title: Development of imageless computer navigation for acetabular component position in total hip replacement.
abstract: The purpose of this study was to develop an imageless (without preoperative computerized tomography (CT) scans or intraoperative fluoroscopy) computer navigation system for total hip replacement. One-hundred and ninety-five hips were operated with imageless computer navigation. Eighty-five hips were operated prior to obtaining precise results, with precision refined in the subsequent 110 hips. Computer accuracy for cup-adjusted anteversion was achieved in 100% of the final 40 hips, and for adjusted inclination in 96.6%. The factors necessary for accurate measurements are mechanical stability of the tools with the light-emitting diodes, adjusted computer anteversion and inclination for the tilt of the pelvis (tilt in the AP plane), and check-and-balance techniques for confirmation of measurements of tilt, anteversion and inclination.
authors.affiliation: The Arthritis Institute, 501 E. Hardy Street, 3rd Floor, Inglewood, CA 90301, USA. patriciajpaul@yahoo.com
authors.forename: Lawrence D
authors.initials: LD
authors.lastname: Dorr
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hishiki
authors.forename: Zhinian
authors.initials: Z
authors.lastname: Wan
authors.forename: Deanne
authors.initials: D
authors.lastname: Newton
authors.forename: Andrew
authors.initials: A
authors.lastname: Yun
mesh_terms: D000077:Acetabulum; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D002138:Calibration; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011187:Posture