Abstract
Multimodal pain management for total knee arthroplasty (TKA) is essential to enhance
functional recovery. Regional anesthesia became a vital component to decrease pain
after TKA. Several studies compared femoral versus adductor canal blocks, including
evaluating medications that can prolong adductor canal blocks. Liposomal bupivacaine
(LB) and continuous local infusion (OnQ) both extend local anesthetic delivery beyond
24 hours. This superiority study compared the use of OnQ versus LB in adductor canal
blocks. A retrospective study was conducted between two cohorts of consecutive patients
who received adductor canal blocks with either LB or a continuous ropivacaine infusion
catheter. Morphine equivalent dose (MED), pain scores, and length of stay (LOS) were
compared between the two groups by using the analysis of covariance test. There were
106 patients in the OnQ group and 146 in the LB group. The OnQ group consumed significantly
fewer opioids compared with the LB group in the recovery room (5.7 MED vs. 11.7 MED,
p = 0.002) and over the entire hospitalization (the recovery room plus on the floor;
33.3 MED vs. 42.8 MED, p = 0.009). Opioid use between the OnQ and LB group did not reach statistical significance
(p = 0.21). The average pain scores at rest and with activity were similar in both groups
(p = 0.894, p = 0.882). The LOS between the OnQ and LB groups was not statistically significant
(1.2 vs. 1.3, p = 0.462). OnQ and LB were equally effective in decreasing opioid consumption on the
floor over the averaged 1.3 days of hospitalization; however, the OnQ group significantly
reduced opioid use in the recovery room. There was no difference in pain scores or
LOS between the two groups. OnQ comparatively prolonged infusion of local anesthetic
is a potential edge over LB. This advantage may offset the inconvenience of catheter
management and infrequent catheter complications.
Keywords
total knee arthroplasty - continuous local infusion - liposomal bupivacaine - continuous
infusion of ropivacaine - Exparel