Use of image-free navigation in determination of acetabular cup orientation: analysis of factors affecting precision.
We have been using an image-free total hip arthroplasty (THA) navigation system (OrthoPilot; Aesculap, Tuttlingen, Germany) to ensure accurate and reproducible acetabular cup orientation. In this study, the accuracy of this system in the assessment of acetabular cup orientation was evaluated by comparing the intraoperative inclination and anteversion angles presented by the navigation system and the corresponding postoperative values obtained by computed tomography measurement. In the intraoperative accuracy analysis, we additionally examined the influence of factors such as body mass index and soft tissue thickness on assessment error. Intraoperative and postoperative results obtained from 115 consecutive navigated THAs were compared and analyzed. In both inclination and anteversion angles, good agreement was observed; a discrepancy of more than 5° was observed in 1 and 3 cases, respectively. In the analysis of factors potentially affecting the accuracy of the intraoperative assessment, no correlation between each parameter and the intraoperative and postoperative discrepancy was demonstrated.
Department of Orthopaedic Surgery, Hyogo College of Medicine, 1-1 Mukogawa-cho Nishinomiya, Hyogo 663-8501, Japan.
Tomokazu
T
Fukui
Shigeo
S
Fukunishi
Shoji
S
Nishio
Nao
N
Shibanuma
Shinichi
S
Yoshiya
D000077:Acetabulum; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D003658:Decision Making, Computer-Assisted; D006801:Humans; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D019637:Orthopedic Procedures / Q000379:methods*; D015207:Osteoarthritis, Hip / Q000601:surgery; D011182:Postoperative Care; D011187:Posture; D017755:Prosthesis Fitting / Q000379:methods*; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000379:methods*; D055815:Young Adult