KNEE-JOINT. 



225 



g 



sion behind the spine of the tibia, and to the posterior extremity of the external 



semilunar fibre-cartilage ; passing upwards, forwards, and inwards, it is inserted 



into the outer and fore part of the inner condyle of the femur. As it crosses the 



anterior crucial ligament, a fasciculus is 



given off from it, which blends with its Fig ' 141 - R 'g ht 



posterior part. It is in relation, in front, 



with the anterior crucial ligament ; behind, 



with the ligamentum posticum Winslowii. 



The Semilunar Fibro-cartilages (fig. 

 142) are two crescentic lamellae attached 

 to the margins of the head of the tibia, 

 serving to deepen its surface for articula- 

 tion with the condyles of the femur. The 

 circumference of each cartilage is thick 

 and convex ; the inner free border, thin 

 and concave. Their upper surfaces are 

 concave, and in relation with the condyles 

 of the femur; their lower surfaces are 

 flat, and rest upon the head of the tibia. 

 Each cartilage covers nearly the outer 

 two-thirds of the corresponding articular 

 surface of the tibia, the inner third being 

 uncovered ; both surfaces are smooth, and 

 invested by synovial membrane. 



The Internal Semilunar Fibro-cartilage 

 is nearly semicircular in form, a little 

 elongated from before backwards, and 

 broader behind than in front ; its convex 

 border is united to the internal lateral 

 ligament, and to the head of the tibia, 

 by means of the coronary ligaments,; its 

 anterior extremity, thin and pointed, is 

 firmly implanted into a depression in front 

 of the inner articular surface of the tibia; 

 its posterior extremity to the depression behind the spine, between the attach- 

 ment of the external cartilage and posterior crucial ligament. 



The External Semilunar Fibro-cartilage forms nearly an entire circle, covering 

 a larger portion of the articular surface 

 than the internal one. It is grooved on 

 its outer side, for the tendon of the Pop- 

 liteus muscle. Its circumference is held 

 in connection with the head of the tibia, 

 by means of the coronary ligaments; 

 and its two extremities are firmly im- 

 planted in the depressions in front and 

 behind the spine of the tibia. These ex- 

 tremities, at their insertion, are interposed 

 between the attachments of the internal 

 cartilage. The external semilunar fibro- 

 cartilage gives off from its anterior bor- 

 der a fasciculus, which forms the trans- 

 verse ligament. By its anterior extremity, it is continuous with the anterior 

 crucial ligament. Its posterior extremity divides into three slips ; two of these 

 pass upwards and forwards, and are inserted into the outer side of the inner 

 condyle, one in front, the other behind the posterior crucial ligament ; the third 

 fasciculus is inserted into the back part of the anterior crucial ligament. 



The Transverse Ligament is a band of fibres, which passes, trans verselv be- 

 15 



Fig. 142. Head of Tibia, with Semilunai 



Cartilages, etc. Seen from above. 



Right Side. 



