Comparison of a Metal Backed Fixed-Bearing Tibial Baseplate and an All-Polyethylene Tibia in Total Knee Arthroplasty

Study Summary

This study is designed to compare prospectively, in a randomized Level 1 evidence fashion, the clinical, functional, and radiographic results of a modular polished tibial (MPT) tray with a moderately cross-linked polyethylene (XLK) insert to an all-polyethylene tibial (APT) design with GVF polyethylene. Comparing these two designs will afford us information in the following areas: 1. Does a MPT/XLK design have improved wear characteristics over a nonmodular APT/GVF design? 2. Is there a clear clinical advantage to the MPT/XLK design in certain patient populations that justify its use over the APT/GVF design? Answering these questions will allow surgeons to use both designs appropriately in different demand populations. This study is designed to address the questions of whether an MPT/XLK design offers improvement in wear characteristics, Knee Society scores, KOOS, WOMAC, SF-36, or radiographic measures, over an APT design. The investigator's primary hypothesis is that there will be no difference in these outcome measures at a minimum two year follow-up. A secondary hypothesis based on the long-term follow-up of this group, up to twenty years, is that there will be no difference in implant survival.

Primary Outcome

Patient recorded outcome measures as noted

Interventions

• PROCEDURE TKA surgery with modular polished tibial baseplate/XLK design
• PROCEDURE TKA surgery with the nonmodular APT/GVF design
• DEVICE P.F.C.® Sigma Knee System