A pilot study of intraoperative application of cooled radiofrequency to reduce post-operative pain following total knee arthroplasty.

Background: Total Knee Arthroplasty (TKA) is a successful treatment for end stage knee osteoarthritis (OA), but can be associated with significant pain in the early post-operative period. Cooled radiofrequency ablation (CRFA) has reported to reduce knee OA pain by targeting the periarticular nerves. The objective of this pilot study was to assess the effectiveness of intra-operative CRFA for reducing pain and opiate use after TKA.

Methods: This was a non randomised prospective study with control group. Participants were sequentially recruited preoperatively and underwent TKA, with CRFA to 6 targeted sites prior to cementing of implants, and were compared to controls who underwent TKA without CRFA. The primary outcome was Day 3 pain scores, and secondary outcomes included week one pain scores, and opiate use up to six weeks post-operative.

Results: 17 participants were recruited to the control group and 12 were recruited to the CRFA group. There was no significant difference in demographics or baseline pain scores between the groups. On day 2 the CRFA group had a lower mean pain VAS score of 3.2 compared to 4.4 in the control group (p = 0.03). The mean post operative VAS pain score did not differ between the groups for Day 1, 3, 4, or any other time points up to 6 weeks. There were no significant reduction in opiate use in the CRFA group compared to the control group. There were no adverse events.

Conclusion: This study demonstrated intra-operative CRFA was not effective in reducing pain by 50% after TKA in a pilot study.