Comparison of biologic scaffolds for augmentation of partial rotator cuff tears in a canine model

Background: This study was designed to test the hypothesis that biologic scaffold augmentation of articular-sided partial-thickness supraspinatus tendon tears would be associated with superior functional, imaging, biomechanical, and histologic properties compared with untreated tears in a preclinical canine model. Methods: With Institutional Animal Care and Use Committee approval, dogs (n = 16) underwent half-thickness resection of the articular portion of the supraspinatus tendon (SST). Defects were treated by debridement (DB) (n = 8) or scaffold augmentation on the bursal side using amnion matrix cord scaffold (AM) (n = 8), decellularized human dermal allograft (AF) (n = 8), or bovine collagen patch (RMP) (n = 8). Control dogs (n = 4; 8 normal shoulders) were included. Assessments included lameness, function, comfortable shoulder range of motion (CROM), pain, ultrasonography, magnetic resonance imaging (MRI), arthroscopy, gross examination, biomechanical testing, and histopathology. Results: At 3 months, CROM was significantly lower and pain significantly higher in DB compared with all other groups. At 6 months, CROM was significantly lower and pain significantly higher in RMP compared with AM and AF, and AM and AF showed significantly less thickening than DB and RMP. AF had the least severe MRI pathology and AM had significantly less MRI pathology than DB. AF SSTs and biceps tendons showed the least severe histopathology, and AM SSTs showed significantly less histopathology than DB and RMP SSTs. Conclusion: Biologic scaffolds can be effective in augmenting healing of articular-sided partial-thickness SST tears when compared with debridement in a preclinical canine model. Decellularized human dermal allograft and amnion matrix cord may have advantages over the bovine collagen patch for use in this indication. (C) 2020 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.