The Effect of Exercises after Local Steroid Injection on the Rabbit Achilles Tendon

ABSTRACT

OBJECTIVE: To evaluate the effects of exercises after local steroid injection on the rabbit Achilles tendon. METHOD: Twenty-one rabbits were received local injection of triamcinolone acetonide in the Achilles tendons. Group I rabbits were exercised passively on the ankle for three consecutive days immediately after injection. Group II were left to rest for three days after the injections, and then exercised for three days. Group III were left to rest without exercise. Triamcinolone was injected intratendinously in the right Achilles tendons (subgroup a), and injected in the paratendinous tissue of the left Achilles tendons (subgroup b). The Achilles tendons were dissected at 7 days after injection. RESULTS: Collagen concentration of group Ia was significantly lower than group IIa or IIIa. Collagen concentration of group Ib was significantly lower than group IIb. Collagen concentration of group Ia was significantly lower than group Ib. In tendons of group Ia, partial necrotic tissues with fragmented tendon fiber bundles were seen in light microscopic examinations. CONCLUSION: These results demonstrate that intratendinous injection of triamcinolone and immediate exercise of injected tendon, regardless of the routes of the injection, may cause damage to the rabbit Achilles tendon.