A Knee Surgery for Arthritis Is Called Sham
nyt aug 24 2002
By GINA KOLATA
popular operation for arthritis of the knee worked no better than a sham procedure in which patients were sedated while surgeons pretended to operate, researchers are reporting today.
The operation — arthroscopic surgery for the pain and stiffness caused by osteoarthritis — is done on at least 225,000 middle-age and older Americans each year at a cost of more than a billion dollars to Medicare, the Department of Veterans Affairs and private insurers.
It involves making three small incisions in the knee; inserting an arthroscope, a thin instrument that allows surgeons to see the joint; and then flushing debris from the knee or shaving rough areas of cartilage from the joint and then flushing it.
In the study, to be published today in The New England Journal of Medicine, investigators at the Houston Veterans Affairs Medical Center and Baylor College of Medicine report that while patients often said they felt better after the surgery, their improvement was just wishful thinking. Tests of knee functions revealed that the operation had not helped, and those who got the placebo surgery reported feeling just as good as those who had had the real operation.
"Here we are doing all this surgery on people and it's all a sham," said Dr. Baruch Brody, an ethicist at Baylor who helped design the study.
The study dealt only with arthroscopic surgery for osteoarthritis, not with other common knee operations.
After learning of the results, Anthony J. Principi, the secretary of veterans affairs, said yesterday that the study would "change the practice of orthopedic medicine in the United States."
But Veterans Affairs Departmentofficials stopped short of saying they would no longer pay for the surgery. Medicare and private insurers typically review such studies before deciding whether to change their reimbursement practices.
The 180 participants in the study were randomly assigned to have the operation or to have placebo surgery in which surgeons simply made cuts in their knees so the patients would not know if they had the surgery.
After they recovered from the procedures, most patients said their knee pain had improved, and they continued to say they were better for the two years that the researchers followed their progress. But Dr. Nelda P. Wray, who is chief of the section of health services research at Baylor, said, "On the objective scale, no one was better at any time point."
Some orthopedists interviewed about the study said they had wondered for some time about the operation's effectiveness. Dr. Kenneth Fine, an orthopedic surgeon at the George Washington University School of Medicine, said the procedure had long seemed to do nothing for patients' underlying arthritis.
"There are pretty good success rates in terms of patient satisfaction," Dr. Fine said, "but I have always been skeptical."
Dr. William J. Tipton Jr., executive vice president and chief executive of the American Academy of Orthopedic Surgeons, also said he had questioned the operation.
"I'm both a patient and a physician," Dr. Tipton said, explaining that he has osteoarthritis. "My knee is buckling now, but I'm not going to have arthroscopy done. I recognize that it's not going to help."
Still, he said he would like to see the study repeated before doctors decided whether to do the operation.
"Gradually," Dr. Tipton speculated, "physicians would say to their patients: `I know you've seen a lot about arthroscopy, but you know what? It doesn't work very well for osteoarthritis of the knee.' "
But a past president of the orthopedic surgeons' academy, Dr. Douglas Jackson of Long Beach, Calif., said that the study's population, mostly men in a veterans' hospital, was not typical of what he had seen in his private practice, but that he would tell his patients about their experience.
The research began when an orthopedic surgeon at the Houston veterans' hospital, Dr. J. Bruce Moseley, who is now the team physician for Houston's two professional basketball teams, approached Dr. Wray suggesting a study that would compare washing the knee joint with washing and scraping in patients with arthritis.
Dr. Wray had a bolder idea.
"She said, `How do you know that what you are seeing is not a placebo effect?' " Dr. Moseley recalled. "My response was, `This is surgery.' She said, `I hate to tell you this, but surgery may have the biggest placebo effect of all.' "
Placebo studies of surgery are almost never done. Many doctors consider them unethical because patients could undergo risks with no benefits. Working with Dr. Brody, the ethicist, the group tried to make the placebo treatment no more dangerous than daily life. Still, of 324 consecutive patients who were asked to participate, 144 declined.
For those who agreed, the day of surgery meant being wheeled into an operating room while neither they nor any of the medical staff knew what their treatment would be. When they were on the operating table, Dr. Moseley, who did all the operations, opened a sealed envelope telling him whether the patient was to have the surgery or not.
Those in the placebo group received a drug that put them to sleep. Unlike those getting the real operation, they did not have general anesthesia.
Dr. Moseley made small cuts in their knees to simulate an operation. He bent and straightened the knee and asked for surgical instruments, just in case the patient was partly conscious. An assistant sloshed water in a bucket to make the sound of a knee being flushed clean.
The paper in The New England Journal is accompanied by two editorials. One, by Sam Horng and Dr. Franklin G. Miller of the National Institutes of Health, asks whether placebo surgery is unethical. The controversy, they wrote, comes because doctors assume that patients in clinical research should not be put at risk if they cannot benefit, and placebo surgery involves risk.
But, they say, clinical research is different from medical therapy; its aim is not to help those in the study but to help future patients.
To be ethical, they say, a study with placebo surgery must meet three criteria: it must not place patients at undue risk; the benefits of learning whether the surgery works must be worth any potential risk to the patients; and the patients must give informed consent.
In the current case, they wrote, all those objectives were met and the study "exemplifies the ethically justified use of placebo surgery."
In the second editorial, Dr. David T. Felson of Boston University and Dr. Joseph Buckwalter of the University of Iowa note that if there were large beneficial effects from the surgery, the study should have found them.
"Although the study may not have been large enough to permit the detection of any small effects," they wrote, "the data presented do not suggest that there were any.,"
In a telephone interview this week, Dr. Felson, a professor of medicine and a rheumatologist by training, praised the research but said it remained to be seen whether doctors and patients would abandon the procedure.
"There's a pretty good-sized industry out there that is performing this surgery," Dr. Felton said. "It constitutes a good part of the livelihood of some orthopedic surgeons. That is a reality."
Knee Surgery called a sham
3 posts
• Page 1 of 1
knee meniscus tear ,debri, torn cartilage removal no help
by malernee » Fri Nov 12, 2004 1:02 pm
Volume 347:81-88July 11, 2002Number 2
Next
A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the
Knee
J. Bruce Moseley, M.D., Kimberly O'Malley, Ph.D., Nancy J. Petersen,
Ph.D., Terri J. Menke, Ph.D., Baruch A. Brody, Ph.D., David H.
Kuykendall, Ph.D.,
John C. Hollingsworth, Dr.P.H., Carol M. Ashton, M.D., M.P.H., and Nelda
P. Wray, M.D., M.P.H.
AbstractPDFPDA Full TextSupplementary Material
Editorial
by Felson, D. T.
Letters
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by Horng, S.
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ABSTRACT
Background Many patients report symptomatic relief after undergoing
arthroscopy of the knee for osteoarthritis, but it is unclear how the
procedure achieves this result. We conducted a randomized,
placebo-controlled trial to evaluate the efficacy of arthroscopy for
osteoarthritis of the knee.
Methods A total of 180 patients with osteoarthritis of the knee were
randomly assigned to receive arthroscopic débridement, arthroscopic
lavage, or placebo surgery. Patients in the placebo group received skin
incisions and underwent a simulated débridement without insertion of
the arthroscope. Patients and assessors of outcome were blinded to the
treatment-group assignment. Outcomes were assessed at multiple points
over a 24-month period with the use of five self-reported scores —
three on scales for pain and two on scales for function — and one
objective test of walking and stair climbing. A total of 165 patients
completed the trial.
Results At no point did either of the intervention groups report less
pain or better function than the placebo group. For example, mean
(±SD) scores on the Knee-Specific Pain Scale (range, 0 to 100, with
higher scores indicating more severe pain) were similar in the placebo,
lavage, and débridement groups: 48.9±21.9, 54.8±19.8, and
51.7±22.4, respectively, at one year (P=0.14 for the comparison
between placebo and lavage; P=0.51 for the comparison between placebo
and débridement) and 51.6±23.7, 53.7±23.7, and 51.4±23.2,
respectively, at two years (P=0.64 and P=0.96, respectively).
Furthermore, the 95 percent confidence intervals for the differences
between the placebo group and the intervention groups exclude any
clinically meaningful difference.
Conclusions In this controlled trial involving patients with
osteoarthritis of the knee, the outcomes after arthroscopic lavage or
arthroscopic débridement were no better than those after a placebo
procedure.
When medical therapy fails to relieve the pain of osteoarthritis of the
knee, arthroscopic lavage or débridement is often recommended. More
than 650,000 such procedures are performed each year1 at a cost of
roughly $5,000 each. In uncontrolled studies of knee arthroscopy for
osteoarthritis, about half the patients report relief from
pain.2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 However, the physiological
basis for the pain relief is unclear. There is no evidence that
arthroscopy cures or arrests the osteoarthritis. Therefore, we conducted
a randomized, placebo-controlled trial to assess the efficacy of
arthroscopic surgery of the knee in relieving pain and improving
function in patients with osteoarthritis. Both patients and assessors of
outcome were blinded to the treatment assignments.
Methods
The college and hospital institutional review board approved the
protocol. A data and safety monitoring board monitored the study.
Study Participants
Participants were recruited from the Houston Veterans Affairs Medical
Center from October 1995 through September 1998. Patients were eligible
if they were 75 years old or younger, had osteoarthritis of the knee as
defined by the American College of Rheumatology,17 reported at least
moderate knee pain on average (4 on a visual-analogue scale ranging from
0 to 10) despite maximal medical treatment for at least six months, and
had not undergone arthroscopy of the knee during the previous two years.
The severity of osteoarthritis in the study knee (that with the greatest
pain-induced limitation of function) was assessed radiographically and
graded on a scale of zero to four.18 The scores for the three
compartments were added together to generate a severity grade of 0 to
12. Criteria for exclusion were a severity grade of 9 or higher, severe
deformity, and serious medical problems.
All patients provided informed consent, which included writing in their
chart, "On entering this study, I realize that I may receive only
placebo surgery. I further realize that this means that I will not have
surgery on my knee joint. This placebo surgery will not benefit my knee
arthritis." Of the 324 consecutive patients who met the criteria for
inclusion, 144 (44 percent) declined to participate. Participants were
younger than those who declined to participate (52.3±11.3 years vs.
55.3±12.4 years, P=0.002), were more likely to be white (62.2 percent
vs. 50.7 percent, P=0.03), and had more severe arthritis (25.0 percent
vs. 12.5 percent with grade 7 or 8 arthritis, P<0.001).
Randomization Process and Treatment Groups
Participants were stratified into three groups according to the severity
of osteoarthritis (grade 1, 2, or 3; grade 4, 5, or 6; and grade 7 or
. A stratified randomization process with fixed blocks of six was
used. Sealed, sequentially numbered, stratum-specific envelopes
containing treatment assignments were prepared and given to the research
assistant. After the patient was in the operating suite, the surgeon was
handed the envelope. The treatment assignment was not revealed to the
patient.
Participants were randomly assigned to arthroscopic débridement,
arthroscopic lavage alone, or the placebo procedure. One orthopedist
performed all the operations. Patients in the débridement group or the
lavage group received standard general anesthesia with endotracheal
intubation. Patients in the placebo group received a short-acting
intravenous tranquilizer and an opioid and spontaneously breathed
oxygen-enriched air.
Lavage
After diagnostic arthroscopy in patients in the lavage group, the joint
was lavaged with at least 10 liters of fluid. Anything that could be
flushed out through arthroscopic cannulas was removed. Normally, no
instruments were used to mechanically débride or remove tissue.
However, if a mechanically important, unstable tear in the meniscus
(e.g., a displaced "bucket-handle" tear) was encountered, the torn
portion was removed and the remaining meniscus was smoothed to a firm,
stable rim. (There is general agreement that it is inappropriate to
leave this type of meniscal tear untreated.11,13,19,20) No other
débridement was performed.
