Benjamin Joseph, MS (Orth), MCh Orth, FRCS Ed, adjunct professor of paediatric orthopaedics, Christian Medical College, Vellore, India; and consultant paediatric orthopaedic surgeon Aster Medcity, Kochi, India Selvadurai Nayagam, BSc, MCh(Orth), FRCS Ed (Trauma and Orth), consultant orthopaedic surgeon, Royal Liverpool Children's Hospital; and honorary reader, University of Liverpool, UK Randall T. Loder, MD, garceau professor of orthopaedic surgery, Indiana University School of Medicine, Indianapolis; and chief of orthopaedics, James Whitcomb Riley Children’s Hospital, Indianapolis, USA