A multimodal opioid-sparing pain management following total knee replacement

Abstract

Objective: The purpose of this study is to compare the pain scores, opioid consumption, and range of motion of the operated knee after total knee replacement (TKR) in the 10-day follow-up period between a traditional opioid-containing pain management protocol and a multimodal opioid-sparing treatment protocol.

Methods: This prospective, randomized, single-center study included 90 patients (24 men and 66 women; mean age 69.7±7.2 years) undergoing TKR for osteoarthritis between October 2019 and October 2020. Patients were randomized into 3 cohorts for comparison: traditional opioid-containing pain management protocol (n=30), multimodal opioid-sparing pain management protocol (n=30), and traditional opioid-containing pain management protocol with additional local infiltration analgesia (LIA). Changes in visual analog scale for pain (VAS), range of motion (ROM), and opioid consumption were compared between groups.

Results: A lower mean postoperative VAS score was observed in the opioid-sparing cohort, which was statistically significant at all time points compared with the traditional cohorts. Mean total morphine consumption was significantly lower in the opioid-sparing cohort (2.7±5.8 MMEs) compared to the traditional (14.0±14.8 MMEs) and traditional with LIA cohorts (8.3±9.5 MMEs; p<0.05). The mean degree of flexion of the operated knee of patients was significantly greater in patients in the opioid-sparing group than in the other groups on the postoperative day 3 (opioid-sparing: 87.0±11.2°; traditional: 74.1±11.6°; traditional with LIA: 84.7±8.9°; p<0.05), as well as on day 10 (opioid-sparing: 99.3±10.8°; traditional: 87.3±12.4°; traditional with LIA: 92.5±9.7°; p<0.05). The rate of adverse events after TKR did not differ between the groups.

Conclusion: The results of this study suggest that a multimodal opioid-sparing pain protocol after TKR, which includes oral non-opioid medications and periarticular injection with bupivacaine, provides better pain relief and early functional gains with fewer rescue opioids compared to traditional opioid-based protocols (Tab. 4, Fig. 2, Ref. 22).

Keywords: pain management opioid-sparing.; postoperative pain; total knee replacement.