Survival of the low contact stress rotating platform total knee replacement is influenced by age: 1058 implants with a minimum follow-up of 10 years ☆ N. Makaram ⁎, N.D. Clement, T. Hoo, R. Nutton, R. Burnett Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK article info abstract Article history: Received 7 February 2018 Received in revised form 19 July 2018 Accepted 27 August 2018 Available online xxxx Background: The low contact stress (LCS) mobile-bearing total knee replacement (TKR) was designed to minimise polyethylene wear, aseptic loosening and osteolysis. However, registry data suggests there is a significantly greater revision rate associated. The primary aim of this study was to assess long-term survivorship of the LCS TKR performed at a single high-volume centre. Secondary aims were to assess survival by mechanism of failure and identify predictors of revision. Methods: During a 13-year period (1993–2006) 1091 LCS TKRs were performed by two senior surgeons. Thirty-three with incomplete data were excluded. The patients were retrospectively iden- tified from an arthroplasty register. Mean age was 69 (range 30–96) years. Five hundred seventy- seven TKRs were performed in females, 481 in males. Mean follow-up was 14 years (SD 4.3). Results: There were 59 revisions during the study period: 14 (23.7%) for infection, 18 (30.5%) for in- stability, and 27 (45.8%) for polyethylene wear. Three hundred ninety-two patients died. All-cause survival at 10 years was 95% (95%CI 91.7–98.3) and at 15 years was 93% (95%CI 88.6–97.8). Survival at 10 years according to mechanism of failure was: infection 99% (95%CI 94–100%), instability 98% (95%CI 94–100%), and polyethylene wear 98% (95%CI 92–100). Of the 27 with polyethylene wear, only 19 (70.4%) had osteolysis requiring component revision, the other eight (29.6%) had polyethyl- ene exchanges. Cox regression analysis identified younger age as the only predictor of revision (HR 0.96, 95%CI 0.94–0.99, p = 0.003), with a four percent decreased risk of revision for each in- crease in year of age. Conclusions: The LCS TKR demonstrates excellent long-term survivorship with a low rate of revi- sion for osteolysis, however this risk is increased in younger patients. Crown Copyright © 2018 Published by Elsevier B.V. All rights reserved. Keywords: Low contact stress Mobile-bearing Total knee arthroplasty Osteolysis Revision 1. Introduction The low contact stress (LCS) mobile-bearing total knee replacement (TKR) was developed to address the established compli- cations observed with the long-term follow-up of fixed-bearing implants, namely of premature polyethylene wear, osteolysis and aseptic loosening [1,2]. The specific design aimed to improve the congruity between the femoral component and the polyethylene insert throughout knee movement, with the intention of limiting the stress across the bone-implant interface [3]. The mobile polyethylene insert in the LCS The Knee xxx (xxxx) xxx–xxx ☆ Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Declarations of interest: none. ⁎ Corresponding author at: Specialty Trainee Trauma and Orthopaedics, Royal Infirmary of Edinburgh, Little France, EH16 4SA, UK. E-mail address: n.makaram@nhs.net. (N. Makaram). THEKNE-02700; No of Pages 9 https://doi.org/10.1016/j.knee.2018.08.020 0968-0160/Crown Copyright © 2018 Published by Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect The Knee Please cite this article as: Makaram N, et al, Survival of the low contact stress rotating platform total knee replacement is influenced by age: 1058 implants with a minimum fol..., Knee (2018), https://doi.org/10.1016/j.knee.2018.08.020