Débridement
After diagnostic arthroscopy in patients in the débridement group, the
joint was lavaged with at least 10 liters of fluid, rough articular
cartilage was shaved (chondroplasty was performed), loose debris was
removed, all torn or degenerated meniscal fragments were trimmed, and
the remaining meniscus was smoothed to a firm and stable rim. No
abrasion arthroplasty or microfracture was performed. Typically, bone
spurs were not removed, but any spurs from the tibial spine area that
blocked full extension were shaved smooth.
Placebo Procedure
To preserve blinding in the event that patients in the placebo group did
not have total amnesia, a standard arthroscopic débridement procedure
was simulated. After the knee was prepped and draped, three 1-cm
incisions were made in the skin. The surgeon asked for all instruments
and manipulated the knee as if arthroscopy were being performed. Saline
was splashed to simulate the sounds of lavage. No instrument entered the
portals for arthroscopy. The patient was kept in the operating room for
the amount of time required for a débridement. Patients spent the
night after the procedure in the hospital and were cared for by nurses
who were unaware of the treatment-group assignment.
Postoperatively, there were two minor complications and no deaths.
Incisional erythema developed in one patient, who was given antibiotics.
In a second patient, calf swelling developed in the leg that had
undergone surgery; venography was negative for thrombosis. In no case
did a complication necessitate the breaking of the randomization code.
Postoperative care was delivered according to a protocol specifying that
all patients should receive the same walking aids, graduated exercise
program, and analgesics. The use of analgesics after surgery was
monitored; during the two-year follow-up period, the amount used was
similar in the three groups.
End Points
Study personnel who were unaware of the treatment-group assignments
performed all postoperative outcome assessments; the operating surgeon
did not participate in any way. Data on end points were collected 2
weeks, 6 weeks, 3 months, 6 months, 12 months, 18 months, and 24 months
after the procedure. To assess whether patients remained unaware of
their treatment-group assignment, they were asked at each follow-up
visit to guess which procedure they had undergone. Patients in the
placebo group were no more likely than patients in the other two groups
to guess that they had undergone a placebo procedure. For example, at
two weeks, 13.8 percent of the patients in the placebo group guessed
that they had undergone a placebo procedure, and 13.2 percent of the
patients in the lavage and débridement groups guessed that they had
undergone a placebo procedure.
The primary end point was pain in the study knee 24 months after the
intervention, as assessed by a 12-item self-reported Knee-Specific Pain
Scale (KSPS) created for this study (see Supplementary Appendix 1,
available with the full text of this article at http://www.nejm.org).
Scores on this scale range from 0 to 100, with higher scores indicating
more severe pain. In addition, to ensure our ability to detect any
benefit, we also used five secondary efficacy end points: two additional
assessments of pain and three assessments of function at all time
points. Arthritis pain in general (i.e., not specifically in the study
knee) was assessed by means of the four-item pain subscale of the
Arthritis Impact Measurement Scales (AIMS2-P).21,22 Higher scores on
this subscale indicate more severe pain. Body pain (i.e., not
necessarily from arthritis and not necessarily in the knee) was assessed
with the 2-item pain subscale of the Medical Outcomes Study 36-item
Short-Form General Health Survey (SF-36-P).23,24 Higher scores on this
subscale indicate less severe pain. The AIMS2-P and the SF-36-P scores
were transformed into scores on a scale from 0 to 100.
Two self-reported measures of physical function were used: the 5-item
walking–bending subscale from the AIMS2 (AIMS2-WB, transformed into
scores on a scale from 0 to 100, with higher scores indicating more
limited function21,22) and the 10-item physical-function subscale from
the SF-36 (SF-36-PF, transformed into scores on a scale from 0 to 100,
with higher scores indicating better function23,24). As an objective
measure, we devised the Physical Functioning Scale (PFS) to record the
amount of time in seconds that a patient required to walk 30 m (100 ft)
and to climb up and down a flight of stairs as quickly as possible.
Longer times indicate poorer functioning.
All six outcome scales had good reliability. The median Cronbach's alpha
(according to analyses of data from eight time points for all scales)
exceeded 0.80. Results for all the outcome measures at all the time
points that are not reported here are summarized in Supplementary
Appendix 2, available with the full text of this article at
http://www.nejm.org.
Statistical Analysis
Our pilot study indicated that it would be feasible to recruit 60
patients per year. The trial was designed to have 90 percent power, with
a two-sided type I error of 0.04, to detect a moderate effect size
(0.55) between the placebo group and the combined arthroscopic-treatment
groups in terms of body pain as measured by the SF-36-P at two years,
with an enrollment of 180 patients and 16 or fewer lost to follow-up
(i.e., 164 or more completing the two-year follow-up). The primary
hypothesis was that the patients in two arthroscopic-intervention groups
combined would report the same amount of knee pain at two years as the
patients assigned to the placebo group. All statistical tests compared
the treatment groups in terms of the values at each visit rather than
analyzing the changes from base line. (Scores for these changes ["change
scores"] were analyzed, with results that did not differ from the
results presented here.) The data and safety monitoring board reviewed
interim data 15 months and 24 months after enrollment began, using the
Haybittle–Peto group-sequential method, with stopping boundaries of
P=0.001 for the two interim analyses.25,26 All reported P values are
two-sided and have not been adjusted for multiple comparisons.
Our prespecified analytic strategy was to test, at all time points, for
the superiority of the arthroscopic procedures over the placebo
procedure. Lacking evidence of superiority, we tested for evidence that
the arthroscopic procedures were equivalent27,28,29 to the placebo
procedure by determining the extent to which the study was powered to
reject the hypothesis that the arthroscopic treatments caused a small
but clinically important improvement (the "minimal important
difference"). The minimal important difference for a scale is the
smallest change score associated with a patient's perception of a change
in health status,30 but it can vary somewhat according to the method of
calculation and the study sample.31,32 Minimal important differences for
each of the six study scales were calculated on the basis of the trial
data by two different methods: the change ratings of patients (their
scores on a single-item scale that asked patients if their condition was
the same, somewhat better [or worse], or much better [or worse] than
before surgery) and the standard error of measurement (the SD of the
instrument multiplied by the square root of one minus its reliability
coefficient).30,31,32 Estimates were also obtained from the
literature.31,32,33 For each scale, we tested the hypothesis that the
placebo procedure was equivalent to the arthroscopic procedures, using
as the minimal important difference the midpoint of the range of the
minimal important differences reported in the literature or calculated
on the basis of our data. If the 95 percent confidence interval around
the estimated size of the effect does not include the minimal important
difference, one can reject the hypothesis that the arthroscopic
procedures have a small but clinically important benefit.27
Results
A total of 180 patients underwent randomization; 60 were assigned to the
placebo group, 61 to the lavage group, and 59 to the débridement
group. Base-line characteristics were similar in the three study groups
(Table 1).
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Table 1. Base-Line Characteristics of the Randomized Patients.
At no point did either arthroscopic-intervention group have greater pain
relief than the placebo group (Figure 1, Table 2, and Supplementary
Appendix 2). For example, there was no difference in knee pain between
the placebo group and either the lavage group or the débridement group
at one year (mean [±SD] KSPS scores, 48.9±21.9, 54.8±19.8, and
51.7±22.4, respectively; P=0.14 for the comparison with the lavage
group, and P=0.51 for the comparison with the débridement group) or at
two years (mean KSPS scores, 51.6±23.7, 53.7±23.7, and 51.4±23.2,
respectively; P=0.64 and P=0.96, respectively). Similarly, there was no
significant difference in arthritis pain between the placebo group and
the lavage group or the débridement group at one or two years (Table
2).
View larger version (13K):
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Figure 1. Mean Values (and 95 Percent Confidence Intervals) on the
Knee-Specific Pain Scale.
Assessments were made before the procedure and 2 weeks, 6 weeks, 3
months, 6 months, 12 months, 18 months, and 24 months after the
procedure. Higher scores indicate more severe pain.
View this table:
[in this window]
[in a new window]
Table 2. Scores on the Pain Subscale of the Arthritis Impact
Measurement Scales.
Furthermore, at no time point did either arthroscopic-intervention group
have significantly greater improvement in function than the placebo
group (Figure 2, Table 3, and Supplementary Appendix 2). For example,
there was no significant difference between the placebo group and either
the lavage group or the débridement group in the self-reported ability
to walk and bend at one year (mean AIMS2-WB scores, 49.4±25.5,
49.6±29.1, and 56.4±28.4, respectively; P=0.98 for the comparison
with the lavage group, and P=0.19 for the comparison with the
débridement group) or at two years (mean AIMS2-WB score, 53.8±27.5,
51.1±28.3, and 56.4±29.4, respectively; P=0.61 and P=0.64,
respectively). Indeed, objectively measured walking and stair climbing
were poorer in the débridement group than in the placebo group at two
weeks (mean PFS score, 56.0±21.8 vs. 48.3±13.4; P=0.02) and one year
(mean PFS score, 52.5±20.3 vs. 45.6±10.2; P=0.04) and showed a trend
toward worse functioning at two years (mean PFS score, 52.6±16.4 vs.
47.7±12.0; P=0.11) (Table 3).
View larger version (14K):
[in this window]
[in a new window]
Figure 2. Mean Values (and 95 Percent Confidence Intervals) on the
Walking–Bending Subscale of the Arthritis Impact Measurement Scales
(AIMS2).
Assessments were made before the procedure and 2 weeks, 6 weeks, 3
months, 6 months, 12 months, 18 months, and 24 months after the
procedure. Higher scores indicate poorer functioning.
View this table:
[in this window]
[in a new window]
Table 3. Scores on the Physical Functioning Scale.
Lacking evidence of the superiority of the arthroscopic treatments over
the placebo procedure in relieving pain or improving function, we
considered whether the 95 percent confidence intervals for the
differences in outcome between each arthroscopic procedure and the
placebo procedure included clinically important differences. The minimal
important differences used for this evaluation were as follows: a
difference of 13.5 points on the KSPS, 10.0 on the AIMS2-P, 11.8 on the
SF-36-P, 12.8 on the AIMS2-WB, 11.3 on the SF-36-PF, and 4.5 on the PFS.
At almost all time points during follow-up (72 of 84 comparisons), the
confidence intervals excluded these minimal important differences.
Discussion
This study provides strong evidence that arthroscopic lavage with or
without débridement is not better than and appears to be equivalent to
a placebo procedure in improving knee pain and self-reported function.
Indeed, at some points during follow-up, objective function was
significantly worse in the débridement group than in the placebo
group.
Arthroscopy is the most commonly performed type of orthopedic surgery,
and the knee is by far the most common joint on which it is performed.1
Numerous uncontrolled, retrospective case series have reported
substantial pain relief after arthroscopic lavage or arthroscopic
débridement for osteoarthritis of the
knee.2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 In the only previous
double-blind, randomized, controlled trial of knee arthroscopy of which
we are aware,34 patients with minimal osteoarthritis as assessed by
radiography were assigned to undergo arthroscopic lavage with either
3000 ml of fluid (treatment) or 250 ml of fluid (control) and were
followed for one year. Both the treatment and the control groups
reported improvement in function at 12 months, and although the report
interprets the study as having proved the efficacy of lavage, there was
no statistically significant difference between the groups in terms of
the primary outcome at any point during follow-up.
To explain the improvement that has been reported after these
procedures, some have proposed that the fluid that is flushed through
the knee during arthroscopy cleanses the knee of painful debris and
inflammatory enzymes.4,6,9,15,16,34 Others have suggested that the
improvement is due to the removal of flaps of articular cartilage, torn
meniscal fragments, hypertrophied synovium, and loose
debris.2,3,4,5,6,7,8,9,10,11,12,13,14 However, our study found that
outcomes after arthroscopic treatment are no better than those after a
placebo procedure. This lack of difference suggests that the improvement
is not due to any intrinsic efficacy of the procedures. Although
patients in the placebo groups of randomized trials frequently have
improvement, it may be attributable to either the natural history of the
condition or some independent effect of the placebo.
