Orthopedic surgeons employ a wide variety of surgical techniques to treat cartilage defects of the knee. Treatment algorithms provide guidance to surgeons for treatment selection, but these treatment algorithms typically only take defect size and patient functional demands (high or low) into consideration. Orthopedic surgeons increasingly recognize that other patient-specific factors need to considered and that no single treatment caters to the needs of all patients.
Orthopedic surgeons especially recognize a treatment-gap for middle-aged patients suffering from cartilage defects and desire improved treatment options and treatment selection guidance for these patients. As regenerative capacity is detrimentally affected beyond the age of 40 or after failed cartilage repair surgery, regenerative cartilage repair therapies are substantially less effective in these patient groups. On the other hand, total knee arthroplasty (TKA) is not an option for middle-aged patients, as it does not provide the demanded functional restoration. In addition, total knee implant survival is substantially lower in more active, middle-aged patients, which inevitably necessitates one or more revision procedure(s) with associated high complication rates. Joint preservation, postponing or avoiding the need for TKA, is therefore the main objective of cartilage repair surgery in the middle-aged population.
Focal knee resurfacing implants (FKRIs) have been introduced in the last 10-15 years, and thereby a new strategy of “resurfacing/restoration” has been introduced to fill the gap between “repair” and “replacement.” First generation FKRIs are fully composed of metal and the availability of limited size and curvature options only contributed to high treatment failure rates. The combination of high implant stiffness and morphological mismatch leads to super-physiological stress peaks in adjacent or opposing cartilage during articulation, which leads to further cartilage degeneration. Second generation implants rely on improving implant fit (patient-specific implants and surgical guides) or more biomimetic material properties (forgiving to morphological mismatch) to overcome these issues.

A synthetic non-degradable polymer FKRI has been developed previously in the Chemelot InSciTe public-private collaboration project “SyCap.” Avalanche Medical BV has been founded as a spin-off company from this project to continue the development of this implant. The current project is intended to help refine the indications for use, design/use considerations, and clinical implementation for this medical device and similar implants.
To generalize across all treatments options, cartilage repair treatment success is influenced by a combination of biological factors (patient demographics, regenerative capacity, catabolic or inflammatory joint condition, etc.) and biomechanical factors (defect size and location, defect fill and joint morphology restoration, repair tissue or implant mechanical properties, surgical accuracy, joint mechanical axis correction, ligamentous repair). As we transition into an era of personalized medicine, selecting the right treatment for each patient is of utmost importance, and therefore the influence of all these factors on treatment outcomes must be elucidated in order to refine treatment selection algorithms.
In this OSTASKILLS project, we aim to explore the effect of the previously mentioned factors on clinical outcomes (or proxies thereof) for various cartilage repair techniques, with a primary focus on FKRIs (medical devices). A wide variety of methods will be employed to explore the influence of biological and biomechanical factors on clinical outcomes: insights gained from ex vivo models (biomechanical testing, surgical implantation accuracy evaluation) and in silico models (finite element modelling, statistical shape models) will be combined with insights from evaluating patient records and data (patient demographics, radiological imaging, patient-reported outcomes). Early health technology assessment will also be performed to evaluate cost-effectiveness of treatments.
These activities mark the first steps towards creating digital patient-twins, to better optimize treatment outcomes.

The research will be performed in the Laboratory for Experimental Orthopedics, Maastricht University, and the Joint Preservation Clinic of Maastricht University Medical Center (MUMC+), under the supervision of dr. P. Emans, dr. ir. Alex Roth, and prof. dr. Tim Welting. Ongoing collaborations with Eindhoven University of Technology (dr. René van Donkelaar) and University of Twente (prof. dr. ir. Gabrielle Tuijthof) will be leveraged for successful completion of this project. The OSTASKILLS project (www.ostaskills.eu) is a Marie Curie COFUND project coordinated by the Dutch Arthritis Society with the objective of training 10 PhD students in translational osteoarthritis research. Intersectoral collaboration and industry exchanges are important aspects of the training.

