Cable Reinforcement Combined With Biologic Tuberoplasty Restores Muscle Forces and Scapular Strain in an Irreparable Rotator Cuff Tear Model: A Cadaveric Study.

PURPOSE: To investigate the biomechanical impact of an irreparable rotator cuff tear and compare the isolated and combined effects of rotator cable reconstruction (CR) and biologic tuberoplasty (BioTB). METHODS: Eight cadaveric shoulders were tested using an ex vivo dynamic shoulder simulator in forward flexion (FF) and scapular plane abduction (SPA). Muscle forces, humeral head translations, and scapular strains were reported across five conditions: intact cuff, irreparable rotator cuff tear involving 100% supraspinatus and 50% of infraspinatus (Tear-alone), rotator CR, combined rotator CR with BioTB, and BioTB alone. Statistical analyses were conducted at three discrete humerothoracic elevation angles. RESULTS: The Tear-alone model produced significant alterations in muscle loading during FF, with supraspinatus forces increased (up to +75% at 30°, P = .002), and middle deltoid and infraspinatus reduced (-51% and -36%, P < .05) relative to intact. During SPA, increased loading was primarily observed in the anterior deltoid (up to +63%, P < .01). Rotator CR and combined rotator CR with BioTB restored muscle forces to near intact levels (P > .05), whereas isolated BioTB resulted in persistent deviations from intact across both motion planes (P < .05). Humeral head translations were unchanged across all conditions (P > .05). Scapular strain differences were region- and motion-specific, with significant increases in Zone 3B during SPA in Tear-alone (+89.8 ± 49.7 με; P = .014) and BioTB (+104.4 ± 57.2 με; P = .013) relative to intact, while FF showed minimal strain differences, limited to higher strain in rotator CR compared with combined rotator CR with BioTB and BioTB at 70° (P < .05). CONCLUSIONS: Combined CR with BioTB resulted in more favorable muscle force patterns than isolated tuberoplasty and improved strain distribution compared with CR alone, when assessed against the intact cuff state. CLINICAL RELEVANCE: This study provides evidence supporting rotator CR combined with BioTB as a promising approach for irreparable rotator cuff tears.