Histologic outcomes of rotator cuff patch augmentation: a literature review

Rotator cuff repairs frequently fail due to inadequate biologic healing at the tendon-bone interface. Patch augmentation has emerged as a strategy to enhance this process by promoting cellular infiltration, organized collagen deposition, and matrix remodeling. This review evaluates the histologic and biochemical effects of scaffold augmentation, compares different augmentation materials, and analyzes commercially available implants based on animal and human studies. A Preferred Reporting Items for Systematic reviews and Meta-Analyses-guided search of PubMed, Scopus, and Embase through May 2025 identified 42 eligible studies that reported histologic or biochemical outcomes following augmented rotator cuff repair. Dermal matrix patches demonstrated accelerated early neovascularization and collagen synthesis but were associated with incomplete fibrocartilage formation and persistent type III collagen. Extracellular matrix-derived patches showed improved collagen alignment but were linked to inflammatory responses. Synthetic polymers produced dense type I collagen with variable immune reactions, while biologically augmented scaffolds achieved high collagen density with minimal macrophage infiltration. Demineralized bone matrix demonstrated early fibrocartilage integration, mature collagen crimp, and low inflammatory response by 8 weeks. Among commercially available products, REGENETEN, ArthroFLEX, and Dynagraft II showed the most complete scaffold resorption and tendon-like remodeling, whereas Conexa and Zimmer patches demonstrated consistent integration, and Permacol and BioEnthesis showed limited improvements. Overall, patch augmentation appears to enhance biologic healing after rotator cuff repair; however, definitive conclusions are limited by the lack of high-quality human studies. These findings may inform scaffold selection and future implant design aimed at improving tendon-bone healing and reducing retear rates.