A prosthesis that mechanically couples with both cancellous bone and cortical bone of a glenoid includes a head portion comprising a rear surface and an articular surface, an anchor member, and a plurality of deformable fins extending radially outward from the anchor member. The anchor member includes a distal end and a proximal end connected to the rear surface of the head portion. The plurality of deformable fins extend radially outward from the anchor member and includes at least a first proximal fin adjacent to the rear surface of the head portion positioned to engage with the cortical bone. The anchor member may also include at least one distal fin located proximate the distal end of the anchor member positioned to engage with the cancellous bone.