Pre-injection of hyaluronic acid does not affect the systemic effects of intra-articular depot betamethasone injection at the knee joint

Intra-articular injection (IAI) of both hyaluronic acid (HA) and depot-steroid preparations had the advantage of quick and prolonged favorable effects on pain relief among patients with symptomatic osteoarthritis of the knee (OAK). The effect of IAI of HA on the systemic effects of the intra-articular steroids had not been investigated. Non-selected patients attending the rheumatology clinic with symptomatic OAK who failed NSAIDS and physical therapy were offered an IAI of HA at the knee joint followed 20 min later by an IAI of 1 ml of Celestone Chronodose at the same joint (group 1). Morning serum levels of cortisol were obtained just prior to the IAI and 1, 2 and 8 days later. Demographic, clinical, and laboratory parameters were obtained also from all the patients. Age- and sex-matched group of patients from the same clinic were recruited as a control group (group 2). Mean baseline serum cortisol levels in group 1 was 381 ± 154 mmol/l vs. 376 ± 119 in group 2 (p = 0.954). Morning serum cortisol levels at day 1 and day 2 were 24 ± 6 and 22 ± 6 mmol/l, respectively, in group 1 patients vs. 27 ± 5.8 (p = 0.214) and 25 ± 5.6 mmol/l (p = 0.200), respectively, in group 2. These levels were significantly lower than baseline levels in each group. Morning serum cortisol levels at day 8 in group 1 and group 2 were 349 ± 128 and 314 ± 99 mmol/l, respectively (p = 0.419). Pre-injection of HA at the knee joint did not affect the systemic effect on the hypothalamic-pituitary-adrenal axis of IAI of Celestone Chronodose.