Daily Dose of Preoperative Opioid Prescriptions Affects Outcomes After Total Knee Arthroplasty

The use of preoperative opioids is associated with complications after total knee arthroplasty (TKA), but the dosing threshold that constitutes this risk is not known. The purpose of this study was to identify the preoperative daily opioid dose associated with increased complications after primary TKA.

Patients who underwent primary TKA in the Humana claims database (2007-2016) with an opioid prescription within 3 months before surgery were identified. All opioids prescribed within 3 months before TKA were converted to milligram morphine equivalents. Patients were stratified based on daily opioid dose: tier 1) <10, tier 2) 10-25, tier 3) 25-50, tier 4) >50 milligram morphine equivalents. Patients were matched to opioid-naïve patients by comorbidities, age, and gender. Emergency department (ED) visits, readmissions, and surgical complications were compared.

A total of 20,019 patients using preoperative opioids were identified and matched. ED visits and readmissions within 90 days were significantly higher in opioid users in all tiers (relative risk (RR) of ED visit: 1.25, 1.28, 1.34, and 1.25, respectively; readmission: 1.13, 1.17, 1.22, and 1.19, respectively). Rates of prosthetic joint infection were increased in opioid users in tiers 2, 3, and 4, and the risk increased in a dose-dependent manner (RR 1.37, 1.39, and 1.50, respectively). Patients in tier 4 had an increased risk of revision surgery (RR 1.44) at 2 years.

Preoperative opioid use is associated with a dose-dependent increase in postoperative complications after TKA. Just two 5mg hydrocodone tablets daily lead to increased ED visits and readmission. Higher doses are associated with an increased risk of prosthetic joint infection and revision surgery.