Background: Recently, genicular nerve block and radiofrequency ablation were introduced to alleviate knee pain in patients with chronic knee osteoarthritis. Both ultrasound- and fluoroscopy-guided genicular nerve blocks have been used. However, whether one is superior to the other 
remains unknown.

Objectives: The present study compares the efficacy of ultrasound- vs fluoroscopy-guided genicular nerve blocks.

Study Design: This research used a prospective randomized comparison design.

Setting: The study took place at a single pain clinic within a tertiary medical center in Seoul, Republic of Korea.

Methods: From July 2015 to September 2017, a randomized controlled study was performed to analyze the difference in the efficacy of ultrasound- vs fluoroscopy-guided genicular nerve blocks. The Numeric Rating Scale (NRS-11), Western Ontario and McMaster Universities Arthritis 
Index (WOMAC), Global Perceived Effect Scales (GPES), and complications were evaluated pre-procedure, and 1 and 3 months after genicular nerve block.

Results: A total of 80 patients were enrolled and randomly distributed to groups U (ultrasound-guided, n = 40) and F (fluoroscopy-guided, n = 40). Those who were lost to follow-up or had undergone other interventions were excluded, resulting in 31 and 30 patients in groups U and F, respectively. No differences in NRS-11 or WOMAC were observed between the 2 groups at baseline or during the follow-up period. GPES and complication rates were also similar between both groups.

Limitations: We were unable to perform double-blind randomization and did not evaluate patients’ baseline emotional states.

Conclusions: Pain relief, functional improvement, and safety were similar between groups receiving ultrasound- and fluoroscopy-guided genicular nerve blocks. Therefore, either of the 2 imaging devices may be utilized during a genicular nerve block for chronic knee pain relief. However, considering radiation exposure, ultrasound guidance may be superior to fluoroscopic guidance.

A PROSPECTIVE RANDOMIZED COMPARISON OF THE EFFICACY BETWEEN ULTRASOUND- AND FLUOROSCOPY-GUIDED GENICULAR NERVE BLOCK FOR CHRONIC KNEE OSTEOARTHRITIS