Analysis of failed premium versus standard total knee arthroplasty designs
Revision total knee arthroplasty (TKA) rates are escalating. Premium knee prostheses have been introduced with the hope of increasing implant longevity to reduce the burden of revision surgery and to provide more natural kinematics. Our goal was to determine if there is a difference in early failure rates between standard and premium TKAs that present for revision, and to examine the indications for early revision in both groups.Methods:
We performed a retrospective cohort study evaluating the in vivo lifespan of TKAs presenting to a single tertiary center for revision during a 5-year period. Failed TKA designs were categorized as standard or premium based on previously published criteria, and the cause for failure was identified. Early failure was defined as revision within 5-years.Results:
Seventy-eight failed TKAs were documented: 40 (51.3%) standard implants and 38 (48.7%) premium implants. Within 5 yr, 76.3% of the premium knees failed compared to 47.5% of standard implants (P=0.018). Premium knees were more likely to fail early as a result of pain or stiffness compared to standard implants (P=0.012), which were more likely to fail early because of infection (P=0.011).Conclusions:
Although we hypothesize that the higher proportion of early premium knee failures is related to the learning curves necessary to master the techniques for implanting these newer designs, their early failure warrants further prospective investigation.