Unusual mechanical complications of unicompartmental low contact stress mobile bearing patellofemoral arthroplasty: A cause for concern?

The Low Contact Stress Patellofemoral Arthroplasty (LCS PFA) is a newer design belonging to the second generation of inlay type implants, addressing the problems encountered in the first generation models (Lubinus & Richard's) The cemented mobile bearing metal backed patellar component in this system is modular; allowing interchangeable usage with either the trochlear component in a PFA or the femoral component of a total knee arthroplasty, thus obviating the need for patellar revision during conversion of PFA to TKA The younger active patient with a PFA may exert extreme Joint reaction forces on then patellar implant, rendering early loosening of the patellar implant The endurance of this implant with repeated flexion beyond 90 is also a concern We describe a series of three unusual mechanical failures associated with this particular design of metal backed patellat component of the umcompartmental LCS patellofemoral arthroplasty (c) 2009 Elsevier B V All rights reserved