The Journal of Bone and Joint Surgery (American). 2006;88:76-82.
doi:10.2106/JBJS.F.00568
© 2006 The Journal of Bone and Joint Surgery, Inc.
Outcomes of Total and Unicompartmental Knee Arthroplasty for Secondary and Spontaneous Osteonecrosis of the Knee
Thomas G. Myers, MD, MPT,
Quanjun Cui, MD,
Michael Kuskowski, PhD,
William M. Mihalko, MD, PhD and
Khaled J. Saleh, MD, MSc, FRCS(C)
Corresponding author: Khaled J. Saleh, MD, MSc, FRCS(C) Division of
Joint Replacement and Adult Reconstructive Surgery, University of Virginia,
400 Ray C. Hunt Drive, Charlottesville, VA 22903
In support of their research for or preparation of this manuscript, one or
more of the authors received grants or outside funding from Smith and Nephew
and Stryker. In addition, one or more of the authors received payments or
other benefits or a commitment or agreement to provide such benefits from a
commercial entity (Smith and Nephew and Stryker). Also, a commercial entity
(Smith and Nephew and Stryker) paid or directed, or agreed to pay or direct,
benefits to a research fund, foundation, educational institution, or other
charitable or nonprofit organization with which the authors are affiliated or
associated.
Background: The reported outcomes of patients who underwent total or
unicompartmental knee arthroplasty for secondary and spontaneous osteonecrosis
of the knee are often from studies that lack the number of subjects necessary
to generate meaningful conclusions. We systematically reviewed the available
literature in order to define the outcomes of patients after total knee
arthroplasty for secondary osteonecrosis and after total or unicompartmental
knee arthroplasty for spontaneous osteonecrosis of the knee.
Methods: A literature review yielded twenty cohorts with demographic
patient information and outcome scores (global knee scores, radiographic
outcomes, and revision rates) for patients who had knee arthroplasty as
treatment for either secondary or spontaneous osteonecrosis of the knee. The
mean preoperative and postoperative global knee scores, the mean revision
rate, and the categorization of the mean "poor" and mean
"good" outcomes for the knees with each underlying disease were
tabulated and reported. The demographic data and the reported mean global knee
scores were weighted by the number of knees in each study.
Results: Total knee arthroplasty was performed in 150 knees with
secondary osteonecrosis and 148 knees with spontaneous osteonecrosis, and
unicompartmental knee arthroplasty was performed in sixty-four knees with
spontaneous osteonecrosis. Total knee arthroplasty for spontaneous
osteonecrosis of the knee was associated with the best outcomes (higher
"good" and postoperative global knee scores and lower revision
[3%] and "poor" outcome [6%] rates compared with the other two
groups). The outcomes after total knee arthroplasty in knees with secondary
osteonecrosis as well as in knees with spontaneous osteonecrosis were better
in the cohorts operated on during or after 1985 than in those operated on
before 1985. Similarly, the outcomes after unicompartmental knee arthroplasty
in knees with spontaneous osteonecrosis of the knee were also better in the
cohorts operated on during or after 1985 than in those operated on before
1985.
Conclusions: Total knee arthroplasty performed as treatment for
either secondary osteonecrosis or spontaneous osteonecrosis and
unicompartmental knee arthroplasty performed as treatment for spontaneous
osteonecrosis were associated with improved outcomes in cohorts with more
recent operative dates. The evidence suggests that the use of contemporary
cemented implants in total knee arthroplasty and the selective use of stems
and augments in patients who have development of secondary osteonecrosis after
total knee arthroplasty are producing outcomes that are comparable to those
seen after total knee arthroplasty for osteoarthritis. Although the outcomes
of patients who have total knee arthroplasty for the treatment of spontaneous
osteonecrosis of the knee have historically been favorable, such outcomes have
also shown particular improvement in the studies from more recent operative
periods. Although poor outcomes were seen after unicompartmental knee
arthroplasty in earlier studies of patients with spontaneous osteonecrosis of
the knee, it is possible that those results were secondary to inappropriate
patient selection, as the authors of the most recent and, to our knowledge,
the only study to follow established operative indications regarding the use
of unicompartmental knee arthroplasty reported excellent results.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors on
jbjs.org for a
complete description of levels of evidence.

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