Page 24 - KNEETA

KNEETA R

Total Knee system

While instability is one

of the leading causes of

short-term failure

of knee implants, aseptic loosening and complications pertaining to
polyethylene wear are still the leading causes of long-term failure for
knee implants. Many companies have attempted to address this
1,2
through the use of alternate materials, such as highly crosslinked
polyethylene and/or the addition of vitamin E. While these
technologies improve wear characteristics in total hip arthroplasty
where bearings are loaded in crossing shear vectors, the value of
highly crosslinked polyethylene in total knee arthroplasty is still

material as it relates to advanced wear characteristics vs. reduction of
mechanical properties and increase in osteolytic potential.

In general, wear can be characterized as the loss of material in
particulate form or deformation as a consequence of contact
between two moving surfaces. 3-5
predominant wear processes in total joint replacement. 3,5,6 FIGURE 1

Abrasive Wear
Third-Body Wear

Adhesive Wear Fatigue Wear
FIGURE 1 | Common modes of wear in total knee arthroplasty

ABRASIVE WEAR

articulating surfaces that are in contact, resulting in the generation
of small debris particles.

ADHESIVE WEAR
The transfer of a softer material (polyethylene) to the surface of a

attaches to the metal and results in breakdown of
the polyethylene.

SUNTEK

Medical Devices
and Electronic
24 Products Trade Co. KNEETA® Medial-Pivot Knee System
24