A hemi-prosthesis implant comprises a replacement-joint part with an articulation surface for tribological pairing with a joint surface of a natural joint counterpart. The articulation surface is embodied with a coating applied on a substrate. The substrate provides a relief for the adhesion of the coating. The relief may comprise one or more of a plurality of grooves, a plurality of teeth, a ribbing, and a roughened surface. The relief may be embodied entirely or partially outside the articulation surface. The replacement joint part may optionally comprise a ventilation feature, and the articulation surface may be formed by injection molding on the substrate. The hemi-prosthesis implant may be part of an implant set that includes both a hemi-prosthesis implant and a total prosthesis implant, either of which can be chosen intraoperatively.