A humeral component, forming a first articulating surface, and an ulnar component
forming a second articulating surface adapted to be disposed around a part of the
first articulating surface and to pivot about its longitudinal axis. This ulnar
component is provided with structure for mounting a locking element which forms
a third articulating surface extending the second and adapted likewise to be disposed
around a part of the first surface. These mounting structure comprise guiding structures
adapted to cooperate with complementary structure provided on the locking element
in order to guide this element in translation with respect to the ulnar component,
up to a position where blocking structure provided respectively on the locking
element and on the ulnar component may be employed to immobilize this element on
this component, these blocking structure being able to be employed only in this position.
