Efficacy of Liposomal Bupivacaine versus Ropivacaine in Adductor Canal Block for Total Knee Arthroplasty

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.