Las inyecciones intrarticulares con ácido hialuronico tienen una eficacia limitada en comparación con inyecciones de placebo en el tratamiento de la osteoartritis de rodilla, de acuerdo con un meta-análisis que escrutó datos de 22 estudios identificados a través de MEDLINE y del registro de ensayos clínicos controlados Cochrane.
Intra-articular injections with hyaluronic acid has limited efficacy compared with placebo injections for the treatment of osteoarthritis of the knee, according to a meta-analysis that scrutinized data from 22 studies identified through MEDLINE and the Cochrane Controlled Trials Register.
«Recommendations for the use of these compounds should be reevaluated based on the findings of this meta-analysis,» writes Grace H. Lo, MD, Boston University School of public Health, Massachusetts, United States, and colleagues. Their analysis included English and non-English randomised controlled trials comparing intra-articular hyaluronic acid administered at least every week for 3 weeks with a placebo injection as a treatment for osteoarthritis of the knee. The studies all assessed pain according to recommendations of the Osteoarthritis Research Society, had a minimum follow up of 2 months, and a drop out rate of less than 50%.
Among the 22 studies analysed, 17 were industry sponsored. Overall, the dropout rate was 12.4% resulting in the analysis of 2,584 participant knees.
The meta-analysis investigators calculated effect as small, large, or equivalent to a total knee replacement for each study and found the pooled effect of the studies was small; 0.32 for hyaluronic acid injections compared with placebo injections. Excluding data from the 3 studies using the highest-molecular-weight formulation of hyaluronic acid caused the pooled effect size to decrease to 0.19.
To determine if treatment benefits came from the hyaluronic acid or the injection itself, the researchers analysed pooled changes from baseline for the treatment and placebo groups separately. In the 8 trials providing such information, the pooled change in the hyaluronic injection groups was 0.82 SD compared with 0.65 SD for the placebo groups. This suggests that the intra-articular placebo effect accounted for 79% of the efficacy of intra-articular hyaluronic acid, and, the authors add, «supports our hypothesis that the majority of the effect of intra-articular hyaluronic acid is an intra-articular placebo effect.»
The authors note that the highest-molecular-weight formulations of hyaluronic acid may result in better treatment benefits for patients with osteoarthritis of the knee, but further independent trials, using intent-to-treat analyses, should make this determination. However, based upon this meta-analysis the authors conclude, «the controversy surrounding the efficacy of intra-articular hyaluronic acid is justified and that the best available data does not support its efficacy.»
JAMA 2003;290:3115-3121. «Intra-articular Hyaluronic Acid in Treatment of Knee Osteoarthritis: A Meta-analysis»