An acetabular implant system, comprising: an acetabular shell including an inner surface and a lip portion defining an opening, wherein the acetabular shell comprises a hemispherical shape and the inner surface is centered on an apex of the hemispherical shape; a liner having an edge portion; and a fitting ring having a fitting ring wall, an alignment portion and an engagement portion engageable to the edge portion of the liner such that the alignment portion extends radially outward from the liner; wherein: the alignment portion is located on an exterior surface of the fitting ring, the alignment portion extending circumferentially around the fitting ring; the engagement portion is located on an interior surface of the fitting ring and defines an opening for receiving the liner; the alignment portion is engageable to the lip portion of the acetabular shell to position the liner within the opening at a predetermined distance from the inner surface; and wherein when a driving force is applied along an axis (A-A) transverse to the apex, the liner is released from the fitting ring and the liner is pushed into engagement with the inner surface of the acetabular shell; characterised in that the engagement portion is formed by a region of reduced radial thickness of the fitting wall, wherein the engagement portion is engageable to the edge portion of the liner. an acetabular shell including an inner surface and a lip portion defining an opening, wherein the acetabular shell comprises a hemispherical shape and the inner surface is centered on an apex of the hemispherical shape; a liner having an edge portion; and a fitting ring having a fitting ring wall, an alignment portion and an engagement portion engageable to the edge portion of the liner such that the alignment portion extends radially outward from the liner; wherein: the alignment portion is located on an exterior surface of the fitting ring, the alignment portion extending circumferentially around the fitting ring; the engagement portion is located on an interior surface of the fitting ring and defines an opening for receiving the liner; the alignment portion is engageable to the lip portion of the acetabular shell to position the liner within the opening at a predetermined distance from the inner surface; and wherein when a driving force is applied along an axis (A-A) transverse to the apex, the liner is released from the fitting ring and the liner is pushed into engagement with the inner surface of the acetabular shell; characterised in that the engagement portion is formed by a region of reduced radial thickness of the fitting wall, wherein the engagement portion is engageable to the edge portion of the liner. the alignment portion is located on an exterior surface of the fitting ring, the alignment portion extending circumferentially around the fitting ring; the engagement portion is located on an interior surface of the fitting ring and defines an opening for receiving the liner; the alignment portion is engageable to the lip portion of the acetabular shell to position the liner within the opening at a predetermined distance from the inner surface; and wherein when a driving force is applied along an axis (A-A) transverse to the apex, the liner is released from the fitting ring and the liner is pushed into engagement with the inner surface of the acetabular shell; characterised in that the engagement portion is formed by a region of reduced radial thickness of the fitting wall, wherein the engagement portion is engageable to the edge portion of the liner.