The invention relates to an implant for the relief of damaged regions of the joint surfaces of hip or shoulder joints which may be introduced into the gap between the joint surfaces of the joint head and the joint socket in the natural joint, the implant being embodied as a shell or cap which is laid in the implanted state with a convex outer surface in the joint socket and a convex inner surface sitting on the joint head. The implant has a body section forming the shell or cap with an opening and a boundary section defining the opening and the implant is made from a flexible material which may be deformed for introduction of the implant into the gap between the joint surfaces.