Abstract
New designs for total hip replacement (THR) are continuously proposed to solve the limitations of the actual solutions. However, before they can reach the clinical practice, a long and expensive procedure is required, with experimental in vitro and in vivo tests. It is possible to simplify this procedure using an approach known as In Silico Trials. The aim of this project is to exploit this approach and develop a complete solution, based on in silico simulations, to quantitatively assess the risk associated with the most common failure modes of new designs for THR before any experimental study is conducted. The research activity is articulated in several steps. At first, a large collection of morpho-densitometric digital models of the hip joint is extracted from the already available dataset to represent well the anatomical variability typical of the patients who receive this kind of treatment. Then, on each model, a THR surgical procedure is simulated, reproducing the best practice, but also the variability normally seen in the real surgical procedures. In this way, a wide cohort is defined combining for each virtual patient multiple surgeries to account for the surgical variability for a total of about 300 case studies. For each case study, patient-specific and surgery-specific musculoskeletal dynamics and finite element models are generated and run with some different boundary conditions, including several motor tasks and accounting for tasks variability and patient specificity. Such simulation cohort represents a proper in silico trial of hip joint replacement to predict the risks of implant failure with respect to three failure modes, i.e. aseptic loosening for the stem, wear for the artificial joint, and impingement and dislocation. These represent 70-80% of the THR failures reported in different outcome registers, and thus provide an excellent starting point for the validation. The clinical validation of this in silico trials technology will be necessarily retrospective, using the results of the RIPO Joint Replacement Outcome Registry. The RIPO register is currently monitoring the outcome of 187,000 hip replacement procedures. From these, we will select a few implant designs that show incidence of the three considered failure modes much higher or much lower than the average. Among them, we will validate our IST4HR simulator using models for which the implant design is available from the manufacturer, in the public domain, or can be reverse-engineered from postoperative CT scans. We already have three designs available, two from Zimmer-Biomet and one in public domain. We will use our IST4HR simulator to predict the incidence of each failure mode considered for each implant design, and then compare it with the real incidence of that failure mode as reported by the RIPO registry. Once validated, the simulator can be extended to include more failure modes, and also other types of joint replacements.
Project details
Unibo Team Leader: Marco Viceconti
Unibo involved Department/s:
Dipartimento di Ingegneria Industriale
Coordinator:
Università di PISA(Italy)
Total Unibo Contribution: Euro (EUR) 81.876,00
Project Duration in months: 24
Start Date:
28/09/2023
End Date:
28/02/2026
