Anatomic shoulder arthroplasty: consequences of humeral head malposition

Details

Serval ID
serval:BIB_1BB0EA5DDF70
Type
Inproceedings: an article in a conference proceedings.
Publication sub-type
Abstract (Abstract): shot summary in a article that contain essentials elements presented during a scientific conference, lecture or from a poster.
Collection
Publications
Institution
Title
Anatomic shoulder arthroplasty: consequences of humeral head malposition
Title of the conference
22th International Congress of Shoulder and Elbow Surgery
Author(s)
Farron A., Terrier A.
Address
Madrid, Espagne, 16-19 September 2009
Publication state
Published
Issued date
2009
Series
Book of Abstracts
Pages
85
Language
english
Abstract
Purpose
Third generation anatomic total shoulder prostheses offer a wide range of adaptability (size, thickness, retroversion and offset of the humeral head, cervico-diaphyseal angle) in order to reproduce anatomy and biomechanics of the shoulder as normal as possible. The large variability of the implants may also induce malposition. Our goal was to analyse the consequences of a humeral head malposition, which is one of the most frequent placement errors.
Material and Methods
A 3D finite element model of the glenohumeral joint, including the rotator cuff muscles and the deltoid, was used with the Aequalis anatomic prosthesis. Active abduction was simulated. Three humeral head placements were compared : anatomic positioning (A), 5 mm inferior positioning (B), 5 mm superior positioning (C). The effect of humeral head malposition was evaluated through the following quantities : the range of motion free of impingements, the glenohumeral contact pattern, and the stress within the polyethylene and the cement.
Results
Inferior positioning (B) of the humeral head produced a superior impingement before 90° of abduction, an inferior eccentric contact point on the glenoid, and 165% increase of cement stress. Superior positioning (C) of the humeral head produced a postero-superior eccentric contact point on the glenoid, 300% increase of glenohumeral contact pressure, 450% increase of polyethylene stress, and 207% increase of cement stress.
Conclusion
Malposition of the humeral head of anatomic prostheses induces biomechanical consequences that may preclude the glenoid survival. Particular attention must be paid to reproduce the humeral anatomy as normal as possible.
Create date
29/01/2010 17:44
Last modification date
20/08/2019 12:52
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