Fig. 176. Left Knee-joint and Surrounding Parts. Seen from the 



outer side. 



Preparation made from a female aged 75 years. Plaster of Paris had been 

 injected into tlie Knee-Johit. Boundaries of the Joint-Cavity (pink) ; the Tibia- 

 Fibular Articulation which does not communicate with the knee-joint, dark red. 

 The independent biirsae around the knee-joint (blue). The lower parts of the 

 Vastus Externus and Biceps Muscles have been removed; the attachment of the 

 Ilio-Tibial Band and the insertion of the Biceps into the Head of the Fibula 



and into the Tibia are preserved. 



The Fascia Lata of the thigh is continuous with the Fascia enclosing the 

 leg, and is reinforced by a broad strand of fibres the Ilio-Tibial Band of Maissiat, 

 which is derived from the Tensor of the Fascia of the Thigh and some fibres of 

 the Gluteus Maximus Muscle; this Band runs down to the Tibia, and blends with 

 the Capsule of the Knee-joint. It checks Adduction of the Thigh. The figure 

 shews the extent of the Knee-joint Cavit}' and of the upper cul-de-sac, which 

 practically always communicates with it, distended as is the case in serous, purulent 

 or haemorrhagic exudations. One observes that the greatest extension of the joint 

 is possible in the forward direction. A tense effusion pushes the Patella and the 

 Common Extensor Tendon away from the bones, so that, under these conditions, 

 the Patella is not in contact with the underlying bones but rides or dances on 

 the fluid. Laterally no great degree of bulging is possible, firstly, because the 

 Synovial Cavity does not reach far eitlier upwards or downwards over the joint- 

 slit ; secondly, because the extremely strong lateral ligaments are tightly stretched. 

 Posteriorly around the Condyles of the Femur, the capsule is more extensible. 



In addition to the Prepatellar Bursa (cf. explanation to Fig. 181), and the 

 deep Infrapatellar Bursa, which lies between the Tibia and the Ligament of the 

 Patella, the almost constant External Inferior Bicipital Bursa is shewn lying be- 

 tween the Biceps Tendon and the External Lateral Ligament. Like the bursa 

 above mentioned, this never communicates with the Knee-joint. 



Further, the vessels which take part in the anastomosis on the outer side 

 of the knee-joint are visible. 



The blood-supply of the Anterior Aspect of the Joint which has to bear 

 much pressure (e. g. in kneeling) is abundant. 



On the inner side, the Superior and Inferior Internal Articular Arteries, 

 on the outer side, the Superior and Inferior External Articular Arteries, form the 

 Anastomosis which is reinforced by the Great Anastomotic Artery, and the 

 Recurrent Tibial Artery. 



The Anastomosis is partly superficial between the Patella and the Skin, 

 partly deep between the Tendons and the Ligaments. 



