Progressive tubularization of interpositional grafts following lower trapezius tendon transfer: implications for clinical and functional outcomes in irreparable rotator cuff tears.

BACKGROUND: Posterosuperior irreparable rotator cuff tears (PSIRCTs) are challenging to manage. Lower trapezius tendon (LTT) transfer using an interpositional graft has shown promise in PSIRCTs, with tubularization of the graft potentially contributing to improved outcomes. This study investigates the graft's morphological changes and their impact on clinical outcomes.

MATERIALS AND METHODS: A retrospective analysis was conducted on 105 patients who underwent LTT transfer using interpositional grafts-65 Achilles tendon allografts and 40 fascia lata autografts-for the treatment of PSIRCTs, with a minimum follow-up of 2 years. Graft morphology was categorized into 4 stages based on magnetic resonance imaging assessments: stage 1 (noncircular shape without contacting edges), stage 2 (noncircular shape with contacting edges), stage 3 (circular shape), and stage 4 (circular with fluid). Clinical assessment, including visual analog scale, Constant, American Shoulder and Elbow Surgeons scores, range of motion, and strength were evaluated, and radiological assessment included acromiohumeral distance and hamada graft, and graft integrity.

RESULTS: The mean tubularization stage increased from 1.5 ± 0.7 at 6 weeks to 2.6 ± 0.8 at 2 years. Patients with advanced tubularization (stages 3 and 4) at 2 years demonstrated significantly improved external rotation, forward elevation, and abduction strength (P < .001) compared to those with less tubularization. Pain scores (visual analog scale: 1.3 ± 0.6 vs. 1.6 ± 0.7) and functional scores-both Constant (56.9 ± 13.0 vs. 64.3 ± 13.2, P = .007) and American Shoulder and Elbow Surgeons (67.3 ± 14.9 vs. 73.7 ± 13.4, P = .027)-were significantly better in the advanced tubularization group compared to the less advanced group, but because the difference is below the minimal clinically important difference for these patient reported outcome measures, the difference may not be clinically meaningful.

CONCLUSION: This study demonstrates that the tubularization of interpositional grafts following LTT transfer is associated with improved clinical outcomes in patients with PSIRCTs. Final clinical outcomes demonstrated significant improvement, particularly in patients with tubularization (stages 3 and 4) compared to those with nontubularization (stages 1 and 2). This study highlights the potential for graft tubularization to become an essential component in the assessment and management of patients undergoing LTT transfer for PSIRCTs.