chap. XXL] THE REGION OF THE KNEE. 



449 



In young subjects care must be taken that the 

 saw-cut do not pass beyond the epiphyseal line. The 

 upper limit of the femoral epiphysis will be repre- 

 sented by a horizontal line drawn across the bone at 

 the level of the tubercle for the adductor magnus. 

 If the whole of the trochlear surface be removed in the 

 excision, the whole of the epiphysis will have been 

 taken away. A single nucleus appears in this 

 epiphysis shortly before birth, and joins the shaft 

 about the twentieth year. The limits of the tibial 

 epiphysis are represented behind and at the sides by a 

 horizontal ]ine that just marks off the tuberosities. 

 It includes, therefore, 

 the depression for the 

 insertion of the semi- 

 membranosus, and also 

 the facet for the fibula. 

 In front the epiphyseal 

 line slopes downwards ^ 

 on either side to a 

 point on the upper end 

 of the shin, so as to en- *| 

 close the whole of the . 

 tubercle of the tibia. 

 The centre joins the 

 main bone at the twen- 

 ty- first or twenty-second 

 year. The popliteal 

 artery runs some risk 

 of being wounded in 

 this procedure. The 

 vessel is separated by 

 some little distance from 

 the popliteal surface of 

 the femur (Fig. 49), 

 but is in very close relation to the tibia, the pos- 

 terior ligament alone intervening at the upper level of 



D D 



Fig. 50. Disarticulation at the Knee-, 

 joint by single Anterior Flap 

 (Agatz). 



a, Int. cotidyle ; 6, ext. condyle ; c, inter- 

 condyloid fossa; d, lig. patellae: e, sar- 

 torius;/, gracilis ; <j, seniitendmosus ; 

 h, ext. lat. ligament ; i, popliteus : j, 

 plantaris ; k, semimernbranosus ; I and 

 m, inner bead of gastroenemius ; n, outer 

 head of gastrocnemius; o, l>iceps ; p t 

 popliteal vessels ; </, int. pop. nerve. 



