Periarticular dextrose prolotherapy instead of intra-articular injection for pain and functional improvement in knee osteoarthritis

Background: Osteoarthritis (OA) is a degenerative disease that can lead to painful and dysfunctional joints. Prolotherapy involves using injections to produce functional restoration of the soft tissues of the joint. Intra-articular injections are controversial because of the introduction of needles into the articular capsule. Objectives: To compare the effect of periarticular versus intra-articular prolotherapy on pain and disability in patients with knee OA. Study design: Randomized double-blind controlled clinical trial. Setting: Single center, university hospital (Imam Hossein Hospital, Tehran, Iran). Methods: A total of 104 patients with chronic knee OA were enrolled. In the intra-articular group, 8 mL of 10% dextrose and 2 mL of 2% lidocaine were injected. Injections were repeated at 1 and 2 weeks after the first injection. In the periarticular group, 5 mL of 20% dextrose and 5 mL of 1% lidocaine were injected subcutaneously at 4 points in the periarticular area. Pain and disability, as assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), were recorded at each follow-up visit at 1, 2, 3, 4, and 5 months post-injection. Results: The visual analog scale score was significantly lower in the periarticular compared with the intra-articular group at the 2-, 3-, 4-, and 5-month visits but not at 1 month. Morning stiffness and difficulty in rising from sitting were improved in both groups and were not significantly different in the peri-and intra-articular groups. Pain, joint locking, and limitation scores were all improved in both groups. Difficulty in walking on flat surfaces or climbing stairs, and sitting and standing pain, were all improved in both groups from 1 to 5 months after treatment. Limitations: WOMAC scores are subjective and could be a limitation of the study. Conclusion: Periarticular prolotherapy has comparable effects on pain and disability due to knee OA to intra-articular injections, while avoiding risks of complications.