1. Department of Orthopaedics, Lund University, Skåne University Hospital, Malmö;
2. The Swedish Hip Arthroplasty Register, Registercentrum Västra Götaland, Gothenburg;
3. Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden
4. Department of Orthopaedics, Visby Hospital, Visby;
5. Department of Orthopaedics, Institute of Surgical Sciences, Uppsala University, Uppsala;