Kinematic alignment results in clinically similar outcomes to mechanical alignment: Systematic review and meta-analysis

James Van Essen; Jarrad Stevens; Michelle M Dowsey; Peter F Choong; Sina Babazadeh

doi:10.1016/j.knee.2022.11.001

Kinematic alignment results in clinically similar outcomes to mechanical alignment: Systematic review and meta-analysis

Knee. 2023 Jan:40:24-41. doi: 10.1016/j.knee.2022.11.001. Epub 2022 Nov 17.

Authors

James Van Essen¹, Jarrad Stevens², Michelle M Dowsey³, Peter F Choong⁴, Sina Babazadeh⁵

Affiliations

¹ University of Melbourne, Parkville, Victoria 3010, Australia.
² St. Vincent's Hospital (Melbourne) - Department of Orthopaedics, PO Box 2900, Fitzroy, Victoria 3065, Australia.
³ University of Melbourne, Parkville, Victoria 3010, Australia; St. Vincent's Hospital (Melbourne) - Department of Orthopaedics, PO Box 2900, Fitzroy, Victoria 3065, Australia. Electronic address: mmdowsey@unimelb.edu.au.
⁴ University of Melbourne, Parkville, Victoria 3010, Australia; St. Vincent's Hospital (Melbourne) - Department of Orthopaedics, PO Box 2900, Fitzroy, Victoria 3065, Australia. Electronic address: pchoong@unimelb.edu.au.
⁵ University of Melbourne, Parkville, Victoria 3010, Australia; St. Vincent's Hospital (Melbourne) - Department of Orthopaedics, PO Box 2900, Fitzroy, Victoria 3065, Australia; Australian Orthopaedic Research Group, Kew East, Victoria 3102, Australia. Electronic address: sbabazadeh@gmail.com.

PMID: 36403396
DOI: 10.1016/j.knee.2022.11.001

Abstract

Purpose: It is unclear whether a difference in functional outcome exists between kinematically aligned (KA) and mechanically aligned (MA) knee replacements. The aim of this study is to perform a comprehensive systematic review and meta-analysis of the available level I-IV evidence.

Methods: A meta-analysis of randomised controlled trials and observational studies comparing patient reported outcome measures (PROMs), range of motion (ROM), gait analysis and complications in TKA with KA and MA was performed. Quality assessment was performed for each study using the Joanna Briggs Institute (JBI) critical appraisal tools.

Results: Twelve randomised controlled trials and fourteen observational studies published between 2014 and 2022 were included in the final analysis. Meta-analysis revealed KA to have significantly better Oxford Knee Score (OKS) (p = 0.02), Forgotten Joint Score (FJS) (p = 0.006), Knee Society Score (KSS) Objective Knee (p = 0.03) and KSS Functional Activity (p = 0.008) scores. However, these improvements did not exceed the minimum clinically important difference (MCID) values reported in the literature. Subgroup analysis showed robotic assisted KA-TKA to have a clinically superior FJS (p = 0.0002) and trend towards KSS Objective Knee score (p = 0.10), compared to PSI. Gait and plantar pressure distribution of KA cohorts more closely represented healthy cohorts, and KA showed a weak association of a decreased knee adduction moment (KAM) compared to MA. Differences in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), range of motion and complications were not significant between groups.

Conclusion: Although KA results in several improved functional outcomes, these do not reach clinical significance. Further standardised large-scale randomised studies are required to improve the quality of evidence. As it stands, it is difficult to recommend one philosophy over the other.

Keywords: Clinical outcomes; Kinematic; Mechanical; Meta-analysis; Systematic review; Total knee arthroplasty.

Publication types

Meta-Analysis
Systematic Review
Review

MeSH terms

Arthroplasty, Replacement, Knee* / methods
Biomechanical Phenomena
Humans
Knee Joint / surgery
Knee Prosthesis*
Osteoarthritis, Knee* / surgery
Range of Motion, Articular