Effect of the humeral neck-shaft angle and glenosphere lateralization on stability of reverse shoulder arthroplasty: a cadaveric study.
Reverse shoulder
arthroplasty
biomechanics
lateralization
neck-shaft angle
shoulder
stability
Journal
Journal of shoulder and elbow surgery
ISSN: 1532-6500
Titre abrégé: J Shoulder Elbow Surg
Pays: United States
ID NLM: 9206499
Informations de publication
Date de publication:
May 2019
May 2019
Historique:
received:
10
08
2018
revised:
19
10
2018
accepted:
28
10
2018
pubmed:
11
1
2019
medline:
20
6
2019
entrez:
11
1
2019
Statut:
ppublish
Résumé
Lateralizing the glenosphere and decreasing the humeral neck-shaft angles are implant design parameters that reduce the risk of scapular impingement. The effects of these parameters on joint stability remain unclear. This study evaluated the effect of glenosphere lateralization and humeral neck-shaft angle on joint stability by quantifying the anterior dislocation force in different arm positions. Reverse shoulder arthroplasty was performed on 19 human shoulder specimens. Anterior dislocation force and maximum external rotation were evaluated using a robot-based shoulder simulator. By varying the neck-shaft angle and magnitudes of glenosphere lateralization, 12 configurations were analyzed with the glenohumeral joint in 30° and 60° of abduction, in neutral, and in 30° of external rotation. At 30° of abduction, measurements showed significantly higher dislocation forces for the 9-mm and 6-mm lateralized glenosphere than for the 0-mm (P < .0001, P = .007) nonlateralized glenosphere. At 60° of abduction, measurements showed significantly higher dislocation forces for the 9-mm and 6-mm lateralized glenosphere than for the 0-mm (P < .0001, P = .0007) and 3-mm (P = .0003, P = .04) glenosphere. Configurations with a neck-shaft angle of 135° showed significantly higher dislocation forces than configurations with a neck-shaft angle of 145° (P = .02) or 155° (P = .02) at 30° of abduction in 30° of external rotation. Neck-shaft angle and glenosphere lateralization had no influence on maximum external rotation capability. Glenosphere lateralization significantly increased anterior stability of the glenohumeral joint without influencing the range of passive external rotation. The humeral neck-shaft angle only had a minor effect on anterior stability.
Sections du résumé
BACKGROUND
BACKGROUND
Lateralizing the glenosphere and decreasing the humeral neck-shaft angles are implant design parameters that reduce the risk of scapular impingement. The effects of these parameters on joint stability remain unclear. This study evaluated the effect of glenosphere lateralization and humeral neck-shaft angle on joint stability by quantifying the anterior dislocation force in different arm positions.
METHODS
METHODS
Reverse shoulder arthroplasty was performed on 19 human shoulder specimens. Anterior dislocation force and maximum external rotation were evaluated using a robot-based shoulder simulator. By varying the neck-shaft angle and magnitudes of glenosphere lateralization, 12 configurations were analyzed with the glenohumeral joint in 30° and 60° of abduction, in neutral, and in 30° of external rotation.
RESULTS
RESULTS
At 30° of abduction, measurements showed significantly higher dislocation forces for the 9-mm and 6-mm lateralized glenosphere than for the 0-mm (P < .0001, P = .007) nonlateralized glenosphere. At 60° of abduction, measurements showed significantly higher dislocation forces for the 9-mm and 6-mm lateralized glenosphere than for the 0-mm (P < .0001, P = .0007) and 3-mm (P = .0003, P = .04) glenosphere. Configurations with a neck-shaft angle of 135° showed significantly higher dislocation forces than configurations with a neck-shaft angle of 145° (P = .02) or 155° (P = .02) at 30° of abduction in 30° of external rotation. Neck-shaft angle and glenosphere lateralization had no influence on maximum external rotation capability.
CONCLUSION
CONCLUSIONS
Glenosphere lateralization significantly increased anterior stability of the glenohumeral joint without influencing the range of passive external rotation. The humeral neck-shaft angle only had a minor effect on anterior stability.
Identifiants
pubmed: 30626537
pii: S1058-2746(18)30783-3
doi: 10.1016/j.jse.2018.10.025
pii:
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
966-973Informations de copyright
Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.