A shoulder inter-spacer implant has a first outer surface having a contoured profile simulating a glenoid surface and a second inner surface for resting on an outer surface of a prepared glenoid. The second inner surface has a flat or contoured profile void of any pegs, keels or bone interlocking projections so that the second inner surface is profiled to rest on the surface of the prepared glenoid when implanted free of any direct anchoring or cementing to the bone structure. In this fashion the inter-spacer is free to move or slide on the prepared glenoid. The inter-spacer may include one or more soft tissue attachment locations to which a tendon, cartilage, ligament or other soft tissue can be secured, the inter-spacer being otherwise free floating relative to the prepared glenoid.