Middle Trapezius Tendon Transfer for Augmentation of In Situ Superior Capsular Reconstruction–Reinforced Partial Rotator Cuff Repair: Short-term Outcomes of a Prospective Cohort Study

BACKGROUND: Middle trapezius tendon (MTT) transfer has been described for dynamic reproduction of supraspinatus function. For management of irreparable rotator cuff (RC) tears, this procedure can be coupled with in situ (long head of the biceps tendon–based) superior capsular reconstruction (SCR) and partial RC repair. PURPOSE: To investigate the functional outcomes of augmentation of in situ SCR–reinforced partial RC repair with MTT transfer for the management of irreparable posterosuperior RC tears. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Conducted between September 2014 and March 2022, this study included 24 patients with irreparable posterosuperior RC tears who were allocated into 2 groups: patients managed with 2-layer tendon construct (in situ SCR–reinforced partial RC repair) (group A; n = 15) and patients managed with 3-layer tendon construct (MTT transfer–augmented, in situ SCR–reinforced partial RC repair) (group B; n = 9). Outcome measures included 2-year postoperative pain, range of motion (ROM) in forward flexion and external rotation, and the American Shoulder and Elbow Surgeons (ASES) and the shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores. For data comparison, independent and paired t tests were used for parametric quantitative variables, and Mann-Whitney and Wilcoxon signed-rank tests were used for nonparametric quantitative variables; Fisher exact and McNemar tests were used for qualitative variables. RESULTS: The mean age of the patients was 58.40 ± 4.54 years in group A and 59.22 ± 4.46 years in group B; there were no between-group differences in baseline patient characteristics. Patients in both groups had significant preoperative to postoperative improvement on all outcome measures (P < .05 for all). Group B had a significantly higher magnitude of postoperative improvement compared with group A in forward flexion ROM (88.88° ± 29.34° vs 46.66° ± 20.93°; P = .001), external rotation ROM (32.22° ± 14.81° vs 16.0° ± 9.10°; P = .002), ASES score (71.07 ± 8.26 vs 57.87 ± 8.39; P = .001), and QuickDASH score (–70.20 ± 6.95 vs –58.34 ± 12.52; P = .007). CONCLUSION: Augmentation of in situ SCR–reinforced partial RC repair with MTT transfer in a 3-layer tendon construct led to significantly greater improvement in postoperative ROM and functional scores compared with a 2-layer construct.