The Effectiveness of Intra-Articular Injection of Hypertonic Saline in Pain Control and Function of Patients with Knee Osteoarthritis

Background: The aim of this study was to report the effectiveness of intra-articular injection of hypertonic saline in pain reduction and functional improvement in patients with knee osteoarthritis (OA). Methods: Patients with knee pain and dysfunction who fulfilled the American College of Rheumatology criteria and whose illness was sub-acute or chronic were enrolled. We performed a single intra-articular injection of 5 cc of hypertonic (5%) saline solution. Measured outcomes were Visual Analogue Scale (VAS) score and Knee Injury and Osteoarthritis Outcome Score (KOOS) evaluated before and 1 month after intervention. Results: A total of 28 patients with mean age of 66.3 years were surveyed. Overall, study participants reported clinically and statistically significant reduction in VAS and KOOS subscales for symptoms, pain, function, daily living, sports, recreational activities, and quality of life in one month of follow-up with respect to the patients’ mean baseline scores (by 24.47%, 42.74%, 54.96%, 43.78%, and 63.63%, respectively). Although obese patients [body mass index (BMI) ≥ 30 kg/m2] showed less improvement in terms of pain, sports, and quality of life subscales of KOOS, compared with non-obese patients (BMI < 30 kg/m2); VAS score difference was not significant. Conclusion: Intra-articular injection of hypertonic saline yields a statistically and clinically significant short-term pain reduction and functional improvement of patients with knee OA.