Glenoid implant for inverted shoulder prosthesis

A glenoid implant for an inverted shoulder prosthesis comprising:

• a base configured to be anchored on a glenoid cavity of a scapula and having a main orifice extends through the base;
• a glenosphere defining a convex articulation surface formed in a hemisphere portion and having a central orifice passing through the glenosphere, wherein the glenosphere is mounted on the base by mutual wedging between a female conical bearing surface on the glenosphere and a male conical bearing surface on the base;
• a main anchoring screw passing through the main orifice of the base and shaped for anchorage of the base on the glenoid cavity, wherein the main anchoring screw comprises a main head and an anchor rod having an end segment with an external tapping;
• and
• a locking screw, coaxial with the main anchoring screw, passing through the central orifice of the glenosphere to lock the glenosphere on the base in a locked position, wherein the locking screw comprises a proximal head and a locking rod having an intermediate segment with an external tapping and extended by an end segment,
• wherein:
• the main anchoring screw has an inner hole opening into the main head and having successively, starting from the main head and in a direction of the end segment of the anchor rod, an inlet portion shaped to cooperate with a screwing tool, an intermediate portion including a threading and a tip portion, and
• the end segment of the locking rod has a length longer than a cumulated length of the inlet portion and of the intermediate portion of the inner hole of the main anchoring screw to slide inside the tip portion of the inner hole of the main anchoring screw to center the female and male conical bearing surfaces relative to one another, and the intermediate segment of the locking rod is adapted to be threadably engaged to the intermediate portion of the inner hole of the main anchoring screw to lock mutual wedging of the female and male conical bearing surfaces, the proximal head of the locking screw abutting on an annular bearing surface inside the central orifice of the glenosphere,
• the central orifice of the glenosphere has successively, starting from the convex articulation surface in the direction of the base, a proximal portion shaped to receive the proximal head of the locking screw, and a distal portion having threading complementary to the external tapping of the intermediate segment of the locking rod of the locking screw, wherein the annular bearing surface of the central orifice of the glenosphere is at an interface between the proximal portion and the distal portion.