Research Summary

Liposomal Bupivacaine via Adductor Canal Block Reduces Pain and Opioid Use After Total Knee Arthroplasty

Miranda Manier, BA

Key Highlights

  • Liposomal bupivacaine via adductor canal block significantly reduced postoperative pain intensity over 96 hours compared with bupivacaine hydrochloride alone.
  • Patients receiving liposomal bupivacaine consumed 23% less opioids and had a longer median time to first opioid use.
  • Safety outcomes were similar between treatment groups, with no meaningful differences in adverse events.

In a multicenter randomized controlled trial, the addition of liposomal bupivacaine to bupivacaine hydrochloride for adductor canal block significantly improved postoperative pain outcomes in patients undergoing total knee arthroplasty (TKA). Patients who received the liposomal formulation reported lower pain intensity and consumed fewer opioids, while maintaining a comparable safety profile to those who received bupivacaine hydrochloride alone.

TKA is a highly effective intervention for advanced knee disease, but it is associated with substantial postoperative pain that often necessitates opioid use. Conventional bupivacaine hydrochloride has a relatively short duration of action, limiting its efficacy in sustaining analgesia. Liposomal bupivacaine, with its extended-release properties, has been developed to prolong local anesthetic effects, reduce the need for systemic opioids, and improve recovery trajectories. This trial was designed to evaluate its efficacy and safety in the context of adductor canal block for TKA.

The double-blind, active-controlled study (NCT05139030) enrolled 167 adults undergoing unilateral primary TKA. Participants were randomized to receive either liposomal bupivacaine 133 mg plus bupivacaine hydrochloride 50 mg or bupivacaine hydrochloride 50 mg with saline, both via a single adductor canal block. The primary endpoint was the area under the curve (AUC) of pain intensity scores during the first 96 hours after surgery. Secondary endpoints included opioid consumption, time to first opioid use, and adverse events.

Results demonstrated that the liposomal bupivacaine group achieved significantly lower pain scores over 96 hours, with an AUC of 568.9 compared with 634.7 in the control group (mean difference, –65.8; 95% CI, –118.7 to –12.9; P = .0074). Opioid use was also reduced: patients receiving liposomal bupivacaine consumed 101.8 morphine milligram equivalents versus 132.8 in the control group, reflecting a 23% reduction (P = .0018). Median time to first opioid use was longer in the liposomal bupivacaine group (4.2 hours vs 3.6 hours; P = .0127). The incidence of treatment-related adverse events was low and similar between groups (3.5% vs 2.5%).

As the investigators concluded, “Liposomal bupivacaine administered via adductor canal block for total knee arthroplasty was associated with concurrent reductions in pain and opioid consumption compared with bupivacaine during the first 96 hours after surgery.”

Reference
Gadsden J, Hamilton M, Schwartz G, et al. A phase 3 active-controlled trial of liposomal bupivacaine via adductor canal block for total knee arthroplasty. J Arthroplasty. 2025;40(10):2605-2614.e5. doi:10.1016/j.arth.2025.07.030