348 Anatomy Applied to Medicine and Surgery. 



Burs it is affecting the Popliteal Bur see. On the 

 outer side of the popliteal space there are four bursae: (1) 

 One beneath the outer head of the gastrocnemius; (2) 

 one between the biceps tendon and the external lateral 

 ligament of the knee joint ; (3) one between this ligament 

 and the popliteus tendon ; (4) one between the latter ten- 

 don and the outer condyle of the femur. On the inner 

 side five are usually found: (1) One beneath the gastroc- 

 nemius, sending a projection between it and the semi- 

 membranosus ; (2) one beneath the sartorius, gracilis and 

 semi-tendinosus and between them and the internal liga- 

 ment; (3) one between this ligament and the tendon of 

 the semi-membranosus ; (4) one between the latter muscle 

 and the head of the tibia; (5) one between the tendon of 

 the semi-membranosus and that of the semi-tendinosus. 

 Of those on the inner side of the space, the most important 

 is the one beneath the inner head of the gastrocnemius 

 and between it and the semi-membranosus. This was 

 found affected twenty times out of thirty cases of bursitis 

 in this region collected by Foucher; while, of the outer 

 bursse, the one beneath the biceps tendon is also of practi- 

 cal importance, since it is situated beneath the tendon, just 

 above the head of the fibula, and the external popliteal 

 nerve is stretched over it, so that, symptoms of disturb- 

 ance of this nerve, such as numbness, pain, etc., may pre- 

 sent themselves when this bursa is inflamed. 



When the bursa between the gastrocnemius and the 

 semi-membranosus is enlarged, it may be mistaken for a 

 popliteal aneurism. This bursa often communicates with 

 the knee joint, since, as Foucher found, out of twelve 

 cases of inflammation of this bursa, a communication with 

 the joint was present in six of them. When enlarged, it may 

 extend inwards towards the middle line of the space, and, 

 receiving pulsation from the popliteal artery, may simu- 



