Acellular Human Dermal Allograft Tuberoplasty Improved the Biomechanics in Mid-Range and Higher Abduction Angles in a Cadaveric Model of Massive Irreparable Rotator Cuff Tears

Abstract

PurposeTo evaluate the biomechanical effects of Acellular Human Dermal Allograft Tuberoplasty (AHDAT) in a cadaveric model of an irreparable supraspinatus + anterior ½ infraspinatus (Stage III) rotator cuff tear . MethodsEight cadaveric shoulders were tested at 20°, 40°, and 60° glenohumeral abduction (AB) and 0°, 30°, 60°, and 90° external rotation (ER). Superior humeral translation, acromiohumeral distance, and subacromial contact were quantified for four conditions: 1) intact, 2) stage III tear (entire supraspinatus and anterior one-half infraspinatus), 3) single-layer AHDAT, and 4) double-layer AHDAT. ResultsStage III tear significantly increased superior translation at 20° and 40°AB and all ER angles and at 60° AB/60° ER (P ≤ 0.045 vs. intact). Compared to the stage III tear, the single-layer AHDAT significantly decreased superior translation at 60° AB/60° ER (P = 0.003); whereas, the double-layer AHDAT significantly decreased superior translation at 40° and 60° AB at all ER angles except 60° AB/0° ER (P ≤ 0.028). The stage III tear significantly decreased acromiohumeral distance at 20° AB (P ≤ 0.003); both grafts increased acromiohumeral distance to intact levels(P ≥ 0.055 vs. intact). Stage III tear increased subacromial contact pressure at 20° and 40° AB/ 0° and 30° ER and at 60° AB/30° and 60° ER (P ≤ 0.034). Both AHDAT groups decreased contact pressure at 40° AB/30° and 60° ER back to intact; whereas the double-layer AHDAT also decreased contact pressure at 20° AB/0° and 60° ER and 60° AB/30° ER (P ≥ 0.051 vs. intact). ConclusionBoth single- and double- layer grafts for AHDAT, improved superior translation, subacromial contact characteristics and acromiohumeral distance after a stage III rotator cuff tear, with varying effectiveness due to the position-dependent nature of greater tuberosity-to-acromial contact with abduction.