247 



of the synovial membrane of the knee-joint and a bursa; from the upper part of it 

 the Articularis genu takes origin. The lateral surface includes the portion between 

 the lateral border and the linea aspera; it is continuous above with the correspond- 

 ing surface of the greater trochanter, below with that of the lateral condyle : from 

 its upper three-fourths the Vastus intermedius takes origin. The medial surface 

 includes the portion between the medial border and the linea aspera; it is continu- 

 ous above with the lower border of the neck, below with the medial side of the 

 medial condyle: it is covered by the Vastus medialis. 



The Lower Extremity (distal extremity] , (Fig. 246) . The lower extremity, larger 

 than the upper, is somewhat cuboid in form, but its transverse diameter is greater 

 than its antero-posterior; it consists of two oblong eminences known as the condyles. 

 In front, the condyles are but slightly prominent, and are separated from one another 

 by a smooth shallow articular depression called the patellar surface ; behind, they 

 project considerably, and the interval between them forms a deep notch, the 

 intercondyloid fossa. The lateral condyle is the more prominent and is the broader 

 both in its antero-posterior and transverse diameters, the medial condyle is the 

 longer and, when the femur is held with its body perpendicular, projects to a lower 



Lateral groove 

 Lateral epicondyle 



Medial groove 



Medial epicondyle 

 Semilunar area 







Fia. 246. Lower extremity of right femur viewed from below. 



evel. When, however, the femur is in its natural oblique position the lower sur- 

 'aces of the two condyles lie practically in the same horizontal plane. The condyles 

 ire not quite parallel with one another; the long axis of the lateral is almost 

 directly antero-posterior, but that of the medial runs backward and medialward. 

 Their opposed surfaces are small, rough, and concave, and form the walls of the 

 ntercondyloid fossa. This fossa is limited above by a ridge, the intercondyloid 

 line, and below by the central part of the posterior margin of the patellar surface. 

 The posterior cruciate ligament of the knee-joint is attached to the lower and front 

 part of the medial wall of the fossa and the anterior cruciate ligament to an impres- 

 sion on the upper and back part of its lateral wall. Each condyle is surmounted 

 by an elevation, the epicondyle. The medial epicondyle is a large convex eminence 

 to which the tibial collateral ligament of the knee-joint is attached. At its upper 

 part is the adductor tubercle, already referred to, and behind it is a rough impres- 

 sion which gives origin to the medial head of the Gastrocnemius. The lateral 

 epicondyle, smaller and less prominent than the medial, gives attachment to the 

 fibular collateral ligament of the knee-joint. Directly below it is a small depression 

 from which a smooth well-marked groove curves obliquely upward and backward 

 to the posterior extremity of the condyle. This groove is separated from the 

 articular surface of the condyle by a prominent lip across which a second, shallower 

 groove runs vertically downward from the depression. In the fresh state these 

 grooves are covered with cartilage. The Popliteus arises from the depression; 

 its tendon lies in the oblique groove when the knee is flexed and in the vertical 



