Prosthesis installation and assembly

A grasper for a head of a modular prosthesis having an opening to a bore complementary to a morse taper of a complementary trunnion of the modular prosthesis, the head including a planar face centered on the opening and a bore axis centered through the opening and aligned with the morse taper, comprising:

• a set of two or more pivoting gripping elements, each gripping element defining a portion of a spherical cavity disposed between a first edge and a second edge with said second edge defining a ledge complementary to a portion of the planar face when the head is disposed within said portion of said spherical cavity;
• a clamp top rotatively coupled to said first edge of each said gripping element and defining a longitudinal clamp axis;
• and
• a locking mechanism, coupled to said clamp top and operatively coupled to said set of pivoting gripping elements, said locking mechanism configured to secure said pivoting locking members in either a first mode or a second mode, said first mode configured to permit said set of pivoting gripping members to pivot about said clamp top to open and close and said second mode configured to secure said set of pivoting gripping members in a closed position while inhibiting said set of pivoting gripping members from transitioning to an opened position, said closed position configured to align an axis of said spherical cavity with said longitudinal clamp axis responsive to a collective interaction of said ledges with the planar face when the head is disposed within all said portions of said spherical cavity;
• wherein said locking mechanism includes a lock ring that includes two positions, a locked position that engages with said set of pivoting gripping elements to inhibit their transition and an unlocked position that disengages from said set of pivoting gripping elements to permit their transition.