A validated single-view radiographic alternative to computed tomography for the measurement of femoral anteversion: a method-comparison study

• Published in: The Journal of arthroplasty 2017-03, Vol.32 (3), p.1018-1023
• Main Authors: Boissonneault, A, Hiranaka, T, Roberson, J, Bradbury, T
• Format: Article
• Language: English
• Subjects: Adult; Aged; Arthroplasty, Replacement, Hip; Female; femoral anteversion; femoral torsion; Femur - diagnostic imaging; Femur - surgery; Hip Prosthesis; Humans; Knee Joint - surgery; Male; Middle Aged; Orthopedics; Prospective Studies; prosthetic hip impingement; prosthetic hip instability; Radiography - methods; Range of Motion, Articular; Tomography, X-Ray Computed; total hip arthroplasty
• ISSN: 0883-5403; 1532-8406
• DOI: 10.1016/j.arth.2016.09.016

Abstract Background Although pre-operative templating in total hip arthroplasty is helpful to ensure appropriate component position, there is no single-view radiographic method to determine femoral anteversion (FA) pre-operatively. The aim of the current study was to validate the use of radiographic measurement of FA using a modified Budin view. Methods This prospective study reports on 105 limbs from 65 patients. Computed tomography (CT) scans and radiographs were obtained to measure native FA. Radiographs were obtained using the modified Budin protocol with 90° flexion at the knee and 90° flexion and 30° abduction at the hip. Pearson correlation analyses, paired-samples t-test, and Bland-Altman plots were performed to assess correlation and agreement between methods. Data was grouped into subsets based on CT-derived FA in 5-degree intervals. Groups included all limbs, FA < 35°, FA < 30°, and FA < 25°. Results For all limbs, Bland-Altman analysis revealed a fixed bias (mean bias -0.8°, 95%CI -1.4 to -0.2°) and showed that radiographic methods underestimated FA. Subset analyses were performed and revealed excellent correlation between CT and radiographic measurements for all subgroups (r=0.97, p