Extract
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.