Bones of the Lower Extremity. 



137 



181. Right shin bone 

 and calf bone, 



tibia and fibula, from behind. 



The inferior extremity of the tibia 



(see also Figs. 180 and 183 185) is quadri- 

 lateral, but not much broadened; the lateral 

 surface is somewhat concave below, incisura 

 fibularis, for the attachment of the malleolus 

 lateralis fibulae; medianward a strong blunt 

 process passes downward, malleolus medialis 

 (0. T. internal malleolus), which on its medial 

 surface is somewhat rough, on its lateral sur- 

 face (fades articularis malleolaris) , is covered 

 with cartilage; on the posterior surface near 

 the malleolus a shallow furrow extends down- 

 ward, sulcus malleolaris (for the tendon of 

 the m. tibialis posterior). The surface directed 

 distalward, fades articularis inferior (for the 

 talus) is slightly concave, quadrangular, and 

 covered with cartilage. 



The fibula (calf bone) (see also Figs. 180 a , 

 180, 182185) is a long, thin cylindrical 

 bone situated in the lateral part of the leg 

 and connected above with the tibia, below 

 with the tibia and the tarsus. It is divisible 

 into a shaft or corpus, an upper extremity, 

 capitulum and a lower extremity, malleohcs 

 lateralis. 



The corpus fibulae or shaft (see also 

 Figs. 180 a , 180, 184 and 185) is nearly 

 triangularly prismatic in shape, but appears 

 at the same time twisted on its long axis. It 

 presents a posterior surface, fades posterior, an 

 anterior medial, fades medialis, and an anterior 

 lateral, fades lateralis. They are separated 

 from one another by three borders; the sharpest 

 looks forward, crista anterior, the second is 

 directed medianward, crista medialis and the 

 third lateralward, crista lateralis; further, 

 running down over the medial surface is the 

 crista interossea , of markedly variable de- 

 velopment. In the middle of the posterior 

 surface a foramen nutridum leads into a 

 canalis nutridus which runs distalward. 



The capitulum fibulae (head) (see also 

 Figs. 180, 182, 184 and 185) is somewhat 

 thickened, runs out proximally into a blunt 

 tip, apex capituli fibulae, and supports on 

 its medial anterior surface a small flat joint 

 surface, fades articularis capituli. 



The malleolus lateralis (0. T. external 

 malleolus) (see also Figs. 180 and 183185) 

 is thickened, projects further downward than 

 the malleolus medialis and ends in a blunt 

 tip. On its medial surface it is covered with 

 cartilage, fades articularis malleoli, and, 

 above this surface, lies in the incisura fibularis 

 tibiae. The other surfaces are rough; on the 

 posterior surface a shallow furrow for the 

 tendons of the mm. peronaei is visible. 



Margo 



infra- 



glenoid. 



Condyl. 

 medial. 



Condylus 

 lateralis 



Apex 



_ Capitulum 

 fibulae 



Linea poplitea 



Foramen _ 

 nutricium 



Facies posterior .. 

 Crista interossea _ 



Margo medialis 



Tibia ->- 





Sulcus 

 malleolaris 



Malleolus 

 medialis 



Foramen 

 nutricium 



Facies posterior 



Crista medialis 



-<- Fibula 



Crista lateralis 



Facies 



articularis 



malleoli 



Sulcus for the 



tendons of the 



/ mm. peronaei 



Malleolus 



lateralis 



