The Effect of Intra-articular Injection of Betamethasone Acetate/Betamethasone Sodium Phosphate at the Knee Joint on the Hypothalamic-pituitary-adrenal Axis: a Case Controlled Study

Consecutive patients attending the rheumatology or orthopedic clinic with osteoarthritic knee pain, not responding satisfactorily to medical or physical therapy were allocated to group-1 after consent and given IACI of 6 mg of betamethasone acetate/betamethasone sodium phosphate. Following completion of this part, consecutive age- and sex-matched patients were allocated to group-2 and given intra-articular injection of 60 mg of sodium hyaluronate. Just prior to the knee injection and 1, 2, 3, 4 and 8 weeks later, patients had 1 µg adrenocorticotropin hormone (ACTH) stimulation test. Secondary adrenal insufficiency (SAI) was defined as levels of less than 18 ng/ml or a rise of < than 7 ng/ml of serum cortisol, 30 minutes following the ACTH stimulation test.