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

Introduction: 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, complication, revision, and mortality rates.

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

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), wound complications (P = 0.033), operative time (P = 0.028), length of hospital stay (P < 0.001), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score (P = 0.013), and Oxford Knee Score (OKS) 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.

Conclusion: 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 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.