title: Radiographic analysis of femoroacetabular impingement with Hip2Norm-reliable and validated.
abstract: The purpose of this study was to validate the accuracy, consistency, and reproducibility/reliability of a new method for correction of pelvic tilt and rotation of radiographic hip parameters for pincer type of femoroacetabular impingement on an anteroposterior pelvic radiograph. Thirty cadaver hips and 100 randomized, blinded AP pelvic radiographs were used for investigation. To detect the software accuracy, the calculated femoral head coverage and classic hip parameters determined with our software were compared to reference measurements based on CT scans or conventional radiographs in a neutral orientation as gold standard. To investigate software consistency, differences among the different parameters for each cadaver pelvis were calculated when reckoned back from a random to the neutral orientation. Intra- and interobserver comparisons were used to analyze the reliability and reproducibility of all parameters. All but two parameters showed a good-to-very good accuracy with the reference measurements. No relevant systematic errors were detected in the Bland-Altman analysis. Software consistency was good-to-very good for all parameters. A good-to-very good reliability and reproducibility was found for a substantial number of the evaluated radiographic acetabular parameters. The software appears to be an accurate, consistent, reliable, and reproducible method for analysis of acetabular pathomorphologies.
authors.affiliation: Department of Orthopaedic Surgery, Inselspital, University of Bern, Freiburgstrasse, 3010 Bern, Switzerland. moritz.tannast@insel.ch
authors.forename: Moritz
authors.initials: M
authors.lastname: Tannast
authors.forename: Sapan
authors.initials: S
authors.lastname: Mistry
authors.forename: Simon D
authors.initials: SD
authors.lastname: Steppacher
authors.forename: Stephan
authors.initials: S
authors.lastname: Reichenbach
authors.forename: Frank
authors.initials: F
authors.lastname: Langlotz
authors.forename: Klaus A
authors.initials: KA
authors.lastname: Siebenrock
authors.forename: Guoyan
authors.initials: G
authors.lastname: Zheng
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002102:Cadaver; D005270:Femur Head / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D015588:Observer Variation; D011187:Posture; D011856:Radiographic Image Enhancement / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results; D012984:Software