THE KNEE-JOINT 



255 



femur, to the inner border and internal surface of the shaft of the tibia, an inch and 

 a half (8-7 cm. ) below the tuberosity. It is three inches and a half (87 cm. ) long, 

 well defined anteriorly, where it l)lends with the expansion of the conjoined extensor 

 tendons; but not so Avell defined posteriorly, where it merges into the posterior 

 ligament. Some of the lower fibres blend with the descending portion of the seint- 

 memhranoms tendon. Its deep surface is firmly adherent to the edge of the internal 

 semilunar cartilage and coronary ligament, while part of the semimembranosus tendon 

 and inferior internal articular vessels and ner've pass between it and the bone. Super- 

 ficially, a liursa separates it from the tendons of the gracilis and semitendinosus 

 muscles and from the aponeurosis of the sartorius muscle. 



The external lateral ligament (fig. 245) consists of two portions: the anterior, 

 which is the longer and better marked, is a strong, rounded cord, about two inches 

 (5 cm. ) long, attached above to the tubercle on the outer side of the external con- 



FiG. 245. — Posterior View of the Knee-joint. 



Outer head of gastroeuemius 



External lateral ligament 

 anterior portion 



Posterior part of external 

 lateral ligament 

 Tendon of popliteus 



Tendon of biceps 



Posterior superior tibio- 

 fibular ligament 



Tendon of adductor magnus 



Inner head of 

 gastrocnemius 



Tendon of semi-membra- 

 nosus with its slip to 

 thicken the posterior liga- 

 ment 



Internal lateral ligament 



dyle of the femur, just below and in front of the origin of the outer head of the 

 f/astrocnemius, whilst the tendon of the popliteus arises from the groove below and in 

 front of it. Below, it is fixed to the middle of the outer surface of the head of the 

 fibula, half an inch (1-25 cm.) or more anterior to the styloid process. Super- 

 ficially is the tendon of the biceps, which splits to embrace its lower extremity; 

 while beneath it pass the popliteus tendon in its sheath, and the inferior external 

 articular vessels and nerve. Some fibres of the peroneus longus occasionally arise 

 from the lower end of the ligament. The posterior jiortion is a third of an 

 inch (8 mm.) behind the anterior. It is broader and less defined; fixed below to 

 the styloid process, it inclines u])wards and somewhat Ixackwards, and ties down the 

 popliteus against the outer tuljerosity, l)lending beneath tlie outer head of the r/a-s- 

 trocnemius with the ])osterior ligament of the knee, of which it is really a portion. 



The posterior ligament or ligamentum Winslowii (fig. 245) is a broad dense 

 structure of interlacing fibres, with large orifices for vessels and nerves. It is 



