Patent ID: 8882845

Claim:
A prosthesis assembly configured for use with a scapula, comprising: a spherical humeral component; a stretched glenoid bearing including a first bearing surface with (i) a first spherical outer portion with a first radius of curvature, (ii) a second spherical outer portion with a second radius of curvature, (iii) a central portion located between the first spherical outer portion and the second spherical outer portion, said central portion including a substantially flat portion, and (iv) a first mating portion extending from a second bearing surface opposite the first bearing surface and including a first locking component; and a base configured to rotatably support the stretched glenoid bearing, the base including a second mating portion configured to receive the first mating portion and including a second locking component, wherein the first radius of curvature is substantially equal to the second radius of curvature and the central portion does not have a radius of curvature that is substantially equal to the second radius of curvature, and the first locking component and the second locking component are configured such then when the first locking component and the second locking component are engaged, the first and second locking components limit (i) axial movement of the first mating portion with respect to the second mating portion, and (ii) rotation of the stretched glenoid bearing to less than 360 degrees.