title: Reliable acetabular cup orientation with a new gravity-assisted guidance system.
abstract: Acetabular cup orientation is a key factor determining hip stability, and standard mechanical guides have shown little help in improving alignment. An in vitro study was carried out to compare the accuracy and precision of a new gravity-assisted guidance system with a standard mechanical guide. Three hundred ten cups were impacted by 5 surgeons, and the final cup orientation was measured. With the new guide, the average error in anteversion was 0.4 degrees , compared with 10.4 degrees with the standard guide and 0.3 degrees and -4.7 degrees , respectively, for abduction angles. The average time required for orienting the cups was similar for both guides. The accuracy and reproducibility obtained with the new guide were better (P < .0001). These good results would require a clinical validation.
authors.affiliation: Hôpital Orthopédique de la Suisse Romande, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland.
authors.forename: Santiago
authors.initials: S
authors.lastname: Echeverri
authors.forename: Pierre-Francois
authors.initials: PF
authors.lastname: Leyvraz
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Zambelli
authors.forename: Brigitte M
authors.initials: BM
authors.lastname: Jolles
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology*; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D006112:Gravitation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008953:Models, Anatomic; D015203:Reproducibility of Results