Comparing Mannitol and Hypertonic Dextrose Injections for Knee Osteoarthritis Pain and Function: A Randomised Trial

Knee osteoarthritis is a chronic and age-related disease that causes joint stiffness, pain, and biomechanical changes in the joint, resulting in decreased activity and performance. Prolotherapy is one of the methods of injection therapy in the management of this disease. Drugs such as hypertonic dextrose and mannitol have been introduced as prolotherapy drugs. The aim of this study is to evaluate the efficacy of intra-articular injection of mannitol compared to prolotherapy with hypertonic dextrose in terms of pain relief and functional improvement in patients with knee osteoarthritis.

A total of 48 patients with KOA were randomly divided into two groups: hypertonic dextrose (24 patients) and mannitol (26 patients). All patients received three intra-articular injections of either hypertonic dextrose or mannitol at two-week intervals. Visual Analogue Pain Scale (VAS), Oxford Knee Scale (OKS), and Western Ontario McMaster University Osteoarthritis Index (WOMAC) questionnaire scores were the outcome measures assessed before and 2, 4, and 8 weeks after the injections.

There were no statistically significant differences in pre-injection demographic characteristics between the two groups (p > 0.05). Results showed that VAS and OKS scores decreased over time (p < 0.001). Both interventions significantly improved the mean scores of WOMAC pain, WOMAC stiffness, WOMAC function, and WOMAC total score. There were not any serious side effects in any of the groups.

The results showed that prolotherapy is an effective and safe treatment. Although both groups had improvements in outcome measures during follow-up up to 8 weeks after the intervention, no statistically significant difference was found between the two groups.