One-stage versus 2-stage bilateral total joint arthroplasty: a matched cohort study.

Background: Patients with bilateral end-stage hip or knee arthritis want to know if it is safe to have bilateral surgery under a single anesthetic, to restore their quality of life as quickly as possible. The purpose of this study was to assess if there is an increase in the rate of postoperative medical adverse events, length of stay (LOS), blood transfusion rate and 30-day readmission rate among patients who undergo 1-stage bilateral total hip arthroplasty (BTHA) and 1-stage bilateral total knee arthroplasty (BTKA) compared with patients who undergo 2-stage BTHA and BTKA.

Methods: Our study cohorts included patients who underwent BTHA and BTKA between Apr. 1, 2009, and Jan. 31, 2016, in Alberta, Canada. To minimize selection bias associated with our retrospective study design, we matched patients who underwent 1-stage BTHA and BTKA with patients with patients who underwent 2-stage BTHA and BTKA, respectively, for age, sex and number of presurgical risk factors using propensity score in a matching ratio of 1:1.

Results: Our study included 1645 patients who underwent BTHA and 4125 patients who underwent BTKA. We matched 195 patients who underwent 1-stage BTHA and 302 patients who underwent 1-stage BTKA with patients who underwent 2-stage BTHA and BTKA, respectively. There was no significant difference in postoperative medical adverse events between the 1-stage and 2-stage matched cohort groups for both BTHA (adjusted odds ratio [OR] 1.3, 95% confidence interval [CI] 0.3-4.9) and BTKA (adjusted OR 0.9, 95% CI 0.3-2.6). There was no difference in inpatient, 30- or 90-day mortality between the 2 groups for BTHA or BTKA. Patients who underwent 1-stage BTHA and BTKA had a shorter acute length of stay but increased total length of stay (acute care and rehabilitation unit) and were less likely to be discharged home postoperatively. One-stage BTHA and BTKA were associated with higher odds of blood transfusion than 2-stage BTHA and BTKA. The 30-day readmission rate was significantly lower for 1-stage BTHA than for the 2-stage BTHA matched cohort (adjusted OR 0.3, 95% CI 0.1-0.8), whereas there was no difference in the 30-day readmission rate (adjusted OR 0.6, 95% CI 0.2-1.7) between the 1-stage and 2-stage BTKA matched cohorts. Finally, operating room time was significantly lower for 1-stage BTHA (49.6 min less) and 1-stage BTKA (66.7 min less) than for the 2-stage arthroplasty procedures.

Conclusion: Healthy patients who undergo 1-stage BTHA and BTKA have postoperative medical complication rates comparable to those of patients who undergo 2-stage procedures with the additional benefits of a shorter acute length of stay, but they do have a higher risk of blood transfusion and are less likely to be discharged directly home from the acute care hospital. A multicentre randomized controlled trial on this topic is currently being condcuted by the Canadian Arthroplasty Society.