A Flinders study demonstrating efficacy of genicular nerve block for the treatment of knee OA pain was awarded best poster at ARA ASM 2022.
The prize for best poster at the ARA ASM was awarded to Professor Michael Shanahan and the Flinders-based team for their research on ultrasound-guided genicular nerve block for the treatment of pain from osteoarthritis.
The study randomised 64 patients who’d had symptomatic knee OA for more than three months into two groups: the treatment group received 5.7mg (1mL) of Celestone and 3mL of 0.5% Bupivacaine injected around three genicular nerves under ultrasound guidance, while the placebo group received 1mL of saline.
The primary outcome was pain, stiffness and disability as measured by the WOMAC score and pain measured by a 10-point visual analogue scale at 2, 4, 8 and 12 weeks.
The scores in the treatment group showed clinical and statistical improvement at all time points relative to baseline, with the greatest effect at weeks 2 and 4. There was also a difference in scores between the two groups at each time point.
The patients, who’d experienced knee OA symptoms for a median of around 10 years, were happy with the treatment and there were no reported adverse events.
In a condition with few effective non-surgical options to relieve pain and reduce disability, genicular nerve blocks had already demonstrated some success and was sometimes used in clinical practice.
But when this study was conceived, there were no published randomised double-blind, placebo-controlled trials to determine their effectiveness, Professor Shanahan told Rheumatology Republic.
“I was aware that some private radiology firms are offering the block, and in fact one of the radiologists from one of our local practices – co-investigator Dr Frank Voyvodic – approached me about undertaking the study because we discovered the lack of evidence as to the intervention’s efficacy,” said Professor Shanahan.
“He was rightly concerned about offering unproven treatments – and that is how we conceived the trial.”
When asked at #ARA22 if the response could be due to the systemic effect of the corticosteroid delivered, rather than any true nerve block from the bupivacaine, Professor Shanahan explained that the combination was quite similar to that used for a suprascapular nerve block where a few studies had shown efficacy with the steroid taken out of the mix.
“In other words, we think it is more likely that the local anaesthetic is more important than the steroid, rather than the other way around,” he said.
Based on the trial results, the authors concluded that genicular nerve blocks can be recommended as a treatment option for the short- to medium-term management of symptomatic knee OA.
Not sure why this interesting abstract missed out on an oral but you can catch it as an e-poster P052
— Catherine Hill (@CatherineL_Hill) May 20, 2022
RCT of genicular nerve block for knee OA; study led by Prof Michael Shanahan @Flinders @FlindersFound #ARA22 pic.twitter.com/H1rORtxMhQ
