title: Evaluation of implant alignment in navigated unicompartmental knee arthroplasty: a comparison of 2D and 3D imaging.
abstract: This study aimed to compare two-dimensional (2D) and three-dimensional (3D) methods for evaluating implant alignment in navigated UKA. Nineteen UKAs in 18 subjects (7 men) were performed using an image-free navigation system. Coronal and sagittal implant alignments were assessed using radiographs (2D evaluation) and 3D image-matching software. The accuracy of 2D evaluation was compared with that of 3D evaluation. A deviation > 3° from the 3D evaluation was defined as an outlier. In the 2D evaluation, outliers for the femoral component were observed in both the coronal plane (6/19 subjects) and the sagittal plane (3/19 subjects). In UKA, assessment of the implant position might be misjudged because of the design of the implant, especially for the femoral component; 3D methods are ideal for assessment of implant alignment.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Ishida
authors.forename: Akihiko
authors.initials: A
authors.lastname: Toda
authors.forename: Nao
authors.initials: N
authors.lastname: Shibanuma
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kuroda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011859:Radiography; D025321:Surgery, Computer-Assisted