The effect of organic silicon injection on Achilles tendon healing in rats

Objective: The aim of this study was to assess the efficacy of a soluble absorbable silicon compound on healing of the Achilles tendon. Methods: The Achilles tendons of 21 Wistar albino rats were cut and repaired. A 0.01 ml organic silicon solution (silanol) was injected peri/intratendinously into the left leg of all rats and the same dose of saline into the right leg postoperatively. Rats were randomly divided into 3 groups for biomechanical testing on Day 10 (7 rats) and Day 20 (7 rats) and histological and immunohistochemical assessment on Day 20 (7 rats). Fibroblast cell count and diameter, tissue vascularity and blood vessel diameter were evaluated by histomorphometry. Basic fibroblast growth factor (bFGF) immunoreactivity was analyzed with immunohistochemistry on Day 20. Failure load and stiffness of the repaired tendons were measured on Days 10 and 20. Results: The number of fibroblasts per area, average fibroblast diameter, number of vessels parallel to collagen bundles per area and average vessel diameter were significantly higher in the organic silicon group than in the control group (p 0.05). Strong immunoreactivity of bFGF in the silicon group was detected. Failure load was significantly higher in the silicon group than in the control group on Day 10 (p=0.041). On Day 20, while a difference still existed, this difference was not significant. There was no effect of the silicon injection on stiffness of healing tendons. Conclusion: Organic silicon appears to have a positive effect on tendon healing and is suitable for further studies on host healing response modification.