Total Knee Replacement



The Problem


 

Overall prevalence of TKR procedures has been increasing and incidence among younger populations is increasing.

Overall prevalence of TKR procedures has been increasing and incidence among younger populations is increasing.

Total Knee Replacement (TKR) procedures are prevalent (700,000 procedures/year) and expensive ($4.5 billion total hospital charges in 2013). Unfortunately, TKR procedures are not permanent; 10% of patients are expected to need a revision 10 years after their first procedure and 20% need a revision after 20 years. As the incidence of TKR procedures increases among young people, a need exists for a TKR device that reduces the need for revision.


 The Solution


In collaboration with 4WEB Medical, this research is focused on the development of an innovative knee replacement component that employs state-of-the-art manufacturing processes and structural engineering design principles to improve the bone/implant interface in total knee replacement (TKR) systems. A Total Knee Replacement (TKR) requires multiple components.

Different possible tibial component design with various fixation elements. Source: P.S. Walker, "Computer Graphics Design of Total Knee Replacement" from Total Knee Replacement (1987) ed Niwa, Paul, Yamamoto

Different possible tibial component design with various fixation elements. Source: P.S. Walker, “Computer Graphics Design of Total Knee Replacement” from Total Knee Replacement (1987) ed Niwa, Paul, Yamamoto

Of particular interest to 4WEB Medical are those components designed to meet the needs of the bone-implant interface. Specifically in TKR, these components are the tibial tray and the femoral component. Current devices typically include “keeled” or “pegged” tibial trays, which may contribute to uplift, loosening, and related complications requiring revision.

4WEB Medical’s innovative design incorporates unique geometric and mechanical properties that have been optimized to address the problems associated with initial and long-term fixation.

The device is a novel bone-implant interface that incorporates a unique network configuration, based on structural engineering principles, that is designed to improve initial fixation and facilitate bone through-growth, and thereby improve long-term fixation, and load transfer/distribution. It is expected that the improvements in fixation and overall TKR performance will significantly improve patient quality of life, as well as reduce and potentially eliminate the need for revision procedures.


Testing


We will examine the TKR device in the following ways

  • Investigate the fixation and fatigue life of the 4WEB design compared to current designs
  • Evaluate the stress distribution of the novel 4WEB design
  • Investigate the mechanical behavior of the novel surface characterization
  • Assess the geometry of the device via range of motion