Dissociation of an Ultra-High Molecular Weight Polyethylene Insert from the Tibial Baseplate After Total Knee Arthroplasty

Dissociation of a modular tibial insert from the metal baseplate is a rare complication after total knee arthroplasty. Davis et al. reported two cases of dissociation of modular PCA components (Howmedica, Rutherford, New Jersey) and postulated that, during flexion of the knee, anterior lift-off of the insert from the metal baseplate occurred, resulting in failure of the insert-baseplate locking mechanism1. Hedlundh et al. reported a case of traumatic dissociation of the tibial component2. The following report of dissociation of a constrained condylar insert from the baseplate in a patient who had quadriceps insufficiency demonstrates that failure of the posterior locking mechanism occurred, leading to posterior lift-off. The patient was informed that data concerning the case would be submitted for publication.