The Effect of Corticosteroid Doses on Pain in Knee Osteoarthritis: A Systematic Review and Meta-Analysis.

Objective: To evaluate the effect of various doses of intra articular corticosteroid injection (IACI) on pain reduction in knee osteoarthritis when compared with normal saline and perform a between-dose comparison.

Methods: A systematic review with meta-analysis was conducted searching four databases until April 2024. RCTs comparing the effect of IACI with normal saline on pain relief in knee osteoarthritis were included. The different doses were pooled into three categories: low (< 40 mg methylprednisolone equivalent), usual (40 mg), or high dose (> 40 mg). Their effect compared to normal saline was evaluated at very short (VST, 1-3 weeks), short (ST, 4-8 weeks) and middle term (MT, 10-16 weeks). A multivariate analysis carried out the influence of dosage on pain relief, at each time point. The Jadad scale was used to assess risks of bias and GRADE for certainty of evidence.

Results: Eleven studies were included in the meta-analyses (n = 1125 patients). Low dose was significantly superior to normal saline in the VST, but not in the ST (low-quality evidence). No data were available for the MT. The usual dose was significantly superior to normal saline in the ST, but not in the VST and MT (moderate-quality evidence). A high dose was significantly superior to normal saline in the ST and MT (low-quality evidence). Multivariate analysis showed that the dose significantly influenced pain reduction at ST and MT, but not in the VST (low-quality evidence).

Conclusion: The dose of IACI doesn't influence pain reduction in the peak effect, but a higher dose seems to have a more prolonged effect.