A limitation of most studies testing intraarticular therapy has been sample size. Combining studies may allow the ability to detect levels of pain relief not found in individual studies. A recent meta-analysis of 6 randomized controlled trials using intra-articular corticosteroid knee injections found short-term relief of pain for 2 weeks (relative risk [RR]=1.66; 95% confidence interval [CI], 1.37–2.01).7 The number needed to treat (NNT) range for these studies is 1.3 to 3.5. Two additional studies included in this study using higher-dose steroids (prednisone equivalent dose of 37.5 to 80 mg), with or without joint lavage, assessed improvement at 16 to 24 weeks. Although neither individual study showed statistically significant differences, the pooled data from the 2 studies favored symptom improvement at 16 to 24 weeks (RR=2.09; 95% CI, 1.2–3.7; NNT=4.4).7
Recommendations from others
Guidelines for the treatment of knee osteoarthritis were outlined by a task force for the European League Against Rheumatism (EULAR) Standing Committee for Clinical Trials. The task force recommended intra-articular steroid injection for acute exacerbation of knee pain. This task force performed an evidence-based review and concluded at least 1 randomized control trial recommended intraarticular steroid for patients with osteoarthritis. It was noted that intra-articular steroid injections were effective for only short-term pain relief and that there are no predictors of success of treatment, such as the presence or absence of such factors as joint effusion, degree of radio-logic change, age, or obesity.2
The American College of Rheumatology Subcommittee on Osteoarthritis Guidelines developed both nonpharmacological and pharmacological recommendations for the treatment of osteoarthritis of the knee.8 These recommendations include: use of intra-articular steroid injection for patients with acute exacerbations who had evidence for joint inflammation, and joint aspiration accompanying the intra-articular injection for “short-term relief.”
CLINICAL COMMENTARY
Intra-articular steroids provide extra relief for patients with acute exacerbations
Wail Malaty, MD
Hendersonville Family Practice Residency Program, Hendersonville, NC
This well-constructed review demonstrates that intra-articular steroid injections provide up to 3 weeks of pain relief for patients with osteoarthritis of the knee. While this may not seem like much, in practice it can be quite helpful in some situations. It provides supplemental pain relief for patients with acute exacerbations of their disease. It is also useful as a temporizing measure for patients who are candidates for total knee replacement but are not quite ready for it psychologically.