Dextrose prolotherapy for knee osteoarthritis: a randomized controlled trial

Abstract

Purpose: Knee osteoarthritis is a common, debilitating chronic disease. Prolotherapy is an injection therapy for chronic musculoskeletal pain. We conducted a 3-arm, blinded (injector, assessor, injection group participants), randomized controlled trial to assess the efficacy of prolotherapy for knee osteoarthritis.

Methods: Ninety adults with at least 3 months of painful knee osteoarthritis were randomized to blinded injection (dextrose prolotherapy or saline) or at-home exercise. Extra- and intra-articular injections were done at 1, 5, and 9 weeks with as-needed additional treatments at weeks 13 and 17. Exercise participants received an exercise manual and in-person instruction. Outcome measures included a composite score on the Western Ontario McMaster University Osteoarthritis Index (WOMAC; 100 points); knee pain scale (KPS; individual knee), post-procedure opioid medication use, and participant satisfaction. Intention-to-treat analysis using analysis of variance was used.

Results: No baseline differences existed between groups. All groups reported improved composite WOMAC scores compared with baseline status (P <.01) at 52 weeks. Adjusted for sex, age, and body mass index, WOMAC scores for patients receiving dextrose prolotherapy improved more (P <.05) at 52 weeks than did scores for patients receiving saline and exercise (score change: 15.3 ± 3.5 vs 7.6 ± 3.4, and 8.2 ± 3.3 points, respectively) and exceeded the WOMAC-based minimal clinically important difference. Individual knee pain scores also improved more in the prolotherapy group (P = .05). Use of prescribed postprocedure opioid medication resulted in rapid diminution of injection-related pain. Satisfaction with prolotherapy was high. There were no adverse events.

Conclusions: Prolotherapy resulted in clinically meaningful sustained improvement of pain, function, and stiffness scores for knee osteoarthritis compared with blinded saline injections and at-home exercises.

Trial registration: ClinicalTrials.gov NCT00085722.

Keywords: dextrose; knee; osteoarthritis; prolotherapy; randomized controlled trial.

Figure 1

Screening, enrollment, and randomization.

Figure 2

Change in WOMAC composite scores over 52 weeks (± standard error). WOMAC = Western Ontario McMaster University Osteoarthritis Index. Note: WOMAC is scored on a range of 0 to 100 points, with higher scores indicating better knee-related quality of life. Nonoverlapping confidence intervals indicate significance of change in dextrose scores compared with change in scores of both saline (P <.05) and exercise (P <.05) groups.