Sagittal alignment of the cemented femoral component in revision total knee arthroplasty influences the anterior and posterior condylar offset: Stem length does not affect these variables.
Cement
Condylar offset
Revision total knee arthroplasty
Sagittal alignment
Stem length
Journal
The Knee
ISSN: 1873-5800
Titre abrégé: Knee
Pays: Netherlands
ID NLM: 9430798
Informations de publication
Date de publication:
Mar 2020
Mar 2020
Historique:
received:
10
12
2018
revised:
15
08
2019
accepted:
28
10
2019
pubmed:
2
1
2020
medline:
5
11
2020
entrez:
2
1
2020
Statut:
ppublish
Résumé
The position of the femoral component can influence knee kinematics by altering the posterior (PCO) and anterior condylar offset (ACO). The primary aim of this study was to assess whether the length of the cemented stem influences the sagittal position of the femoral component after revision total knee arthroplasty (rTKA). The secondary aim was to determine the influence of the sagittal position on PCO and ACO. There were 172 consecutive patients over a seven-year period that underwent rTKA with a cemented semi-constrained prosthesis. The 172 patients were separated into two groups: 115 with short stems (50 mm) and 57 with longer stems (100 or 150 mm). Using rotationally acceptable lateral radiographs, the degree of flexion(+)/extension(-) of the femoral components, PCO, and ACO were measured. There was no significant difference (p > 0.25) between the two groups for sagittal position, PCO, or ACO. The average flexion of the femoral component with short stems was 2.2 ± 4.1° and 2.2 ± 3.4° for long stems (difference = 0.0, 95% confidence intervals (CI) -1.3 to 1.2). The average PCO ratio was 1.02 ± 0.15 for short stems and 0.99 ± 0.17 for long stems (difference = 0.03, 95% CI -0.02 to 0.08). The average ACO ratio was at 0.07 ± 0.08 for short stems and 0.08 ± 0.08 for long stems (difference = 0.01, 95% CI -0.01 to 0.04). There was a significant correlation between sagittal alignment of the femoral component and PCO (flexion increased PCO, r = 0.39, p < 0.0001) and ACO (flexion decreased ACO, r = -0.34, p < 0.0001). Cemented stem length does not influence the position of femoral component in the sagittal axis, PCO, or ACO. Surgical technique and sizing of the femoral component may be more predictive.
Sections du résumé
BACKGROUND
BACKGROUND
The position of the femoral component can influence knee kinematics by altering the posterior (PCO) and anterior condylar offset (ACO). The primary aim of this study was to assess whether the length of the cemented stem influences the sagittal position of the femoral component after revision total knee arthroplasty (rTKA). The secondary aim was to determine the influence of the sagittal position on PCO and ACO.
METHODS
METHODS
There were 172 consecutive patients over a seven-year period that underwent rTKA with a cemented semi-constrained prosthesis. The 172 patients were separated into two groups: 115 with short stems (50 mm) and 57 with longer stems (100 or 150 mm). Using rotationally acceptable lateral radiographs, the degree of flexion(+)/extension(-) of the femoral components, PCO, and ACO were measured.
RESULTS
RESULTS
There was no significant difference (p > 0.25) between the two groups for sagittal position, PCO, or ACO. The average flexion of the femoral component with short stems was 2.2 ± 4.1° and 2.2 ± 3.4° for long stems (difference = 0.0, 95% confidence intervals (CI) -1.3 to 1.2). The average PCO ratio was 1.02 ± 0.15 for short stems and 0.99 ± 0.17 for long stems (difference = 0.03, 95% CI -0.02 to 0.08). The average ACO ratio was at 0.07 ± 0.08 for short stems and 0.08 ± 0.08 for long stems (difference = 0.01, 95% CI -0.01 to 0.04). There was a significant correlation between sagittal alignment of the femoral component and PCO (flexion increased PCO, r = 0.39, p < 0.0001) and ACO (flexion decreased ACO, r = -0.34, p < 0.0001).
CONCLUSIONS
CONCLUSIONS
Cemented stem length does not influence the position of femoral component in the sagittal axis, PCO, or ACO. Surgical technique and sizing of the femoral component may be more predictive.
Identifiants
pubmed: 31892431
pii: S0968-0160(19)30251-0
doi: 10.1016/j.knee.2019.10.025
pii:
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
477-484Informations de copyright
Copyright © 2019 Elsevier B.V. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of competing interest All authors have no conflicts of interest to declare.