101 



Fig. 64. 



groove in which passes a tendinous cord ; it is excavated, in front, by a 

 vertically elongated fossa which lodges the middle ligament of the patella. 

 The -.!(< //(;/ /' /'*////, medium in size and the most detached, has outwardly 

 an articular facet for the head of the fibula. The 

 inl'-rmil titbcrofiili/, the largest and least detached, 

 presents: on the sides, ligamentous imprints; behind, 

 a small tubercle which gives attachment to the pos- 

 terior crucial ligament of the femoro-tibial articu- 

 lation. The superior face of the two lateral tube- 

 rosities is occupied by two large irregular and 

 undulated articular surfaces, which respond to the 

 condyles of the femur through the medium of the 

 two meniscus- shaped fibro cartilages interposed be- 



i the two bones. Of these two surfaces the 



ual is always the widest, because it serves, by 

 its posterior part, for the gliding movements of the 

 popliteal tendon. They are separated from each 

 other by the tibial spine, a conical articular eminence 

 divided into two lateral parts by a groove of inser- 

 tion excavated at its base, and in front by two lateral 

 facets for the insertion, anteriorly, of the two inter- 

 articular cartilages; it is bordered behind by another 

 fossa which receives the posterior insertion of the 

 internal meniscus. 



The inferior extremity, flattened behind and before, 

 exhibits an articular surface moulded on the pulley 

 of the astragalus, and two lateral tuberosities. The 

 articular surface is formed by two deep cavities oblique 

 from behind to before and within outwards, and 

 separated by a median tenon which terminates pos- 

 teriorly by a very prominent projection on which the 

 bone rests when it is made to stand vertically on 

 a horizontal plane. The external tuberosity 1 projects 

 but little, and is traversed in its middle by a vertical 

 fissure. The internal ///</*////,- better defined, is 



i iorly by an oblique channel. 

 Structure ami development. Tbe tibia is very 

 compact in its inferior portion, and is developed from 

 four chief centres of ossification. The body is formed 

 by one and the superior extremity by two, the anterior 

 tuberosity taking one of these; the last develops the 

 whole of the inferior extremity. It is rare to see 

 tin external tuberosity of this extremity formed from 

 a separate nucleus. 



2. Fibula (or 



A small, undeveloped li >ne, elongated and sty- 



loid in shape, situated outside the tibia, and extend- 

 ing from tlie superior extremity of that bone to the 

 mid'lle or lower third of its b< ily. 



The mill-Hi- jinrtinn of the fibula is thin and cylin- 

 drical, and forms above, in common with the external K.nler of tin- larger 

 1 The -jl'i-iKil mallcolus of Man. * The int<ni<il mull- 



POCTKKIOU Vli;\V OF 



RIGHT Tllil.V. 

 1, Tibial s|>iiie; .. 



fur the in>ertion of the 

 internal menisrii^ : :;. 

 Kxternal tubero>ity with 

 artirulatioti fur the fib- 

 ula; 4, Fossa for the 

 insertion of external 

 ineiiixii^: .">. Fibula, 

 forinin*; with the tibia 

 the tibial arch; >',, Shaft. 

 or body of the tibia; 

 7, 8, K\ternal and in- 

 tern. il malk-oli. inferior 

 Inborn, ities, or lateral 

 M's of the tibia ; 

 '.'. Art it-ii la r trochlea* 

 with a mi- I:. in rid;i'. 

 : tii-iilatioii with the 

 astragalus. 



