The effect of local injection of methylprednisolone acetate on the hypothalamic-pituitary-adrenal axis among patients with greater trochanteric pain syndrome.

Abstract

Greater trochanteric pain syndrome (GTPS) is a common clinical entity for which the most effective treatment is local corticosteroid injection (LCI). There are no studies on the effect of LCI among patients with GTPS on the hypothalamic-pituitary-adrenal axis. The present study recruited nonselected patients diagnosed with GTPS. After consenting, participants received low dose (1μg) of adrenocorticotropin hormone (ACTH) stimulation test at 09:00. Immediately following the test, participants received a LCI of 80mg of methylprednisolone acetate at the greater trochanteric region. The ACTH stimulation test was repeated 1, 2, 4, and 6weeks following the LCI. Cortisol samples were obtained at just prior to (basal) and 30min (post-stimulation) following every ACTH stimulation test. Serum cortisol levels of <500μmol/l obtained 30min following the ACTH stimulation test were considered evidence of secondary adrenal insufficiency. The study enrolled 22 patients, 21 of whom completed participation. There were 19 female participants (~90%), and mean age of all the participants was 55.2±8.6years. Four participants showed evidence of secondary adrenal insufficiency, which was observed only at weeks 1 and 2 following the LCI. Mean serum cortisol level among these four participants 30min following the ACTH stimulation test was 354μmol/l, with a range of 268-430μmol/l. LCI of 80mg of methylprednisolone acetate in the greater trochanteric area among patients with GTPS was associated with transient secondary adrenal insufficiency in ~20% of the patients, mainly 1week following the injection.