Reduction in Opioid Requirements Following Changes to Regional Anesthesia for Patients Undergoing Total Knee Arthroplasty.

Abstract

Background: Newer analgesic techniques to reduce opioid use and pain after total knee arthroplasty (TKA) include preoperative cryoneurolysis, adductor canal block (ACB), and local anesthetic infiltration between the popliteal artery and capsule of the knee (iPACK) block. The purpose of this study was to evaluate whether changing the regional analgesic from ropivacaine to liposomal bupivacaine would provide superior pain relief and reduce opioid requirements at 2 and 12 weeks following TKA.

Methods: We conducted a retrospective medical records review of 140 consecutive patients who underwent primary TKA at a single site and received ACB with ropivacaine (multimodal-ropivacaine [MM-R] group, n=70) or ACB/iPACK with liposomal bupivacaine (multimodal-liposomal bupivacaine [MM-LB] group, n=70). The primary outcomes were the morphine milligram equivalent (MME) of filled opioid prescriptions at discharge and during the first 12 weeks after TKA, as well as the Knee injury and Osteoarthritis Outcome Score and the Patient-Reported Outcomes Measurement Information System pain intensity and pain interference scores at 2 and 12 weeks postsurgery.

Results: The median MMEs for discharge opioid prescriptions and all opioid prescriptions were, respectively, 65% (P<0.0001) and 48% (P<0.0001) lower for patients in the MM-LB group vs the MM-R group. The MM-LB group had significantly better patient-reported outcomes 2 weeks after TKA compared to the MM-R group.

Conclusion: Compared with ropivacaine-based regional analgesia, liposomal bupivacaine-based regional analgesia in the context of a modern multimodal pain regimen may reduce opioid requirements and improve patient-reported outcomes during acute and short-term recovery after TKA.