title: The accuracy of extramedullary guides for tibial component placement in total knee arthroplasty.
abstract: Anteroposterior radiographs that included the whole tibia were taken before and after 75 total knee arthroplasties in 48 patients. The same tibial extra-medullary alignment guide system was used in every knee. The average tibial component alignment was 0.4 (SD 2.5, range -4.9 to 6.4) degrees of valgus post-operatively. 59 tibial components (78.7%) had a tibial cut within 3 degrees from being perpendicular to the mechanical axis, ten were too valgus (13.3%) and six were too varus (8%). The chance of the tibial components becoming too varus was higher if there was lateral tibial bowing, compared with no tibial bowing (p=0.048). A smaller lateral width of the leg increased the chance of the tibial components becoming too valgus (p=0.047).
authors.affiliation: Division of Joint Replacement Surgery, Department of Orthopedics and Traumatology, The University of Hong Kong, Hong Kong, China. pkychiu@hkucc.hku.hk
authors.forename: K Y
authors.initials: KY
authors.lastname: Chiu
authors.forename: W P
authors.initials: WP
authors.lastname: Yau
authors.forename: T P
authors.initials: TP
authors.lastname: Ng
authors.forename: W M
authors.initials: WM
authors.lastname: Tang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D017760:Bone Malalignment / Q000517:prevention & control*; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D013977:Tibia / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome