The number of screws, bone quality, and friction coefficient affect acetabular cup stability
| Autor: | Chih Han Chang, Kai Nan An, Weng Pin Chen, Kuo An Lai, Mark E. Zobitz, Heng-Li Huang, Jui-Ting Hsu |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
musculoskeletal diseases
medicine.medical_specialty Materials science Friction medicine.medical_treatment Bone Screws Finite Element Analysis Biomedical Engineering Biophysics Prosthesis Design Bone and Bones Pelvis Materials Testing Bone quality Alloys medicine Humans Reduction (orthopedic surgery) Fixation (histology) Orthodontics Friction coefficient Hip Stiffness Initial stability Models Theoretical equipment and supplies musculoskeletal system Biomechanical Phenomena Surgery surgical procedures operative medicine.anatomical_structure Subchondral bone Hip Joint Hip Prosthesis Stress Mechanical sense organs medicine.symptom Tomography X-Ray Computed |
| Zdroj: | Medical Engineering & Physics. 29:1089-1095 |
| ISSN: | 1350-4533 |
| Popis: | One of the major causes of loosening of cementless acetabular cup implants is insufficient initial stability. This study used three-dimensional finite element models of the pelvis and acetabular components to investigate the effects of the number of screws, bone quality, and friction coefficient of the acetabular cup on the initial stability under normal walking. A commercially available hemispherical acetabular cup with five screw holes was used as the default model. The stiffness of the pelvis and the friction coefficient of the cup were systematically varied, within a realistic range, to assess the initial stability of the acetabular cup. The simulations showed that the inserted screws provide only a localized reduction in the relative micromotion between the cup and pelvis therefore inserting several screw closed together might not be useful. Changes in the pelvic stiffness have a non-linear effect on the initial stability of acetabular cup and the subchondral bone provides good support for fixation of the cementless cup. The friction coefficient of the acetabular cup plays a limited role, comparing with the factor of bone quality, in resisting relative micromotion in the cup-pelvis interface. |
| Databáze: | OpenAIRE |
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