Because we found no evidence that lavage or débridement is superior to
a placebo procedure, the question arises whether these arthroscopic
procedures could have small but clinically important benefits that we
missed because of our limited sample size. To evaluate this possibility,
we determined the size of the clinical benefit that the trial was able
to rule out, using the minimal important difference for each of our
scales. Because estimates of minimal important differences based on
different samples and different methods do not yield the same values, we
used the midpoint of the range of available minimal important
differences in order to test our hypothesis about the equivalence of the
three procedures. For the great majority of comparisons, the 95 percent
confidence intervals did not contain the minimal important difference,
indicating that there was not a clinically important improvement that
the study had simply failed to detect.
One surgeon performed all the procedures in this study. Consequently,
his technical proficiency is critical to the generalizability of our
findings. Our study surgeon is board-certified, is fellowship-trained in
arthroscopy and sports medicine, and has been in practice for 10 years
in an academic medical center. He is currently the orthopedic surgeon
for a National Basketball Association team and was the physician for the
men's and women's U.S. Olympic basketball teams in 1996.
The principal limitation of this study is that our participants may not
be representative of all candidates for arthroscopic treatment of
osteoarthritis of the knee. Almost all participants were men, because
the study was conducted at a Veterans Affairs medical center. We do not
know whether our findings may be generalized to women, although
uncontrolled studies do not indicate that there are differences between
the sexes in responses to arthroscopic procedures.8,10,13 A selection
bias might have been introduced by the fact that 44 percent of the
eligible patients declined to participate in the study. We believe this
high rate of refusal to participate resulted from the fact that all
patients knew they had a one-in-three chance of undergoing a placebo
procedure. Patients who agreed to participate might have been so sure
that an arthroscopic procedure would help that they were willing to take
a one-in-three chance of undergoing the placebo procedure. Such patients
might have had higher expectations of benefit or been more susceptible
to a placebo effect than those who chose not to participate.
If the efficacy of arthroscopic lavage or débridement in patients with
osteoarthritis of the knee is no greater than that of placebo surgery,
the billions of dollars spent on such procedures annually might be put
to better use. This study has also shown the great potential for a
placebo effect with surgery, although it is unclear whether this effect
is due solely to the natural history of the condition or whether there
is some independent effect. Researchers should reconsider the best ways
of testing the efficacy of surgical procedures performed purely for the
improvement of symptoms. In the debate about placebo-controlled trials
of surgery, the critical ethical considerations surround the choice of
the placebo. Finally, health care researchers should not underestimate
the placebo effect, regardless of its mechanism.35
Supported by a grant from the Department of Veterans Affairs.
Source Information
From the Houston Veterans Affairs Medical Center (J.B.M., K.O., N.J.P.,
T.J.M., D.H.K., C.M.A., N.P.W.); the Department of Orthopedic Surgery
(J.B.M.), the Department of Medicine, Section of Health Services
Research (K.O., N.J.P., T.J.M., C.M.A., N.P.W.), and the Center for
Medical Ethics and Health Policy (B.A.B.), Baylor College of Medicine;
and International Survey Research (D.H.K.) — all in Houston; and the
Laguna Honda Hospital, San Francisco (J.C.H.).
Address reprint requests to Dr. Wray at the Section of Health Services
Research, Baylor College of Medicine, 2002 Holcombe Blvd. (M.R. 152),
Houston, TX 77030, or at nwray@bcm.tmc.edu.
References
Owings MF, Kozak LJ. Ambulatory and inpatient procedures in the United
States, 1996. Vital and health statistics. Series 13. No. 139.
Hyattsville, Md.: National Center for Health Statistics, November 1998.
(DHHS publication no. (PHS) 99-1710.)
Baumgaertner MR, Cannon WD Jr, Vittore JM, Schmidt ES, Maurer RC.
Arthroscopic debridement of the arthritic knee. Clin Orthop
1990;253:197-202.[Medline]
Bert JM, Maschka K. The arthroscopic treatment of unicompartmental
gonarthrosis: a five-year follow-up study of abrasion arthroplasty plus
arthroscopic debridement and arthroscopic debridement alone. Arthroscopy
1989;5:25-32.[Medline]
Chang RW, Falconer J, Stulberg SD, Arnold WJ, Manheim LM, Dyer AR. A
randomized, controlled trial of arthroscopic surgery versus
closed-needle joint lavage for patients with osteoarthritis of the knee.
Arthritis Rheum 1993;36:289-296.[ISI][Medline]
Gross DE, Brenner SL, Esformes I, Gross ML. Arthroscopic treatment of
degenerative joint disease of the knee. Orthopedics
1991;14:1317-1321.[ISI][Medline]
Jackson RW, Silver R, Marans H. Arthroscopic treatment of degenerative
joint disease. Arthroscopy 1986;2:114-114.
Jennings JE. Arthroscopic debridement as an alternative to total knee
replacement. Arthroscopy 1986;2:123-124.
McLaren AC, Blokker CP, Fowler PJ, Roth JN, Rock MG. Arthroscopic
debridement of the knee for osteoarthritis. Can J Surg
1991;34:595-598.[ISI][Medline]
Ogilvie-Harris DJ, Fitsialos DP. Arthroscopic management of the
degenerative knee. Arthroscopy 1991;7:151-157.[Medline]
Rand JA. Role of arthroscopy in osteoarthritis of the knee. Arthroscopy
1991;7:358-363.[Medline]
Richards RN Jr, Lonergan RP. Arthroscopic surgery for relief of pain in
the osteoarthritic knee. Orthopedics 1984;7:1705-1707.[ISI]
Salisbury RB, Nottage WM, Gardner V. The effect of alignment on results
in arthroscopic debridement of the degenerative knee. Clin Orthop
1985;198:268-272.[Medline]
Sprague NF III. Arthroscopic debridement for degenerative knee joint
disease. Clin Orthop 1981;160:118-123.[Medline]
Timoney JM, Kneisl JS, Barrack RL, Alexander AH. Arthroscopy in the
osteoarthritic knee: long-term follow-up. Orthop Rev 1990;19:371-3,
376.[Medline]
Ike RW, Arnold WJ, Rothschild EW, Shaw HL. Tidal irrigation versus
conservative medical management in patients with osteoarthritis of the
knee: a prospective randomized study. J Rheumatol
1992;19:772-779.[ISI][Medline]
Livesley PJ, Doherty M, Needoff M, Moulton A. Arthroscopic lavage of
osteoarthritic knees. J Bone Joint Surg Br
1991;73:922-926.[ISI][Medline]
Workshop on etiopathogenesis of osteoarthritis. J Rheumatol
1986;13:1126-1160.[ISI]
Kellgren JH, Lawrence JS. Radiological assessment of osteo-arthrosis.
Ann Rheum Dis 1957;16:494-502.[ISI]
Jackson RW, Rouse DW. The results of partial arthroscopic meniscectomy
in patients over 40 years of age. J Bone Joint Surg Br
1982;64:481-485.[ISI][Medline]
Rand JA. Arthroscopic management of degenerative meniscus tears in
patients with degenerative arthritis. Arthroscopy
1985;1:253-258.[Medline]
Meenan RF, Mason JH, Anderson JJ, Guccione AA, Kazis LE. AIMS2: the
content and properties of a revised and expanded Arthritis Impact
Measurement Scales health status questionnaire. Arthritis Rheum
1992;35:1-10.[ISI][Medline]
Liang MH, Fossel AH, Larson MG. Comparisons of five health status
instruments for orthopedic evaluation. Med Care
1990;28:632-642.[ISI][Medline]
Ware JE, Sherbourne CD. The MOS 36-item short-form health survey
(SF-36). I. Conceptual framework and item selection. Med Care
1992;30:473-483.[ISI][Medline]
Kantz ME, Harris WJ, Levitsky K, Ware JE Jr, Davies AR. Methods for
assessing condition-specific and generic functional status outcomes
after total knee replacement. Med Care
1992;30:Suppl:MS240-MS252.[ISI][Medline]
Haybittle JL. Repeated assessment of results in clinical trials of
cancer treatment. Br J Radiol 1971;44:793-797.[ISI][Medline]
Peto R, Pike MC, Armitage P, et al. Design and analysis of randomized
clinical trials requiring prolonged observation of each patient. I.
Introduction and design. Br J Cancer 1976;34:585-612.[ISI][Medline]
Jones B, Jarvis P, Lewis JA, Ebbutt AF. Trials to assess equivalence:
the importance of rigorous methods. BMJ 1996;313:36-39. [Erratum, BMJ
1996;313:550.][Full Text]
Altman DG, Bland JM. Absence of evidence is not evidence of absence. BMJ
1995;311:485-485.[Full Text]
Greene WL, Concato J, Feinstein AR. Claims of equivalence in medical
research: are they supported by the evidence? Ann Intern Med
2000;132:715-722.[Abstract/Full Text]
Jaeschke R, Singer J, Guyatt GH. Measurement of health status:
ascertaining the minimal clinically important difference. Control Clin
Trials 1989;10:407-415.[CrossRef][ISI][Medline]
Kosinski M, Zhao SZ, Dedhiya S, Osterhaus JT, Ware JE Jr. Determining
minimally important changes in generic and disease-specific
health-related quality of life questionnaires in clinical trials of
rheumatoid arthritis. Arthritis Rheum
2000;43:1478-1487.[CrossRef][ISI][Medline]
Wyrwich KW, Tierney WM, Wolinsky FD. Further evidence supporting an
SEM-based criterion for identifying meaningful intra-individual changes
in health-related quality of life. J Clin Epidemiol
1999;52:861-873.[CrossRef][ISI][Medline]
Angst F, Aeschlimann A, Stucki G. Smallest detectable and minimal
clinically important differences of rehabilitation intervention with
their implications for required sample sizes using WOMAC and SF-36
quality of life measurement instruments in patients with osteoarthritis
of the lower extremities. Arthritis Rheum
2001;45:384-391.[CrossRef][Medline]
Kalunian KC, Moreland LW, Klashman DJ, et al. Visually-guided irrigation
in patients with early knee osteoarthritis: a multicenter randomized,
controlled trial. Osteoarthritis Cartilage
2000;8:412-418.[CrossRef][ISI][Medline]
Hróbjartsson A, Gøtzsche PC. Is the placebo powerless? An analysis
of clinical trials comparing placebo with no treatment. N Engl J Med
2001;344:1594-1602. [Erratum, N Engl J Med
2001;345:304.][Abstract/Full Text]
AbstractPDFPDA Full TextSupplementary Material
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Extract | Full Text | PDF
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A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the
Knee
J. Bruce Moseley, M.D., Kimberly O'Malley, Ph.D., Nancy J. Petersen,
Ph.D., Terri J. Menke, Ph.D., Baruch A. Brody, Ph.D., David H.
Kuykendall, Ph.D.,
John C. Hollingsworth, Dr.P.H., Carol M. Ashton, M.D., M.P.H., and Nelda
P. Wray, M.D., M.P.H.
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ABSTRACT
Background Many patients report symptomatic relief after undergoing
arthroscopy of the knee for osteoarthritis, but it is unclear how the
procedure achieves this result. We conducted a randomized,
placebo-controlled trial to evaluate the efficacy of arthroscopy for
osteoarthritis of the knee.
Methods A total of 180 patients with osteoarthritis of the knee were
randomly assigned to receive arthroscopic débridement, arthroscopic
lavage, or placebo surgery. Patients in the placebo group received skin
incisions and underwent a simulated débridement without insertion of
the arthroscope. Patients and assessors of outcome were blinded to the
treatment-group assignment. Outcomes were assessed at multiple points
over a 24-month period with the use of five self-reported scores —
three on scales for pain and two on scales for function — and one
objective test of walking and stair climbing. A total of 165 patients
completed the trial.
