Ultrasound-Guided Adductor Canal Block Versus Intraoperative Transarticular Saphenous Nerve Block: A Retrospective Analysis.

Abstract

The ultrasound-guided adductor canal block (High-ACB) is an effective option for pain control in total knee arthroplasty (TKA), but its use can add substantial cost and preparatory time to a TKA procedure. An intraoperative adductor canal block (Low-ACB) performed by the operative surgeon has been described as an alternative. The hypothesis of this study is that the Low-ACB would achieve noninferior pain control and opioid utilization postoperatively when compared to the High-ACB. This is a retrospective study of a prospectively maintained database comparing the High-ACB vs the Low-ACB. The primary outcome measure was morphine milligram equivalents consumed. Secondary outcome measures included Visual Analog Scale pain scores, postoperative outcomes (Patient-Reported Outcome Measurement Information System, Knee Injury and Osteoarthritis Outcome Score, knee range of motion), length of stay, postoperative speed of mobilization, and complications related to the type of block. There were 139 patients in the study. There was lower opioid use in the first 24hours in the Low-ACB compared to the High-ACB group respectively (26.3 vs 30, P= .29) but this did not reach statistical significance. There was a statistically significant difference in Visual Analog Scale score on postoperative day 1 in the Low-ACB vs High-ACB groups respectively (4.6 vs 3.7, P= .02) but this did not reach the level of clinical significance. There was no statistical difference in the Patient-Reported Outcome Measurement Information System, Knee Injury and Osteoarthritis Outcome Score, or postoperative range of motion. There were no block-related complications in either group. The Low-ACB is a safe, effective, and cost-saving alternative to the traditional High-ACB for pain control in TKA.