Adipose-Derived Mesenchymal Cells and Platelet Rich Plasma to Repair Rotator Cuff Injuries in Rats - Abstract
Introduction: Rotator cuff injury is a common disease that may lead to persistent pain and functional impairment. Despite the improvement in the surgical technique, rotator cuff repairs are subject to a high rate of retears. A fibrovascular scar tissue is formed instead of true regenerative tissue. The use of biologic therapies could improve the healing of the tendon-to-bone insertion. We hypothesized that the combined use of adipose-derived stem cells (ASCs) and platelet-rich plasma (PRP) could improve the biomechanical and histological properties of the repair. Material and methods: A controlled experimental study conducted on 48 Sprague-Dawley rats. The supraspinatus tendon was sectioned and repaired and was randomly allocated to two groups: application of PRP alone or PRP and ASCs. Biomechanical and histological analysis was performed at 3 days, 1, 2 and 4 weeks. Results: There were no statistically significant differences in the biomechanical study. In the PRP group, load to failure at two weeks was 3.89 N ± 0.99 and in the ASCs group was 7.87 N ± 2.18 (p=0.05). Histological examination showed an increase in the presence of vessels at one and four weeks in the ASCs group (p=0.047). Collagen fibers were present in 25% of the repaired tissue in the ASCs group at one week and absent in the PRP group (p=0.047). Maximum differences in collagen concentration occurred at two weeks in favor of the ASCs group (p=0.059). Conclusion: The use of ASCs does not improve the biomechanical properties of the repair. However, increased vascularity and collagen fibers type I were promising findings in the group treated with ASC.