Eligibility criteria for candidates
An application to the doctoral training programme will only be considered eligible if it meets the following conditions:

1. Candidates have no more than four years full-time equivalent research experience and have not been awarded with a doctoral degree at the time of recruitment (call deadline).
2. Candidates must not have resided or carried out her/ his main activity (work, studies etc) in the country of their prospective host for more than 12 months in the 3 years immediately prior to the call deadline.
3. Applicants prove they are in possession of a Masters degree, approved by the prospective hosting organization.

The successful candidate will have a MSc degree in the field of medicine, (bio)medical engineering, or human movement sciences, with affinity for both biomechanics and clinical reasoning. Due to the multi-disciplinary nature of this project, we are seeking candidates with a proven multi-disciplinary background and a get-go mentality. Experience in more than one of the following domains is desired: finite element modeling, medical imageanalysis, medical device design and evaluation, mechanical/biomechanical testing, and epidemiological/clinical studies. The candidate will be open and communicative, proficient in the English language and be familiar with statistical methods. We are looking for a candidate who can work in a multidisciplinary team in a collaborative spirit, with an intrinsic dedication and motivation for improving the treatment of cartilage defects and osteoarthritis. The PhD student will be participating in Maastricht University educational activities.

Fixed-term contract: 1 + 3 years.

We offer a full-time position (38 hours/week) within Maastricht University at the Laboratory for Experimental Orthopedics, Department of Orthopedic Surgery at the Faculty of Health, Medicine and Life Sciences, School CAPHRI, Maastricht University, the Netherlands.

This full-time position is offered for four years (1+3), with a yearly evaluation. Your salary would be € 2.443,- gross per month in the first year up to € 3.122,- gross per month in the fourth year according to the PhD-candidate salary scale. On top of this, there is an 8% holiday and an 8.3% year-end allowance.

The terms of employment of Maastricht University are set out in the Collective Labour Agreement of Dutch Universities (CAO). Furthermore, local UM provisions also apply. For more information look at the website www.maastrichtuniversity.nl > About UM > Working at UM.

Maastricht University

Maastricht University is renowned for its unique, innovative, problem-based learning system, which is characterized by a small-scale and student-oriented approach. Research at UM is characterized by a multidisciplinary and thematic approach, and is concentrated in research institutes and schools. Maastricht University has around 22,000 students and about 5,000 employees. Reflecting the university's strong international profile, a fair amount of both students and staff are from abroad. The university hosts 6 faculties: Faculty of Health, Medicine and Life Sciences, Faculty of Law, School of Business and Economics, Faculty of Science and Engineering, Faculty of Arts and Social Sciences, Faculty of Psychology and Neuroscience. For more information, visit www.maastrichtuniversity.nl

Department Orthopaedic Surgery, School Caphri

School CAPHRI 

CAPHRI provides high quality multidisciplinary research and teaching aimed at the improvement of the individual's quality of life and the population's health through innovation in public health and health care.

Research and teaching in the School are devoted to contribute to improvements in the area of public health and primary care. CAPHRI focuses on interventions in the chain of care, starting with prevention and primary care, and ending with aftercare and rehabilitation. The aim of the research is to get insight into the effectiveness of interventions, and their adequacy in meeting prospective patients' needs.

https://www.caphri.nl

Department of Orthopaedic Surgery

The Department of Orthopaedic Surgery of the Faculty of Health, Medicine and Life Sciences (FHML) of the Maastricht University Medical Center, in Maastricht, the Netherlands has a long-standing clinical expertise in treatment of osteoarthritis and regeneration of cartilage defects within the joint preserving clinic and Orthopaedic Clinical Trial Center. The Laboratory for Experimental Orthopedics is a young, enthusiastic and multidisciplinary team with an established specialization in osteoarthritis and regenerative medicine
research. Due to the combination of clinical and technical work, the PhD candidate will work both at the laboratory as well as in the clinic (Orthopaedic Clinical Trial Center).

http://orthopedie.mumc.nl