Results At no point did either of the intervention groups report less
pain or better function than the placebo group. For example, mean
(±SD) scores on the Knee-Specific Pain Scale (range, 0 to 100, with
higher scores indicating more severe pain) were similar in the placebo,
lavage, and débridement groups: 48.9±21.9, 54.8±19.8, and
51.7±22.4, respectively, at one year (P=0.14 for the comparison
between placebo and lavage; P=0.51 for the comparison between placebo
and débridement) and 51.6±23.7, 53.7±23.7, and 51.4±23.2,
respectively, at two years (P=0.64 and P=0.96, respectively).
Furthermore, the 95 percent confidence intervals for the differences
between the placebo group and the intervention groups exclude any
clinically meaningful difference.
Conclusions In this controlled trial involving patients with
osteoarthritis of the knee, the outcomes after arthroscopic lavage or
arthroscopic débridement were no better than those after a placebo
procedure.
When medical therapy fails to relieve the pain of osteoarthritis of the
knee, arthroscopic lavage or débridement is often recommended. More
than 650,000 such procedures are performed each year1 at a cost of
roughly $5,000 each. In uncontrolled studies of knee arthroscopy for
osteoarthritis, about half the patients report relief from
pain.2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 However, the physiological
basis for the pain relief is unclear. There is no evidence that
arthroscopy cures or arrests the osteoarthritis. Therefore, we conducted
a randomized, placebo-controlled trial to assess the efficacy of
arthroscopic surgery of the knee in relieving pain and improving
function in patients with osteoarthritis. Both patients and assessors of
outcome were blinded to the treatment assignments.
Methods
The college and hospital institutional review board approved the
protocol. A data and safety monitoring board monitored the study.
Study Participants
Participants were recruited from the Houston Veterans Affairs Medical
Center from October 1995 through September 1998. Patients were eligible
if they were 75 years old or younger, had osteoarthritis of the knee as
defined by the American College of Rheumatology,17 reported at least
moderate knee pain on average (4 on a visual-analogue scale ranging from
0 to 10) despite maximal medical treatment for at least six months, and
had not undergone arthroscopy of the knee during the previous two years.
The severity of osteoarthritis in the study knee (that with the greatest
pain-induced limitation of function) was assessed radiographically and
graded on a scale of zero to four.18 The scores for the three
compartments were added together to generate a severity grade of 0 to
12. Criteria for exclusion were a severity grade of 9 or higher, severe
deformity, and serious medical problems.
All patients provided informed consent, which included writing in their
chart, "On entering this study, I realize that I may receive only
placebo surgery. I further realize that this means that I will not have
surgery on my knee joint. This placebo surgery will not benefit my knee
arthritis." Of the 324 consecutive patients who met the criteria for
inclusion, 144 (44 percent) declined to participate. Participants were
younger than those who declined to participate (52.3±11.3 years vs.
55.3±12.4 years, P=0.002), were more likely to be white (62.2 percent
vs. 50.7 percent, P=0.03), and had more severe arthritis (25.0 percent
vs. 12.5 percent with grade 7 or 8 arthritis, P<0.001).
Randomization Process and Treatment Groups
Participants were stratified into three groups according to the severity
of osteoarthritis (grade 1, 2, or 3; grade 4, 5, or 6; and grade 7 or
. A stratified randomization process with fixed blocks of six was
used. Sealed, sequentially numbered, stratum-specific envelopes
containing treatment assignments were prepared and given to the research
assistant. After the patient was in the operating suite, the surgeon was
handed the envelope. The treatment assignment was not revealed to the
patient.
Participants were randomly assigned to arthroscopic débridement,
arthroscopic lavage alone, or the placebo procedure. One orthopedist
performed all the operations. Patients in the débridement group or the
lavage group received standard general anesthesia with endotracheal
intubation. Patients in the placebo group received a short-acting
intravenous tranquilizer and an opioid and spontaneously breathed
oxygen-enriched air.
Lavage
After diagnostic arthroscopy in patients in the lavage group, the joint
was lavaged with at least 10 liters of fluid. Anything that could be
flushed out through arthroscopic cannulas was removed. Normally, no
instruments were used to mechanically débride or remove tissue.
However, if a mechanically important, unstable tear in the meniscus
(e.g., a displaced "bucket-handle" tear) was encountered, the torn
portion was removed and the remaining meniscus was smoothed to a firm,
stable rim. (There is general agreement that it is inappropriate to
leave this type of meniscal tear untreated.11,13,19,20) No other
débridement was performed.
Débridement
After diagnostic arthroscopy in patients in the débridement group, the
joint was lavaged with at least 10 liters of fluid, rough articular
cartilage was shaved (chondroplasty was performed), loose debris was
removed, all torn or degenerated meniscal fragments were trimmed, and
the remaining meniscus was smoothed to a firm and stable rim. No
abrasion arthroplasty or microfracture was performed. Typically, bone
spurs were not removed, but any spurs from the tibial spine area that
blocked full extension were shaved smooth.
Placebo Procedure
To preserve blinding in the event that patients in the placebo group did
not have total amnesia, a standard arthroscopic débridement procedure
was simulated. After the knee was prepped and draped, three 1-cm
incisions were made in the skin. The surgeon asked for all instruments
and manipulated the knee as if arthroscopy were being performed. Saline
was splashed to simulate the sounds of lavage. No instrument entered the
portals for arthroscopy. The patient was kept in the operating room for
the amount of time required for a débridement. Patients spent the
night after the procedure in the hospital and were cared for by nurses
who were unaware of the treatment-group assignment.
Postoperatively, there were two minor complications and no deaths.
Incisional erythema developed in one patient, who was given antibiotics.
In a second patient, calf swelling developed in the leg that had
undergone surgery; venography was negative for thrombosis. In no case
did a complication necessitate the breaking of the randomization code.
Postoperative care was delivered according to a protocol specifying that
all patients should receive the same walking aids, graduated exercise
program, and analgesics. The use of analgesics after surgery was
monitored; during the two-year follow-up period, the amount used was
similar in the three groups.
End Points
Study personnel who were unaware of the treatment-group assignments
performed all postoperative outcome assessments; the operating surgeon
did not participate in any way. Data on end points were collected 2
weeks, 6 weeks, 3 months, 6 months, 12 months, 18 months, and 24 months
after the procedure. To assess whether patients remained unaware of
their treatment-group assignment, they were asked at each follow-up
visit to guess which procedure they had undergone. Patients in the
placebo group were no more likely than patients in the other two groups
to guess that they had undergone a placebo procedure. For example, at
two weeks, 13.8 percent of the patients in the placebo group guessed
that they had undergone a placebo procedure, and 13.2 percent of the
patients in the lavage and débridement groups guessed that they had
undergone a placebo procedure.
The primary end point was pain in the study knee 24 months after the
intervention, as assessed by a 12-item self-reported Knee-Specific Pain
Scale (KSPS) created for this study (see Supplementary Appendix 1,
available with the full text of this article at http://www.nejm.org).
Scores on this scale range from 0 to 100, with higher scores indicating
more severe pain. In addition, to ensure our ability to detect any
benefit, we also used five secondary efficacy end points: two additional
assessments of pain and three assessments of function at all time
points. Arthritis pain in general (i.e., not specifically in the study
knee) was assessed by means of the four-item pain subscale of the
Arthritis Impact Measurement Scales (AIMS2-P).21,22 Higher scores on
this subscale indicate more severe pain. Body pain (i.e., not
necessarily from arthritis and not necessarily in the knee) was assessed
with the 2-item pain subscale of the Medical Outcomes Study 36-item
Short-Form General Health Survey (SF-36-P).23,24 Higher scores on this
subscale indicate less severe pain. The AIMS2-P and the SF-36-P scores
were transformed into scores on a scale from 0 to 100.
Two self-reported measures of physical function were used: the 5-item
walking–bending subscale from the AIMS2 (AIMS2-WB, transformed into
scores on a scale from 0 to 100, with higher scores indicating more
limited function21,22) and the 10-item physical-function subscale from
the SF-36 (SF-36-PF, transformed into scores on a scale from 0 to 100,
with higher scores indicating better function23,24). As an objective
measure, we devised the Physical Functioning Scale (PFS) to record the
amount of time in seconds that a patient required to walk 30 m (100 ft)
and to climb up and down a flight of stairs as quickly as possible.
Longer times indicate poorer functioning.
All six outcome scales had good reliability. The median Cronbach's alpha
(according to analyses of data from eight time points for all scales)
exceeded 0.80. Results for all the outcome measures at all the time
points that are not reported here are summarized in Supplementary
Appendix 2, available with the full text of this article at
http://www.nejm.org.
Statistical Analysis
Our pilot study indicated that it would be feasible to recruit 60
patients per year. The trial was designed to have 90 percent power, with
a two-sided type I error of 0.04, to detect a moderate effect size
(0.55) between the placebo group and the combined arthroscopic-treatment
groups in terms of body pain as measured by the SF-36-P at two years,
with an enrollment of 180 patients and 16 or fewer lost to follow-up
(i.e., 164 or more completing the two-year follow-up). The primary
hypothesis was that the patients in two arthroscopic-intervention groups
combined would report the same amount of knee pain at two years as the
patients assigned to the placebo group. All statistical tests compared
the treatment groups in terms of the values at each visit rather than
analyzing the changes from base line. (Scores for these changes ["change
scores"] were analyzed, with results that did not differ from the
results presented here.) The data and safety monitoring board reviewed
interim data 15 months and 24 months after enrollment began, using the
Haybittle–Peto group-sequential method, with stopping boundaries of
P=0.001 for the two interim analyses.25,26 All reported P values are
two-sided and have not been adjusted for multiple comparisons.
Our prespecified analytic strategy was to test, at all time points, for
the superiority of the arthroscopic procedures over the placebo
procedure. Lacking evidence of superiority, we tested for evidence that
the arthroscopic procedures were equivalent27,28,29 to the placebo
procedure by determining the extent to which the study was powered to
reject the hypothesis that the arthroscopic treatments caused a small
but clinically important improvement (the "minimal important
difference"). The minimal important difference for a scale is the
smallest change score associated with a patient's perception of a change
in health status,30 but it can vary somewhat according to the method of
calculation and the study sample.31,32 Minimal important differences for
each of the six study scales were calculated on the basis of the trial
data by two different methods: the change ratings of patients (their
scores on a single-item scale that asked patients if their condition was
the same, somewhat better [or worse], or much better [or worse] than
before surgery) and the standard error of measurement (the SD of the
instrument multiplied by the square root of one minus its reliability
coefficient).30,31,32 Estimates were also obtained from the
literature.31,32,33 For each scale, we tested the hypothesis that the
placebo procedure was equivalent to the arthroscopic procedures, using
as the minimal important difference the midpoint of the range of the
minimal important differences reported in the literature or calculated
on the basis of our data. If the 95 percent confidence interval around
the estimated size of the effect does not include the minimal important
difference, one can reject the hypothesis that the arthroscopic
procedures have a small but clinically important benefit.27
Results
A total of 180 patients underwent randomization; 60 were assigned to the
placebo group, 61 to the lavage group, and 59 to the débridement
group. Base-line characteristics were similar in the three study groups
(Table 1).
View this table:
[in this window]
[in a new window]
Table 1. Base-Line Characteristics of the Randomized Patients.
At no point did either arthroscopic-intervention group have greater pain
relief than the placebo group (Figure 1, Table 2, and Supplementary
Appendix 2). For example, there was no difference in knee pain between
the placebo group and either the lavage group or the débridement group
at one year (mean [±SD] KSPS scores, 48.9±21.9, 54.8±19.8, and
51.7±22.4, respectively; P=0.14 for the comparison with the lavage
group, and P=0.51 for the comparison with the débridement group) or at
two years (mean KSPS scores, 51.6±23.7, 53.7±23.7, and 51.4±23.2,
respectively; P=0.64 and P=0.96, respectively). Similarly, there was no
significant difference in arthritis pain between the placebo group and
the lavage group or the débridement group at one or two years (Table
2).
View larger version (13K):
[in this window]
[in a new window]
Figure 1. Mean Values (and 95 Percent Confidence Intervals) on the
Knee-Specific Pain Scale.
