The Relationship Between Implant Design and Joint Stability After Total Knee Replacement

Investigators

Douglas E. Padgett, MD; Timothy Wright, PhD

Scope

Constrained condylar knee (CCK) implants are widely used in both primary and revision total knee replacements (TKR). In comparison to posterior stabilized (PS) TKA, the larger tibial post of the CCK improves the stability of the artificial knee joint by providing more constraint with the intercondylar box of the femoral component. The increased constraint, however, increases the susceptibility of the tibial component to polyethylene wear and aseptic loosening at the implant-bone interface. Thus, our primary research question is: how does the design of the tibial post and intercondylar box affect the stability of a CCK knee replacement? A 6 degree of freedom robotic testing system combined with a 3D computational knee model will be used to establish the load-displacement characteristics of the knee implant and compare stability among different implant designs. An important secondary research question is how surrounding soft tissues (collateral ligaments and joint capsule) share load with the implant, especially under loading conditions such as varus-valgus moments that are known to put a severe mechanical burden on the knee.

Contact

Timothy Wright, PhD
wrightt@hss.edu