Purpose: This study aimed to evaluate whether cilostazol (phosphodiesterase III inhibitor) could enhance the healing of Achilles tendon ruptures in rats.
Materials and methods: The Achilles tendons of 24 healthy male adult rats were incised and repaired. The rats were randomly allocated to cilostazol and control groups. The cilostazol group received daily intragastric administration of 50 mg/kg cilostazol for 28 days, while the control group did not receive any medication. The rats were sacrificed on the 30th day, and the Achilles tendon was evaluated for biomechanical properties, histopathological characteristics, and immunohistochemical analysis.
Results: All rats completed the experiment. The Movin sum score of the control group was significantly higher (p = 0.008) than that of the cilostazol group, with means of 11 ± 0.63 and 7.50 ± 1.15, respectively. Similarly, the mean Bonar score was significantly higher (p = 0.026) in the control group compared to the cilostazol group (8.33 ± 1.50 vs. 5.5 ± 0.54, respectively). Moreover, the Type I/Type III Collagen ratio was notably higher (p = 0.016) in the cilostazol group (52.2 ± 8.4) than in the control group (34.6 ± 10.2). The load to failure was substantially higher in the cilostazol group than in the control group (p = 0.034), suggesting that the tendons in the cilostazol group were stronger and exhibited greater resistance to failure.
Conclusions: The results of this study suggest that cilostazol treatment significantly improves the biomechanical and histopathological parameters of the healing Achilles tendon in rats. Cilostazol might be a valuable supplementary therapy in treating Achilles tendon ruptures in humans. Additional clinical studies are, however, required to verify these outcomes.
Keywords: Achilles tendon; Bonar score; Movin score; cilostazol; phosphodiesterase III inhibitor.