Pharmacological interventions for early-stage frozen shoulder: a systematic review and network meta-analysis.

OBJECTIVES: To evaluate the efficacy of pharmacological interventions for treating early-stage, pain predominant, adhesive capsulitis, also known as frozen shoulder. METHODS: We performed a systematic review in accordance with PRSIMA guidelines. Searches were conducted on PUBMED, EMBASE and Cochrane Central Register of Controlled Trials on the 24th of February 2022. Outcomes were shoulder pain, shoulder function and range of movement. Synthesis involved both qualitative analysis for all studies and pairwise meta-analyses followed by a network meta-analysis for randomised controlled trials (RCTs). RESULTS: A total of 3,252 articles were found, of which 31 met inclusion criteria, and 22 of these were RCTs. Intraarticular (IA) injection of corticosteroids (8 RCTS, 340 participants) and IA injection of platelet-rich plasma (PRP) (3 RCTs, 177 participants) showed benefit at 12 weeks compared with physical therapy in terms of shoulder pain and function, while oral non-steroidal anti-inflammatories (NSAIDs) (2 RCTs, 44 participants) and IA injection of hyaluronate (2 RCTs, 42 participants) did not show a benefit. Only IA PRP showed benefit over physical therapy for shoulder range of movement. CONCLUSION: These results shows that IA corticosteroids IA PRP injections are beneficial for early-stage frozen shoulder. These findings should be appraised with care considering the risk of bias, heterogeneity, and inconsistency of the included studies. We believe that research focused on early interventions for frozen shoulder could improve patient outcomes and lead to cost-savings derived from avoiding long-term disability. Further well-designed studies comparing with standardised physical therapy or placebo are required to improve evidence to guide management.