1. Swedish Hip Arthroplasty Register, Center for Registers, Västra Götaland, Gothenburg;
2. Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg;
3. Department of Orthopedics, Hywel Dda University Health Board, Prince Philip Hospital, Bryngwynmawr, Llanelli, UK.
4. Department of Orthopedics, Lund University, Skåne University Hospital, Malmö, Sweden;