title: An optimized image matching method for determining in-vivo TKA kinematics with a dual-orthogonal fluoroscopic imaging system.
abstract: This study presents an optimized matching algorithm for a dual-orthogonal fluoroscopic image system used to determine six degrees-of-freedom total knee arthroplasty (TKA) kinematics in-vivo. The algorithm was evaluated using controlled conditions and standard geometries. Results of the validation demonstrate the algorithm's robustness and capability of realizing a pose from a variety of initial poses. Under idealized conditions, poses of a TKA system were recreated to within 0.02+/-0.01 mm and 0.02+/-0.03 deg for the femoral component and 0.07+/-0.09 mm and 0.16+/-0.18 deg for the tibial component. By employing a standardized geometry with spheres, the translational accuracy and repeatability under actual conditions was found to be 0.01+/-0.06 mm. Application of the optimized matching algorithm to a TKA patient showed that the pose of in-vivo TKA components can be repeatedly located, with standard deviations less than +/-0.12 mm and +/-0.12 deg for the femoral component and +/-0.29 mm and +/-0.25 deg for the tibial component. This methodology presents a useful tool that can be readily applied to the investigation of in-vivo motion of TKA kinematics.
authors.affiliation: Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Bingham
authors.forename: Guoan
authors.initials: G
authors.lastname: Li
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D003198:Computer Simulation; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D008954:Models, Biological; D009068:Movement; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome