Multimodal Pain Management With Adductor Canal Block Decreases Opioid Consumption Following Total Knee Arthroplasty

Ease of access to opioids in the perioperative period is a risk factor for subsequent opioid misuse. The purpose of this study was to quantify a decrease in opioid consumption following implementation of a new analgesic protocol after total knee arthroplasty (TKA).

A retrospective cohort study was performed analyzing patients who underwent TKA at a US Department of Veterans Affairs medical center. Patients were divided into 2 groups by multimodal analgesic regimen: Analgesia with intraoperative general anesthesia, a patient-controlled analgesia pump, and oral opioids (control group) or analgesia with intraoperative spinal anesthesia, a multimodal medication regimen, and an adductor canal block (protocol group).

A total of 533 TKAs were included. The mean (SD) IV morphine equivalent dose (MED) requirement was 178.2 (98.0) for the control and 12.0 (24.6) for the protocol group (P < .001). Total mean (SD) opioid MED requirement was 241.7 (120.1) for the control group and 74.8 (42.7) for the protocol group (P < .001). The protocol group required only 6.7% of the IV opioids and the control group 30.9%. No difference in oral opioid requirements was found (P = .85). The control group required more opioid refills at the first postoperative visit (P < .001).

The described analgesic protocol resulted in significant decreases in IV and total opioid requirement, and lower rates of opioid prescriptions at the first postoperative visit. These findings demonstrate a decrease in opioid utilization with modern perioperative analgesia protocols and reinforce multiple recommendations to decrease opioid exposure and access.