Assessments were made before the procedure and 2 weeks, 6 weeks, 3
months, 6 months, 12 months, 18 months, and 24 months after the
procedure. Higher scores indicate more severe pain.
View this table:
[in this window]
[in a new window]
Table 2. Scores on the Pain Subscale of the Arthritis Impact
Measurement Scales.
Furthermore, at no time point did either arthroscopic-intervention group
have significantly greater improvement in function than the placebo
group (Figure 2, Table 3, and Supplementary Appendix 2). For example,
there was no significant difference between the placebo group and either
the lavage group or the débridement group in the self-reported ability
to walk and bend at one year (mean AIMS2-WB scores, 49.4±25.5,
49.6±29.1, and 56.4±28.4, respectively; P=0.98 for the comparison
with the lavage group, and P=0.19 for the comparison with the
débridement group) or at two years (mean AIMS2-WB score, 53.8±27.5,
51.1±28.3, and 56.4±29.4, respectively; P=0.61 and P=0.64,
respectively). Indeed, objectively measured walking and stair climbing
were poorer in the débridement group than in the placebo group at two
weeks (mean PFS score, 56.0±21.8 vs. 48.3±13.4; P=0.02) and one year
(mean PFS score, 52.5±20.3 vs. 45.6±10.2; P=0.04) and showed a trend
toward worse functioning at two years (mean PFS score, 52.6±16.4 vs.
47.7±12.0; P=0.11) (Table 3).
View larger version (14K):
[in this window]
[in a new window]
Figure 2. Mean Values (and 95 Percent Confidence Intervals) on the
Walking–Bending Subscale of the Arthritis Impact Measurement Scales
(AIMS2).
Assessments were made before the procedure and 2 weeks, 6 weeks, 3
months, 6 months, 12 months, 18 months, and 24 months after the
procedure. Higher scores indicate poorer functioning.
View this table:
[in this window]
[in a new window]
Table 3. Scores on the Physical Functioning Scale.
Lacking evidence of the superiority of the arthroscopic treatments over
the placebo procedure in relieving pain or improving function, we
considered whether the 95 percent confidence intervals for the
differences in outcome between each arthroscopic procedure and the
placebo procedure included clinically important differences. The minimal
important differences used for this evaluation were as follows: a
difference of 13.5 points on the KSPS, 10.0 on the AIMS2-P, 11.8 on the
SF-36-P, 12.8 on the AIMS2-WB, 11.3 on the SF-36-PF, and 4.5 on the PFS.
At almost all time points during follow-up (72 of 84 comparisons), the
confidence intervals excluded these minimal important differences.
Discussion
This study provides strong evidence that arthroscopic lavage with or
without débridement is not better than and appears to be equivalent to
a placebo procedure in improving knee pain and self-reported function.
Indeed, at some points during follow-up, objective function was
significantly worse in the débridement group than in the placebo
group.
Arthroscopy is the most commonly performed type of orthopedic surgery,
and the knee is by far the most common joint on which it is performed.1
Numerous uncontrolled, retrospective case series have reported
substantial pain relief after arthroscopic lavage or arthroscopic
débridement for osteoarthritis of the
knee.2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 In the only previous
double-blind, randomized, controlled trial of knee arthroscopy of which
we are aware,34 patients with minimal osteoarthritis as assessed by
radiography were assigned to undergo arthroscopic lavage with either
3000 ml of fluid (treatment) or 250 ml of fluid (control) and were
followed for one year. Both the treatment and the control groups
reported improvement in function at 12 months, and although the report
interprets the study as having proved the efficacy of lavage, there was
no statistically significant difference between the groups in terms of
the primary outcome at any point during follow-up.
To explain the improvement that has been reported after these
procedures, some have proposed that the fluid that is flushed through
the knee during arthroscopy cleanses the knee of painful debris and
inflammatory enzymes.4,6,9,15,16,34 Others have suggested that the
improvement is due to the removal of flaps of articular cartilage, torn
meniscal fragments, hypertrophied synovium, and loose
debris.2,3,4,5,6,7,8,9,10,11,12,13,14 However, our study found that
outcomes after arthroscopic treatment are no better than those after a
placebo procedure. This lack of difference suggests that the improvement
is not due to any intrinsic efficacy of the procedures. Although
patients in the placebo groups of randomized trials frequently have
improvement, it may be attributable to either the natural history of the
condition or some independent effect of the placebo.
Because we found no evidence that lavage or débridement is superior to
a placebo procedure, the question arises whether these arthroscopic
procedures could have small but clinically important benefits that we
missed because of our limited sample size. To evaluate this possibility,
we determined the size of the clinical benefit that the trial was able
to rule out, using the minimal important difference for each of our
scales. Because estimates of minimal important differences based on
different samples and different methods do not yield the same values, we
used the midpoint of the range of available minimal important
differences in order to test our hypothesis about the equivalence of the
three procedures. For the great majority of comparisons, the 95 percent
confidence intervals did not contain the minimal important difference,
indicating that there was not a clinically important improvement that
the study had simply failed to detect.
One surgeon performed all the procedures in this study. Consequently,
his technical proficiency is critical to the generalizability of our
findings. Our study surgeon is board-certified, is fellowship-trained in
arthroscopy and sports medicine, and has been in practice for 10 years
in an academic medical center. He is currently the orthopedic surgeon
for a National Basketball Association team and was the physician for the
men's and women's U.S. Olympic basketball teams in 1996.
The principal limitation of this study is that our participants may not
be representative of all candidates for arthroscopic treatment of
osteoarthritis of the knee. Almost all participants were men, because
the study was conducted at a Veterans Affairs medical center. We do not
know whether our findings may be generalized to women, although
uncontrolled studies do not indicate that there are differences between
the sexes in responses to arthroscopic procedures.8,10,13 A selection
bias might have been introduced by the fact that 44 percent of the
eligible patients declined to participate in the study. We believe this
high rate of refusal to participate resulted from the fact that all
patients knew they had a one-in-three chance of undergoing a placebo
procedure. Patients who agreed to participate might have been so sure
that an arthroscopic procedure would help that they were willing to take
a one-in-three chance of undergoing the placebo procedure. Such patients
might have had higher expectations of benefit or been more susceptible
to a placebo effect than those who chose not to participate.
If the efficacy of arthroscopic lavage or débridement in patients with
osteoarthritis of the knee is no greater than that of placebo surgery,
the billions of dollars spent on such procedures annually might be put
to better use. This study has also shown the great potential for a
placebo effect with surgery, although it is unclear whether this effect
is due solely to the natural history of the condition or whether there
is some independent effect. Researchers should reconsider the best ways
of testing the efficacy of surgical procedures performed purely for the
improvement of symptoms. In the debate about placebo-controlled trials
of surgery, the critical ethical considerations surround the choice of
the placebo. Finally, health care researchers should not underestimate
the placebo effect, regardless of its mechanism.35
Supported by a grant from the Department of Veterans Affairs.
Source Information
From the Houston Veterans Affairs Medical Center (J.B.M., K.O., N.J.P.,
T.J.M., D.H.K., C.M.A., N.P.W.); the Department of Orthopedic Surgery
(J.B.M.), the Department of Medicine, Section of Health Services
Research (K.O., N.J.P., T.J.M., C.M.A., N.P.W.), and the Center for
Medical Ethics and Health Policy (B.A.B.), Baylor College of Medicine;
and International Survey Research (D.H.K.) — all in Houston; and the
Laguna Honda Hospital, San Francisco (J.C.H.).
Address reprint requests to Dr. Wray at the Section of Health Services
Research, Baylor College of Medicine, 2002 Holcombe Blvd. (M.R. 152),
Houston, TX 77030, or at nwray@bcm.tmc.edu.
References
Owings MF, Kozak LJ. Ambulatory and inpatient procedures in the United
States, 1996. Vital and health statistics. Series 13. No. 139.
Hyattsville, Md.: National Center for Health Statistics, November 1998.
(DHHS publication no. (PHS) 99-1710.)
Baumgaertner MR, Cannon WD Jr, Vittore JM, Schmidt ES, Maurer RC.
Arthroscopic debridement of the arthritic knee. Clin Orthop
1990;253:197-202.[Medline]
Bert JM, Maschka K. The arthroscopic treatment of unicompartmental
gonarthrosis: a five-year follow-up study of abrasion arthroplasty plus
arthroscopic debridement and arthroscopic debridement alone. Arthroscopy
1989;5:25-32.[Medline]
Chang RW, Falconer J, Stulberg SD, Arnold WJ, Manheim LM, Dyer AR. A
randomized, controlled trial of arthroscopic surgery versus
closed-needle joint lavage for patients with osteoarthritis of the knee.
Arthritis Rheum 1993;36:289-296.[ISI][Medline]
Gross DE, Brenner SL, Esformes I, Gross ML. Arthroscopic treatment of
degenerative joint disease of the knee. Orthopedics
1991;14:1317-1321.[ISI][Medline]
Jackson RW, Silver R, Marans H. Arthroscopic treatment of degenerative
joint disease. Arthroscopy 1986;2:114-114.
Jennings JE. Arthroscopic debridement as an alternative to total knee
replacement. Arthroscopy 1986;2:123-124.
McLaren AC, Blokker CP, Fowler PJ, Roth JN, Rock MG. Arthroscopic
debridement of the knee for osteoarthritis. Can J Surg
1991;34:595-598.[ISI][Medline]
Ogilvie-Harris DJ, Fitsialos DP. Arthroscopic management of the
degenerative knee. Arthroscopy 1991;7:151-157.[Medline]
Rand JA. Role of arthroscopy in osteoarthritis of the knee. Arthroscopy
1991;7:358-363.[Medline]
Richards RN Jr, Lonergan RP. Arthroscopic surgery for relief of pain in
the osteoarthritic knee. Orthopedics 1984;7:1705-1707.[ISI]
Salisbury RB, Nottage WM, Gardner V. The effect of alignment on results
in arthroscopic debridement of the degenerative knee. Clin Orthop
1985;198:268-272.[Medline]
Sprague NF III. Arthroscopic debridement for degenerative knee joint
disease. Clin Orthop 1981;160:118-123.[Medline]
Timoney JM, Kneisl JS, Barrack RL, Alexander AH. Arthroscopy in the
osteoarthritic knee: long-term follow-up. Orthop Rev 1990;19:371-3,
376.[Medline]
Ike RW, Arnold WJ, Rothschild EW, Shaw HL. Tidal irrigation versus
conservative medical management in patients with osteoarthritis of the
knee: a prospective randomized study. J Rheumatol
1992;19:772-779.[ISI][Medline]
Livesley PJ, Doherty M, Needoff M, Moulton A. Arthroscopic lavage of
osteoarthritic knees. J Bone Joint Surg Br
1991;73:922-926.[ISI][Medline]
Workshop on etiopathogenesis of osteoarthritis. J Rheumatol
1986;13:1126-1160.[ISI]
Kellgren JH, Lawrence JS. Radiological assessment of osteo-arthrosis.
Ann Rheum Dis 1957;16:494-502.[ISI]
Jackson RW, Rouse DW. The results of partial arthroscopic meniscectomy
in patients over 40 years of age. J Bone Joint Surg Br
1982;64:481-485.[ISI][Medline]
Rand JA. Arthroscopic management of degenerative meniscus tears in
patients with degenerative arthritis. Arthroscopy
1985;1:253-258.[Medline]
Meenan RF, Mason JH, Anderson JJ, Guccione AA, Kazis LE. AIMS2: the
content and properties of a revised and expanded Arthritis Impact
Measurement Scales health status questionnaire. Arthritis Rheum
1992;35:1-10.[ISI][Medline]
Liang MH, Fossel AH, Larson MG. Comparisons of five health status
instruments for orthopedic evaluation. Med Care
1990;28:632-642.[ISI][Medline]
Ware JE, Sherbourne CD. The MOS 36-item short-form health survey
(SF-36). I. Conceptual framework and item selection. Med Care
1992;30:473-483.[ISI][Medline]
Kantz ME, Harris WJ, Levitsky K, Ware JE Jr, Davies AR. Methods for
assessing condition-specific and generic functional status outcomes
after total knee replacement. Med Care
1992;30:Suppl:MS240-MS252.[ISI][Medline]
Haybittle JL. Repeated assessment of results in clinical trials of
cancer treatment. Br J Radiol 1971;44:793-797.[ISI][Medline]
Peto R, Pike MC, Armitage P, et al. Design and analysis of randomized
clinical trials requiring prolonged observation of each patient. I.
