title: Accuracy of computer navigation for acetabular component placement in THA.
abstract: The accuracy and precision of any computer-aided surgical device is critical to its utility. We asked the following question: how accurate and precise are the values measured by an imageless computer navigation system as compared with those measured using postoperative CT scans? Twenty-five patients (26 hips) underwent primary THA using an imageless computer navigation system for placement of the acetabular component. Inclination and anteversion were measured in the operative coordinate system as defined by Murray. Accuracy, precision, and bias were computed, and Bland-Altman analysis was used to assess levels of agreement. The accuracy (mean +/- standard deviation of the absolute difference between computer-assisted navigation and CT) was 1.8 degrees +/- 1.2 degrees for inclination and 2.0 degrees +/- 2.0 degrees for anteversion. Precision was 3.4 degrees for inclination and 5.5 degrees for anteversion. Bias was 0.52 degrees for inclination and 0.35 degrees for anteversion. Limits of agreement were 4.26 degrees for inclination and 5.58 degrees for anteversion. An imageless computer navigation system can precisely determine acetabular cup position.
authors.affiliation: Sutter General Hospital, Sacramento, CA 95816, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Ryan
authors.forename: Amir A
authors.initials: AA
authors.lastname: Jamali
authors.forename: William L
authors.initials: WL
authors.lastname: Bargar
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods