332 



SYNDESMOLOGY 



ligaments of the metacarpophalangeal articulations. Its volar surface is concave 

 where the Flexor tendons pass over it; behind it the tendons of the Interossei pass 

 to their insertions. 



X. Metacarpophalangeal Articulations (Articulationes Metacarpophalangeae ; 

 Metacarpophalangeal Joints) (Figs. 337, 338). 



These articulations are of the condyloid kind, formed by the reception of the 

 rounded heads of the metacarpal bones into shallow cavities on the proximal ends 

 of the first phalanges, with the exception of that of the thumb, which presents 

 more of the characters of a ginglymoid joint. Each joint has a volar and two 

 collateral ligaments. 





Metacarpal bone 



Transverse 



metacarpal 



ligament 



Groove for 

 Flexor tendons 



1st phalanx 



Volar ligament 



Volar ligament 



Metacarpal 

 bone 



3rd phalanx 





Collateral 

 ligament 



Collateral 

 ligament 



2nd phalanx 



Collateral 

 'ligament 



FIQ. 337. Metacarpophalangeal articulation and 

 articulations of digit. Volar aspect. 



Fia. 338. Metacarpophalangeal articulation and 

 articulations of digit. Ulnar aspect. 



The Volar Ligaments (glenoid ligaments of Cruveilhier; palmar or vaginal ligaments} . 

 The volar ligaments are thick, dense, fibrocartilaginous structures, placed upon 

 the volar surfaces of the joints in the intervals between the collateral ligaments, to 

 which they are connected; they are loosely united to the metacarpal bones, but are 

 very firmly attached to the bases of the first phalanges. Their volar surfaces are 

 intimately blended with the transverse metacarpal ligament, and present grooves 

 for the passage of the Flexor tendons, the sheaths surrounding which are connected 

 to the sides of the grooves. Their deep surfaces form parts of the articular facets 

 for the heads of the metacarpal bones, and are lined by synovial membranes. 



The Collateral Ligaments (ligamenta collateralia; lateral ligaments). The col- 

 lateral ligaments are strong, rounded cords, placed on the sides of the joints; 



