Chronic Use of Opioids Before and After Total Knee Arthroplasty: A Retrospective Cohort Study.

BACKGROUND: Opioids are commonly used for the management of preoperative and postoperative pain among patients undergoing total knee arthroplasty (TKA). There is limited literature on the chronic use of opioids pre-TKA and post-TKA. The aim of this study was to characterize the use of opioids in TKA patients before and after surgery and identify risk factors of chronic opioid use.

METHODS: Opioid use among 15,020 patients undergoing TKA (01/01/2001-31/12/2012) was examined. Generalized estimating equations assessed change in total oral morphine equivalents pre-TKA and post-TKA, and logistic regression estimated risk factors of chronic opioid use.

RESULTS: Of the total sample, 7782 (52.0%) patients had at least 1 opioid (38.6% pre-TKA and 34.4% post-TKA). The most commonly prescribed opioids were oxycodone, codeine + acetaminophen, and tramadol. Pre-TKA, 720 (4.8%) patients were chronic opioid users, of which 241 (33.5%) stopped being chronic users after surgery and 479 (66.5%) continued but had a 16% reduction (incidence rate ratio = 0.84; 95% confidence interval, 0.78-0.90) in total oral morphine equivalents. Of the 5077 (33.8%) occasional opioid user pre-TKA, 2407 (47.4%) stopped after surgery. Compared to nonopioid users, chronic users were younger, were female, had more comorbidity, and had longer hospital stays. Older age was associated with ceasing chronic opioid use post-TKA.

CONCLUSION: There was a reduction in opioid use following TKA. Almost 50% of occasional users and more than 30% of chronic users pre-TKA ceased opioids postoperatively. There was a reduction in use for those chronic users who continued to take opioids postsurgery.