226 



SPECIAL ANATOMY OF THE SKELETON 



and from before backward, and articulate with the corresponding surfaces of 

 the tibia. They are marked off from the trochlea by two irregular grooves. 

 The outer groove runs obliquely outward and forward from the anterior extremity 

 of the intercondyloid notch to the outer side of the external condyle. The inner 

 is less well marked and placed farther forward than the one on the external 

 condyle; it extends obliquely outward and backward. In the grooves the semilunar 

 cartilages fit when the knee is extended. The opposed surfaces of the condyles 

 form the lateral walls of the intercondyloid notch. 



Outer groove. 

 Older tuberosity. 



Inner groove. 



Inner tuberosity. 

 Semilunar area. 



FIG. 179. Lower extremity of right femur viewed from below. 



The outer surface of the external condyle presents, a little behind its centre, 

 an eminence, the outer tuberosity, or outer epicondyle (epicondylus lateralis] ; it is 

 less prominent than the inner tuberosity, and gives attachment to the external 

 lateral ligaments of the knee. Immediately beneath it is the popliteal groove 



(sulcus popliteus), which commences at a de- 

 pression a little behind the centre of the lower 

 border of this surface; the front part of this 

 depression gives origin to the Popliteus mus- 

 cle, the tendon of which is lodged in the 

 groove during flexion of the knee. The groove 

 is smooth, covered with hyaline cartilage in 

 the recent state, and runs upward and back- 

 ward to the posterior extremity of the condyle. 

 The posterior extremity is convex and smooth ; 

 just above and to the outer side of the artic- 

 ular surface is a depression for the tendon of 

 the outer head of the Gastrocnemius, above 

 which is the origin of the Plantaris. 



The inner surface of the inner condyle 

 presents a convex eminence, the inner tuber- 

 osity, or inner epicondyle (epicondylus medialis), 

 rough for the attachment of the internal lateral ligament. Just above the auric- 

 ular surface of this condyle, behind, is a depression for the tendon of origin of 

 the inner head of the Gastrocnemius. 



The intercondyloid notch is bounded laterally by the opposed surfaces of the 

 condyles, and lodges the crucial ligaments of the knee-joints. The inner wall 

 of the notch at its front part has attached to it the posterior crucial ligament. 

 The external wall at its upper and back part affords attachment to the anterior 

 crucial ligament. Above it is separated from the popliteal surface by a ridge 

 the linea intercondyloidea. 



FIG. 180. Scheme showing disposition of 

 principal cancellous lamellie in upper extrem- 

 ity of femur. 



