The Magnitude and Duration of the Effect of Intra-articular Corticosteroid Injections on Pain Severity in Knee Osteoarthritis: A Systematic Review and Meta-Analysis

Abstract

Objectives: The aims of the study were to clarify the evidence on the magnitude and duration of treatment effect of intra-articular corticosteroid injections for knee osteoarthritis compared with placebo, to evaluate a treatment effect by steroid type, and to describe the reported adverse effects.

Design: Cochrane Controlled Trials Register, Medline, Embase, CINAHL, Scopus, and Web of Science databases were searched. The risk of systematic bias was assessed according to the Cochrane Collaboration's domain-based evaluation framework.

Results: The final sample included eight randomized controlled studies with follow-ups from 1 to 26 wks. The risk of systematic bias was considered low in five and high in three studies. The pooled standardized mean difference was -0.58 (95% confidence interval = -0.88 to -0.27) and number needed to treat 5.1 (95% confidence interval = 10.0 to 3.7). The heterogeneity was considerable. The pooled effect size approached the level of statistical insignificance at 4 mos. The pooled risk ratio of adverse effects was insignificant 0.95 (95% confidence interval = 0.34 to 2.55).

Conclusions: The intra-articular corticosteroid had a mild to moderate effect on pain severity up to 3 mos after the injection-much longer than it had previously been reported. The effect may vary substantially in different patient groups and appropriate patient selection is important. The risk of adverse effects was low.