Outcomes of total knee arthroplasties performed with modern all-polyethylene tibial components have been found to be comparable with or better than those of arthroplasties done with metal-backed modular components in numerous mid-to-long-term follow-up studies, radiostereometric analyses, and the few prospective randomized trials available. Advantages of an all-polyethylene tibial component over a metal-backed modular component include lower cost, avoidance of locking-mechanism issues and backside wear, and increased polyethylene thickness after identical bone resections. Disadvantages of an all-polyethylene tibial component compared with a metal-backed modular component include a lack of modularity, limiting intraoperative options; no option for liner removal in the setting of acute irrigation and débridement; and no option for late liner exchange. Primary total knee arthroplasty with a modern all-polyethylene design can be done in many patients, with substantial cost savings across the health-care system.