The outcome of isolated patellar component revisions after metal-backed patellar failure is variable with satisfactory results
reported from 78% to 100%. To supplement information in the literature we determined the failure rate and the functional outcome
based on the Knee Society clinical and roentgenographic evaluation systems of isolated patellar component revisions after
metal-backed patellar component failure. We retrospectively reviewed 27 patients with 28 isolated patellar component revisions
for metal-backed patellar component failure performed between 1988 and 2005. Twenty-five knees in 24 patients were available
for review with a minimum followup of 24 months (mean, 90 months; range, 24–210 months). All knees were revised with a cemented
all-polyethylene patellar component and all tibial polyethylene components were routinely exchanged. One failure (4%) occurred
122.6 months after the isolated patellar component revision secondary to femoral and tibial component loosening. The average
Knee Society knee score improved from 73 to 89 points, whereas the average Knee Society function score improved from 56 to
65. Our data confirm those in the literature suggesting a successful outcome can be achieved with an isolated patellar component
revision for metal-backed patellar component failure.
Level of Evidence: Level IV, retrospective case series. See the Guidelines for Authors for a complete description of levels of evidence.
Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest,
patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
Each author certifies that his or her institution has approved the human protocol for this investigation and that all investigations
were conducted in conformity with ethical principles of research. A waiver of informed consent was granted and obtained before
the collection of data for this study.