Changes in ultrasound assessed markers of inflammation following intra-articular steroid injection combined with exercise in knee osteoarthritis: exploratory outcome from a randomized trial.

ABSTRACT

OBJECTIVE: Knee osteoarthritis (KOA) is a multifactorial joint disease affecting many people worldwide. Recommended treatments for KOA include exercise and steroid injections, or a combination of these. The objective of this exploratory outcome analysis of a randomized trial was to assess changes in inflammation markers assessed by ultrasound imaging (US) in KOA secondary to intra-articular corticosteroid injection given prior to exercise therapy. DESIGN: This study is a sub-study to a larger clinical trial which compared the clinical effects of steroid injection in KOA to placebo injection, both given prior to exercise therapy. The US outcomes were changes from baseline in US-assessed synovial size, Doppler activity presence in the synovial membrane, and numbers of US-detected Baker's cysts. US was performed at baseline, week 14 (exercise stop), and week 26 (follow-up). RESULTS: Fifty participants received steroid injection, and 50 received placebo injection. All participants received 12 weeks of exercise. Forty-five and 44, respectively, completed the study. At week 14, the group difference in the change in synovium thickness was 2.2 mm (95%, confidence interval (CI) -0.5 to 4.8), P = 0.11. There were no group differences in the changes in distribution of patients with presence of synovial Doppler activity (P = 0.98) or Baker's cysts (P = 0.35). There were no statistically significant differences between groups at week 26 in any outcome. CONCLUSION: Intra-articular steroid injection of KOA-patients prior to a 3 months exercise programme did not reduce synovial hypertrophy, synovial Doppler activity, or Baker's cyst presence more than a placebo saline injection according to US-assessments. TRIAL REGISTRATION EudraCT 2012-002607-18.