The Impact of Coronal Plane Alignment on Polyethylene Wear and Damage in Total Knee Arthroplasty: A Retrieval Study.

Abstract

Coronal plane alignment is one of the contributing factors to polyethylene wear in total knee arthroplasty. Based on 95 retrieved polyethylene inserts, wear and damage patterns were analyzed in relationship to the overall mechanical alignment and to the position of the tibial component. A progression of wear was observed with progressively mechanical varus alignment. However, there was significantly more damage in the lateral compartment in the mild and moderate varus group compared to the valgus group. No difference in damage was seen between all groups for tibial component positioning in valgus or varus. Progressive wear was observed with progressively varus alignment with more damage at the lateral side. This observation is unique and might be explained by lateral condylar lift-off inducing impact and shear loading in the varus group.