Equivalent 2-year stabilization of uncemented tibial component migration despite higher early migration compared with cemented fixation: an RSA study on 360 total knee arthroplasties. (4th March 2019)

• Record Type: Journal Article
• Authors: Laende, Elise K; Astephen Wilson, Janie L; Mills Flemming, Joanna; Valstar, Edward R; Richardson, C Glen; Dunbar, Michael J
• Is Part Of: Acta orthopaedica. Volume 90:Number 2(2019)
• Page Start: 172
• Page End: 178
• Publication Date: 2019-03-04
• Subjects: Orthopedics -- Periodicals; 616.7005
• DOI: 10.1080/17453674.2018.1562633
• Languages: English
• ISSNs: 1745-3674

Abstract

Abstract : Background and purpose — Thresholds of implant migration for predicting long-term successful fixation of tibial components in total knee arthroplasty have not separated cemented and uncemented fixation. We compared implant migration of cemented and uncemented components at 1 year and as the change in migration from 1 to 2 years. Patients and methods — Implant migration of 360 tibial components measured using radiostereometric analysis was compared at 1 year and as the change in migration from 1 to 2 years in 222 cemented components (3 implant designs) and 138 uncemented components (5 implant designs). Results — 1-year maximum total point motion was lower for the cemented tibial components compared with the uncemented components (median = 0.31 mm [0.03–2.98] versus 0.63 mm [0.11–5.19] respectively, p < 0.001, mixed model). The change in migration from 1 to 2 years, however, was equivalent for cemented and uncemented components (mean [SD] 0.06 mm [0.19] and 0.07 mm [0.27] mm respectively, p = 0.6, mixed model). Interpretation — These findings suggest that current thresholds of acceptable migration at 1 year may be better optimized by considering cemented and uncemented tibial components separately as higher early migration of uncemented components was not associated with decreased stability from 1 to 2 years.