1 Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg SE 413 45, Sweden
2 Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
3 Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden
4 Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden