Introduction

Knee osteoarthritis (OA) is one of the most common and disabling forms of arthritis, affecting millions of people worldwide. It develops when the cartilage—the smooth, protective tissue that cushions the ends of bones in the knee joint—gradually wears down over time. This can lead to pain, stiffness, and difficulty moving the knee. However, thanks to recent scientific advances, we now better understand what causes knee OA. We also have new ways to detect the disease and treat it more effectively. In this article, we’ll explore the main risk factors for knee OA, explain the role of biomarkers (biological signs of disease), and highlight promising new treatments that are making a real difference for patients.

What is Knee Osteoarthritis?

Osteoarthritis is the most common type of arthritis, and the knee is one of the joints most frequently affected. Because our knees support much of our body weight and are essential for movement, they’re particularly vulnerable to wear and tear. But knee OA isn’t just an inevitable part of aging—it’s a complex condition driven by a combination of factors, including genetics, lifestyle habits, and environmental influences. By understanding how these elements interact, researchers and doctors are finding better ways to diagnose and treat this condition. Let’s break down what causes knee OA and why it happens.

New Insights from Research

Recent research has changed the way we think about the causes of knee OA. It’s more than just “wear and tear” from using the joint. Inflammation—a natural process that can become harmful when it lasts too long—is now recognized as a major contributor. Genetics also play a role; some people inherit genes that make their joints more vulnerable to OA. On top of that, injuries such as torn ligaments or damage from sports can accelerate the onset of knee OA.

Population studies highlight just how widespread knee OA is, especially as people age. For example, studies in certain high-altitude villages have found that as many as 75% of people over age 50 are affected. The prevalence can vary between men and women and often increases with age, especially in women. These findings show that knee OA is a global health challenge, affecting people in many different environments.

One of the most promising areas of research is the investigation of biomarkers—measurable substances in the body, like specific proteins or molecules, that reveal the presence or progress of disease. Biomarkers can be detected in blood, joint fluid, or seen through imaging tests like MRI scans. By identifying these signs, doctors can sometimes detect knee OA before symptoms appear, leading to earlier and more effective treatment.

Understanding the Risk Factors

Several factors can increase the likelihood of developing knee OA. One of the most significant is obesity. Extra body weight puts more stress on the knee joints and can speed up cartilage breakdown. In addition, fat tissue releases substances that promote inflammation, which can further damage knee tissues.

A history of knee injuries also increases OA risk. Damage to ligaments or cartilage, whether from sports or accidents, can make the joint less stable and more susceptible to further wear and tear. Conversely, too little physical activity and weak muscles around the knee can also raise the risk, since strong muscles help stabilize and protect the joint.

Genetics are important too—if your close relatives have knee OA, your risk is higher. Some jobs that involve a lot of kneeling, squatting, or heavy lifting can also put extra strain on the knee joints. Understanding these risk factors allows individuals and healthcare providers to take steps to prevent or slow down the progression of knee OA.

Biomarkers: A New Window into Knee OA

Biomarkers are changing how we diagnose and monitor knee OA. These measurable indicators—like proteins released when cartilage breaks down—can be found in blood or joint fluid. Higher levels of certain biomarkers often signal more extensive joint damage.

Modern imaging techniques, including MRI scans, provide even deeper insights. They can reveal early changes in cartilage and bone that traditional X-rays might miss. This allows doctors to detect knee OA at earlier stages and monitor its progression more precisely. With this information, treatment can be better tailored to each patient’s needs, leading to more personalized and effective care.

Innovative Treatments on the Horizon

Thanks to new discoveries about risk factors and biomarkers, knee OA treatment is evolving beyond traditional pain relief and physical therapy. Regenerative medicine is an exciting frontier, with treatments like platelet-rich plasma (PRP) injections—made from a patient’s own blood—helping to promote healing and reduce inflammation. Stem cell therapy is also being investigated for its potential to regenerate damaged cartilage.

Additionally, doctors are increasingly using biomarker information to personalize treatment plans, choosing therapies that are most likely to work for each individual patient. Lifestyle changes—especially weight loss and muscle strengthening—remain fundamental for managing knee OA and enhancing the effects of newer therapies.

Conclusion

Care for knee osteoarthritis is progressing rapidly, with better understanding of risk factors, new uses of biomarkers, and innovative treatment options. By combining lifestyle changes, earlier diagnosis, and personalized therapies, there is new hope for those living with knee OA. As research continues, we can look forward to even more effective ways to prevent, predict, and treat this condition—helping millions maintain mobility and improve their quality of life.

References

Magnusson, K., Kumm, J., Turkiewicz, A., & Englund, M. (2018). Early knee osteoarthritis or healthy ageing? [Abstract].