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Introduction
There has been a renewed interest in treatment
options for patients with isolated advanced
patellofemoral arthritis. Reported surgical
options for early stage disease and/or patellar
malalignment include arthroscopic debridement
with or without lateral retinacular release, tibial
tubercle elevation or anterior medialization,
cartilage stimulation techniques (such as
microfracture or abrasion arthroplasty), and
cartilage replacement procedures [1-3]. For
advanced patellofemoral arthritis, patellectomy
and patellar resurfacing have been described
but have fallen out of favor due to generally
unsatisfactory results [2-5].
Total knee arthroplasty
(TKA) is an accepted
method of treatment for advanced isolated
patellofemoral arthritis [6-9]. Although TKA
has been reported to provide pain relief and
functional improvement in this population, its
indications and benefits relative to patello
femoralarthroplasty(PFA)remaincontroversial
[10]. A paucity of literature exists with regards
to comparison of results of TKA versus PFA
using modern implants. In this comparative
retrospective study, we hypothesized that
patients who underwent PFA for treatment of
isolated advanced patellofemoral arthritis
would have similar outcomes to patients treated
with TKA for the same pathology.
Methods
All patients who underwent knee arthroplasty
at our institution between January 2003 and
December 2005 were reviewed. From this
Joint Arthroplasty Registry, we selected only
those patients diagnosed with patellofemoral
arthritis. Patients were further screened for
isolated disease using the following criteria: a
Kellgren and Lawrence score less than or equal
to 2 at the tibial femoral joint and an Iwano
score greater than 2 at the patellofemoral joint,
determined radiographically by consensus of
two of the authors [11, 12]. Patellofemoral
arthroplasties were performed using the Avon
patellofemoral prosthesis (Stryker Howmedica
Osteonics, Mahwah NJ). A single surgeon
performed all but two of the patellofemoral
arthroplasties included in this study and none
of the total knee arthroplasties. The total knee
arthroplasties were performed by surgeons
who did not have experience with patello
femoral arthroplasty. A total of 8 surgeons used
one of two modern total knee arthroplasty
designs (Zimmer, Warsaw IN of Sigma
Orthopedics Inc., Johnson & Johnson, Warsaw
IN). Thirteen designs were posterior cruciate
ligament (PCL substituting) and 9 were PCL
retaining implants. All procedures were
performed using a standard medial parapatellar
arthrotomy.
Comparative Results of TKA
and PFA for Isolated
Patellofemoral
Osteoarthritis
D.L. Dahm