Primärstabilität von Press-fit Hüftpfannen – eine in-vitro Studie – / Initial Stability Of Press-fit Acetabular Cups – An In-Vitro Study –
| Autor: | R Wetzel, G. Scheller, M Simnacher |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
medicine.medical_specialty
Materials science genetic structures Biomedical Engineering chemistry.chemical_element Initial stability Edge (geometry) engineering.material Surgery Hip arthroplasty chemistry Coating engineering medicine In vitro study sense organs Implant Composite material Titanium A titanium |
| Zdroj: | Biomedizinische Technik/Biomedical Engineering. 50:400-403 |
| ISSN: | 1862-278X 0013-5585 |
| DOI: | 10.1515/bmt.2005.055 |
| Popis: | AIM OF THE STUDY Mechanical lever-out tests were performed in vitro to investigate the initial stability of press fit acetabular cups. METHOD Five different uncemented, hemispherical press-fit cups were implanted in a standardized manner into Sawbones, Polyurethane foam blocks. Each cup was levered-out by using a 250 mm stainless steel rod, which was connected to the acetabular cup. Loads were then applied to the rod causing the cup to be diplaced. Lever-out forces were recorded by a computer. RESULTS The results of the lever-out forces ranged between 39,2 and 50,8 Nm. The highest initial stability was achieved by two Titanium cups with a Titanium plasmaspray coating, a flattened pole and a sharp equatorial edge. According to our trials the equatorial rim of the polyurethane cavity is the crucial area for the implant's initial stabilty. There the highest amount of attrition was observed. CONCLUSION To guarantee a high reproducibilty of the tests it is essential to pay particular attention to the quality of the polyurethane foam blocks, to the exactness of the reaming procedure and to a defined cup insertion. However as our trials were carried out under optimized labaratory conditions one must be careful not to over-interpret its results. Intraoperatively primary stability is also influenced by the quality of the bone. |
| Databáze: | OpenAIRE |
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