Intra‐articular corticosteroids: Systematic review of effects of multiple injections and different doses.

Summary: Background: Corticosteroids are commonly used for intra‐articular (IA) treatment of osteoarthritis (OA); however, controversy exists regarding its use as a multiple‐injection treatment and for appropriate dosing. Objectives: This systematic review collected and critically appraised evidence regarding the effects of (1) multiple injections protocols for OA treatment in horses and humans; (2) different doses of corticosteroids for treating OA in horses and humans; (3) different doses of corticosteroids in challenged joint tissues/cells in vitro. Study design: Systematic review. Methods: Titles published up to June 2022 generated by searches in PubMed, CAB and the Web of Science were screened using general inclusion criteria. Each question (multiple treatments; different doses in vivo and in vitro) had further inclusion requirements. The risk of bias was assessed according to the study design. Horses were the species of interest but human studies were also considered. Results: Of 6417 titles generated by the systematic search, only nine met all inclusion criteria for question 1, one was included for question 2 and 11 for question 3. Most studies showed unclear/high risk of bias. Multiple‐injection protocols showed better symptom‐modifying changes at first injections with decreasing improvements over time or for shorter follow‐ups in both humans and horses. Disease‐modifying changes improved over shorter follow‐ups; however, at longer periods, negative effects were seen. Determining the dose effect of different doses of corticosteroids was challenging as only one in vivo study met the inclusion criteria. In vitro, lower doses appeared to be safer for articular tissues. Main limitations: Lack of studies meeting inclusion criteria. Conclusions: No benefits but drawbacks of multiple IA injections in the long term were found in this review. Results regarding the dose of corticosteroids in OA joints were poorly available in vivo and support the use of lower doses. In vitro, studies pointed out that lower doses might be safer for joint tissues. [ABSTRACT FROM AUTHOR]