Intramuscular Glucocorticoid Injection Shows Some Efficacy as Intra-Articular Alternative for Knee Osteoarthritis
April 30, 2021

By Nancy Melville

VIRTUAL -- April 30, 2021 -- Intramuscular glucocorticoid injection for the treatment of knee osteoarthritis (OA) shows similar efficacy in pain improvement as the more common intra-articular glucocorticoid injection over 24 weeks, according to a study presented at the 2021 Virtual Osteoarthritis Research Society International (OARSI) World Congress

“Intramuscular injection could present inferior effects to intra-articular injection in some cases at 4 weeks after injection; however, we found that intramuscular is non-inferior to intra-articular injection at 8 and 24 weeks,” reported Qiuke Wang, MD, Erasmus Medical Center, Rotterdam, the Netherlands. “We believe intramuscular injection is effective and the results of this trial provide evidence for shared decision-making, because in some cases, patients may have a preference for intramuscular injection.”

To compare the 2 techniques, the authors randomised 145 patients aged 45 years and older with symptomatic knee OA to receive an injection of triamcinolone acetonide 40 mg either with intra-articular injection in the knee joint or intramuscular in the ipsilateral ventrogluteal area.

Of the patients, 65% were female, and their mean baseline Knee Injury and Osteoarthritis Outcome Score (KOOS) was 48 (scale (0-100, with 0 indicating extreme pain).

In a per-protocol analysis of 66 patients in the intra-articular group and 72 in the intramuscular group, knee pain improvement occurred in both groups from week 2 to 24, with no significant differences between the groups in terms of superiority. While there were no statistically significant differences in terms of KOOS pain score at the 4-week follow-up, the intra-articular group showed stronger improvement, with a mean difference of -3.4 after adjusting for baseline score, sex, depression, and duration of knee OA.

Non-inferiority in pain scores between the 2 techniques -- defined as within a margin of 7 points on the KOOS pain score -- were achieved at weeks 8 and 24. Similar results were observed in an intent-to-treat analysis.

The adverse event rate was 33% in the intramuscular group and 42% in the intra-articular group.

[Presentation title: Intramuscular Gluteal Glucocorticoid Injection Versus Intra-Articular Glucocorticoid Injection in Knee Osteoarthritis: a 24-Week Multicenter Randomized
Controlled Non-Inferiority Trial. Abstract 4]