1. Department of Orthopaedic Surgery; Kangwon National University Hospital; Kangwon Korea
2. Department of Orthopaedic Surgery; Airlangga University Dr Soetomo Hospital; East Java Indonesia
3. Division of Statistics; Medical Research Collaborating Center; Seoul National University Bundang Hospital; Kyungki Korea
4. Department of Orthopaedic Surgery; Seoul National University Bundang Hospital; Kyungki Korea