The effect of erythropoietin on rat rotator cuff repair model: An experimental study

Abstract

Objectives: The aim of this study was to determine whether erythropoietin (EPO) can enhance rotator cuff healing in rats as measured by histological analysis and biomechanical testing. Methods: A total of 72 rats were included in this study. In the control group ( n = 24), repair was performed without EPO injection. In the local group ( n = 24) EPO was injected in the repair site. In the systemic group ( n = 24) EPO was administered as an intraperitoneal injection every day for 10 days after repair. Rats were euthanized on day 10 ( n = 12 from each group) and day 28 ( n = 12 from each group). Histopathological ( n = 6) and biomechanical examinations ( n = 6) were done. Results: Biomechanical results reveal that the maximum load to failure values of the early control group were statistically lower than those of the early systemic group ( p = 0.006). Comparing the the total Bonar values histopathologically reveal that the early systemic group was statistically higher than those of the early local group ( p = 0.043). The late control group was statistically higher than those of the late local group ( p = 0.003) and the late systemic group ( p = 0.034). The late systemic group was statistically higher than those of the late local group ( p = 0.003). Conclusions: EPO application had a positive effect biomechanically in the early euthanized group and histopathologically in the late euthanized group.