Risk of chronic opioid use after simultaneous versus staged bilateral knee arthroplasty.

BACKGROUND

Several studies have identified excess risk associated with undergoing simultaneous (compared with unilateral or staged) bilateral total knee arthroplasty (BTKA). However, few have addressed subsequent chronic opioid use. Given the substantial morbidity and mortality associated with prolonged opioid use, we evaluated the incidence of postoperative chronic opioid use following simultaneous versus staged BTKA, based on the different timing strategies of staged procedures.

METHODS

In this retrospective cohort study, patients who underwent BTKA procedures (2012-2016; Truven Health MarketScan; n=14 407) were classified as having undergone simultaneous or staged BTKA (<3 months, 3-6 months or 6-12 months apart). Outcomes were postoperative chronic opioid use and oral morphine equivalents prescribed on discharge. Multivariable regression models measured associations between type/timing of BTKA and outcomes. ORs and 95% CIs were reported.

RESULTS

Unadjusted frequency of chronic opioid use did not differ between groups, (Simultaneous: 11.3%, staged <3 months: 10.7%, staged 3-6 months: 11.7%, staged >6 months: 10.2%; p=0.247). In an adjusted model, there was no significant difference in the odds of becoming chronic opioid users between staged and simultaneous BTKA (staged <3 months OR 1.03, 95% CI 0.88 to 1.21/staged 3-6 months OR 0.94, 95% CI 0.79 to 1.12/staged >6 months OR 0.96, 95% CI 0.82 to 1.13; p=0.755). Patients undergoing staged BTKAs <6 months apart (compared with simultaneous) were prescribed slightly greater oral morphine equivalents on hospital discharge (staged <3 months 6% increase, 95% CI 3% to 10%; staged 3-6 months 4%, 95% CI 1% to 8%; p=0.002).

CONCLUSION

Although patients undergoing staged BTKA <6 months apart were prescribed greater quantities of opioids on discharge, there was no significant difference in the odds of postoperative chronic opioid use compared with simultaneous BTKA. The timing of BTKA procedures does not appear to influence the likelihood of postoperative chronic opioid dependence.