ARTICULATIONS. 



tilages to the circumference of the tibial head, while a round 

 band (transverse ligament) passes between their anterior con- 

 vex margins. [301] 



The synovial membrane, beside lining the capsule, covers the 

 deep surface of the common extensor tendon and extends above 

 the patella. Over the fatty pad (infra-patellar) in the interval 

 between the femur, tibia, and patella, it extends in a band (liga- 

 mentum mucosum) from the front of the intercondyloid notch 

 to below the level of the patellar facet, its lower part expand- 

 ing on each side in fatty fringes (alar ligaments). It covers 

 the surfaces of the nbro-cartilages and the parts of their outer 

 margins not attached to the capsule. It invests the intracap- 

 sular part of the Popliteus tendon and separates this from the 

 tibia. A prolongation from behind partly covers the crucial 

 ligaments. [302] 



The joint cavity may communicate with the superior tibio- 

 fibular joint, with bursse under the inner head of the Gastroc- 

 nemius and the Semi-membranosus tendon, and with a bursa 

 (supra-patellar) above its extension upward under the Quad- 

 riceps extensor. [303] 



Tibio-fibular Joints. These are arthrodial, with but little 

 motion. [304] 



The superior joint is between the facets on the head of the 

 fibula and tuberosity of the tibia, and may communicate with 

 the knee joint. It has a capsule which is lined by a synovial 

 membrane, and presents the following special bands: anterior 

 superior tibio-fibular ligament, running from the front of the fib- 

 ular head, upward and inward to the adjoining part of the tu- 

 berosity ; and posterior superior tibio-fibular ligament, running 

 from the back of the fibular head, upward and inward to the 

 back of the tuberosity, just below the orifice for the Popliteus 

 tendon in the knee-joint capsule. [304] 



The interosseous membrane acts as an accessory ligament for 

 both joints and connects the interosseous borders of the tibia 

 and fibula. Its fibres run chiefly downward and outward. It 



[263] 



