types of wear

Poly Design and Wear

Loss of material from solid surface due to mechanical action

TKR

- more complex movements compared with THR

- rolling, sliding and rotation

- delamination, pitting and fatigue failure of the poly surface

Types

- adhesive wear (most common in TKR)

- abrasive wear

- third body wear

- fatigue wear - delaminating

1. Fixed bearing

Insall-Burstein II knee

- cannot be fully conforming

- otherwise would be very constrained to axial rotation

- would transfer large rotational stresses to the prosthesis bone interface

2. Mobile bearing

LCS (meniscal bearing)

- allow fully conforming articulations