The duration of response to intra-articular steroid injections in patients with osteoarthritis of the knee: a single centre's experience

Abstract

Background: The burden of Osteoarthritis (OA) is huge, with a sizable proportion of patients that have failed the analgesic treatment and are not candidates for surgery or have refused surgery. Intraarticular corticosteroid injections (IASI) are considered standard of care for pain relief and control of local inflammation in this category of OA patients. However, there is a wide variation in the duration of response to steroid injections. This study was designed to determine the duration of response to IASI in patients with osteoarthritis of the knee in our environment.

Methods: Fifty-four patients aged between 30 and 80 years who have been diagnosed with osteoarthritis using the American College of Rheumatology criteria and have met the inclusion criteria were enrolled in the study and were given intra-articular steroid injections to the knee. Their responses were assessed using visual analogue scale (VAS) score, Western Ontario, and McMaster Universities Osteoarthritis Index (WOMAC) score at 2, 4 and 12 weeks. The patients were classified as responders if there was a fifty percent improvement in the WOMAC scores and a fifty percent reduction in the VAS score and non-responders if there is less than fifty percent improvement in the WOMAC score and less than fifty percent reduction in the VAS score.

Results: Fifty-two patients completed the study; 78.4% and 100% of these had good WOMAC and VAS responses

respectively at 2 weeks but this proportion gradually reduced to 47.9% and 56.3% for WOMAC and VAS respectively at 3 months.

Conclusion: Intra-articular steroid injections provide sustained response in patients with osteoarthritis of the knee who have failed analgesic therapy and are not candidates for total knee replacement for up to three months and the response decreases with advancing age.