Ceramic acetabular cup

A one-piece ceramic acetabular cup devoid of a separate liner and comprising:

• a part-spherical inner articulating surface to non-captively receive a femoral head;
• an outer surface to enable direct to bone fixation and to support one or more layers of bio-compatible coating;
• an inner radius at or adjacent to a rim of the cup and extending to or adjacent to a surface edge of the inner articulating surface to prevent or reduce undesirable effects of impingement of an associated femoral head and/or neck;
• the rim having an inner radiused edge, an outer radiused edge, and a flat therebetween;
• an inner radius of the inner articulating surface defining an active arc over which an in use femoral head can articulate;
• the flat being an uppermost portion of the rim defining an offset datum plane;
• an offset between an equatorial centre of the inner articulating surface and the offset datum plane being in a range of 1 mm towards a pole of the inner articulating surface and 3.5 mm away from the said pole;
• the active arc extending in a range from 150 degrees to less than 180 degrees;
• and
• a distance between the inner articulating surface and outer surface on a straight line from the said equatorial centre and passing through the surface edge being equal to or less than 4 mm;
• wherein a wall thickness between the inner articulating surface and the outer surface is non-uniform such that the wall thickness of the acetabular cup increases from the flat towards the pole to be thickest at the pole.