One-Stage Versus Two-Stage Bilateral Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

Background: Bilateral total knee arthroplasty (B-TKA) represents an increasingly used option to address advanced bilateral knee osteoarthritis (OA). The aim of this study was to quantify and compare one-stage and two-stage B-TKA results in terms of clinical outcomes, perioperative parameters, complications, revisions, and mortality rates.

Methods: The literature search was conducted using three databases (PubMed, Cochrane, and Web of Science) in February 2024 according to the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analysis. The inclusion criteria were as follows: comparative studies, English language, with no time filter on the comparison of one-stage and two-stage B-TKA for bilateral knee osteoarthritis treatment. The quality of each article was assessed using the Cochrane risk of bias in nonrandomized studies of interventions tool.

Results: Among the 2,130 articles retrieved, 69 studies (366,722 patients) were included. One-stage B-TKA showed lower rates of TKA-related complications (P = 0.043), deep infections (P < 0.001), and wound complications (P = 0.033), as well as lower operative time (P = 0.028), shorter length of hospital stay (P < 0.001), and higher improvements of Western Ontario and McMaster Universities Osteoarthritis Index score (P = 0.013) and Oxford Knee Score (P = 0.004), but higher mortality rates at the 1-month (P < 0.001), 3-month (P < 0.001), and 1-year (P = 0.001) follow-ups, as well as higher rates of neurological (P = 0.013) and gastrointestinal (P < 0.001) complications, deep vein thrombosis (P = 0.016), and pulmonary embolism (P < 0.001). The risk of bias was "low" in 26 studies, "moderate" in 36 studies, "serious" in six studies, and "critical" in one study.

Conclusions: One-stage B-TKA was associated with a higher mortality rate and thromboembolic risk while presenting lower TKA-related and infective complications compared to two-stage B-TKA. One-stage B-TKA also reduced hospital stay and total surgical time but provided only marginal improvement in clinical outcomes compared to two-stage B-TKA while showing a higher risk of neurologic and gastrointestinal complications. These results offer important information for both patients and surgeons in evaluating the most appropriate surgical approach, thereby contributing to optimize the management of patients undergoing B-TKA.

Level Of Evidence: Level I.