Simultaneous bilateral total knee arthroplasty (sim-BTKA) is reported to be safe in a select group of patients. Patients with symptomatic bilateral knee arthritis who are not candidates for sim-BTKA require staged surgery (stag-BTKA). This study aimed to compare the safety and complications associated with sim-BTKA with stag-BTKA performed at 2 time intervals.
This retrospective study of prospectively collected data includes bilateral TKA cases performed between 2001 and 2019. A cohort of sim-BTKA (n = 2728) was compared to a cohort of stag-BTKA (n = 1658). The staged group was subdivided according to the interval between surgeries: ≤90 days (early) and ≥91 days (later). Multivariate logistic regression analyses were used to adjust for confounding variables.
In-hospital complication rates were lower in both arms of the stag-BTKA groups vs the sim-BTKA. The sim-BTKA group had higher odds ratio of anemia, electrolyte disturbances, pulmonary embolism, and respiratory, urinary, gastrointestinal, and neurological complications. Lower rates of all-cause revision were found in stag-BTKA vs sim-BTKA groups. There was a trend toward revision due to deep infection when increasing the interim before the second stag-BTKA procedure. No differences in complication rates after the second surgery were detected between the early and later stag-BTKA.
This study demonstrates that sim-BTKA is associated with more complications and revisions when compared to stag-BTKA. Performing the second-stage TKA at 90 days or less after the first TKA is not associated with increased risk of complications. Performing sim-BTKA, simply for convenience, is not warranted and should be reserved for a select group of patient matching specific criteria.