Does the cup insert also have to be replaced during a stem revision?
The ball head must always be replaced along with the stem. Entirely non-wearing pairings have not yet been developed in hip endoprosthetics, even if signs of wear may not actually be visible. The following procedure is suitable for the removal of polyethylene inserts without weakening the cup shell-bone connection. Using a 3.2 mm diameter spiral drill bit, drill through the PE insert diagonally down to the cup shell. Screw a 4.5 mm diameter cortical screw into the borehole until the screw tip touches the cup shell and the PE cup insert springs out.
