1. Department of Paediatric- and Neuro- Orthopaedics/Foot and Ankle Surgery, Orthopaedic Clinic Volmarstein, Wetter (Ruhr), Germany
2. Department of Orthopaedics and Traumatology Surgery, Hippokration General Hospital, Thessaloniki, Greece
3. Department of Paediatric Orthopaedics, St Luke’s Hospital, Thessaloniki, Greece
4. Department of Orthopaedics and Traumatology Surgery, Papageorgiou General Hospital, Thessaloniki, Greece