title: Separation of the apex hole eliminator screw in four failed hybrid total hip arthroplasties.
abstract: 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 4 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.
authors.affiliation: Hip Surgery Unit, Institute of Orthopaedics Carlos E. Ottolenghi, Italian Hospital, Buenos Aires, Argentina. fernando.comba@hospitalitaliano.org.ar
authors.forename: F
authors.initials: F
authors.lastname: Comba
authors.forename: M A
authors.initials: MA
authors.lastname: Buttaro
authors.forename: F
authors.initials: F
authors.lastname: Piccaluga