1. Institution of Clinical Sciences, Department of Orthopaedics, Sahlgrenska Academy, University of Gothenburg, 416 45 Gothenburg, Sweden
2. Department of Orthopedics, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
3. Institution of Biomedicine, Department of Infectious Diseases, University of Gothenburg, 413 90 Gothenburg, Sweden