Prophylactic muscle injection treatment for fatty degeneration in rotator cuff injury: A systematic review of animal studies

Abstract

Introduction: Fatty degeneration is the most important factor affecting massive rotator cuff tear (RCT) function. However, the mechanism underlying fatty degeneration and treatment after massive rotator cuff injury remains to be elucidated. This study sought to systematically scoping review published animal studies to explore effective treatment options for fatty degeneration following human rotator cuff injury, focusing on fibro-adipogenic progenitor (FAP). Materials and methods: MEDLINE, PubMed, and Embase were systematically searched for articles published in June 2022, using relevant keywords. Animal species, injury and repair types, study duration, and fatty degeneration parameters were summarized. Results: Of the 120 studies, 51 were secondarily evaluated for cell treatment of fatty degeneration in rotator cuff injury. Finally, 6 studies examining the effects of FAP on fatty degeneration were selected for analysis. Six studies showed positive effects on the SS muscle following fibro/adipogenic progenitor (FAP) (n = 3) or pluripotent stem cell (n = 3) injections. Conclusion: Following the review, we concluded the following: 1) FAP cell injections effectively inhibit fatty degeneration after rotator cuff injury. Level of evidence: Level IV, review article.