Introduction and design. Br J Cancer 1976;34:585-612.[ISI][Medline]
Jones B, Jarvis P, Lewis JA, Ebbutt AF. Trials to assess equivalence:
the importance of rigorous methods. BMJ 1996;313:36-39. [Erratum, BMJ
1996;313:550.][Full Text]
Altman DG, Bland JM. Absence of evidence is not evidence of absence. BMJ
1995;311:485-485.[Full Text]
Greene WL, Concato J, Feinstein AR. Claims of equivalence in medical
research: are they supported by the evidence? Ann Intern Med
2000;132:715-722.[Abstract/Full Text]
Jaeschke R, Singer J, Guyatt GH. Measurement of health status:
ascertaining the minimal clinically important difference. Control Clin
Trials 1989;10:407-415.[CrossRef][ISI][Medline]
Kosinski M, Zhao SZ, Dedhiya S, Osterhaus JT, Ware JE Jr. Determining
minimally important changes in generic and disease-specific
health-related quality of life questionnaires in clinical trials of
rheumatoid arthritis. Arthritis Rheum
2000;43:1478-1487.[CrossRef][ISI][Medline]
Wyrwich KW, Tierney WM, Wolinsky FD. Further evidence supporting an
SEM-based criterion for identifying meaningful intra-individual changes
in health-related quality of life. J Clin Epidemiol
1999;52:861-873.[CrossRef][ISI][Medline]
Angst F, Aeschlimann A, Stucki G. Smallest detectable and minimal
clinically important differences of rehabilitation intervention with
their implications for required sample sizes using WOMAC and SF-36
quality of life measurement instruments in patients with osteoarthritis
of the lower extremities. Arthritis Rheum
2001;45:384-391.[CrossRef][Medline]
Kalunian KC, Moreland LW, Klashman DJ, et al. Visually-guided irrigation
in patients with early knee osteoarthritis: a multicenter randomized,
controlled trial. Osteoarthritis Cartilage
2000;8:412-418.[CrossRef][ISI][Medline]
Hróbjartsson A, Gøtzsche PC. Is the placebo powerless? An analysis
of clinical trials comparing placebo with no treatment. N Engl J Med
2001;344:1594-1602. [Erratum, N Engl J Med
2001;345:304.][Abstract/Full Text]
AbstractPDFPDA Full TextSupplementary Material
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BMJ 2004;329:1220-1224 (20 November), doi:10.1136/bmj.329.7476.1220
Orthopaedic and Trauma Surgery
Clinical review
The orthopaedic approach to managing osteoarthritis of the knee
Sam Gidwani, specialist registrar1, Adrian Fairbank, consultant2
1 Department of Orthopaedics, Kingston Hospital, Kingston upon Thames, Surrey KT2 7QB, 2 Department of Orthopaedics, St George's Hospital, London SW17 0QT
Osteoarthritis of the knee is common, affecting almost a tenth of the population aged over 55.1 This proportion is likely to increase with extended longevity and a bigger body mass index. Most patients with osteoarthritis of the knee are able to manage their symptoms without medical treatment, but a large proportion of those referred to orthopaedic surgeons have debilitating disease, presenting chiefly with pain and stiffness. Classically the pain depends on activity, and in severe cases not only limits the distance patients can walk and their daily activities, but also disrupts sleep. Moreover, whereas most patients are past retirement, a major proportion is of working age, leading to difficulties with work and presenting an important economic cost to society.
Non-surgical treatment of osteoarthritis of the knee is primarily carried out in the community. This article concentrates on the interventions and surgical options used by orthopaedic surgeons for the treatment of this disease, indications for their use, and likely outcomes.
We searched Medline (1966 to May 2004) using the terms "osteoarthritis", "knee", "knee replacement/arthroplasty", "osteotomy", "arthroscopy", "and outcome". We were particularly interested in papers from leading peer reviewed orthopaedic and rheumatological journals. We searched the Cochrane database of systematic reviews, the health technology assessment database, and the database of abstracts of reviews of effects.
Non-operative treatment
Management of patients with mild osteoarthritis should be tailored to the individual while avoiding over-medicalisation of the condition.w1 A variety of interventions are available, including advice on changes to lifestyle and physical and pharmacological therapies. The effectiveness of many of these treatments has been reviewed elsewhere.2 3
Intra-articular steroid injections
Intra-articular steroid injections can alleviate pain in patients with moderate osteoarthritis of the knee, but this is usually short lived,2 and therefore we believe they have a limited role in treating acute exacerbations of the disease. A recent randomised double blind trial, however, has suggested that repeated injections of the steroid triamcinolone hydrochloride every three months for up to two years can lead to improved symptoms when compared with injections of saline.4 The effect was more noticeable at one year. Evidence that steroids accelerate cartilage damage is still inconclusive, but there is a small risk of septic arthritis (between 1 in 15 000 and 1 in 50 000).2 A Cochrane review of the available evidence is in preparation.
Summary points
The outcome of total knee replacement is comparable to that of total hip replacement
85% of total knee replacements are carried out for patients with osteoarthritis
Arthroscopic debridement and washout has a role as a temporising procedure in early osteoarthritis associated with mechanical symptoms
In some cases alternative surgical procedures such as unicompartmental knee replacement may be more appropriate than total knee replacement
The role and success of new techniques such as image guidance and minimally invasive surgery remain to be established
Viscosupplementation
Several hyaluronan preparations are available as intraarticular injections. Relief of symptoms is thought to result from increased viscosity of the synovial fluid—hence the term "viscosupplementation" for this type of treatment. The molecular weights of the hyaluronan derivatives vary as do the duration of courses and the numbers of injections recommended. The results of trials also differ, with some implying little benefit and others showing excellent results.5 w2 w3 A recent systematic review concluded that injections of hyaluronic acid were no more effective than nonsteroidal anti-inflammatory drugs for improving pain, physical function, and stiffness, and did not support public funding of viscosupplementation.6
Surgical intervention
Top
Introduction
Sources and selection criteria
Non-operative treatment
Surgical intervention
References
Indications
The impact of disease on lifestyle is the most important factor in assessment of patients with osteoarthritis of the knee. Surgery should be resisted when symptoms can be managed by non-surgical means. Indications for surgical intervention are debilitating pain and major limits on daily activities and distance walked, or impaired ability to sleep or work.
Another consideration is the patient's health and fitness for anaesthesia. The risks as well as potential benefits of surgery need to be discussed with the patient. Several surgical techniques are available (box).
Arthroscopic washout and debridement
The role of arthroscopic debridement for degenerative arthritis of the knee is controversial. It has been shown that improvement of symptoms in an unselected cohort of patients allocated to either washout or washout and debridement could be attributed to a placebo effect.7 Prospective randomised controlled trials looking at subsets of patients with differing levels of symptoms and disease are scarce. Some studies do suggest that arthroscopic treatment used in a more selective manner can control symptoms of osteoarthritis of the knee for up to five years.8 9 Factors correlating with a better outcome include the presence of mechanical symptoms of painful locking or catching of the knee, mild to moderate radiographic evidence of arthritis, and a younger age at the time of surgery. The presence of limb malalignment is associated with a less successful outcome. For this reason we believe that arthroscopic debridement should principally be used in younger patients with osteoarthritis, with meniscal lesions or chondral flaps amenable to debridement. Delaying inevitable joint replacement is particularly desirable in these patients. Further clinical study of this subset of patients within the context of a randomised controlled trial would be helpful.
Osteotomy of the proximal tibia or distal femur
In healthy knees, the weightbearing axis passes from the centre of the hip to the centre of the ankle joint, through the centre of the knee. In osteoarthritis, the alignment of the leg changes because of wear. Medial wear creates a bow legged appearance (varus), and the weightbearing axis moves medially. Lateral wear creates a knock knee (valgus) deformity, and the weightbearing axis moves laterally. Osteotomy around the knee moves the weightbearing axis to the less damaged compartment (fig 1).
Fig 1 Preoperative and postoperative radiographs of a varus knee with medial compartment osteoarthritis before and after opening wedge tibial osteotomy
Surgical options for osteoarthritis of the knee
Established techniques
Arthroscopic washout and debridement of the joint
Osteotomy of the proximal tibia or distal femur
Unicompartmental knee replacement
Patellofemoral replacement
Total knee replacement
Evolving techniques
Computer assisted surgery (image guidance)
Minimally invasive knee replacement
Recovery is prolonged and relief of symptoms often incomplete, but osteotomy may delay the need for total knee replacement for five to 10 years.10 11 Successful treatment could allow a return to sport—something ill advised after arthroplasty. The risks specific to this surgery depend on the technique, and include non-union at the osteotomy site, common peroneal nerve injury, pain from the proximal tibiofibular joint, and over-correction or under-correction of the deformity. Part of an ongoing debate within the orthopaedic community concerns the relative merits of high tibial osteotomy compared with unicompartmental knee replacement in younger patients. The evidence for osteotomy in itself is the subject of an ongoing Cochrane review.
Unicompartmental knee replacement
Up to a quarter of patients with osteoarthritis of the knee have predominantly arthritis of the medial compartment. The surgical options for such patients are medial unicompartmental knee replacement (fig 2), proximal tibial or distal femoral osteotomy, and total knee replacement.
Fig 2 Unicompartmental knee replacement in a patient with medial compartment osteoarthritis (varus deformity corrected)
Unicompartmental knee replacement requires a smaller surgical approach than for total knee replacement, leading to less blood loss and quicker rehabilitation. The range of knee motion after unicompartmental knee replacement is generally superior to that after total knee replacement. Finally, revision of a unicompartmental knee replacement to a total knee replacement is potentially more straightforward than revision of a total knee replacement.w4
The prerequisites for unicompartmental knee replacement are well defined. These include stability of the joint, a correctable varus deformity, a fixed flexion deformity of less than 10 degrees, and minimal lateral compartment disease. Radiographic evidence of patellofemoral osteoarthritis is not necessarily a problem provided that patients do not have major anterior knee pain. Two studies have reported survivorship rates for implants of 95% and 98% at 10 years.12 13 These rates are comparable to the best reported for total knee replacement and are an improvement on rates previously reported for unicompartmental knee replacement. A recent systematic review of the evidence supports the use of the Oxford unicompartmental knee replacement in patients with arthritis of the medial compartment provided they fulfil the indications.14
The relative merits of unicompartmental knee replacement over total knee replacement or proximal tibial osteotomy in young (less than 60 years) active patients continue to be debated. Unicompartmental knee replacement has now become an accepted treatment for older patients with medial compartment arthritis. The results of unicompartmental knee replacement in lateral compartment disease have yet to be fully determined.
Patellofemoral replacement
Isolated disease of the patellofemoral joint occurs in up to a tenth of patients with osteoarthritis of the knee, and many of these patients are younger than those with tricompartmental arthritis. The surgical options for these patients are arthroscopic debridement, patellofemoral replacement, total knee replacement, or, rarely, patellectomy.
