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Why PAS?

Why PAS?

Hip and knee replacements are very successful procedures, despite the fact they are affected by non-negligible rates of residual symptoms and complications. Unsatisfactory clinical outcomes are primarily explained by poor biomechanics of prosthetic joints.

Interestingly, recent advances in both material and design of prosthetic components, as well as precise technologically-assisted implantation, have not been game-changers. This may be due to the fact that gold-standard techniques for implanting hip and knee components aim to implant all patients similarly, thus neglecting the unique joint anatomy and kinematics of each individual.

Systematic techniques for joint replacement were originally devised for simplifying implantation, making it more reliable in the surgeon’s hands.

Why PAS2

Since the initial worldwide spread of these systematic techniques in the 70s’ (hip) and 80s’ (knee), the world of arthroplasty has dramatically changed.  Surgeons have become much more specialized, often fellowship-trained, with the aim of being an expert of a single joint (hip or knee) or type of procedure (joint replacement). Implant designs have become much more sophisticated; hard-wearing material, available in various shapes, sizes and with high modularity, resulting in a more anatomical fit overall. Finally, precision and accuracy of implantation have significantly improved through the use of assistive technological tools (e.g. computed or robotic-assisted surgery, patient-specific cutting guides) and pre- or intra-operative tri-dimensional dynamic planning, respectively. These changes in practice over the last few decades, combined with recent evidence highlighting the detrimental clinical effect of neglecting individual joint anatomy and kinematics, have led to the development of a more personalised philosophy for arthroplasty.

In order to improve clinical outcomes of prosthetic joints, more personalised and anatomical/soft-tissue friendly techniques have recently been developed. Bone preserving (HR/UKA) and/or Kinematic alignment techniques for implanting hip (THR/HR) and knee (UKA/TKA) components are therefore gaining popularity. These techniques aim to reproduce patients’ native anatomy and physiological joint laxity, therefore improving the prosthetic hip/knee kinematics and functional outcomes. Compared to conventional techniques, personalized hip and knee replacements seem to be clinically advantageous. In addition, they often enable preservation of bone stock (partial knee replacement and hip resurfacing), easing eventual revision surgery. These advantages are becoming even more important in the current environment, where patients are younger, with higher expectations and a longer life expectancy.

We came to the decision to create an International Society named ‘personalized arthroplasty Society (PAS)’ that will pave the way for the paradigm shift from systematic to personalised surgery.

PAS Objectives

The objectives of the Society are:

  • To improve the profile of the ‘Personalized Arthroplasty’ philosophy, through publications (research articles and textbooks) and educational events such as congresses and workshops.

  • To foster networking, information sharing, mentoring, career opportunities, leadership training, and professional development in the field of ‘Personalized Arthroplasty’.

  • To standardise the teaching of ‘Personalized Arthroplasty’ through textbooks, articles (peer-reviewed PAS edition published by OTSR journal), educational events (annual congress, webinars, workshops), and fellowship travel tours.

  • To assess & refine ‘Personalized Arthroplasty’ via support of research & audit projects.

PAS Board

  • President: Charles Rivière

  • Vice-President: Pascal-André Vendittoli

  • Secretary General: 

  • Treasurer: 



Charles Rivière, MD, PhD,

is a French orthopaedic surgeon who specializes in hip and knee joint replacement. He currently performs his surgical practice at different hospitals between London (UK) and Bordeaux-Mérignac (France, Centre de l’Arthrose - Clinique du Sport). He undertakes research at the MSK Lab at Imperial College London, where he is an Honorary Senior Clinical Lecturer in orthopaedics. Dr. Rivière completed 3 years of fellowship training in joint reconstruction at acclaimed institutions in Paris (Prof. T. Judet), London (Mrs. Sarah Muirhead-Allwood), and Montréal (Prof. P. Vendittoli). Another of his mentors is Pr. Justin Cobb, whose expertise in conservative techniques for joint replacement significantly influenced Charles’ surgical philosophy. His practice and surgical philosophy for hip and knee replacement is oriented towards personalised (kinematic alignment) and bone-preserving surgical techniques, with promotion of an “à la carte" bespoke surgical strategy in order to provide optimal patient outcomes. Research from Dr. Rivière and his team has been published in peer-reviewed journals and presented at international congresses. He acts as a journal reviewer for multiple notorious international orthopaedic journals.

Pascal-André Vendittoli

Pascal-André Vendittoli

Pascal-André Vendittoli, MD, MSc, FRCS,

is Professor of Surgery and Clinical Researcher in orthopaedic surgery at Maisonneuve-Rosemont Hospital, University of Montreal (UdM). His principal research activities are the evaluation of new surgical techniques, technologies, and orthopaedic implants. He completed a fellowship training in hip and knee reconstruction in Melbourne, Australia and in knee replacement with Paolo Aglietti in Florence, Italy. Dr. Vendittoli has the Research Director of the Orthopaedics Division of UdM and Professor of Surgery, supervised multiple doctors in specialized training in arthroplasty.  He is the Program Director of the UdM postdoctoral program in hip and knee reconstruction. He is recognized as a senior clinical researcher by his government’s institution (F.R.Q.S.). To date he has published more than 100 articles on hip and knee arthroplasty in peer-reviewed journals. Dr. Vendittoli has received a number of awards, including the John Charnley Award from the American Hip Society (2009), the Founders’ Medal for best basic science research work from the Canadian Orthopaedic Association (2010), and the highest recognition from the Canadian Orthopaedic Association, the Edward Samson Award (2016).