 Internal Articular 



Superior 

 xtemal Articular 



Inferior Int 

 Articular 



Inferior 

 -Ext. Articular 



Head of Fibula 



Anterior Tibial 

 Recurrent 



Fig. 257. — The Deep Anastomoses round the 

 Knee-Joint (Anterior View) (Tiedemann). 



Movements — Femoro- 

 tibial Joints. — The 



movements between the 

 condyles of the femur 

 and the condylar ar- 

 ticular surfaces of the 

 tibia are of two kinds, 

 namely, flexion and ex- 

 tension, and rotation, the latter movement being only possible when the 

 knee-joint is flexed. 



Flexion and Extension. — These movements are complicated by the spiral 

 outUne of the femoral condyles, and they partake partly of gliding and partly 

 of rolling. During extension the two condyles move parallel to each other 

 up to a certain stage, namely, towards the end of extension. When this 

 stage has been reached, the anterior part of the outer condyle is in contact 

 with the outer tibial articular surface. The inner condyle, however, being 

 longer than the outer, continues to glide backwards so as to bring its oblique 

 anterior part into contact with the inner tibial articular surface. The result 

 is that the femur is rotated inwards on the tibia. Hence, at the very com- 



