The meta-analysis and systematic review of arthroscopic lower trapezius tendon transfer for massive irreparable rotator cuff tears

Background Lower trapezius tendon (LTT) was increasingly used to restore external rotation in massive irreparable posterosuperior rotator cuff tears (PSRCTs), yet its performance remained unclear. Methods Following PRISMA 2020, PubMed, EMBASE, and Scopus were searched. Studies reporting ≥12-month outcomes after arthroscopically assisted LTT for irreparable PSRCTs were included; screened 259 records and retained 14 studies (433 shoulders) (PROSPERO CRD420251079171). Quality was assessed with MINORS and certainty with GRADE. Change scores for ER, FE, VAS, ASES, and Constant scores were pooled as standardized mean difference (SMDs); subgroup and leave-one-out analyses assessed heterogeneity, and publication bias was evaluated. Results ER improved +27.9° (SMD 1.80, 95% CI 1.35–2.25; I 2 = 83.9%), FE +37.0° (SMD 1.10, 95% CI 0.73–1.47; I 2 = 82.8%), VAS −4.2 (SMD −2.23, 95% CI −2.57 to −1.89; I 2 = 72.7%), ASES +32.5 (SMD 1.95, 95% CI 1.35–2.54; I 2 = 84.9%), and Constant +22.7 (SMD 1.63, 95% CI 1.27–1.98; I 2 = 17.2%). Graft healing was 89.4% (9 studies; 317 shoulders; 80.6%–100%); complications occurred in 3.70%, reoperation in 3.46%, and conversion to reverse total shoulder arthroplasty in 2.08%. Discussion Arthroscopically assisted LTT improved motion, pain, and function with high graft-healing and low complication rates, with outcomes consistent across grafts and ages. Level of evidence Level IV; Meta-Analysis