Joints of the Upper Extremity. 



187 



Ulna 



Radius - 



Ligamentum radiocarpeum volare 



Ligamentum collaterale carpi - 

 radiale 



Tuberculum ossis navicularis 

 Ligamentum carpi radiatum ^ _ j- 



Articulatio 

 carpometacarpea pollicis 



Os capitatum 



Ligamentum carpometacarpeum volare 



Articulatio radioulnaris 

 distalis 



Processus styloideus ulnae 



Ligamentum collaterale 

 carpi ulnare 



Os lunatum 

 Os pisiforme 



Ligamentum pisohamatum 



Ligamentum 

 pisometacarpeum 



Hamulus ossis hamati 

 Ligamentum hamato- 



metacarpeum 

 Ligamentum piso- 

 metacarpeum 

 Ligamenta basium 

 ossium metacarpaliumj 

 volaria 



II III 



Ossa metacarpalia 



238. Joints of the right hand, articulatio manus, 



from the volar surface. 



The articulatio manus (joint of the hand) (see also Figs. 239 and 240) is divisible 

 into the articulatio radiocarpea and the articulatio intercarpea. 



In the formation of the articulatio radiocarpea (wrist-joint) the proximal joint surfaces 

 of the ossa naviculare, lunatum, triquetrum move upon the fades articularis carpea of the radius 

 and upon the distal surface of the discus articularis. Its wide loose capsula articularis is attached 

 to the circumference of the articular surfaces. It is strengthened by the ligamentum collaterale 

 carpi radiale (0. T. external lateral ligament) which extends from the processus styloideus radii 

 to the os naviculare, and by the ligamentum collaterale carpi ulnare (0. T. internal lateral liga- 

 ment) which extends from the processus styloideus ulnae to the os triquetrum. On the volar 

 surface runs also the broad ligamentum radiocarpeum volare (0. T. anterior ligament) which 

 arises from the processus styloideus and from the volar margin of the facies articularis carpea 

 of the radius and goes in several bundles to the ossa naviculare, lunatum, triquetrum, capitatum. 



The articulatio intercarpea connects and permits motion among the bones of the wrist; the 

 individual bones are connected among one another by small capsulae articulares. On the volar 

 surface there are several strengthening ligaments, short, flat, almost transversely directed, liga- 

 mentum intercarpea volaria (0. T. palmar ligaments) ; of these, those which radiate out from the 

 os capitatum to the adjoining bones are grouped together as the ligamentum carpi radiatum. 



In the formation of the articulatio ossis pisiformis, the dorsal surface of the os pisiforme 

 glides upon the volar surface of the os triquetrum; a small, loose capsula articularis connects the 

 borders of these surfaces. From the os pisiforme, the powerful ligamentum pisohamatum goes 

 to the hamulus ossis hamati; the ligamentum pisometacarpeum to the basis ossis metacarpalis 

 III V, both ligaments being really continuations of the tendon of the m. flexor carpi ulnaris. 



