Inverse shoulder prosthesis with improved glenosphere

An inverse shoulder prosthesis comprising:

• a glenoid implant comprising a glenoid body having an articulating surface, wherein the articulating surface:
• has a convex dome shape,
• defines a first right hand coordinate system having a first x-axis, a first y-axis, a first z-axis, and a first point of origin, the first z-axis extending along a center axis of the glenoid body,
• (1) extending into a positive direction of the first z-axis, in positive and negative directions of the first x-axis, and in positive and negative directions of the first y-axis, or (2) being oriented towards a humerus and having a base in an anterior-posterior and a lateral-medial direction, and
• (1) having a first radius in a plane defined by the first y-axis and the first z-axis, and a second radius in a plane defined by the first x-axis and the first z-axis, or (2) having a first radius in a sagittal plane, and a second radius in a frontal plane;
• and
• a humerus implant comprising a humeral body and an inlay, wherein the inlay:
• has a concave shape,
• has a second coordinate system having a second x-axis, a second y-axis, a second z-axis, and a second point of origin, the second z-axis extending along a center axis of the inlay,
• (1) extending into a negative direction of the second z-axis, or (2) having a center axis oriented towards a glenoid of a shoulder, and a base in an anterior-posterior direction and a craniocaudally direction, and
• having an inner radius,
• wherein the second radius is from 0.8 to 0.95 times of the first radius, and the first radius is smaller than the inner radius of the inlay.