THE LIMB IN SECTION 29 



into the lower end of the groove, which runs vertically down the front of 

 the anterior tuberosity, whilst the internal ligament is inserted into the 

 inner portion of the anterior tuberosity, slightly below the level of the 

 section. 



In the interval between the portion of the anterior tuberosity repre- 

 sented and the anterior aspect of the external tuberosity, is a well-defined 

 tendon surrounded by a plainly visible sheath. This is the tendon 

 which is common to the extensor pedis, and the superficial or tendinous 

 division of the flexor metatarsi muscle. It arises from the deep pit 

 which is placed between the outer lip of the trochlea and the external 

 condyle of the femur. The tendon is thick and very powerful, 

 and is not attached to either of the two tibial tuberosities mentioned, 

 but plays freely through the notch between them. 



The articular surface of the external tibial tuberosity is usually 

 referred to as being saddle-shaped. It is separated from the tibial spine 

 by a roughened area which affords attachment to ligaments already 

 described. To the outer surface of this tuberosity the external lateral 

 ligament of the stifle is attached. The ligament is plainly visible in the 

 Plate, and the position of its attachment is represented on the dried bone 

 by a roughened area just below the articular surface. 



Posteriorly the joint is closed by the posterior common liga- 

 ment. It is attached to the back of the posterior tuberosities of the 

 tibia. 



Lying on the posterior surface of the ligament, and consequently in 

 intimate relationship to the joint are two large vessels, the outer 

 and smaller is the pophteal artery, whilst the inner is the popliteal 

 vein. It will be noticed that the vessels are covered posteriorly 

 by a muscle, which stretches across the back of the joint. This is the 

 popliteus muscle, the tendon of origin of which arises from the more 

 inferior of the two roughened depressions on the outer side of the 

 external condyle of the femur. 



Crossing the popliteus muscle, and placed almost in the median 



