Method and apparatus for replication of angular position of a humeral head of a shoulder prosthesis

A jig for transferring spatial orientation of a humeral head to a conjoining member of a first construct to a humeral head and conjoining member of a second construct, the jig comprising:

• a body having an upper surface, a spherical cavity, and an opening in said upper surface;
• a sphere disposed in said spherical cavity and having a bore configured to receive a neck of a first construct, said sphere adapted to freely rotate within said spherical cavity and without translation relative to said body;
• and
• locking means situated in said body and adapted to selectively engage said sphere to releasably fix a rotational position of said sphere;
• wherein said configured bore is adapted to receive a neck of the first construct and orient said neck relative to a position of the head on said flat surface of said body via rotation of said sphere, said locking means releasably fixing rotational position of said sphere during which the first construct is removed and a neck of a second construct is placed therein for alignment according to the fixed rotational position of said sphere as a head of the second construct is placed on the position of the head of the first construct on said body, the neck then affixed to the head of the second implant construct.

A method of transferring spatial orientation of a first construct having a humeral head adapted to be releasably affixed to a conjoining member to a second construct having a humeral head adapted to be releasably affixed to a conjoining member, the method comprising the steps of:

• fixing a spatial orientation of a humeral head relative to a conjoining member of a first construct;
• placing the conjoining member of the first construct into a jig, the jig comprising:
• a body defining a flat surface;
• a cavity within said body;
• a pivoting member disposed within said cavity, said pivoting member having a configured bore and adapted to freely rotate within said cavity;
• and
• locking means situated in said body and adapted to selectively engage said pivoting member to releasably fix a rotational position of said pivoting member;
• wherein said configured bore is adapted to receive a conjoining member of the first construct and orient said conjoining member relative to a position of the head on said flat surface of said body via rotation of said pivoting member;
• fixing the rotational position of said pivoting member the locking means;
• removing the first construct;
• and
• placing a conjoining member of a second construct in the jig for alignment according to the fixed rotational position of said pivoting member as a head of the second construct is placed on the position of the head of the first construct on said body, the conjoining member then affixed to the head of the second construct.