ABSTRACT
AIMS: To determine the impact of perioperative sustained-release (SR) opioid use on total inpatient opioid consumption and longer-term outpatient dispensing for three months following elective total knee arthroplasty (TKA). METHODS: Patients who underwent primary unilateral TKA between 1 January and 31 December 2018 at Counties Manukau Health were retrospectively identified. Participants were stratified into two groups by inpatient use or avoidance of strong SR opioids (OxyContin or M-Eslon). The primary outcome was the percentage of patients receiving prescriptions for opioid medications at thirty-day intervals for three months after discharge. RESULTS: Two hundred and thirty-two patients were eligible for inclusion. The baseline demographics of both groups were similar. In the SR opioid use group, the majority (79%) received OxyContin. Overall, inpatient opioid use between postoperative days (POD) zero and three was lower in the SR opioid avoidance group, although this was not statistically significant (157.5 [IQR 110.0-220.0] vs 167.5mg OME [110.0-290.0], p=0.14). Outpatient postoperative opioid dispensing between 0-30 days was significantly greater in patients who received inpatient SR opioids (p=0.01). Dispensing of oxycodone was significantly higher in the SR opioid use group at one- and two- months (p=0.01 and 0.03 respectively). CONCLUSION: The postoperative use of SR opioids is not routinely recommended following TKA. Their use is associated with greater overall inpatient opioid use, sustained opioid dispensing during and after the expected recovery period, and the potential for significant harm.
