A Review of Biological Augmentation for Rotator Cuff Repair: a Single Laboratory's History

Purpose Rotator cuff tears and frequent re-tears place a significant financial burden on the healthcare system as well as a physical and emotional burden on suffering patients. Significant progress has been made in exploring modes of biological augmentation for implementation into complex soft-tissue repairs. This article reviews these findings and their translation into improved clinical outcomes and current and future studies. Methods This is a review of recent studies regarding biological augmentation of rotator cuff repair performed at the Human Soft Tissue Research Laboratory at UConn Health. Each section addresses one aspect of biological augmentation: characterizing biological interactions at the site of injury, connective tissue progenitor cell sources, extracellular matrix scaffolds, platelet-rich plasma, and clinical applications of these findings. Results It is possible to recreate the biological interactions of tendon and bone at the site of injury, allowing for characterization of healing as well as a testing medium for future biologics. Two high-quality sources of connective tissue progenitor cells (CTPs), concentrated bone marrow aspirate and subacromial bursa cells, can easily be extracted, processed, and reintroduced to the site of injury during a single operation. The scaffold that biologics are delivered on can be tailored to maximize healing potential. Improved clinical outcomes have been demonstrated with a variety of combinations of biologics. Conclusion Current and future studies include analysis of operating room clot preparation techniques, exploring the effects of doxycycline and PRP in a rat co-culture model, and continued clinical outcomes studies. Lay Summary This paper reports on the advances in the understanding and implementation of biological augmentation in rotator cuff repair that have been made at the Human Soft Tissue Research Laboratory at UConn Health. Many biologics show promise in improving the outcomes for operations that currently have very high re-tear and failure rates. The subsequent high costs associated with these ailments are another burden on the patient, the provider, and the healthcare system as a whole. Significant progress has been made regarding the sourcing, processing, and introduction of these biologics in clinical settings, guiding future studies and advances in clinical practice.