Patients considered for patellofemoral replacement must be assessed for degenerative changes in the rest of the knee joint. Several types of patellofemoral arthroplasties are available but the results have been variable, highlighting the need for careful selection of patients.w4-w6 The most common problems are maltracking of the patella, excessive wear of the polyethylene implant, and disease progression in the rest of the knee joint. The Avon patellofemoral arthroplasty shows promise, although so far published results are only available for five years' follow up.15 Meanwhile, total knee replacement has a place in the treatment of older patients with primarily patellofemoral arthritis, with results that are comparable to patients with tricompartmental disease.16
Total knee replacement
Total knee replacement is a well established treatment for patients with moderate to severe osteoarthritis, with long term results comparable to those of total hip replacement. Between 1991 and 2000 the number of episodes of primary knee replacement registered by the NHS in England more than doubled, to around 33 000 per year. Taking into account the changing demographics of the population, this figure has been estimated to increase by as much as 60% over the next decade, requiring a substantial increase in provision of services.17
Long term studies on survivorship of implants generally use primary end points such as decision to revise the knee replacement (cumulative revision rate). Studies have shown survival rates of between 84% and 98% at 15 years.18 19 w7-w9 The decision on when to revise a knee replacement is largely influenced by the severity of symptoms and the patient's lifestyle, fitness for surgery, and radiological and clinical evidence of complications (usually infection or aseptic loosening). The Swedish knee arthroplasty register has revision rates for over 57 000 knee replacements and revisions carried out since 1975.20 The United Kingdom national joint registry began in 2003, and data on a large proportion of joint replacements are now being recorded.
During the last two decades of the 20th century the designs of total knee prostheses used for primary knee replacement converged towards a bicondylar unconstrained replacement with a polyethylene bearing or insert contained between the femoral and tibial components. These prostheses are classified as either cruciate retaining, where the posterior cruciate ligament is preserved, or posterior stabilised, where the posterior cruciate ligament is removed (fig 3).w10 The posterior stabilised type of prosthesis incorporates a central peg and cam mechanism, theoretically allowing for a greater range of flexion while maintaining anteroposterior stability. Both designs have their advocates and advantages but provide similar long term results.
Fig 3 Posterior stabilised total knee replacement, with resurfacing of patella
Consensus has still not been reached in some areas of total knee replacement. For example, resurfacing of the patella with a patellar button is practised routinely, selectively, or not at all. The use of a mobile rather than a fixed bearing theoretically reduces contact stresses and therefore wear of the polyethylene (a major cause of osteolysis and aseptic loosening) and provides a better range of motion and functional outcome, although this has not been substantiated to date.21 A major UK multicentre health and technology assessment trial, due for completion in 2011, is looking at these and other contentious issues in knee replacement.
Another ongoing debate concerns the timing of knee replacement surgery. Support is increasing for the view that good results can be obtained in relatively early stages of osteoarthritis, and that there is little advantage in waiting until the patient is in extremis.22 Symptoms do not always seem to correlate with the radiological degree of osteoarthritis,w11 so that a patient with severe symptoms but only moderate radiological changes may none the less merit referral.
As part of informed consent for total knee replacement, patients need to be made aware of potential risks, to both their knee and their general health (table). Complications from total knee replacement have been reported in 5% of patients and 8% of knees.23 More specifically, deep infection occurs in between 0.5% and 1.5% of patients. The incidence of asymptomatic deep vein thrombosis in the perioperative period is high—as much as 50% in some studies. The extent of symptomatic deep vein thrombosis or pulmonary embolism is much lower, around 1% to 3%.23 The risk of death from total knee replacement is around 0.5% within the first 90 days of the procedure.w12
View this table:
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[in a new window]
Potential complications of surgery for total knee replacement
Additional educational resources
Arthritis Research Campaign (www.arc.org.uk/about_arth/)—A review of the diagnosis and management of osteoarthritis of the hip and knee and guidelines for referral to specialists
British Orthopaedic Association (www.boa.ac.uk)—A consensus statement from the British Orthopaedic Association and British Association for Surgery of the Knee on best practice in total knee replacement
Robertsson O, Knutson K, Lewold S, Lidgren L. The Swedish Knee Arthroplasty Register 1975-1997. An update with special emphasis on 41,223 knees operated on in 1988-1997. Acta Orthop Scand 2001;71: 503-13[ISI]
Information for patients
Arthritis Research Campaign (www.arc.org.uk/about_arth/)—Booklet on undergoing knee replacement surgery; part of a comprehensive website providing detailed information for patients and healthcare professionals
Arthritis Care (www.arthritiscare.org.uk)—Provides a range of information booklets, runs self management courses, and helps patients access local care groups run by volunteers
American Academy of Orthopaedic Surgeons (orthoinfo.aaos.org)—Detailed information on osteoarthritis of the knee, total knee replacement, and rehabilitation
The American National Library of Medicine and the Patient Education Institute (www.nlm.nih.gov/medlineplus/tutorials/k ... 49101.html)—Information focusing on knee replacement
Predictable long term side effects of total knee replacement include difficulty squatting or kneeling, numbness lateral to the scar, and mechanical noises, or "clunking," from the prosthesis.
Strong evidence shows that most patients experience a reduction in pain and improved function after total knee replacement, quantified by specific outcome measures, or "knee scores."24 However, around half of revision knee replacements occur in the first two to four years after the primary operation. A risk factor for revision shown by the Swedish knee registry was young age at the time of primary surgery.20 Although total knee revision generally improves function, the overall complication rate is significantly greater, at about 26%.23 In one study, an eighth of patients who underwent a revision required re-revision due to complications. These data underpin the reluctance of orthopaedic surgeons to carry out total knee replacements in younger patients, particularly if alternative treatments can, albeit temporarily, control their symptoms.
Several authors have been frustrated by the search for evidence on precise indications for total knee replacement.23 w13 Important progress has been made since the 1980s, particularly in the formulation of knee scoring systems. Some would argue, however, that more careful consideration now needs to be given to the influence of patient characteristics and timing of surgery on the outcome of total knee replacement.
Evolving techniques
Minimal incision approach
A minimal incision approach to unicompartmental knee replacement has become popular, and excellent results have been shown. Modifications have now been made to some total knee replacement systems to allow a minimally invasive approach. Encouraging results have been reported for blood loss, length of hospital stay, and accuracy of implantation.25 Longer term outcome studies are required before this technique can be established more widely.
Image guidance
Computer navigation or "image guidance" in total knee replacement is currently more widely used in Europe and Australia than in the United Kingdom. A variety of systems are available, some of which require data from computed tomograms or magnetic resonance imaging scans before surgery. The technique involves the attachment of infrared beacons or transmitters to specific anatomical landmarks, the surgical instruments, and cutting blocks. Infrared cameras sited around the patient enable the computer to track the position of the instruments relative to the patient's knee. This system may provide a greater degree of accuracy during surgery, particularly for positioning the prosthetic components. The effect of this new technology on the outcome, complications, and survivorship of total knee replacement needs long term evaluation. As more simple, user friendly image guidance systems develop, they will increasingly be combined with minimally invasive surgical techniques and may evolve to be the optimum technique for total knee replacement surgery.
A patient's perspective
I'm 47 and work as a reprographics manager running three university print departments, so I'm always on my feet. I've suffered with osteoarthritis of the right knee for 10 years, but in the last four months the pain became much worse. Walking 100 yards was agonising. Stairs were impossible. The pain stopped me sleeping, so it was affecting my social life too.
I was admitted for a total knee replacement. This was my first operation so I was very nervous. I had a general anaesthetic and knew nothing about the op until I came round. The first 24 hours were uncomfortable, but I had control over the amount of painkiller I required by pressing a button. On the second day I was made to get up, bend the knee a little, and walk a few steps with a frame. The next day I walked to the corridor. After four days I was using crutches to walk up and down the corridor and stairs. I went home after seven days.
It's now five months since my operation. I've just returned home from a holiday in Spain where I managed to walk three miles along the beach. I'm totally pain free and have returned to work. I feel 100% better, can sleep well, and can continue with my life!
Martin Reid
--------------------------------------------------------------------------------
References w1-w13 are on bmj.com
See also p 1216
Contributors: SG and AF jointly developed the idea for this article. SG carried out the literature search and wrote the first draft. AF carried out a detailed review of the draft and further changes. AF is the guarantor.
Competing interests: None declared.
References
Top
Introduction
Sources and selection criteria
Non-operative treatment
Surgical intervention
References
Felson DT. Epidemiology of hip and knee osteoarthritis. Epidemiol Rev 1988;10: 1-28.[ISI][Medline]
Dieppe P, Brandt K. What is important in treating osteoarthritis? Whom should we treat and when should we treat them? Rheum Dis Clin North Am 2003;29: 687-716.[ISI][Medline]
Walker-Bone K, Javaid K, Arden N, Cooper C. Medical management of osteoarthritis. BMJ 2000;321: 936-40.[Free Full Text]
Raynauld JP, Buckland-Wright C, Ward R, Choquette D, Haraoui B, Martel-Pelletier J, et al. Safety and efficacy of long-term intraarticular steroid injections in osteoarthritis of the knee: a randomized, double-blind, placebo-controlled trial. Arthritis Rheum 2003;48: 370-7.[CrossRef][ISI][Medline]
Leopold SS, Redd BB, Warme WJ, Wehrle PA, Pettis PD, Shott S. Corticosteroid compared with hyaluronic acid injections for the treatment of osteoarthritis of the knee. A prospective, randomized trial. J Bone Joint Surg Am 2003;85-A: 1197-203.[Medline]
Medical Services Advisory Committee. Intra-articular viscosupplementation for treatment of osteoarthritis of the knee. Canberra, Australia: MSAC Application 1045:88; 2003.
Moseley JB, O'Malley K, Petersen NJ, Menke TJ, Brody BA, Kuykendall DH, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2002;347: 81-8.[Abstract/Free Full Text]
Fond J, Rodin D, Ahmad S, Nirschl RP. Arthroscopic debridement for the treatment of osteoarthritis of the knee: 2- and 5-year results. Arthroscopy 2002;18: 829-34.[Medline]
Hanssen AD, Stuart MJ, Scott RD, Scuderi GR. Surgical options for the middle-aged patient with osteoarthritis of the knee joint. Instr Course Lect 2001;50: 499-511.[Medline]
Naudie D, Bourne RB, Rorabeck CH, Bourne TJ. The install award. Survivorship of the high tibial valgus osteotomy. A 10- to -22-year follow up study. Clin Orthop 1999;367: 18-27.[Medline]
Billings A, Scott DF, Camargo MP, Hofmann AA. High tibial osteotomy with a calibrated osteotomy guide, rigid internal fixation, and early motion. Long-term follow-up. J Bone Joint Surg Am 2000;82-A: 70-9.
Murray DW, Goodfellow JW, O'Connor JJ. The Oxford medial unicompartmental arthroplasty: a ten-year survival study. J Bone Joint Surg Br 1998;80-B: 983-9.[CrossRef]
Svard UC, Price AJ. Oxford medial unicompartmental knee arthroplasty. A survival analysis of an independent series. J Bone Joint Surg Br 2001;83-B: 191-4.[CrossRef]
Brown A. The Oxford unicompartmental knee replacement for osteoarthritis. Issues Emerg Health Technol 2001;23: 1-4.[Medline]
Ackroyd CE, Newman JH. The Avon patellofemoral arthroplasty: two to five year results. J Bone Joint Surg Br 2003;suppl II: 162-3.
Mont MA, Haas S, Mullick T, Hungerford DS. Total knee arthroplasty for patellofemoral arthritis. J Bone Joint Surg Am 2002;84-A: 1977-81.[Medline]
Dixon T, Shaw M, Ebrahim S, Dieppe P. Trends in hip and knee joint replacement: socioeconomic inequalities and projections of need. Ann Rheum Dis 2004;63: 825-30.[Abstract/Free Full Text]
Ritter MA, Berend ME, Meding JB, Keating EM, Faris PM, Crites B. Long-term follow-up of anatomic graduated components posterior cruciate-retaining total knee replacement. Clin Orthop 2001;388: 51-7.[Medline]
Khaw FM, Kirk LM, Gregg PJ. Survival analysis of cemented press-fit condylar total knee arthroplasty. J Arthroplasty 2001;16: 161-7.[CrossRef][ISI][Medline]
Robertsson O, Knutson K, Lewold S, Lidgren L. The Swedish Knee Arthroplasty Register 1975-1997. An update with special emphasis on 41,223 knees operated on in 1988-1997. Acta Orthop Scand 2001;71: 503-13.[ISI]
Jacobs W, Anderson P, Limbeek J, Wymenga A. Mobile bearing vs fixed bearing prosthesis for total knee arthroplasty for post-operative functional status in patients with osteoarthritis and rheumatoid arthritis. Cochrane Database Syst Rev 2004(2): CD003130.
