Acellular dermal matrix alone or in combination with subacromial bursa and humeral bone marrow concentrate for augmentation of massive rotator cuff tear repair: a double-blind randomized controlled trial protocol (MODA).

Background: Massive rotator cuff tears are challenging injuries, and there is currently a clinical need to improve treatment outcomes and reduce the re-tear rate. In recent years, both mechanical augmentation with acellular matrices, such as acellular dermal matrix and orthobiologics, including concentrated humeral bone marrow or subacromial bursal tissue, have been proposed to enhance clinical outcomes of the rotator cuff repair. Methods: Seventy-two patients (aged 18-65 years) with repairable large to massive rotator cuff tears involving supraspinatus and infraspinatus tendons are randomized in a 1:1 ratio to receive either acellular dermal matrix alone (Group A: mechanical augmentation) or a combination of acellular dermal matrix enriched with bone marrow concentrated from the humeral head and subacromial bursal tissue (Group B: mechanical and biological augmentation). The primary outcome is the re-tear rate at 1 year follow-up, assessed via MRI using Sugaya classification. Secondary outcomes include clinical and functional evaluations using the Constant-Murley, Visual Analogue Scale, PASS and DASH scores at 1, 3, 6, and 12 months. Work loss and restricted activity days and adverse events are also recorded. Biological and biomechanical characterization of acellular dermal matrix, concentrated humeral bone marrow and subacromial bursa are measured and correlated with clinical outcomes to find parameters affecting the tendon repair. Expected outcomes: A more robust tendon-to-bone reattachment, vascularization and cell colonization are expected to face to patient's functional demand and to diminish the psychological and economic burden resulting from re-tears, revisions, additional rehabilitation and missed work. The use of decellularized human matrix provides benefits, since it derives from donation of human tissue, with low production and distribution costs in comparison with commercially available acellular matrices. Clinical trial registration: [clinicaltrials.gov], identifier [NCT05855759].