Research trends and emerging treatment in frozen shoulder research: A bibliometric analysis and meta-analysis

Frozen shoulder (FS), characterized by pain and restricted mobility, remains a challenging condition with unclear optimal treatment. This study aims to investigate the development of FS research, identify hotspot treatments, and verify their efficacy. Analyzing 3139 FS-related publications from the Web of Science Core Collection revealed a significant rise in publications (R² = 0.9478), with the United States as a leader in this research area. Our keyword analysis pinpointed suprascapular nerve block (SSNB) as a notable research focus since 2021. To assess the effectiveness of SSNB, we conducted a meta-analysis of eight randomized controlled trials including 435 patients. The results at the 6-8 weeks follow-up showed SSNB significantly reduced pain and improved active shoulder function compared to intra-articular corticosteroid injections (IACI). Specifically, SSNB led to considerable enhancements in abduction (SMD: 12.88; 95 % CI: 4.13, 21.64; p = 0.004; I² = 54 %), flexion (SMD: 9.16; 95 % CI: 6.50, 11.82; p < 0.00001; I² = 0 %), and external rotation (SMD: 18.03; 95 % CI: 6.59, 29.48; p = 0.008; I² = 59 %). Additionally, there was a significant reduction in Shoulder Pain and Disability Index (SPADI) scores (SMD: 4.46; 95 % CIs: 7.75, -1.17; p = 0.008; I² = 59 %). Despite these findings, no differences were observed in the improvement of passive activities between the SSNB and IACI groups at any follow-up. This study supports the short-term benefits of SSNB for FS, prompting further investigation into its long-term efficacy and comparison with other treatments.