Decoding the PAAG Advantage: How Age, Lower KL Grade, and Non-Diabetic Status Shape Knee OA Outcomes

Introduction

Knee osteoarthritis (OA) is a widespread and often painful joint condition that affects millions of people, especially as we age. For those living with OA, simple activities can become challenging, and quality of life can suffer. Because of this, there's a constant search for treatments that are both effective and gentle on the body. One newer option showing promise is polyacrylamide hydrogel (PAAG) injections—a minimally invasive therapy meant to ease pain and restore knee function. However, outcomes with PAAG vary from person to person. Recent research highlights three important factors that play a big role in how well someone responds to PAAG: age, the severity of their OA (measured by the Kellgren–Lawrence or KL grade), and whether the patient has diabetes . In this article, we’ll break down how each of these factors impacts results and help you understand who is most likely to benefit from PAAG.

Who Gets the Most Benefit from PAAG?

PAAG injections don’t work the same for everyone with knee OA . Interestingly, evidence shows that older adults are more likely to experience significant improvement. This may seem unexpected, but research indicates that older patients tend to respond better. Another important factor is the KL grade, a scale doctors use based on X-ray findings to describe the severity of osteoarthritis . Patients with lower KL grades, meaning their OA is less advanced, typically see better outcomes. Diabetes is the third factor: individuals without diabetes report greater relief and improved function after PAAG treatment. Diabetes can impact the body’s healing abilities and may worsen inflammation, which could dampen the effectiveness of treatments like PAAG. All together, this means that the ideal candidate for PAAG is generally someone who is older, has mild to moderate knee OA , and does not have diabetes.

How Do We Know PAAG Is Working?

To determine if PAAG injections are truly helping, doctors rely on patient-reported outcome measures (PROMs). These include the Oxford Knee Score (OKS), which assesses how the knee performs in daily life; the Lysholm score, which evaluates stability and symptoms; and the Visual Analogue Scale (VAS), which lets patients rate their pain on a simple scale. Studies find that after receiving PAAG, many patients see meaningful improvements in these scores—and these benefits can last for at least two years. Most importantly, these improvements often surpass what’s known as the Minimal Clinically Important Difference (MCID). In other words, patients not only show statistical improvements, but they actually feel better and notice real changes in their everyday lives. This lasting relief shows PAAG can offer genuine benefits for the right people.

Personalizing Treatment: Why It Matters

No two cases of knee osteoarthritis are exactly alike, so treatments shouldn’t be one-size-fits-all. The research on PAAG highlights how important it is to tailor therapy to each individual. Understanding that older age, a lower KL grade, and the absence of diabetes predict better results allows doctors to recommend PAAG more confidently to those who will gain the most from it. This personalized approach ensures patients receive treatments more likely to help them, and avoids unnecessary interventions for those less likely to benefit. There’s even some evidence that people with OA in both knees (bilateral OA), rather than just one, might do better with PAAG, although more research is needed to confirm this. While factors such as body weight (BMI) could also play a role, these relationships aren’t fully understood yet. Overall, the key message is that customizing treatment leads to the best possible outcomes.

Conclusion

In summary, research clearly shows that PAAG injections are most effective for older adults who do not have diabetes and whose knee OA is in its earlier stages (lower KL grade). Improvements in pain and function—measured by user-friendly tools like the VAS, OKS, and Lysholm—support this targeted, individualized approach. For healthcare providers, considering each patient’s age, OA severity, and diabetes status is crucial when recommending PAAG. As research continues, our understanding will become even clearer, allowing more people with knee OA to benefit from new and better therapies. By personalizing care, we can help patients reclaim their mobility, reduce pain, and live fuller lives.

References

Gao, H. C. K., Akhtar, M., Creedon, C., Nar, Ö. O., Verma, T., & Lee, P. Y. F. (2025). Polyacrylamide hydrogel injections in knee osteoarthritis: A PROMs-based 24 month cohort study. Journal of Clinical Orthopaedics and Trauma. https://doi.org/10.1016/j.jcot.2025.103136