Fig. 184. Popliteal Space. 



The immediate continuation of the Fascia Lata is known as the Popliteal 

 Fascia which, after covering the Popliteal Space, becomes directly continuous with 

 the Fascia of the leg. On this lies the Short Saphenous Vein which sinks into 

 the Popliteal Space and opens into one of the Popliteal Veins. After removal of 

 this fascia, the Popliteal Space is exposed. This space is formed by the diverging 

 Flexors of the leg (Biceps on the outer side inserted into the Head of the Fibula, 

 Semimembranosus and Semitendinosus on the inner side inserted into the Crest of 

 the Tibia), while out of the depth of the space, emerge the two converging heads 

 of the Gastrocnemius. In this way a lozenge-shaped space is formed (void of 

 muscles), which contains, well surrounded by fat, the Large Vessels and Nerves. 

 The most superficial structure is the Internal Popliteal Nerve which traverses the 

 space almost vertically, to di.sappear, after giving off its Communicating Tibial 

 Branch, under cover of the Gastrocnemius Muscle. The division of the Great 

 Sciatic Nerve into Internal and External Popliteal Nerves, has occurred at about 

 or above the middle of the thigh. While the Internal Popliteal Nerve passes 

 almost verticall}' downwards in the middle line, the External runs downwards and 

 outwards along the inner border of the Biceps Muscle. 



Somewhat internal and on a deeper plane is situated the Popliteal Vein, 

 i. e. the largest of the 2 or 3 Veins which accompany the Artery; this vein is 

 closely bound down to the Artery b}' connective-tissue. The Artery lies at a still 

 deeper plane and more towards the middle of the space, it is here separated by 

 a layer of fat, 72 inch thick, from the Femur; near the articular surfaces of the 

 Tibia it is closely applied to the capsule of the joint. Now the artery, having left 

 the middle line, lies somewhat to the outer side (cf. Fig. 181). In cases of Excision 

 of the Knee-joint, it could only be wounded at this spot. Its branches are the 

 Superior and Inferior Internal and External Articular Arteries and the Azygos 

 Articular Artery which pierces the posterior waU of the Capsule. 



Close to the Internal Popliteal Nerve, is a small L)'mphatic Gland: another 

 may lie subcutaneously on the fascia, but there are rarely ever more than 4 

 (cf. Figs. 182, 183). 



This figure also shews the Bursa under the Inner Head of the Gastro- 

 cnemius Muscle, which may communicate with the Knee-joint (Fig. 179). (Cf. Figs. 182 

 and 183, Text.) 



This is of importance, because this Bursa may be the seat of a Hygroma 

 which needs removal. It is, therefore, possible to infect the Knee-joint during an 

 operation on this Bursa. 



