1. Department of Orthopedic Surgery Arabellaklinik Munich Germany
2. Consultant Endoscopic Spine Surgeon, Senior Lecturer Manchester University, The Medical Director The Spinal Foundation, The Weymouth Hospital 42 ‐ 46 Weymouth Street London, 27 Harley Street London W1G 9QP
3. Department of Neurosurgery, Rhode Island Hospital The Warren Alpert Medical School of Brown University Providence RI USA
4. Staff Orthopaedic Spine Surgeon Center for Advanced Spine Care of Southern Arizona and Surgical Institute of Tucson
5. Associate Professor of Orthopaedic Surgery, Department of Orthopaedics Fundación Universitaria Sanitas Bogotá D.C. Colombia
6. Department of Neurosurgery UNIRIO Rio de Janeiro Brazil