1. Ichan School of Medicine at Mount Sinai, Leni & Peter W. May Department of Orthopaedics, 5 East 98th Street, Box 1188, New York, New York 10029, USA.
2. Asan Medical Center, University
of Ulsan College of Medicine, 388-1, Pungnap2-dong, Songpa-gu, Seoul, South Korea.