Abstract
Adductor canal block (ACB) is advantageous for postoperative analgesia in total knee
arthroplasty (TKA) because it results in minimal motor block. Liposomal bupivacaine
(LB) is Food and Drug Administration-approved extended-release formulation of bupivacaine
for interscalene peripheral nerve blocks. Its use is increasing in the TKA setting,
mainly as a local infiltration agent. We compared the efficacy of ACB using LB versus
ropivacaine in TKA. Two cohorts of patients were retrospectively analyzed at a single
institution receiving ropivacaine and LB ACB for TKA. Duration of LB ACB, time to
first opioid use postrecovery room, amount of opioid use postrecovery room, length
of stay (LOS), and average and highest pain scores were collected. A total of 91 and
142 TKA patients received ropivacaine and LB for ACB, respectively. At 8 hours postrecovery
room, more patients in the LB group required no opioids compared with the ropivacaine
group (p = 0.026). Mean opioid consumption was lower in the LB group than in the ropivacaine
group at 8 and 24 hours postrecovery room, although statistical significance was only
observed at 8 hours (p = 0.022). The highest pain score for patients in the two groups was not statistically
different. The average pain score for patients with a 2-day LOS was higher in the
LB group, but average pain scores were similar for patients with 1- and 3-day LOS.
Median LOS for the LB and ropivacaine groups was 1 and 2 days, respectively (p < 0.0001). Significantly lower opioid use at 8 hours postrecovery room was seen in
the LB group compared with the ropivacaine group. There was no difference in opioid
use at 24 and 48 hours. There was also no advantage with LB ACB in decreasing pain
scores. However, the LB ACB group demonstrated a significantly shorter LOS compared
with the ropivacaine ACB group.
Keywords
liposomal bupivacaine - adductor canal block - total knee arthroplasty
