All-Polyethylene Tibias Equal to Metal-Backed Tibias in Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

We sought to conduct a systematic review of the literature and a meta-analysis of post-operative outcomes following TKA with an all-polyethylene tibial (APT) or a metal-backed tibial component (MBT). A systematic review of the literature was conducted to identify all studies comparing APT and MBT for TKA based upon rates of complications, revisions, reoperation, and patient-reported outcomes. Data was pooled and relative risk of each outcome measure at short (< 5 year), mid (5-10 year), and long (> 10 year) follow-up was calculated. Thirty-eight studies met criteria and were included for analysis, totaling 113,413 primary TKAs performed in 106,490 patients. Of these, 21,752 were performed with an APT and 91,661 with an MBT. APT had a statistically significant decrease in the relative risk of revisions, reoperations, total complications, septic complications, and aseptic complications at one-to-five-year follow-up. There was no statistically significant difference in the relative risk of these metrics between APT and MBT beyond 5 years. This study demonstrates that patients with APT components, compared to the MBT tibial components, had significantly lower rates of complications and revisions at 1-to-5-year follow-up, and no difference in these metrics beyond five years. Further prospective studies are warranted for better external validity of results found in this study.