Comparative Efficacy of Intra-articular vs. MRI-guided Extra-articular Dextrose Injections in Knee Osteoarthritis Management

Osteoarthritis (OA) is a serious worldwide public health concern, causing increased disability-adjusted life years (DALY), the reasons of which include rising prevalence of obesity and increasing older populations. The knee is one of the most easily injured joint in the body, and knee OA can become a chronic and disabling condition that pose a threat to not only the patient but also his or her caretakers and healthcare resources. The prevalence of knee OA is 5% - 15% in men over 60 years, and 10% - 25% in women aged more than 60. Knee OA can result from injuries, diseases, or wear and tear from overuse. It refers to structural changes that affect subchondral bone, articular cartilage, menisci, ligaments, synovium, and other joint structures. Currently, there are several conservative management of knee OA, including physiotherapy (therapeutic exercise, diathermy, electrotherapy), oral or topical medications, intra-articular and extra-articular injections, and radiofrequency. There are various substances used in injections for knee OA, among which are corticosteroid, platelet-rich plasma (PRP), AmnioFix, exosome, dextrose, and hyaluronic acid (HA). Compared with PRP, AmnioFix, exosome, and HA, which are not covered by the health insurance system, dextrose is a readily available and cost-effective substance. The principle of hypertonic dextrose injection, "prolotherapy", is injection of small volumes of the irritant solution at or around the lesion in order to stimulate fibroblast and vascular proliferation, local tissue healing, reduction of joint instability, thus resulting in pain relief. Previous studies have demonstrated that prolotherapy resulted in clinically meaningful sustained improvement of function and pain in knee OA, and there were no severe adverse events related to hypertonic dextrose injection. A study in 2023 showed that among various dextrose concentrations, higher concentrations demonstrated greater improvement of knee OA, thus 20% dextrose is rec