Edward Valstar (1970–2017)

© 2017 The Author(s). Published by Taylor & Francis on behalf of the Nordic Orthopedic Federation. This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non-Commercial License (https://creativecommons.org/licenses/by-nc/3.0) DOI 10.1080/17453674.2017.1375341 Edward Valstar at TedX Delft: Joined at the Hip “Awkward, I am not longer around and indeed as I forecasted the research and education programs continue at the same pace as before....” Or was there, almost invisible, a vague dimple in the mirrored water of your memory. May 17 of this year, our dear friend and colleague Professor Edward Valstar, PhD, died at the age of only 47 years. Your battle against just a “bunch of deteriorated pancreatic cells” could not be won, although you were ready to beat them with any technical means, for Carola and your lovely daughters Floor (12) and Merel (8). Edward started his scientifi c career at the Department of Orthopaedics at Leiden University Medical Center (LUMC), The Netherlands in 1993, just after fi nishing his master in Mechanical Engineering at Delft University of Technology. His assignment was to start clinical RSA research, since RSA in Leiden was until then only used in the anatomy lab by Cees Spoor, PhD. His fi rst appointment in Leiden was for three months, which was gradually renewed and renewed. As an engineer in a clinical environment, he was in a challenging position and we admire him for his perseverance in these early days. For Edward, collaboration was important and he succeeded in building many bridges between scientists, engineers and clinicians. Working together with Prof. Hans Reiber, PhD and Henry Vrooman, PhD from the Division of Image Processing at the LUMC, he succeeded in developing the fi rst Digital RSA system that is still the basis of our current Model-based RSA software. With his clinical counterpart, Rob Nelissen, he started clinical RSA studies with the Leiden RSA system. The close collaboration between both the engineer and the clinician stimulated not only the initiation of a multitude of clinical and more technical studies, but also the development of hardware for RSA: a tantalum marker insertion instrument which was easy to handle during surgery, development of the calibration box (which was of glass during the fi rst study), necessary to calibrate the stereoroentgen images. When the fi rst clinical studies with the Leiden RSA software were presented at the EFORT/EORS congress in Barcelona in 1997 some discussions were provoked by the up to that timepoint dominant groups in the RSA fi eld from Sweden, who became close friends in the years to follow. The latter was not only due to the RSA expertise from Leiden, but mainly due to Edward’s gift to bring people together even when they had opposing ideas. Eventually an EU travel grant between Lund (Leif Ryd) and Leiden started, giving an extra boost to model-based RSA. Again, the social aspects of the visits to Lund, having social interactions between Leif, Mike Dunbar, Edward and Rob promoted to a great extent the possibilities on bringing RSA to the next level. One of the papers was a comparison between the Leiden and the Lund RSA systems, but also the RSA standardization paper and the ISO certifi cation of RSA originated during dinner and a beer or two in the evening. In 2001, Edward defended his PhD thesis (with professor Leif Ryd and professor Rik Huiskes as member of the opposition committee) entitled: “Digital Roentgen Stereophotogrammetry: Development, Validation, and Clinical Application.” In Leiden. we still call his thesis “The RSA Bible”. After fi nishing his PhD, Edward founded the Biomechanics and Imaging Group (BIG). Eric Garling was his fi rst PhD student as co-supervisor and Bart Kaptein started his work on further development of the RSA software. The focus of his research was broadened by interest in the minimally invasive re-fi xation techniques for loosened implants developed in