Fig. 1

The search results and selection procedure. The literature search identified 389 citations. Of these, 290 duplicates were removed. After reviewing the 99 remaining articles’ titles and abstracts, we excluded 74 papers according to the inclusion and exclusion criteria; 25 full texts were retrieved. Because some articles did not compare the suprascapular nerve block with interscalene nerve block, five studies were excluded. Finally, we identified 1255 patients assessed in 17 randomized controlled trials