Does preoperative opioid use predict outcomes to 6 months following primary unilateral knee or hip arthroplasty for osteoarthritis? A data-linked retrospective study.

Background: Few Australian studies have examined the incidence of prescribed opioid use prior to primary total knee or total hip arthroplasty (TKA, THA) and whether it predicts post-surgery outcomes. A recent Australian study demonstrated that the prevalence of pre-arthroplasty opioid use was approximately 16%. In the United States, approximately 24% of people undergoing TKA or THA are chronic opioid users preoperatively.

Purpose: This study aimed to determine (i) the proportion of TKA and THA patients who use prescribed opioids regularly (daily) before surgery (i.e., opioid use reported between the time of waitlisting and any time up to 3 months before surgery), (ii) if opioid use before surgery predicts (a) complication/readmission rates to 6-months post-surgery, and (b) patient-reported outcomes to 6-months post-surgery.

Methods: A retrospective cohort study of patients who underwent TKA or THA between January 2013 and June 2018 from two Australian public hospitals was undertaken utilizing linked individual patient-level data from two prospectively collected independent databases comprising approximately 3,500 and 9,500 people (database contained known opioid usage data within the 5-year time frame). Inclusion criteria included (i) primary diagnosis of osteoarthritis of the index joint, (ii) primary elective THA or TKA, and (iii) age ≥ 18 years. Exclusion criteria included (i) revision arthroplasty, (ii) non-elective arthroplasty, (iii) hip hemiarthroplasty, (iv) uni-compartmental knee arthroplasty, and (v) previous unilateral high tibial osteotomy.

Results: Analysis was completed on 1,187 study participants (64% female, 69% TKA, mean (SD) age 67 [9.9]). 30% were using regular opioids preoperatively. Adjusted regression analyses controlling for multiple co-variates indicated no significant association between preoperative opioid use and complications/readmission rates or patient-reported outcomes to 6 months post-surgery. Model diagnostics produced poor discrimination for area under the curves and non-significant goodness of fit tests. Pre-arthroplasty opioid use was associated with lower health-related quality of life (EuroQol-Visual Analogue Scale) compared to non-opioid users undergoing primary THA (mean difference -5.04 [-9.87, -0.22], P = 0.04, Adjusted R = 0.06) CONCLUSION: In this study, 30% of patients were using prescribed opioids daily prior to primary TKA or THA. Pre-arthroplasty opioid use was not associated with postoperative adverse events or patient-reported pain, function, or global perceived improvement up to six months post-surgery.