Separation of the Apex Hole Eliminator Screw in Four Failed Hybrid Total hip Arthroplasties

Advancement or separation of the apex hole eliminator screw in uncemented Duraloc 100 cups (DePuy®, Warsaw, Indiana, USA) has been recently reported as a radiographic finding without clinical effects.

We report four patients with a separation of the apex hole eliminator screw in Duraloc 300 uncemented cups and aseptic failures of a hybrid total hip arthroplasty (acetabular osteolysis and femoral stem loosening). Revision surgery was performed when disabling pain and radiographic signs of loose components were present.

Although difficult to determine, a relationship between the screw migration and the failure could have existed in these cases. Migration of the screw might not only be interpreted as a radiographic, clinically irrelevant finding. Its presence should alert the orthopaedic surgeon that the prosthesis is exposed to high intraarticular fluid pressures.