Polyethylene failure in two total knees. Wear of thin, metal-backed PCA tibial components

Two women underwent a PCA total knee arthroplasty of the metal-backed type in which the tibial insert was only 4 mm thick in its thinnest portion. After 2 and 4 years, both women had pain on weight bearing due to polyethylene breakdown causing metal-to-metal contact. Such thin polyethylene components should not be used for knee replacements.