Is There an Optimal Time for the Second Surgery of Staged Bilateral Total Knee Arthroplasty When the Intervals Are Determined by Patients?

Abstract

Abstract Purpose The decision to perform a second surgery in terms of staged bilateral total knee arthroplasty (BTKA) remains undetermined. The purpose of this study was to evaluate the optimal time frame for the second surgery in staged BTKA. Methods We retrospectively reviewed 528 patients (1,056 knees) who underwent staged BTKA between January 1, 2015, and December 31, 2019. Considering the different intervals, all patients were divided into 3 groups using 3 different cut-off points: group A (≤ 180 days), group B (> 180 days and ≤ 365 days), and group C (> 365 days). Comparison was done among the 3 groups for the second arthroplasties (A2 vs. B2 vs. C2). In each group, comparison was conducted between two surgeries (A1 vs. A2, B1 vs. B2, and C1 vs. C2, respectively). We evaluated demographics and clinical outcomes, major complications, and hospital adverse events. Results There were no statistically significant differences in any of the clinical outcomes, major complications, and hospital adverse events among the 3 groups (A2 vs. B2 vs. C2). When C1 and C2 were compared, LOS (12.23 ± 3.41 vs 10.12 ± 2.76, P < 0.0001), drainage volume (115.62 ± 45.67 vs 101.26 ± 49.28, P = 0.003), additional morphine analgesics consumption (131.52 ± 259.11 vs 69.78 ± 159.89, P = 0.016), and the rate of hospital adverse events (58.33% vs 46.15%, P = 0.026) were significantly better in group C2. Conclusion The time frame of staged BTKAs has no influence on postoperative outcomes when the intervals are determined by patients. If patients are willing to wait, we advise that patients could take second surgery over a year after the first surgery. Trial registration number：ZE2020-139-01, for retrospectively registered trials. Level of Evidence： Retrospective cohort study，LEVEL III