Increased Opioid Consumption Following Total Knee Arthroplasty Is Associated With an Increased Risk of Manipulation Under Anesthesia.

Abstract

Manipulation under anesthesia (MUA) is performed to treat knee stiffness following total knee arthroplasty (TKA). Many surgeons have empirically noted decreased pain tolerance to be a risk factor for MUA; however, there are limited data to link postoperative opioid consumption with the risk of MUA. The present study sought to examine the relationship between inpatient postoperative opioid consumption and the risk of MUA. A health care database was queried to identify all patients who underwent primary, elective TKA from 2016 to 2023. Logistic regressions were used to create restricted cubic splines describing the relationship between patient morphine milligram equivalent (MME) consumption and the risk of postoperative MUA within 90 days of surgery. In total, 936,653 TKA patients were included. Of these, 14,774 (1.6%) underwent MUA. The cohort average for opioid consumption was 64.4 MME. There was an approximate 2.8% increase in relative risk for MUA for every 20 MME increment above the cohort mean. Restricted cubic spline modeling revealed an approximately 8.5% increase in relative risk for MUA at 129 MME, approximately double the cohort average MME. There was a 17.4% relative risk increase for MUA at 193 MME opioid consumption. The findings of the present study demonstrate an association between increased postoperative opioid consumption after TKA and risk of MUA. Poor postoperative pain tolerance and increased opioid requirements may serve as early predictive markers that portend an increased risk of postoperative knee stiffness and subsequent MUA.