Background: Studies have shown that intra-articular glucocorticoid injection treatment for knee synovitis has a better outcome in resting patients than in mobile patients. One reason for this observation might be that rest retards steroid resorption, causing an enhanced local treatment effect.
Objectives: To study drug resorption and the impact on hormone production in the hypothalamic-pituitary-adrenal axis after intra-articular glucocorticoid administration, with and without postinjection rest.
Methods: Twenty patients with rheumatoid arthritis and knee synovitis were randomised to either 24 hour bed rest or normal activity after intra-articular glucocorticoid treatment with 20 mg triamcinolone hexacetonide (THA). Serum levels of THA, cortisol, and adrenocorticotropic hormone (ACTH) were followed during 2 weeks.
Results: Short term and reversible decreases in serum cortisol and ACTH levels (p<0.001) were seen, without any significant differences between resting and mobile patients. The THA levels increased similarly in both groups, with the median serum peak seen after 8 hours.
Conclusion: Immobilisation does not appear to retard glucocorticoid resorption after intra-articular administration. Further studies are therefore needed to clarify the mechanism behind the beneficial effects of rest after intra-articular glucocorticoid treatment for knee synovitis.