Comparative Effectiveness of Contemporary Alignment Strategies in Total Knee Arthroplasty: A Systematic Review and Network Meta-Analysis
In brief
Functional alignment improved knee-feel scores by 14 points, but evidence is weak
Across 61 studies involving 7,822 patients, functional alignment improved Forgotten Joint Scores by about 14 points versus mechanical alignment, the only strategy to exceed the threshold for a clinically meaningful difference. High heterogeneity, weaker results in randomized trials, and very low certainty for most comparisons mean no alignment strategy can yet be preferred.
- Journal
- The Journal of arthroplasty (Q1)
- Published
- 6 November 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Guan Hao Chester Tan, Hui-Shan Angela Lim, Leah Robin Thorpe, Charles Kon Kam King, Ing How Moo
- PMID
- 42994644
- DOI
- 10.1016/j.arth.2026.11.002
Why clinicians should know about it
- Picked for Orthopedics and Sports Medicine (top studies of the week, 8 November 2026): Comparative TKA alignment strategies and patient-reported outcomes
Abstract
BACKGROUND: Patient-specific alignment strategies are increasingly used in total knee arthroplasty (TKA), but comparative clinical benefit over mechanical alignment (MA) remains uncertain. We compared contemporary alignment strategies using the Forgotten Joint Score (FJS) as the primary outcome. METHODS: There were four bibliographic databases searched from January 2000 to February 2026 for randomized controlled trials (RCTs) and comparative observational studies of primary TKA. Eligible studies compared unrestricted kinematic alignment (uKA), restricted kinematic alignment (rKA), functional alignment (FA), adjusted MA, or inverse restricted kinematic alignment with MA or another strategy. Random-effects pairwise meta-analysis and frequentist network meta-analysis (NMA) were performed to synthesize sparse direct and indirect comparisons across connected alignment strategies. Secondary outcomes were Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and range of motion (ROM)/flexion. Certainty was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. There were 61 studies (22 RCTs, 39 observational; 7,822 patients) that were included. RESULTS: Compared with MA, FJS improved with FA (mean difference [MD] 14.24, 95% confidence interval [CI] 3.32 to 25.16), uKA (MD 12.28, 95% CI 9.06 to 15.51), and rKA (MD 8.75, 95% CI 3.41 to 14.08). Only FA exceeded the lower FJS minimal clinically important difference threshold, but heterogeneity was high. Study-design stratification reduced several favorable estimates, including the FJS advantage of uKA over MA, which was larger in observational studies than in RCTs (MD 13.76 versus 7.49). The secondary OKS, WOMAC, and ROM/flexion effects were smaller and generally below accepted clinical thresholds. In NMA, FA and uKA ranked highest for FJS in all-study analyses, whereas RCT-only rankings were less decisive. The GRADE certainty was Low for rKA versus MA FJS and Very Low for other Tier 1 comparisons. CONCLUSION: Contemporary non-mechanical alignment strategies statistically improve FJS after TKA, but clinically meaningful and certain superiority over MA is not established. Longer, adequately powered RCTs are needed before one strategy can be preferred.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.