433 



SURGICAL APPLIED ANATOMY. [Chap. xxi. 



Fluctuation is soon to be detected, and tlie patella, 

 being pushed away from the femur, is said to " float " 

 upon the distending fluid (Fig. 46). 



The inflamed knee-joint, if left to itself, almost 



Fig. 46. Vertical Section of Knee-joint distended with Fluid 

 (Braune). 



a, Vastus externus ; 6, crureus ; c, short head, and d, long head, of biceps ; e, plan- 

 taris : /, gastrocnemius; g, popliteus ; h, soleus; i, tibialis posticus ; j, bursa 

 patellae; k, ligamentum patellae ; I, ligamentum imicosum ; in anterior crucial 

 ligament; n, external semilunar cartilage; 1, external popliteal nerve; 

 2, popliteal artery. 



invariably assumes the flexed position. This may be 

 explained upon three hypotheses, and it is probable 

 that each of the three reputed factors takes part in 

 producing this position in cases of disease. 



(1) The capacity of the joint is increased on 



