Influence of local steroid injections on traumatized tendon properties

Abstract

We investigated the effects of peritendon injections of hydrocortisone acetate on the separation force required to completely avulse a posttraumatized Achilles tendon of the adult male rat. One hundred thirty-five rats were randomly assigned to 3 groups and subsequently trau matized, treated, and sacrificed. One group was used to examine the effect of trauma; the second to examine effects of trauma and injections of hydrocortisone ace tate on the tension to failure strength of tendons; the third group was the control group. Injected animals received one, three, or five injections of 0.10 cc (125 mg/ml) hydrocortisone acetate and were sacrificed 3, 6, or 9 weeks following initial injection. Experimental animals (anesthetized) were traumatized by dropping a weight onto the Achilles tendon. The tendon was tested in tension to failure employing a soft tissue linear dis seminator. Histologic analysis using light microscopy was performed. We concluded that hydrocortisone ace tate has no deleterious effect on the rat Achilles tendon as measured biomechanically or histologically.