Fixed-Bearing vs Mobile-Bearing Total Ankle Replacement Survivorship. A Meta-Analysis

Category: Ankle Arthritis; Ankle Introduction/Purpose: Main objective of this research is to know if there is a different survival ‎rate between fixed bearing (FB) and mobile bearing (MB) total ankle replacement ‎‎(TAR). We hypothesized that there are no differences between the survival rates of ‎both implants.‎ Methods: A systematic search was performed in PubMed, Cochrane, EMBASE and ‎ClinicalTrials.gov databases‎ to identify published studies from August 2018 to ‎September 2022 including results for FB and MB TAR survivorship. Inclusion criteria ‎included 1) primary TAR in one or both feet in which implant could be identified‎, 2) a ‎minimum of 20 procedures reported, 3) reported implant survivorship or calculable ‎and 4) a minimum of 12 months follow-up for level 1-3 studies or 60 months for level ‎‎4 studies.‎ Results: 3902 ankles in 28 studies were included. 719 were FB and 3104 MB with an overall ‎survivorship of 94% (95% CI [0.89; 0.97]) and 89% (95% CI [0.86; 0.92]) respectively. ‎After subgroup analysis, we did not find differences among both groups (p = ‎0.429‎). ‎Meta-regression analysis showed that longer follow-up was associated with lower ‎survival rates in MB group (p = 0.000) while no other relationships were found with ‎other factors (age, level of evidence or conflict of interests).‎ Conclusion: No differences in survival rates between both groups were found. Age and other ‎studied confounders were not found to be related with implant survivorship. ‎However, longer follow-up was found to be related with lower survival rates. Studies ‎with longer follow-up and higher level of evidence are needed to confirm results.‎