What factors influence tibial tray-cement interface bond strength? We developed a laboratory model to investigate this issue with the goal of providing technical recommendations to mitigate the risk of tibial tray-cement loosening. Forty-eight size 4 Triathlon® tibial trays were cemented into an acrylic holder using two different cements: Simplex® and Palacos®; three different cementing times: early (low viscosity), per manufacturer (normal, medium viscosity), and late (high viscosity); two different cementation techniques: cementing tibial plateau only and cementing tibial plateau and keel; and two different fat (marrow) contamination conditions: metal/cement interface and cement/cement interface. A push-out test was applied at a velocity of 0.05 mm/s, and the load recorded continuously throughout the test at a rate of 10 Hz. The test was stopped when the plate debonded from the cement (i.e. the tray visibly separated from the acrylic support and the load dropped substantially). Statistical analysis was performed using Welch's t-tests and Cohen's d tests.Questions/purposes:
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