Hypertonic dextrose injection (prolotherapy) for knee osteoarthritis: Long term outcomes

• Hypertonic dextrose injection (prolotherapy) was tested for knee osteoarthritis.
• A validated knee pain, stiffness and function outcome measure was used.
• Improvement at 2.5 ± 0.6 years was statistically significant and clinically important.
• Data quality was high; there were no unanticipated side effects or adverse events.
• Prolotherapy was safe and effective for most knee osteoarthritis in the long term.

SummaryObjectiveKnee osteoarthritis (OA) is a common, debilitating chronic disease. Prolotherapy is an injection therapy for chronic musculoskeletal pain. Recent 52-week randomized controlled and open label studies have reported improvement of knee OA-specific outcomes compared to baseline status, and blinded saline control injections and at-home exercise therapy (p < 0.05). However, long term effects of prolotherapy for knee OA are unknown. We therefore assessed long-term effects of prolotherapy on knee pain, function and stiffness among adults with knee OA.DesignPost clinical-trial, open-label follow-up study.SettingOutpatient; adults with mild-to-severe knee OA completing a 52-week prolotherapy study were enrolled.Intervention and outcome measuresParticipants received 3–5 monthly interventions and were assessed using the validated Western Ontario McMaster University Osteoarthritis Index, (WOMAC, 0–100 points), at baseline, 12, 26, 52 weeks, and 2.5 years.Results65 participants (58 ± 7.4 years old, 38 female) received 4.6 ± 0.69 injection sessions in the initial 17-week treatment period. They reported progressive improvement in WOMAC scores at all time points in excess of minimal clinical important improvement benchmarks during the initial 52-week study period, from 13.8 ± 17.4 points (23.6%) at 12 weeks, to 20.9 ± 2.8 points, (p < 0.05; 35.8% improvement) at 2.5 ± 0.6 years (range 1.6–3.5 years) in the current follow-up analysis. Among assessed covariates, none were predictive of improvement in the WOMAC score.ConclusionsProlotherapy resulted in safe, significant, progressive improvement of knee pain, function and stiffness scores among most participants through a mean follow-up of 2.5 years and may be an appropriate therapy for patients with knee OA refractory to other conservative care.