Influence of radial head prosthetic design on radiocapitellar joint contact mechanics.
J Shoulder Elbow Surg
; 23(4): 456-62, 2014 Apr.
Article
em En
| MEDLINE
| ID: mdl-24630544
ABSTRACT
HYPOTHESIS:
Our aim was to test whether anatomically designed metallic radial head implants could better reproduce native radiocapitellar contact pressure and areas than nonanatomic implants.METHODS:
The distal humerus and proximal radius from 6 cadaveric upper extremities were serially tested in supination with 100 N of compression force at 4 angles of flexion (0°, 30°, 60°, and 90°). By use of a thin flexible pressure transducer, contact pressures and areas were measured for the native radial head, an anatomic implant, a nonanatomic circular monopolar implant, and a bipolar nonanatomic implant. The data (mean contact pressure and mean contact area) were modeled using a 2-factor repeated-measures analysis of variance with P ≤ .05 considered to be significant.RESULTS:
The mean contact areas for the prosthetic radial heads were significantly less than those seen with the intact radial heads at every angle tested (P < .01). The mean contact pressures increased significantly with all prosthetic radial head types as compared with the native head. The mean contact pressures increased by 29% with the anatomic prosthesis, 230% with the monopolar prosthesis, and 220% with the bipolar prosthesis. Peak pressures of more than 5 MPa were more commonly observed with both the monopolar and bipolar prostheses than with the anatomic or native radial heads.CONCLUSIONS:
The geometry of radial head implants strongly influences their contact characteristics. In a direct radius-to-capitellum axial loading experiment, an anatomically designed radial head prosthesis had lower and more evenly distributed contact pressures than the nonanatomic implants that were tested.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Desenho de Prótese
/
Rádio (Anatomia)
/
Articulação do Cotovelo
/
Prótese de Cotovelo
/
Úmero
Tipo de estudo:
Prognostic_studies
Limite:
Aged
/
Female
/
Humans
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Male
/
Middle aged
Idioma:
En
Revista:
J Shoulder Elbow Surg
Assunto da revista:
ORTOPEDIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Estados Unidos