196 



Joints of the Lower Extremity. 



Ligamenta 

 sacroiliaca posteriora 



Ligamenta sacroiliaca 

 interossea 



Os ilium 



Canalis sacralis 



Os sacrum 



Cavum articulare 



Ligamenta sacroiliaca anteriora 



245. Articulatio sacroiliaca dextra, frontal section. 



Posterior half of section, from in front. 



Articulatio sacroiliaca (continued). It possesses an unevenly curved joint 

 slit; the adjoining articular surfaces are completely covered by cartilage and smooth, 

 but they present several irregular projections which fit in to corresponding depressions 

 of the other bone. 



On the dorsal surface there are present, as strengthening ligaments, the ligamenta 

 sacroiliaca interossea. Under this name are included the mass of short .fibre bands 

 which are covered over completely behind by the ligamenta sacroiliaca posteriora and 

 which extend obliquely upward and backward from the tuberositas sacralis [ossis sacri] 

 to the tuberositas iliaca [ossis ilium], eventually, also to the sulcus paraglenoidalis ; they 

 fill completely the irregular depression which is situated behind the joint cavity between 

 these two rough surfaces, and are not visible in the uninjured joint. 



