Background: The management of the patella in
total knee arthroplasty is still problematic. We aimed to identify
differences in the clinical outcome of total knee arthroplasty according
to whether or not patellar resurfacing had been performed in a prospective,
randomized study of 220 osteoarthritic knees.
Methods: Two hundred and twenty total knee arthroplasties
in 201 patients were randomly assigned to be performed with either resurfacing
or retention of the patella, and the results were followed for a
mean of forty-eight months (range, thirty-six to seventy-nine months)
in a double-blind (both patient and clinical evaluator blinded),
prospective study. Evaluation was performed annually by an independent
observer and consisted of assessment with the Knee Society clinical
rating system, specific evaluation of anterior knee pain, a stair-climbing
test, and radiographic examination.
Results: Fifteen (12%) of the 128 knees
without patellar resurfacing and nine (10%) of the ninety-two
knees with patellar resurfacing underwent a revision or another
type of reoperation related to the patellofemoral articulation.
This difference was not significant (chi square with one degree
of freedom = 0.206, p = 0.650). At the time of
the latest follow-up, there was a significantly higher incidence
of anterior pain (chi square with one degree of freedom = 5.757,
p = 0.016) in the knees that had not had patellar resurfacing.
Conclusions: Patients who underwent patellar resurfacing
had superior clinical results in terms of anterior knee pain and
stair descent. However, anterior knee pain still occurred in patients with
patellar resurfacing, and nine (10%) of the ninety-two patients
in that group underwent a revision or another type of reoperation
involving the patellofemoral joint. Weight but not body mass index
was associated with the development of anterior knee pain in the
patients without patellar resurfacing, a finding that suggests that
patellofemoral dysfunction may be a function of joint loading rather