Imaging of osteoarthritis-related bone marrow lesions in clinical trials

This narrative review aims to summarize current evidence regarding the imaging detection of bone marrow lesions (BMLs), their prognostic value for osteoarthritis (OA) progression and pain, as well as potential therapeutic interventions targeting BMLs in OA clinical trials. We performed a literature search in PubMed and Google Scholar for articles focusing on OA-related BMLs. Studies were included if they examined detection, pathophysiology, clinical significance, or treatments of knee BMLs. Non-OA etiologies (e.g., malignancy, rheumatologic diseases) were excluded. BMLs, present in approximately two-thirds of patients with knee OA, are considered key indicators of subchondral bone damage or microfracture. MRI is highly sensitive for detecting BMLs, using validated semi-quantitative and quantitative measurement methods. The lack of disease-modifying OA drugs has shifted interest toward targeting BMLs for potential therapeutic interventions. Clinical studies have shown that changes in BML volume can predict the subsequent incidence of OA in joints without established disease, and that their presence is associated with pain progression and structural deterioration when OA is already established. Potential treatments for OA-related BMLs include pharmacological agents that modify subchondral bone turnover, anti-inflammatory interventions, biomechanical stress reduction techniques, cellular therapies, dietary modifications, and surgical approaches. A holistic and personalized approach is essential for advancing OA management and improving patient outcomes by effectively targeting BMLs. Incorporating patient-reported outcomes and quality-of-life measures, as well as considering combined treatment strategies, will strengthen future trials aimed at modifying BMLs.