In-Hospital Exposure and Opioids Prescribed After Total Knee Arthroplasty.

Abstract

Opioids are frequently used intraoperatively and during post-anesthesia care unit (PACU) care in total knee arthroplasty (TKA) cases and are commonly prescribed after surgery despite known adverse effects. This study examined whether in-hospital opioid exposure is related to postoperative opioid prescribing in opioid-naïve TKA patients. This retrospective study included opioid-naïve patients (no opioid prescriptions filled during the three months before TKA) who had unilateral primary TKA between May 1, 2020 and November 30, 2023, performed by an orthopaedic surgeon. All patients were treated using the same multimodal pain protocol. Opioid prescriptions filled by patients during the three months following TKA (no opioids prescribed [NOP-T] versus opioids prescribed [OP-T]) were analyzed as a function of in-hospital opioid exposure. In the three months after surgery, 29.8% of patients filled an opioid prescription (OP-T group) with a median morphine milligram equivalent (MME) of 210. The OP-T and NOP-T groups had similar demographic characteristics except for a significant difference in opioid prescribing by insurance type, with Medicaid enrollees having the highest percentage of postoperative opioid prescriptions. In addition, the NOP-T group reported significantly less pain and better function preoperatively. A higher percentage of patients in the OP-T group received intravenous opioids in the PACU (45.2 versus 27.3%, P = 0.037). Multivariable analyses showed that a lower preoperative pain score was the only variable associated with a reduced likelihood of filling an opioid prescription after TKA (adjusted odds ratio = 0.675, P = 0.002). This study highlights the importance of a modern opioid-free multimodal analgesia regimen in optimizing pain management after TKA. By minimizing opioid exposure before TKA and during in-hospital treatment, TKA patients can achieve good pain control while avoiding the hazards of opioid exposure.