We spent 4 rich and intense days at the 2024 International Workshop of Osteoarthritis Imaging (18th IWOAI) in Marrakech, Morocco, with enlightening lectures on the relationship between pain and structure in osteoarthritis. There was great opportunity to establish new contacts and nurturing existing friendship amongst researchers from academia and industry, hopefully soon bringing the first and long-awaited disease modifying osteoarthritis drug (DMOAD) to market.

Felix Eckstein with Jamie Collins were invited to speak about multi-component and composite outcomes vs. single endpoints tailored to the specific mechanism of action (MOA) in putative DMOAD trials. This will be followed by a “Perspective” on this topic in the “Osteoarthritis Imaging” Journal (OSTIMA) and will be hopefully available for reading soon.

Wolfgang Wirth presented on the clinical validation of cartilage transverse relaxation time by MRI (T2), known to be related to cartilage composition and mechanical properties. Segmentation was performed using new fully automated convolutional-neural-network (CNN)-based models, and a novel high-resolution qDESS MRI sequence. The study was conducted in close collaboration with Annegret Mündermann and Simon Herger from the University of Basel, Switzerland. It was found that knees with anterior cruciate ligament (ACL) injury exhibit longer T2 (suggesting early cartilage pathology) in the deep femorotibial cartilage compared with contra-lateral knees or healthy reference knees. The superficial cartilage T2 and the cartilage thickness, in contrast, were not significantly different between case and reference knees. This work was supported by a Eurostars OA-BIO consortium grant and represents a big step forward in achieving time- and cost-efficient analysis of cartilage T2 and thickness from the same image acquisition (qDESS) and (automated) segmentation algorithm.

Anna Wisser displayed a poster on a rapid (<30 min) sample acquisition protocol, encompassing MRI sequences for (quantitatively) assessing synovitis (no contrast), cartilage thickness and cartilage T2, and (semi-quantitative scored) structural pathologies of articular tissue. This first study in the PROTO Horizon project was co-authored by Chondrometrics GmbH team members and Nicholas Brisson, Georg Duda, Tazio Maleike, and project head Tobias Winkler from the Universitätsmedizin Berlin.

Susanne Maschek presented a poster on sexual dimorphism of radiographic joint space width (JSW) in joint space narrowing (JSN) strata of almost 1000 subjects. Med higher values of greater JSW than women, but the difference decreased with greater JSN. She further assessed “genuine” sex differences in femorotibial cartilage thickness, independent of other demographic factors. Women matched for the same body height-, age-, and BMI and without radiographic disease values than women still displayed approx. 10% less cartilage thickness and also smaller joint surface areas, indicating that women may be structurally disadvantaged in terms of suffering from knee osteoarthritis (for the poster, please see the OARSI 2024 NEWs section)

Felix Eckstein eventually compared the performance of coronal FLASH and sagittal DESS MRI in discriminating progressor vs. non-progressor knees in the OAI FNIH Biomarker sample (FNIH1), using fully automated segmentation of cartilage thickness. Co-authored by Wolfgang Wirth from Chondrometrics, Akshay Chaudhari (Standford University) and David Hunter (University of Sydney), the novely of that study is that the comparison is without potential reader preference or bias, given that the analysis was done fully automated using a CNN-based deep learning AI algorithm that was trained on the FLASH and DESS images of a different set of knees. The study reported greater rates of progression by FLASH than DESS, but also greater standard deviations and progression in control subjects, so that the actual discrimination of both groups was very similar across both MRI sequences

Impressions from Marrakesh

Ali Guermazi, MD, PhD Guermazi is to be hugely thanked for organizing a fantastic conference and venue that kept us without sleep not only for the day but also for most of the nights. We all look forward to meet in Cambridge for the 19th IWOAI hosted by Tom Turmezei in July 2025.