1. Department of Pediatrics, Máxima Medical Centre, Veldhoven, The Netherlands.
2. Department of Orthopaedic Surgery, Medisch Spectrum Twente (MST), Enschede, The Netherlands.
3. Department of Orthopaedic Surgery, Máxima Medical Centre, Veldhoven, The Netherlands.
4. Department of Orthopaedic Surgery, University Medical Centre Utrecht, Utrecht, The Netherlands.