Extent of in vivo sagittal bearing movement and its relationship with tibial posterior slopes in Oxford mobile-bearing unicompartmental knee arthroplasty.
Bearing dislocation
Kinematics
Mobile bearing
Oxford knee score
Posterior slope
Unicompartmental 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:
12 2020
12 2020
Historique:
received:
01
06
2020
revised:
10
08
2020
accepted:
13
08
2020
pubmed:
24
8
2020
medline:
30
4
2021
entrez:
24
8
2020
Statut:
ppublish
Résumé
The effect of increased tibial slope on the bearing movement and clinical results in mobile-bearing unicompartmental knee arthroplasty has not been well discussed. We aimed to clarify the extent of in vivo sagittal bearing movement and bearing overhang using fluoroscopy and their relationship with the tibial posterior slopes and clinical results. This retrospective study included 40 patients who underwent Oxford unicompartmental knee arthroplasty for anteromedial osteoarthritis or osteonecrosis of the knee. Intraoperative posterior translation and posterior overhang of the bearing were assessed during flexion. The tibial posterior slopes were evaluated before and 2 weeks after surgery, and its increment was recorded. Clinical evaluations were also performed preoperatively and at 2 years postoperatively (maximum flexion angle, Oxford Knee Score). Single linear regression analysis was performed to assess the correlation between the tibial posterior slopes and the posterior translation and the posterior overhang and determine if these could affect the clinical outcomes. The average posterior translation was 10.7 ± 4.3 mm, and posterior overhang of the mobile bearing was found in 35% of overall patients. They were associated with increased tibial slope as well as poorer improvement in Oxford Knee Score at 2 years postoperatively. In Oxford unicompartmental knee arthroplasty, mobile bearing can probably move posteriorly beyond the posterior margin of the tibial component during flexion when the tibial posterior slope increases more than the original magnitude. Additionally, the posterior translation and posterior overhang closely correlated with the poorer improvement in Oxford Knee Score at 2 years postoperatively.
Sections du résumé
BACKGROUND
The effect of increased tibial slope on the bearing movement and clinical results in mobile-bearing unicompartmental knee arthroplasty has not been well discussed. We aimed to clarify the extent of in vivo sagittal bearing movement and bearing overhang using fluoroscopy and their relationship with the tibial posterior slopes and clinical results.
METHODS
This retrospective study included 40 patients who underwent Oxford unicompartmental knee arthroplasty for anteromedial osteoarthritis or osteonecrosis of the knee. Intraoperative posterior translation and posterior overhang of the bearing were assessed during flexion. The tibial posterior slopes were evaluated before and 2 weeks after surgery, and its increment was recorded. Clinical evaluations were also performed preoperatively and at 2 years postoperatively (maximum flexion angle, Oxford Knee Score). Single linear regression analysis was performed to assess the correlation between the tibial posterior slopes and the posterior translation and the posterior overhang and determine if these could affect the clinical outcomes.
FINDINGS
The average posterior translation was 10.7 ± 4.3 mm, and posterior overhang of the mobile bearing was found in 35% of overall patients. They were associated with increased tibial slope as well as poorer improvement in Oxford Knee Score at 2 years postoperatively.
INTERPRETATION
In Oxford unicompartmental knee arthroplasty, mobile bearing can probably move posteriorly beyond the posterior margin of the tibial component during flexion when the tibial posterior slope increases more than the original magnitude. Additionally, the posterior translation and posterior overhang closely correlated with the poorer improvement in Oxford Knee Score at 2 years postoperatively.
Identifiants
pubmed: 32829237
pii: S0268-0033(20)30267-9
doi: 10.1016/j.clinbiomech.2020.105148
pii:
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
105148Informations de copyright
Copyright © 2020 Elsevier Ltd. All rights reserved.