title: The effect of patient positioning on the precision of model-based radiostereometric analysis.
abstract: A repeatable method for in vivo and in vitro measurement of polyethylene wear in total knee replacement (TKA) is needed. This research examines the model-based radiostereometric analysis' (MBRSA) in vitro precision under different patient-radiograph orientations and flexion angles of the knee using a TKA phantom. Anterior-posterior and medial-lateral imaging orientations showed the highest precision; better than 0.036mm (3-dimensional translation) and 0.089° (3-dimensional rotation). Flexion of the knee did not affect MBRSA precision. Medial-lateral imaging is advantageous as it allows for flexion of the knee joint during an RSA examination, thus providing greater information for wear measurement.
authors.affiliation: Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, Canada; Concordia Joint Replacement Group, Concordia Hip and Knee Institute, Winnipeg, MB, Canada. Electronic address: tgascoyne@cjrg.ca.
authors.forename: Trevor C
authors.initials: TC
authors.lastname: Gascoyne
authors.affiliation: Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Morrison
authors.affiliation: Department of Surgery, University of Manitoba, Winnipeg, MB, Canada; Concordia Joint Replacement Group, Concordia Hip and Knee Institute, Winnipeg, MB, Canada.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Turgeon
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery*; D056888:Patient Positioning; D019047:Phantoms, Imaging; D020959:Polyethylene / Q000737:chemistry*; D011475:Prosthesis Failure; D059869:Radiostereometric Analysis; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012399:Rotation
chemical_list: D020959:Polyethylene
keywords: Micromotion; Phantom; Precision; Radiostereometric analysis; Total knee replacement; Wear analysis