Evaluation of translation in the normal and dysplastic hip using three-dimensional magnetic resonance imaging and voxel-based registration.
Osteoarthritis Cartilage
; 19(6): 700-10, 2011 Jun.
Article
em En
| MEDLINE
| ID: mdl-21315165
ABSTRACT
OBJECTIVE:
To elucidate in vivo hip instability by comparing normal hips to hips with acetabular dysplasia by evaluating three-dimensional (3D) translations of the femoral head center (FHC) at different hip positions using magnetic resonance imaging (MRI).DESIGN:
Forty normal hips and 22 dysplastic female hips were examined. MRI was performed at four different positions bilaterally neutral, 45° of flexion, 15° of extension, and the Patrick position. Femoral and pelvic bones were separately extracted at the neutral position and superimposed over the images of each different position using voxel-based registration. The distance between the acetabular center and FHC at neutral position was defined as 3D-migration. The distance between FHC at neutral position and that at each different position was defined as 3D-translation. Two-way repeated measures analysis of variance was performed to consider the dependency between right and left-side data, and multiple linear regression analyses were performed to assess independent relationships.RESULTS:
The center-edge (CE) angle was the determinant for 3D-migration (ß=-0.415, P=0.001), and there was a statistical significant difference in 3D-migration between normal female hips and dysplastic hips (P=0.047). From neutral to the Patrick position, the FHC of normal and dysplastic hips translated postero-infero-medially by 1.12±0.39mm (0.45-1.85mm) and 1.97±0.84mm (0.95-4.34mm), respectively, and the difference between the groups was statistically significant (P=0.005). CE angle was the determinant for 3D-translation from neutral to the Patrick position (ß=-0.730, P<0.001). The average root mean square error in 3D-translation was 0.172mm and 0.193mm for intra- and interobserver reproducibility, respectively.CONCLUSIONS:
Hip instability was increased in proportion to the severity of acetabular dysplasia. A 3D MRI voxel-based registration technique can show in vivo morphology and kinematics of the native hip without exposure to radioactivity.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Imageamento por Ressonância Magnética
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Luxação do Quadril
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Instabilidade Articular
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article