title: Evaluation of the accuracy of computed tomography-based navigation for femoral stem orientation and leg length discrepancy.
abstract: Although there is a great deal in the literature about the clinical accuracy of computed tomography (CT)-based navigation systems for acetabular cup orientation and leg length discrepancy in total hip arthroplasty, there is little analysis of femoral stem orientation. Thirty total hip arthroplasties in which CT-based navigation system had been used had their anteversion, valgus angle of stem, and leg length discrepancy measured on postoperative CT data. Differences in postoperative measurements from intraoperative records were -0.6° ± 4.8° (range, -11° to 10°) for stem anteversion, -0.2° ± 1.8° (range, -4° to 3°) for valgus angle of stem, and 1.3 ± 4.1 mm (range, -6 to 10 mm) for leg length. Although this system may need further improvement for stem orientation, it was helpful for intraoperative leg length adjustment.
authors.affiliation: Center of Arthroplasty, Kyowakai Hospital, Osaka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kitada
authors.forename: Nobuo
authors.initials: N
authors.lastname: Nakamura
authors.forename: Daiki
authors.initials: D
authors.lastname: Iwana
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kakimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishii
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sugano
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D017760:Bone Malalignment / Q000000981:diagnostic imaging / Q000517:prevention & control; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D007870:Leg Length Inequality / Q000000981:diagnostic imaging / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015207:Osteoarthritis, Hip / Q000601:surgery*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome