Varus alignment after total knee arthroplasty results in greater axial rotation during deep knee bend activity.
Axial rotation
Coronal alignment
Fluoroscopy
Kinematics
Total knee arthroplasty
Journal
Clinical biomechanics (Bristol, Avon)
ISSN: 1879-1271
Titre abrégé: Clin Biomech (Bristol, Avon)
Pays: England
ID NLM: 8611877
Informations de publication
Date de publication:
07 2020
07 2020
Historique:
received:
05
01
2020
revised:
01
04
2020
accepted:
15
05
2020
pubmed:
29
5
2020
medline:
23
4
2021
entrez:
29
5
2020
Statut:
ppublish
Résumé
The correlation between in vivo knee kinematics and alignment has not been fully elucidated. Recently, similar or better clinical outcomes have been reported by restoration of mild varus alignment after total knee arthroplasty for preoperative varus knees. The aim of this study was to evaluate the effect of postoperative alignment on knee kinematics during a deep knee bend activity. In vivo knee kinematics of 36 knees (25 patients) implanted with tri-condylar total knee arthroplasty were analyzed with a three dimensional model fitting approach using fluoroscopy. Under fluoroscopic surveillance, individual video frames were digitized at 30° increments from full extension to maximum flexion. Postoperative coronal and sagittal alignments were assessed using radiographs, and rotational alignment was assessed with computed tomography. Pearson correlation coefficients were calculated to determine the correlations between the alignment data and kinematic factors. Correlation analysis showed that coronal alignment was significantly correlated with knee kinematics. The varus alignment of the limb and tibial component led to a greater axial rotation from full extension to maximum flexion and more rotated position in the mid to deep flexion range. Neither the rotational alignment of the femoral nor tibial components showed significant correlation with axial rotation from full extension to maximum flexion. Varus alignment resulted in greater axial rotation, which could represent near-normal knee kinematics. The current study can be a kinematic rationale reporting similar or better clinical and functional outcomes for the total knee arthroplasty with residual varus alignment.
Sections du résumé
BACKGROUNDS
The correlation between in vivo knee kinematics and alignment has not been fully elucidated. Recently, similar or better clinical outcomes have been reported by restoration of mild varus alignment after total knee arthroplasty for preoperative varus knees. The aim of this study was to evaluate the effect of postoperative alignment on knee kinematics during a deep knee bend activity.
METHODS
In vivo knee kinematics of 36 knees (25 patients) implanted with tri-condylar total knee arthroplasty were analyzed with a three dimensional model fitting approach using fluoroscopy. Under fluoroscopic surveillance, individual video frames were digitized at 30° increments from full extension to maximum flexion. Postoperative coronal and sagittal alignments were assessed using radiographs, and rotational alignment was assessed with computed tomography. Pearson correlation coefficients were calculated to determine the correlations between the alignment data and kinematic factors.
FINDINGS
Correlation analysis showed that coronal alignment was significantly correlated with knee kinematics. The varus alignment of the limb and tibial component led to a greater axial rotation from full extension to maximum flexion and more rotated position in the mid to deep flexion range. Neither the rotational alignment of the femoral nor tibial components showed significant correlation with axial rotation from full extension to maximum flexion.
INTERPRETATION
Varus alignment resulted in greater axial rotation, which could represent near-normal knee kinematics. The current study can be a kinematic rationale reporting similar or better clinical and functional outcomes for the total knee arthroplasty with residual varus alignment.
Identifiants
pubmed: 32464429
pii: S0268-0033(20)30169-8
doi: 10.1016/j.clinbiomech.2020.105051
pii:
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
105051Informations de copyright
Copyright © 2020 Elsevier Ltd. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of Competing Interest S. Nakamura, R. D. Komistek, and S. Matsuda received research grant from Kyocera (Kyoto, Japan).