Artikel
CT-Free Assisted Hip-Plasmacup Replacement (Navigation OrthoPilot)
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Autoren
Veröffentlicht: | 19. Oktober 2004 |
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Gliederung
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Introduction
The cup orientation is one of the most important aspects having influence not only to the stability of the replacement but also to the polyethylene wear and the long-term clinical results. The purpose of this study is to evaluate the position of press-fit plasmacups implanted by the OrthoPilot versus conventional free-hand hip-cup replacement.
Methods
Since October 2001 we performed a prospective randomized trial in 90 hips with primary osteoarthritis. Fifty patients had the press-fit Plasmacup (Aesculap) implanted with use of the CT-free OrthoPilot navigation system. This CT-free navigation system gives informations about reaming depth and cup orientation. In the control group, we evaluated 40 conventional free-hand hip-cups placement. All patients were followed with standard anteroposterior radiographs. We measured the acetabular cup inclination and anteversion according to the method of Ackland et al.
Results
No dislocation occurs in our patients sample. In the first group, we found out the range of inclination of the navigated cups from 43° to 46°. The anteversion ranged from 13° to 18°. In the control group of acetabular components implanted without navigation, we measured the inclination between 36° and 51° and anteversion between 0° and 32°.
Conclusions
CT-free assisted hip-cup placement OrthoPilot improves process quality. It reduces hip-cup malplacement and diffraction of cup position significantly in comparison to the established free-hand method. Accurate position of the cup has an influence to longer survival of the implant.