All-Polyethylene Tibial Components in Total Knee Arthroplasty: A Radiostereometric Analysis Comparing Posterior Stabilizing and Condylar Stabilizing Implants

With healthcare expenditures rising as our population ages, there have been significant efforts targeted towards streamlining costs associated with various medical treatments. One area of substantial spending in the orthopaedic surgery field is total joint replacements. The effort to reduce costs has sparked a renewed interest in the use of allpolyethylene (AP) tibial components in total knee arthroplasty (TKA).

In recent years, there has been ample research demonstrating that AP tibial components have performed as good as, or better, than metal-backed (MB) tibial components. Some studies have estimated that cost savings could be as high as 50% with routine use of AP tibial components. While sufficient literature exists demonstrating the equivalence or superiority of AP versus MB designs, there is a paucity of work done comparing different types of AP tibial components.

Tibial components in TKA can be of the posterior stabilizing (PS) or cruciate retaining (CR) variety. To date, we are unaware of any study that directly compares AP tibial PS components to AP tibial CR components.

Radiostereometric analysis (RSA) has evolved as an exceptionally precise and reliable method for assessing the migration of components in total joint arthroplasty. Using RSA data, it is possible to accurately predict, within the first 24 months post-operatively, the survival of a total joint arthroplasty. Furthermore, the use of RSA outcomes in arthroplasty research allows for adequately powered studies with significantly smaller sample sizes than previously required.

The main objective of this project will be to determine which AP tibial component offers the greatest stability. Additionally, we will seek to determine whether patient body mass index (BMI) significantly impacts the stability of AP tibial components.