Efficacy of Intra-articular Corticosteroids for Knee Osteoarthritis

Intra-articular corticosteroid injections for osteoarthritis of the knee may improve pain and physical function for up to 6 weeks, but the quality of available evidence is low, according to a summary of a Cochrane meta-analysis published in the Journal of the American Medical Association.¹

Osteoarthritis of the knee is a major cause of chronic pain and disability and is characterized by cartilage degeneration, joint pain and stiffness. Intra-articular corticosteroid injections have been used to treat knee osteoarthritis for decades, but the American College of Rheumatology guidelines only provide a weak recommendation for their use in patients for whom basic treatment has failed.^2,3

The benefit vs harm of intra-articular corticosteroid therapy for knee osteoarthritis is unclear; some fear this treatment may only mask pain, allowing patients to inappropriately increase mobility and enable further joint damage.²

The researchers, led by Peter Jüni, MD, FESC, of St Michael’s Hospital and University of Toronto in Canada, evaluated the safety and efficacy of intra-articular corticosteroids for knee osteoarthritis in a meta-analysis and systematic review and published their results in the Cochrane Database of Systematic Reviews.²

Data from 1767 patients in 27 randomized controlled trials that compared treatment with intra-articular corticosteroids with control (sham injection or no treatment) were included in the analysis.

Intra-articular corticosteroids provided moderate improvement in knee pain compared with controls with a standardized mean difference of −0.40, or a 1.0-cm difference on a 10-cm visual analog pain scale. This finding suggests that for every 8 patients treated with corticosteroids, 1 patient will experience a reduction in knee pain (number needed to treat, 8).

A small benefit in physical function was also seen with intra-articular corticosteroids compared with control (standardized mean difference, −0.33), with a number needed to treat of 10.

Improvements in knee pain and physical function were greatest within 1 to 2 weeks after intra-articular corticosteroid treatment and persisted for up to 13 weeks for knee pain and 6 weeks for physical function.

However, improvements at 13 weeks were only seen in small trials, but not in moderate to large trials, and statistical tests suggested that the benefits of corticosteroids were overestimated in small trials.²

No difference in the risk for adverse events was found with intra-articular corticosteroids compared with control.

Summary and Clinical Applicability

Intra-articular corticosteroids are commonly used to treat osteoarthritis of the knee, although the risks and benefits of treatment have not been clearly demonstrated. In this meta-analysis, researchers examined the safety and efficacy of intra-articular corticosteroids compared with sham injection or no treatment.²

“Intra-articular corticosteroids may be associated with moderate improvement in pain and a small improvement in physical function. However, the quality of evidence is low. Associations of intra-articular steroids with benefit decreased over time. There was no association of intra-articular steroids with benefit at 6-month follow-up,” the researchers wrote.¹

“We have evidence that intra-articular corticosteroid therapy works short-term, but the evidence that this treatment works mid-term is not that robust,” Dr. Jüni told Clinical Pain Advisor. “The trials are contradictory and most suffer from poor design and small sample size.” 

“We need adequately powered randomized clinical trials that are well-designed and include a sham injection control group, use a sufficiently high dose of corticosteroids, and require sonographic guidance of injections to ensure that the drug actually ends up in the joint. These trials will need to include patients with stable disease and patients who have flare-ups of osteoarthritis after exercise or minor trauma,” he added.

Limitations

Heterogeneity among trials included in the analysis and small study effects contributed to low quality of evidence.

None of the trials specifically evaluated patients with acute osteoarthritis exacerbations.

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References

1. da Costa BR, Hari R, Jüni P. Intra-articular corticosteroids for osteoarthritis of the knee. JAMA. 2016;316(24):2671-2672. doi: 10.1001/jama.2016.17565
2. Jüni P, Hari R, Rutjes AWS, et al. Intra-articular corticosteroid for knee osteoarthritis (Review). Cochrane Database Syst Rev. 2015;(10):CD005328. doi: 10.1002/14651858.CD005328.pub3
3. Hochberg MC, Altman RD, April KT, et al; American College of Rheumatology. American College of Rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthritis Care Res (Hoboken). 2012;64(4):465-474.