More Bad News About Knee Injections

Monday, August 27, 2012 // Uncategorized

Patients with deterioration of the cartilage on the knee are frequently prescribed injections derived from hyaluronic acid derivatives.  These substances are supposed to reduce pain and stiffness when injected in the knees of patients with osteoarthritis.  I have never been impressed by their efficacy when used in my patients and the studies supporting their use show questionable efficacy.  The most recent study adds support to the doubters.

Meta-Analysis: Viscosupplementation for Knee Osteoarthritis Ineffective

Viscosupplementation, the intra-articular injection of hyaluronic acid, offers few benefits for knee osteoarthritis but can lead to serious adverse events, according to an Annals of Internal Medicine analysis.

Examining 89 trials comprising over 12,000 adults, researchers found “a small, clinically irrelevant effect” on pain from viscosupplementation. At the same time, treatment was associated with increased risk for overall serious adverse events (for example, those resulting in significant disability or inpatient hospitalization).

The researchers criticize the methodological and reporting quality of many of the studies, and the fact that safety data were often not reported at all. Nonetheless, they conclude that “the administration of these preparations should be discouraged.”

Here is the abstract from The Annals of Internal Medicines:

Viscosupplementation for Osteoarthritis of the Knee: A Systematic Review and Meta-analysis ONLINE FIRST

Anne W.S. Rutjes, PhD; Peter Jüni, MD; Bruno R. da Costa, MSc; Sven Trelle, MD; Eveline Nüesch, PhD; and Stephan Reichenbach, MD, MSc

Ann Intern Med. 12 June 2012
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Background: Viscosupplementation, the intra-articular injection of hyaluronic acid, is widely used for symptomatic knee osteoarthritis.

Purpose: To assess the benefits and risks of viscosupplementation for adults with symptomatic knee osteoarthritis.

Data Sources: MEDLINE (1966 to January 2012), EMBASE (1980 to January 2012), the Cochrane Central Register of Controlled Trials (1970 to January 2012), and other sources.

Study Selection: Randomized trials in any language that compared viscosupplementation with sham or nonintervention control in adults with knee osteoarthritis.

Data Extraction: Primary outcomes were pain intensity and flare-ups. Secondary outcomes included function and serious adverse events. Reviewers used duplicate abstractions, assessed study quality, pooled data using a random-effects model, examined funnel plots, and explored heterogeneity using meta-regression.

Data Synthesis: Eighty-nine trials involving 12 667 adults met inclusion criteria. Sixty-eight had a sham control, 40 had a follow-up duration greater than 3 months, and 22 used cross-linked forms of hyaluronic acid. Overall, 71 trials (9617 patients) showed that viscosupplementation moderately reduced pain (effect size, −0.37 [95% CI, −0.46 to −0.28]). There was important between-trial heterogeneity and an asymmetrical funnel plot: Trial size, blinded outcome assessment, and publication status were associated with effect size. Five unpublished trials (1149 patients) showed an effect size of −0.03 (CI, −0.14 to 0.09). Eighteen large trials with blinded outcome assessment (5094 patients) showed a clinically irrelevant effect size of −0.11 (CI, −0.18 to −0.04). Six trials (811 patients) showed that viscosupplementation increased, although not statistically significantly, the risk for flare-ups (relative risk, 1.51 [CI, 0.84 to 2.72]). Fourteen trials (3667 patients) showed that viscosupplementation increased the risk for serious adverse events (relative risk, 1.41 [CI, 1.02 to 1.97]).

Limitations: Trial quality was generally low. Safety data were often not reported.

Conclusion: In patients with knee osteoarthritis, viscosupplementation is associated with a small and clinically irrelevant benefit and an increased risk for serious adverse events.

Primary Funding Source: Arco Foundation.

Bottom Line:  Don’t waste your time.  You could consider an intra-articular( within the joint) injection of a steroid.

“Intraarticular glucocorticoids slow cartilage catabolism and osteophyte formation in animals [32-35]; they are also effective for short-term pain relief and can increase quadriceps strength after knee injection. A year 2004 meta-analysis of placebo/sham controlled trials found those receiving glucocorticoid injections for OA of the knee to be twice as likely as controls to have short term improvement [36]. A randomized, placebo-controlled trial of fluoroscopically guided glucocorticoid injection for osteoarthritis of the hip demonstrated benefits lasting up to three months in many cases [37].”

Steroid injection for osteoarthritis of the hip: a randomized, double-blind, placebo-controlled trial.
Lambert RG, Hutchings EJ, Grace MG, Jhangri GS, Conner-Spady B, Maksymowych WP
Arthritis Rheum. 2007;56(7):2278.
OBJECTIVE: To determine the efficacy of fluoroscopically guided corticosteroid injection for hip osteoarthritis (OA) in a randomized, double-blind, placebo-controlled trial.
METHODS: Fifty-two patients with symptomatic hip OA were randomly allocated to receive placebo (10 mg bipuvicaine, 2 ml saline) (n = 21) or corticosteroid treatment (10 mg bipuvicaine, 40 mg triamcinolone hexacetonide) (n = 31). Patients were followed up for 1, 2, 3, and 6 months. The primary outcome measure was the pain improvement response, defined as a 20% decrease in the Western Ontario and McMaster Universities OA Index (WOMAC) pain score (on 5 100-mm visual analog scales [VAS]) (WOMAC20) from baseline to 2 months postinjection. Secondary outcomes were a 50% decrease in the WOMAC pain score (WOMAC50), changes in other WOMAC subscale scores, patient’s global assessment of health (on a 100-mm VAS), and Short Form 36 (SF-36) quality of life indices. Analyses were based on the intent-to-treat principle.
RESULTS: The mean WOMAC pain score fell 49.2% (decreasing from 310.1 mm to 157.4 mm)at 2 months postinjection in patients receiving corticosteroid, compared with a decrease of 2.5% (from 314.3 mm to 306.5 mm) in the placebo group (P<0.0001). The proportion of WOMAC20 responders at 2 months’ followup was significantly higher in the corticosteroid group (67.7%) compared with the placebo group (23.8%) (P = 0.004); similar proportions of WOMAC50 responders were observed between groups (61.3% in the corticosteroid group versus 14.3% in the placebo group; P = 0.001). Response differences were maintained at 3 months’ followup (58.1% responders in the corticosteroid group versus 9.5% responders in the placebo group; P = 0.004). Significant differences in the WOMAC stiffness and physical function scores (P<0.0001), patient’s global health scores (P = 0.005), and SF-36 physical component scores (P = 0.04) were observed, with patients in the corticosteroid group showing greater improvements. There were no differences in the frequency of adverse events between groups.
CONCLUSION: This placebo-controlled trial confirms that corticosteroid injection can be an effective treatment of pain in hip OA, with benefits lasting up to 3 months in many cases. Future studies should address questions related to the benefits of repeated steroid injection and the effects of this treatment on disease modification.
Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada. [email protected]

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