18/01/2026
Hot off the Press 🔥
𝗢𝘀𝘁𝗲𝗼𝗮𝗿𝘁𝗵𝗿𝗶𝘁𝗶𝘀 𝗮𝘀 𝗮 𝘀𝘆𝘀𝘁𝗲𝗺𝗶𝗰 𝗱𝗶𝘀𝗲𝗮𝘀𝗲
Historically, osteoarthritis (OA) has been narrowly understood as an unavoidable, cartilage-centric, wear-and-tear disease that is inevitable with ageing (https://pubmed.ncbi.nlm.nih.gov/22392533/). Growing evidence from both preclinical and clinical research, however, challenges this narrow perspective. Instead, OA is increasingly understood as a systemic condition that affects the whole person, shaped by ongoing interactions between joint tissues and biological processes throughout the body (https://pubmed.ncbi.nlm.nih.gov/41339496/).
⚖️Rather than being limited to mechanical damage, OA involves a combination of disrupted cellular metabolism, breakdown of the extracellular matrix, impaired repair mechanisms, and activation of innate immune pathways. These processes are not confined to the joint itself. They are strongly influenced by broader systemic factors, including ageing, obesity, sex-specific biology, metabolic disturbances, chronic inflammation, and inter-organ communication (https://pubmed.ncbi.nlm.nih.gov/30209413/, https://pubmed.ncbi.nlm.nih.gov/31621562/, figure 1 top). This broader view also helps explain a common clinical observation: structural joint damage seen on imaging often correlates poorly with pain severity. Pain in OA appears to be shaped not only by local tissue pathology but also by central and systemic mechanisms such as pain sensitization and psychosocial influences (https://pubmed.ncbi.nlm.nih.gov/31621573/, https://pubmed.ncbi.nlm.nih.gov/30307131/).
📘 A brand-new review by Collins and colleagues (https://pubmed.ncbi.nlm.nih.gov/41339496/) emphasizes the role of adipose tissue and metabolic dysfunction as active drivers of OA, rather than passive consequences of increased joint loading. Experimental studies show that adipokines, including leptin (a satiety hormone), as well as components of the complement system, can directly promote both joint damage and pain (https://pubmed.ncbi.nlm.nih.gov/32078923/, https://pmc.ncbi.nlm.nih.gov/articles/PMC5341385/). Notably, obesity-related OA can develop even in the absence of excessive mechanical stress on the joints (https://pubmed.ncbi.nlm.nih.gov/33443201/).
💪Loss of muscle mass and conditions such as sarcopenic obesity further increase the risk of OA and contribute to functional decline, highlighting the importance of body composition rather than body weight alone (https://pubmed.ncbi.nlm.nih.gov/23312414/, https://pubmed.ncbi.nlm.nih.gov/40746030/).
💊 The authors also stress the need to move beyond a one-size-fits-all view of OA by applying phenotyping and endotyping approaches. Identifying distinct biological subtypes of OA may help explain why disease-modifying osteoarthritis drugs (DMOADs) have repeatedly failed in clinical trials (https://pubmed.ncbi.nlm.nih.gov/41339496/). Factors such as heterogeneous patient populations, treatment initiation at advanced disease stages, and an overemphasis on single tissues or pathways have likely limited therapeutic success (https://pubmed.ncbi.nlm.nih.gov/29609224/). Encouragingly, systemically acting treatments—including GLP-1 receptor agonists, metformin, and anti-inflammatory drugs originally developed for metabolic or cardiovascular conditions—are emerging as promising options for specific OA subgroups (https://pubmed.ncbi.nlm.nih.gov/39476339/, https://pubmed.ncbi.nlm.nih.gov/40179178/).
🔄 In addition to the concept that systemic factors can influence OA, there is growing evidence that shows the effects of knee pain and damage on the rest of the organism, illustrating a bidirectional relationship. This concept has also been demonstrated in studies showing that knee injury and pain might cause changes to the cardiovascular system (https://www.oarsijournal.com/article/S1063-4584(24)00059-1/fulltext) , brain (https://pubmed.ncbi.nlm.nih.gov/36593507/, https://pubmed.ncbi.nlm.nih.gov/36374499/) adipose tissue (https://pubmed.ncbi.nlm.nih.gov/40279436/) and other organ systems (figure 1, bottom). These data suggest that systemic factors can drive OA and, in turn, OA can have systemic consequences (figure)). This bidirectional relationship reinforces the idea of OA as a chronic, multi-organ condition rather than an isolated joint disorder.