TY - JOUR T1 - Does oxidized zirconium make a difference? Midterm cohort survivorship of symmetric posterior condyle posterior-stabilized total knee arthroplasty JF - Canadian Journal of Surgery JO - CAN J SURG SP - 118 LP - 122 DO - 10.1503/cjs.007518 VL - 62 IS - 2 AU - A. Ross Demcoe AU - Eric R. Bohm AU - David R. Hedden AU - Colin D. Burnell AU - Thomas R. Turgeon Y1 - 2019/04/01 UR - http://canjsurg.ca/content/62/2/118.abstract N2 - Background: A novel symmetric posterior condylar design and option of a femoral component with an outer zirconium oxide layer were introduced to a successful asymmetric condylar total knee arthroplasty system in 2005. Given the paucity of information on this modified design, we performed a study to determine its early to midterm survivorship and performance.Methods: Patients who received the Genesis II Symmetric Posterior Condyle or Legion Primary total knee (cobalt–chromium [CoCr] or oxidized zirconium–niobium [OxZr]) (Smith & Nephew) implanted at the study centre between March 2007 and December 2013 were enrolled into a prospective database. We retrospectively reviewed the database and performed survival analysis using Kaplan–Meier techniques.Results: There were 2178 patients (1359 women [62.4%]; mean age 64.6 yr; mean body mass index 35.0) with 2815 knee replacements available for analysis. Survival rates were 98.2% (95% confidence interval [CI] 97.6%–98.7%) for failure for any reason at 2 years and 96.8% (95% CI 96.0%–97.7%) at 5 years. Age (hazard ratio [HR] 0.97, 95% CI 0.94–0.997) and female sex (HR 0.45, 95% CI 0.27–0.75) were protective, whereas body mass index (HR 1.02, 95% CI 0.99–1.05) and OxZr implant (HR 1.11, 95% CI 0.57–2.18) did not influence survivorship. Oxford Knee Score values improved from a mean of 40.2 to 21.8 by 2 years (p < 0.001), with no difference between the CoCr and OxZr groups.Conclusion: The symmetric posterior condylar posterior-stabilized knee offers excellent midterm survivorship. Implant bearing surface did not have an influence on survivorship to 5 years, and, thus, use of OxZr implants may not be justified. ER -