EVIDENCE-BASED ANSWER
Intra-articular steroid injections appear to provide 2 to 6 weeks of pain relief for patients with knee osteoarthritis (strength of recommendation [SOR]: A). Higher-dose steroids with or without joint lavage can provide pain relief up to 24 weeks (SOR: A). Steroid injections may be an appropriate adjunct in the treatment of osteoarthritis, which includes nonpharmacologic treatments (education, weight loss, physical therapy) and pharmacologic therapy (nonsteroidal anti-inflammatory drugs [NSAIDs], topical and opioid analgesics).1,2
Evidence summary
Osteoarthritis, also known as degenerative joint disease, is the most prevalent form of arthritis in the United States.3 For the elderly, it is a common cause of pain and disability, affecting patients’ ability to perform activities of daily living. Common causes of osteoarthritis include past and present biomechanical stresses affecting the articular cartilage, sub-chondral bone changes, and biochemical changes in the articular cartilage and synovial membrane.3
Treatment of patients with osteoarthritis of the knee should be individualized to the severity of symptoms for each patient. A treatment plan can include patient education, physical and occupational therapy, non-opioid oral and topical agents, NSAIDs, intra-articular corticosteroid injections, viscosupplementation injections, arthroscopic lavage, and total knee replacements.
Our knowledge of the long-term safety and efficacy of intra-articular knee corticosteroid injection is based on limited data. In a randomized, double-blind, placebo-controlled crossover study, investigators randomized 59 patients aged 51 to 89 years to receive either an intra-articular injection of 1 mL of 40 mg methylprednisolone or 1 mL of 0.9% saline. After 3 weeks, patients receiving steroid injection had a minimal change in baseline visual analogue score for pain compared with those receiving saline (median change: –2.0 mm vs 0 mm on a 100-mm scale).4
A randomized, single-blinded study involving 84 patients demonstrated significant self-report-ed “overall improvement” for patients given intra-articular triamcinolone hexacetonide (78%) compared with placebo (49%) after 1 week (P<.05).5 It also confirmed reports that visual analogue score for pain and distance walked in 1 minute improves significantly for both steroid- and placebo-treated groups up to 6 weeks. Only the steroid-treated patients exhibited improved walking distance at 1 week compared with baseline (P<.001).
A recent randomized, double-blind, placebo-controlled trial studied the long-term safety and efficacy of treatment of knee osteoarthritis with repeated steroid injections.6 These investigators studied 66 patients aged 40 to 80 years recruited from rheumatology clinics. One half (n=33) received injections of triamcinolone acetonide 40 mg, and the other half received saline injections every 3 months for 2 years. At 1- and 2-year interval follow-ups, no statistically significant difference was seen between the 2 groups in loss of joint space and no progression of degenerative disease, as demonstrated by measurements of joint space widths by standardized fluoroscopically guided radiographs. Although the primary outcome measure of this study was to assess radiologic joint space narrowing with repeated injections, knee pain and stiffness appeared to improve after 2 years, although these results were not well quantified.