Are genicular nerve blocks effective in relieving pain in adults with degenerative joint disease of the knee?
In adults experiencing moderate to severe knee pain due to DJD, genicular nerve blocks provide 2 weeks to 4 weeks of clinically meaningful pain relief compared with placebo.
Randomized controlled trial (single-blinded)
Adults with symptomatic knee degenerative joint disease (DJD) with a severity at least 4 out of 10 for the preceding 3 months who were seeking care at rheumatology or orthopedic clinics were randomized to receive ultrasound-guided genicular nerve blocks (celestone plus bupivacaine; n = 33) or placebo (n = 31). The patients rated their pain on a visual analog scale (VAS) and also assessed their function using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and then at 2, 4, 8, and 12 weeks. Five participants (7.8%) did not complete the study. The VAS scores in the intervention group improved until 8 weeks, while VAS scores in the placebo group did not appreciably change at each interval. The net difference in pain scores at 2, 4, 8, and 12 weeks were 2.1, 1.9, 1.2, and 0.6. Although the differences in the first 3 intervals are statistically significant, only the first 2 are clinically important. Similarly, the WOMAC scores in the intervention group improved at weeks 2 and 4 and increased gradually thereafter, while those in the placebo group remained flat for the duration of the study. The net changes at 2 and 4 weeks exceeded the minimum clinically important difference (10 points on the 100-point scale). The authors report no complications among any of the participants, but the study was so small it is likely that serious adverse events would not be seen.
Henry C. Barry, MD, MS
Michigan State University
East Lansing, MI