Themistoklis K. Tzatzairis, MD, MSc, PhD, is Assistant Professor of Orthopaedics and Paediatric Orthopaedics at the School of Medicine, Aristotle University of Thessaloniki, Greece.

He graduated from the Democritus University of Thrace Medical School in 2010. He holds a Master of Science (MSc) in Clinical and Surgical Anatomy and a Doctor of Philosophy (PhD) from the Democritus University of Thrace. He completed his Orthopaedic Surgery training in 2018 and subsequently undertook subspecialty training in Paediatric Orthopaedics at the Royal London Hospital, Barts Health NHS Trust, United Kingdom, where he served as Senior Clinical Fellow and later as Consultant Paediatric Orthopaedic Surgeon.

His clinical and research interests focus on Paediatric Orthopaedics, with particular emphasis on developmental dysplasia of the hip (DDH), scoliosis, limb deformity correction, neuromuscular disorders, and the use of musculoskeletal ultrasound in the diagnosis and management of paediatric orthopaedic conditions.

Dr Tzatzairis has an active academic and research profile, with numerous publications in peer-reviewed international journals and participation in international research collaborations. He is a member of several leading orthopaedic societies, including the European Paediatric Orthopaedic Society (EPOS), the Paediatric Orthopaedic Society of North America (POSNA), the American Academy of Orthopaedic Surgeons (AAOS), the British Society for Children’s Orthopaedic Surgery (BSCOS), and the International Pediatric Orthopaedic Society (IPOS). Since 2025, he has served as a member of the Educational Committee of EPOS, contributing to the development of educational initiatives and training activities at a European level. He has also served as a Board Member of the International Committee on Developmental Dysplasia of the Hip Evaluation and Treatment (ICODE).

His academic activities include undergraduate and postgraduate medical teaching, resident training, and participation in the organization of national and international educational courses, workshops, and scientific meetings.