High- versus Low-dose Steroid Injection for Adhesive Capsulitis (Frozen Shoulder): A Systematic Review and Meta-analysis

Background: Intraarticular steroid injections are a commonly used and proven treatment for frozen shoulder; however, there is no scientific basis for a certified dose. Objectives: This study aimed to identify the difference between high-and low-dose steroid injections treatments and suggest an appropriate dose. Study Design: Systematic review and meta-analysis. Methods: The MEDLINE, EMBASE, and Cochrane electronic databases were searched through February 15, 2023 for eligible randomized controlled trials. The effects of high-and low-dose steroid injections were calculated as standardized mean differences (SMD) in pain, shoulder range of motion (ROM), and functional improvement. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to evaluate evidence quality. Results: Four studies with 274 patients were included in the final analysis. The meta-analysis showed that improvement in pain (SMD, 0.10; 95% CI,-0.12 to 0.32), ROM (SMD, 0.07; 95% CI,-0.05 to 0.19), and functional improvement (SMD, 0.08; 95% CI,-0.10 to 0.26) did not differ significantly between the high-and low-dose steroid injections. Subgroup follow-up analyses also showed no clinically significant differences in SMD for pain, ROM, and functional scale measurement in any subgroups (after 3 weeks, 6 weeks, and one year). One article described that, although there was no significant difference in adverse events frequency between the high-and low-dose groups, flushing tended to occur more frequently in the high-dose group. Limitations: Limitations are the small number of studies included in the meta-analysis, no disease stage considered, and a short follow-up period. Conclusions: This meta-analysis suggests there are no significant differences between the high -and low-dose steroid groups in pain, ROM, or functional improvement. Therefore, considering the side effects of high-dose steroids, starting with low-dose steroids is recommended. However, further studies are needed to establish exact protocols according to disease severity.