1. Hofstra North Shore-LIJ School of Medicine, 500 Hofstra University, Hempstead, NY 11549, USA
2. Department of Orthopaedics, North Shore Long Island Jewish Medical Center, 270-05 76th Avenue, New Hyde Park, NY 11040, USA
3. Biostatistics Unit, Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
4. Department of Orthopaedic Surgery, Johns Hopkins University, 601 N. Caroline Street, Baltimore, MD 21287, USA