1 Department of Orthopedic Surgery, Clinical Orthopaedic Research Hvidovre (CORH), Copenhagen University Hospital Hvidovre, Copenhagen, Denmark. kirgromov@gmail.com.
2 Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Science, University of Oxford, Oxford, UK.
3 Department of Orthopedics, Sahlgrenska University Hospital, Gothenburg, Sweden.
4 Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA.