Background: Patellofemoral arthroplasty is an effective treatment
for isolated arthritis of the anterior compartment of the knee, but it is
unclear whether it compromises the results of total knee arthroplasty if
revision is necessary. The purpose of this study was to review the results of
total knee arthroplasty after a prior patellofemoral arthroplasty.
Methods: Twelve failed patellofemoral replacements in ten patients
were revised to total knee arthroplasties for isolated progressive
tibiofemoral arthritis (six knees), isolated patellofemoral catching and
maltracking (three), or a combination of both (three). Revisions were
performed at a mean of four years after the patellofemoral arthroplasty. A
posterior stabilized implant was used in each knee, without a need for stems,
augments, or structural bone graft. Patients were assessed by clinical and
radiographic follow-up, including Knee Society clinical and functional scores.
Baseline preoperative Knee Society scores were obtained at the time of
evaluation of the failed patellofemoral arthroplasty.
Results: At a mean follow-up of 3.1 years, the mean Knee Society
clinical and functional scores had increased from 57 points preoperatively to
96 points and from 51 points preoperatively to 91 points, respectively. At the
most recent follow-up, there was no clinical or radiographic evidence of
patellofemoral maltracking, loosening, or wear.
Conclusions: On the basis of our experience in this relatively small
series with short-term follow-up, the results of total knee arthroplasty do
not seem to be compromised after revision of the failed patellofemoral
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.