%0 Journal Article
%T Effects of implant precoating and fat contamination on the stability of the tibial baseplate.
%A Silva MMB
%A Gjertsen JE
%A Moldestad IO
%A Furnes ON
%A Khan M
%A Høl PJ
%J Knee
%V 49
%N 0
%D 2024 Aug 25
%M 39059126
%F 2.423
%R 10.1016/j.knee.2024.07.007
%X <B>BACKGROUND: </B>Approximately 5% of primary total knee arthroplasty patients require revision within 10 years, often due to distal component loosening. Application of a thin layer of PMMA cement as precoating on the tibial component aims to prevent aseptic loosening. This study investigates the impact of precoating and fat contamination on tibial baseplate stability.<BR><B>METHODS: </B>Two groups of NexGen® stemmed tibial implants (size 4) were studied: Option implants (N = 12) and PMMA Precoat implants (N = 12). Each implant design was divided into two subgroups, (N = 6), with one subgroup featuring bone marrow fat at the implant-cement interface and the other without contamination. In a mechanical testing machine, the implants underwent uniaxial loading for 20,000 cycles, while recording vertical micromotion and migration of the tibial baseplates. Subsequently, a push-out test assessed fixation strength at the cement interfaces. Results were compared using non-parametric statistics and presented as median and min-to-max ranges.<BR><B>RESULTS: </B>Option implants exhibited higher micromotion in dry conditions compared to precoated implants (p = 0.03). Under contamination, both designs demonstrated similar micromotion values. Fixation strength did not significantly differ between designs under dry, uncontaminated conditions (p > 0.99). However, under contaminated conditions, the failure load for the non-coated Option implant was nearly half that of the uncontaminated counterparts (3517 N, 2603-4367 N vs 7531 N, 5163-9000 N; p = 0.002). Precoat implants displayed less susceptibility to fat contamination (p = 0.30).<BR><B>CONCLUSIONS: </B>NexGen® implant PMMA precoating might reduce the risk of aseptic loosening and revision surgery in case of eventual bone-marrow fat contamination.