title: Improved radiographic outcomes with patient-specific total knee arthroplasty.
abstract: Patient-specific guides can improve limb alignment and implant positioning in total knee arthroplasty, although not all studies have supported this benefit. We compared the radiographs of 100 consecutively-performed patient-specific total knees to a similar group that was implanted with conventional instruments instead. The patient-specific group showed more accurate reproduction of the theoretically ideal mechanical axis, with fewer outliers, but implant positioning was comparable between groups. Our odds ratio comparison showed that the patient-specific group was 1.8 times more likely to be within the desired +3° from the neutral mechanical axis when compared to the standard control group. Our data suggest that reliable reproduction of the limb mechanical axis may accrue from patient-specific guides in total knee arthroplasty when compared to standard, intramedullary instrumentation.
authors.affiliation: University of Missouri Department of Orthopaedic Surgery, Columbia, Missouri.
authors.forename: Conrad B
authors.initials: CB
authors.lastname: Ivie
authors.affiliation: University of Missouri School of Medicine, Columbia, Missouri.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Probst
authors.affiliation: Asheville School, Asheville, North Carolina.
authors.forename: Amrit K
authors.initials: AK
authors.lastname: Bal
authors.affiliation: Comparative Orthopaedic Laboratory, University of Missouri, Columbia.
authors.forename: James T
authors.initials: JT
authors.lastname: Stannard
authors.affiliation: University of Missouri Department of Orthopaedic Surgery, Columbia, Missouri.
authors.forename: Brett D
authors.initials: BD
authors.lastname: Crist
authors.affiliation: University of Missouri Department of Orthopaedic Surgery, Columbia, Missouri.
authors.forename: B
authors.initials: B
authors.lastname: Sonny Bal
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation; D017760:Bone Malalignment / Q000000981:diagnostic imaging / Q000517:prevention & control; D006801:Humans; D021621:Imaging, Three-Dimensional; D007592:Joint Diseases / Q000000981:diagnostic imaging* / Q000601:surgery; D007717:Knee / Q000000981:diagnostic imaging*; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D011859:Radiography; D025321:Surgery, Computer-Assisted / Q000295:instrumentation
keywords: computed tomography; frontal plane limb alignment; limb mechanical axis; patient-specific cutting guides; total knee arthroplasty