poly wear

Definition

Loss of material from solid surface due to mechanical action

Types of wear

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

Aim

UKA is intended to be load sharing

- correct to neutral or slight varus

HTO is a load-shifting / load-sparing procedure

- over correct into valgus

UKA v TKR

Advantages UKA

1.  Rapid rehabilation

Definition

Biological response to particulate matter

- characterised by periprosthetic osteolysis

- stimulated by wear debris

- debris gains access to any area accessible by fluid

Sources of particulate debris

1.  Wear

Mechanisms of wear