Christoph Kolja Boese1, Sebastian Wilhelm2, Stefan Haneder3, Philipp Lechler4, Peer Eysel2, Jan Bredow5,6. 1. Department of Orthopaedic and Trauma Surgery, University Hospital of Cologne, Joseph-Stelzmann-Str. 9, 50924, Cologne, Germany. christoph.boese@uk-koeln.de. 2. Department of Orthopaedic and Trauma Surgery, University Hospital of Cologne, Joseph-Stelzmann-Str. 9, 50924, Cologne, Germany. 3. Institute of Diagnostic and Interventional Radiology, University Hospital of Cologne, Cologne, Germany. 4. Center of Orthopedic and Trauma Surgery, University of Giessen and Marburg, Marburg, Germany. 5. Department of Spine Surgery, Schön Klinik Düsseldorf, Düsseldorf, Germany. 6. Center for Orthopedics, Schön Klinik Düsseldorf SE & Co. KG, Am Heerdter Krankenhaus 2, 40549, Düsseldorf, Germany.
Abstract
PURPOSE: Digital templating is considered a standard for total hip arthroplasty. Different means for the necessary calibration of radiographs are known. While single marker calibration with radiopaque spheres is the most common, it is associated with possible significant deviations from the true magnification of the hip. Notably, fixed magnification factors showed better results. Therefore, a dual-position calibration marker method was simulated and compared to the established methods. METHODS: First, an empirical fixed magnification factor was identified and applied to a series of radiographs. Second, three magnification factors were generated based on sagittal patient data of 398 CT scans. These methods were compared to the fixed factor. RESULTS: The fixed factor was 122.6%. In the clinical application, the error of the fixed factor was 2.5% while the error of the single marker was 5.2%. In the CT cohort, the mean reference factor was 120.5% in females and 120.3% in males. The reference factor was compared to sex-specific means, sex-specific linear functions, and sex-specific cubic functions. The best results were found for the linear regression model with a mean difference of 0.8% from the reference value. No proportional bias was found (p = 0.623). CONCLUSION: The simulation of the dual-position marker method using the linear regression model showed promising results, superior to all other methods. In future studies, its clinical application should be tested.
PURPOSE: Digital templating is considered a standard for total hip arthroplasty. Different means for the necessary calibration of radiographs are known. While single marker calibration with radiopaque spheres is the most common, it is associated with possible significant deviations from the true magnification of the hip. Notably, fixed magnification factors showed better results. Therefore, a dual-position calibration marker method was simulated and compared to the established methods. METHODS: First, an empirical fixed magnification factor was identified and applied to a series of radiographs. Second, three magnification factors were generated based on sagittal patient data of 398 CT scans. These methods were compared to the fixed factor. RESULTS: The fixed factor was 122.6%. In the clinical application, the error of the fixed factor was 2.5% while the error of the single marker was 5.2%. In the CT cohort, the mean reference factor was 120.5% in females and 120.3% in males. The reference factor was compared to sex-specific means, sex-specific linear functions, and sex-specific cubic functions. The best results were found for the linear regression model with a mean difference of 0.8% from the reference value. No proportional bias was found (p = 0.623). CONCLUSION: The simulation of the dual-position marker method using the linear regression model showed promising results, superior to all other methods. In future studies, its clinical application should be tested.
Entities:
Keywords:
Arthroplasty; Calibration; Diagnostic imaging; Planning techniques; Total hip replacement
Authors: Christoph Kolja Boese; Philipp Lechler; Leonard Rose; Jens Dargel; Johannes Oppermann; Peer Eysel; Hansjörg Geiges; Jan Bredow Journal: PLoS One Date: 2015-07-13 Impact factor: 3.240
Authors: Y Warschawski; I Shichman; S Morgan; O Shaked; S Garceau; N Amzallag; N Snir; A Gold Journal: Arch Orthop Trauma Surg Date: 2020-08-13 Impact factor: 3.067
Authors: Christoph Kolja Boese; Tim Rolvien; Matthias Trost; Michael Frink; Jan Hubert; Frank Timo Beil; Christian Ries Journal: Int J Comput Assist Radiol Surg Date: 2021-04-17 Impact factor: 2.924