Next-generation functional diagnostic paradigm for musculoskeletal diseases based on live SWIR imaging

Abstract The pursuit of accurate diagnosis for musculoskeletal diseases has driven significant advancements in imaging technologies. However, fully understanding the complexity of the diseases requires monitoring multiple functional components, particularly during locomotion. Here, we present a live short-wave infrared (SWIR) imaging strategy designed to capture functional variations of musculoskeletal diseases in male murine models, and further extend it to male rabbit models and human knee joint. This approach directly visualized the kinematics of synovial fluid during normal locomotion, identifying distinct peak of fluid flow. When applied to injury evaluation, it revealed significant kinematic differences in patellar maltracking between isolated tendon injuries and combined tendon and muscle injuries, providing mechanical insights into their long-term outcomes. The versatility of this technique was further demonstrated by simultaneously examining bone and vascular kinematics during bone healing. This enabled the monitoring of large arteries in bone, and revealed an initial divergence from the bone regeneration. Overall, this advanced live SWIR imaging methodology enables dynamic, motion-robust, and multi-componential assessments of functional variations, positioning it as a next-generation functional diagnostic tool for musculoskeletal diseases.