Abstract

In revising knee replacements 3 wear patterns have been noted; severe single facet wear which only occurs when the patella is dislocated or severely tilted, mild single facet wear from contact with the trochlear groove, and double facet wear. Double facet wear can occur when the knee flexes to more than 105-110 degrees, the edges of the patellar component then making contact with the edges of the femoral condyles across the cruciate gap. This double facet wear is potentially serious and may result in the patellar component wearing through.