January 14, 2015
Annals of Internal Medicine
TAKE-HOME MESSAGE
- In this meta-analysis, researchers assessed 137 studies to determine the efficacy of treatments for knee osteoarthritis. Hyaluronic acid was considered the most effective for pain control, and acetaminophen was considered the least effective. Intra-articular corticosteroids did not improve function when compared with placebo, and none of the interventions differed in the ability to improve stiffness.
- Researchers suggest that this information can be used as another resource for individualizing treatment decisions.
Written by Tricia C Elliott MD, FAAFP
Osteoarthritis (OA) of the knees is a common joint condition seen in primary care practice that appears to be increasing in prevalence as our population continues to increase in longevity and body mass. It is a progressive disease of the joint that causes symptoms of pain, stiffness, and decreased function and may lead to increased disability and increased medical costs.
In a systematic review of randomized controlled trials, Bannuru and colleagues analyzed data comparing common recommended treatments for knee OA including acetaminophen, NSAIDs (ie, naproxen, ibuprofen, diclofenac, celecoxib), intra-articular (IA) corticosteroids, viscosupplementation (ie, IA hyaluronic acid), IA placebo, and oral placebo. They compared efficacy with regard to pain, function, and stiffness. For pain, the active IA treatments were most effective, with IA hyaluronic leading the way followed by IA corticosteroids. Active IA treatments were superior to oral medications, with acetaminophen being the least effective active oral treatment. This is of significance as acetaminophen is one of the most widely used over-the-counter pain medications for knee OA, although it appears to be the least effective for pain relief. Even IA placebo proved more effective than oral NSAIDS, demonstrating a placebo response secondary to needle placement in the knee. The exact mechanism leading to this clinical benefit is not clear. Of the NSAIDs, diclofenac showed slightly more favorable efficacy for pain treatment, followed by ibuprofen, naproxen, and celecoxib.
With regard to efficacy for improving function, NSAIDs and IA hyaluronic acid were all better than IA corticosteroids. For stiffness, NSAIDs were statistically significantly better than acetaminophen, and IA hyaluronic acid was better than IA placebo. IA corticosteroids did not show statistically significant effects.
Overall, IA treatments, especially hyaluronic acid, are superior to NSAIDs for pain control. Most patients with knee OA present to their primary care physician complaining of pain. Assessing the risks and benefits of treatment for each patient along with patient preferences is critical to guide treatment decisions. There are limitations to all these treatment interventions; however, oral medications may pose a greater potential for adverse systemic effects and toxicities. With localized joint disease, we may now have a stronger consideration for IA treatments, which can significantly reduce pain and pose a lower risk of adverse effects. Performing such IA treatments is well within the purview of a well-trained primary care physician and can contribute to lower overall health care costs and increased patient satisfaction.
Abstract
BACKGROUND
The relative efficacy of available treatments of knee osteoarthritis (OA) must be determined for rational treatment algorithms to be formulated.
PURPOSE
To examine the efficacy of treatments of primary knee OA using a network meta-analysis design, which estimates relative effects of all treatments against each other.
DATA SOURCES
MEDLINE, EMBASE, Web of Science, Google Scholar, Cochrane Central Register of Controlled Trials from inception through 15 August 2014, and unpublished data.
STUDY SELECTION
Randomized trials of adults with knee OA comparing 2 or more of the following: acetaminophen, diclofenac, ibuprofen, naproxen, celecoxib, intra-articular (IA) corticosteroids, IA hyaluronic acid, oral placebo, and IA placebo.
DATA EXTRACTION
Two reviewers independently abstracted study data and assessed study quality. Standardized mean differences were calculated for pain, function, and stiffness at 3-month follow-up.
DATA SYNTHESIS
Network meta-analysis was performed using a Bayesian random-effects model; 137 studies comprising 33 243 participants were identified. For pain, all interventions significantly outperformed oral placebo, with effect sizes from 0.63 (95% credible interval [CrI], 0.39 to 0.88) for the most efficacious treatment (hyaluronic acid) to 0.18 (CrI, 0.04 to 0.33) for the least efficacious treatment (acetaminophen). For function, all interventions except IA corticosteroids were significantly superior to oral placebo. For stiffness, most of the treatments did not significantly differ from one another.
LIMITATION
Lack of long-term data, inadequate reporting of safety data, possible publication bias, and few head-to-head comparisons.
CONCLUSION
This method allowed comparison of common treatments of knee OA according to their relative efficacy. Intra-articular treatments were superior to nonsteroidal anti-inflammatory drugs, possibly because of the integrated IA placebo effect. Small but robust differences were observed between active treatments. All treatments except acetaminophen showed clinically significant improvement from baseline pain. This information, along with the safety profiles and relative costs of included treatments, will be helpful for individualized patient care decisions.