Osteoarthritis year in review 2025: Imaging.

OBJECTIVE: To conduct a narrative review of selected imaging studies published in the past year, with a focus on how emerging methods and multi-tissue assessments are contributing to disease characterization, early detection, and intervention strategies. DESIGN: We conducted a comprehensive search strategy of PubMed, Embase, and CINAHL for original English-language human studies on imaging in osteoarthritis, published between March 2024 and March 2025. From the 262 full-text studies that met inclusion criteria, we identified a set of representative studies through independent review and group discussion. These studies are organized into five themes that emerged from this study: effusion-synovitis, infrapatellar fat pad, muscle, subchondral bone, and subcutaneous fat. Within each theme, one highlighted study and several additional studies were synthesized, followed by a summary of cross-cutting insights and future directions. RESULTS: A total of 26 studies were included. Collectively, the studies reinforce the importance of viewing osteoarthritis as a condition involving multiple joint structures, with inflammation as a recurring feature across tissues. Muscle quality and local adiposity emerged as consistent imaging biomarkers, while accessible tools such as ultrasound and AI-enhanced radiography demonstrated potential for scalable clinical application. Links between imaging findings and biomechanics, particularly gait and loading patterns, also featured prominently. Cross-cutting themes emphasized the value of considering multiple tissues, expanding the reach of imaging to clinical and community settings, and integrating imaging with functional measures. CONCLUSIONS: Imaging research in the osteoarthritis continues to broaden in scope and application. The studies highlighted in this review illustrate how advances in methods and metrics are improving opportunities for earlier detection, more precise assessment of symptoms, and the development of targeted, structure-informed interventions.