Abstract
PURPOSE: Based on its close anatomic features and nearly-collinear force vector to those of supraspinatus muscle, the current article describes a technique of middle trapezius tendon transfer for reproduction of supraspinatus function in the context of rotator cuff irreparability/re-tear management. METHODS: While seating the patient in beach-chair position, arthroscopic gleno-humeral examination and sub-acromial decompression are initially performed. Hamstring tendons are harvested and fashioned as flattened quadruple sheet. Through McKenzie approach, infraspinatus and subscapularis tendons are repaired. Then, medial half of middle trapezius insertion tendon is harvested from most medial 5-6 cm of the scapular spine. Through McKenzie approach, hamstring sheet is retrieved via a sub-trapezius/sub-acromial corridor from the scapular wound. Hamstring sheet is re-attached to cuff footprint by double row/suture bridge repair configuration. While retracting the scapula and placing gleno-humeral joint in 45(O)-abduction/45(O)-external rotation, hamstring sheet is re-attached to released middle trapezius tendon by non-absorbable sutures. Finally, tendon reconstruct is dynamically-tested in different positions of range of motion. RESULTS: Transfer of medial portion of middle trapezius insertion tendon (lengthened by interposition hamstring tendon sheet) to cuff footprint was technically feasible. Dynamic testing showed smooth sub-acromial gliding motion of the tendon reconstruct. CONCLUSION: For reproduction of supraspinatus function, hamstring tendon augmented-middle trapezius tendon transfer to cuff footprint heralds a number of technical and biomechanical advantages; thus offering a potential effective modality of cuff irreparability/re-tear management in relatively young patients of high functional demands. However, current description should be investigated in further biomechanical and clinical studies to validate its long-term outcomes.