Gidwani S, Tauro B, Whitehouse S, Newman JH. Do patients need to earn total knee arthroplasty? J Arthroplasty 2003;18: 199-203.[CrossRef][ISI][Medline]
Kane RL, Saleh KJ, Wilt TJ, Bershadsky B, Cross WW III, MacDonald RM, et al. Total knee replacement. Rockville, MD: Agency for Healthcare Research and Quality, 2003. (Evidence report/technology assessment No 86.)
Callahan CM, Drake BG, Heck DA, Dittus RS. Patient outcomes following tricompartmental total knee replacement: a meta-analysis. JAMA 1994;271: 1349-57.[Abstract]
Tria AJ Jr, Coon Tm. Minimal incision total knee arthroplasty: early experience. Clin Orthop 2003;416: 185-90.[Medline]
(Accepted 13 August 2004)
Other related articles in BMJ:
Primary care
Acupuncture as a complementary therapy to the pharmacological treatment of osteoarthritis of the knee: randomised controlled trial.
Jorge Vas, Camila Méndez, Emilio Perea-Milla, Evelia Vega, María Dolores Panadero, José María León, Miguel Ángel Borge, Olga Gaspar, Francisco Sánchez-Rodríguez, Inmaculada Aguilar, and Rosario Jurado
BMJ 2004 329: 1216. [Abstract] [Abridged text] [Full text]
BMJ 2004;329:1220-1224 (20 November), doi:10.1136/bmj.329.7476.1220
Orthopaedic and Trauma Surgery
Clinical review
The orthopaedic approach to managing osteoarthritis of the knee
Sam Gidwani, specialist registrar1, Adrian Fairbank, consultant2
1 Department of Orthopaedics, Kingston Hospital, Kingston upon Thames, Surrey KT2 7QB, 2 Department of Orthopaedics, St George's Hospital, London SW17 0QT
Osteoarthritis of the knee is common, affecting almost a tenth of the population aged over 55.1 This proportion is likely to increase with extended longevity and a bigger body mass index. Most patients with osteoarthritis of the knee are able to manage their symptoms without medical treatment, but a large proportion of those referred to orthopaedic surgeons have debilitating disease, presenting chiefly with pain and stiffness. Classically the pain depends on activity, and in severe cases not only limits the distance patients can walk and their daily activities, but also disrupts sleep. Moreover, whereas most patients are past retirement, a major proportion is of working age, leading to difficulties with work and presenting an important economic cost to society.
Non-surgical treatment of osteoarthritis of the knee is primarily carried out in the community. This article concentrates on the interventions and surgical options used by orthopaedic surgeons for the treatment of this disease, indications for their use, and likely outcomes.
We searched Medline (1966 to May 2004) using the terms "osteoarthritis", "knee", "knee replacement/arthroplasty", "osteotomy", "arthroscopy", "and outcome". We were particularly interested in papers from leading peer reviewed orthopaedic and rheumatological journals. We searched the Cochrane database of systematic reviews, the health technology assessment database, and the database of abstracts of reviews of effects.
Non-operative treatment
Management of patients with mild osteoarthritis should be tailored to the individual while avoiding over-medicalisation of the condition.w1 A variety of interventions are available, including advice on changes to lifestyle and physical and pharmacological therapies. The effectiveness of many of these treatments has been reviewed elsewhere.2 3
Intra-articular steroid injections
Intra-articular steroid injections can alleviate pain in patients with moderate osteoarthritis of the knee, but this is usually short lived,2 and therefore we believe they have a limited role in treating acute exacerbations of the disease. A recent randomised double blind trial, however, has suggested that repeated injections of the steroid triamcinolone hydrochloride every three months for up to two years can lead to improved symptoms when compared with injections of saline.4 The effect was more noticeable at one year. Evidence that steroids accelerate cartilage damage is still inconclusive, but there is a small risk of septic arthritis (between 1 in 15 000 and 1 in 50 000).2 A Cochrane review of the available evidence is in preparation.
Summary points
The outcome of total knee replacement is comparable to that of total hip replacement
85% of total knee replacements are carried out for patients with osteoarthritis
Arthroscopic debridement and washout has a role as a temporising procedure in early osteoarthritis associated with mechanical symptoms
In some cases alternative surgical procedures such as unicompartmental knee replacement may be more appropriate than total knee replacement
The role and success of new techniques such as image guidance and minimally invasive surgery remain to be established
Viscosupplementation
Several hyaluronan preparations are available as intraarticular injections. Relief of symptoms is thought to result from increased viscosity of the synovial fluid—hence the term "viscosupplementation" for this type of treatment. The molecular weights of the hyaluronan derivatives vary as do the duration of courses and the numbers of injections recommended. The results of trials also differ, with some implying little benefit and others showing excellent results.5 w2 w3 A recent systematic review concluded that injections of hyaluronic acid were no more effective than nonsteroidal anti-inflammatory drugs for improving pain, physical function, and stiffness, and did not support public funding of viscosupplementation.6
Surgical intervention
Top
Introduction
Sources and selection criteria
Non-operative treatment
Surgical intervention
References
Indications
The impact of disease on lifestyle is the most important factor in assessment of patients with osteoarthritis of the knee. Surgery should be resisted when symptoms can be managed by non-surgical means. Indications for surgical intervention are debilitating pain and major limits on daily activities and distance walked, or impaired ability to sleep or work.
Another consideration is the patient's health and fitness for anaesthesia. The risks as well as potential benefits of surgery need to be discussed with the patient. Several surgical techniques are available (box).
Arthroscopic washout and debridement
The role of arthroscopic debridement for degenerative arthritis of the knee is controversial. It has been shown that improvement of symptoms in an unselected cohort of patients allocated to either washout or washout and debridement could be attributed to a placebo effect.7 Prospective randomised controlled trials looking at subsets of patients with differing levels of symptoms and disease are scarce. Some studies do suggest that arthroscopic treatment used in a more selective manner can control symptoms of osteoarthritis of the knee for up to five years.8 9 Factors correlating with a better outcome include the presence of mechanical symptoms of painful locking or catching of the knee, mild to moderate radiographic evidence of arthritis, and a younger age at the time of surgery. The presence of limb malalignment is associated with a less successful outcome. For this reason we believe that arthroscopic debridement should principally be used in younger patients with osteoarthritis, with meniscal lesions or chondral flaps amenable to debridement. Delaying inevitable joint replacement is particularly desirable in these patients. Further clinical study of this subset of patients within the context of a randomised controlled trial would be helpful.
Osteotomy of the proximal tibia or distal femur
In healthy knees, the weightbearing axis passes from the centre of the hip to the centre of the ankle joint, through the centre of the knee. In osteoarthritis, the alignment of the leg changes because of wear. Medial wear creates a bow legged appearance (varus), and the weightbearing axis moves medially. Lateral wear creates a knock knee (valgus) deformity, and the weightbearing axis moves laterally. Osteotomy around the knee moves the weightbearing axis to the less damaged compartment (fig 1).
Fig 1 Preoperative and postoperative radiographs of a varus knee with medial compartment osteoarthritis before and after opening wedge tibial osteotomy
Surgical options for osteoarthritis of the knee
Established techniques
Arthroscopic washout and debridement of the joint
Osteotomy of the proximal tibia or distal femur
Unicompartmental knee replacement
Patellofemoral replacement
Total knee replacement
Evolving techniques
Computer assisted surgery (image guidance)
Minimally invasive knee replacement
Recovery is prolonged and relief of symptoms often incomplete, but osteotomy may delay the need for total knee replacement for five to 10 years.10 11 Successful treatment could allow a return to sport—something ill advised after arthroplasty. The risks specific to this surgery depend on the technique, and include non-union at the osteotomy site, common peroneal nerve injury, pain from the proximal tibiofibular joint, and over-correction or under-correction of the deformity. Part of an ongoing debate within the orthopaedic community concerns the relative merits of high tibial osteotomy compared with unicompartmental knee replacement in younger patients. The evidence for osteotomy in itself is the subject of an ongoing Cochrane review.
Unicompartmental knee replacement
Up to a quarter of patients with osteoarthritis of the knee have predominantly arthritis of the medial compartment. The surgical options for such patients are medial unicompartmental knee replacement (fig 2), proximal tibial or distal femoral osteotomy, and total knee replacement.
Fig 2 Unicompartmental knee replacement in a patient with medial compartment osteoarthritis (varus deformity corrected)
Unicompartmental knee replacement requires a smaller surgical approach than for total knee replacement, leading to less blood loss and quicker rehabilitation. The range of knee motion after unicompartmental knee replacement is generally superior to that after total knee replacement. Finally, revision of a unicompartmental knee replacement to a total knee replacement is potentially more straightforward than revision of a total knee replacement.w4
The prerequisites for unicompartmental knee replacement are well defined. These include stability of the joint, a correctable varus deformity, a fixed flexion deformity of less than 10 degrees, and minimal lateral compartment disease. Radiographic evidence of patellofemoral osteoarthritis is not necessarily a problem provided that patients do not have major anterior knee pain. Two studies have reported survivorship rates for implants of 95% and 98% at 10 years.12 13 These rates are comparable to the best reported for total knee replacement and are an improvement on rates previously reported for unicompartmental knee replacement. A recent systematic review of the evidence supports the use of the Oxford unicompartmental knee replacement in patients with arthritis of the medial compartment provided they fulfil the indications.14
The relative merits of unicompartmental knee replacement over total knee replacement or proximal tibial osteotomy in young (less than 60 years) active patients continue to be debated. Unicompartmental knee replacement has now become an accepted treatment for older patients with medial compartment arthritis. The results of unicompartmental knee replacement in lateral compartment disease have yet to be fully determined.
Patellofemoral replacement
Isolated disease of the patellofemoral joint occurs in up to a tenth of patients with osteoarthritis of the knee, and many of these patients are younger than those with tricompartmental arthritis. The surgical options for these patients are arthroscopic debridement, patellofemoral replacement, total knee replacement, or, rarely, patellectomy.
Patients considered for patellofemoral replacement must be assessed for degenerative changes in the rest of the knee joint. Several types of patellofemoral arthroplasties are available but the results have been variable, highlighting the need for careful selection of patients.w4-w6 The most common problems are maltracking of the patella, excessive wear of the polyethylene implant, and disease progression in the rest of the knee joint. The Avon patellofemoral arthroplasty shows promise, although so far published results are only available for five years' follow up.15 Meanwhile, total knee replacement has a place in the treatment of older patients with primarily patellofemoral arthritis, with results that are comparable to patients with tricompartmental disease.16
Total knee replacement
Total knee replacement is a well established treatment for patients with moderate to severe osteoarthritis, with long term results comparable to those of total hip replacement. Between 1991 and 2000 the number of episodes of primary knee replacement registered by the NHS in England more than doubled, to around 33 000 per year. Taking into account the changing demographics of the population, this figure has been estimated to increase by as much as 60% over the next decade, requiring a substantial increase in provision of services.17
Long term studies on survivorship of implants generally use primary end points such as decision to revise the knee replacement (cumulative revision rate). Studies have shown survival rates of between 84% and 98% at 15 years.18 19 w7-w9 The decision on when to revise a knee replacement is largely influenced by the severity of symptoms and the patient's lifestyle, fitness for surgery, and radiological and clinical evidence of complications (usually infection or aseptic loosening). The Swedish knee arthroplasty register has revision rates for over 57 000 knee replacements and revisions carried out since 1975.20 The United Kingdom national joint registry began in 2003, and data on a large proportion of joint replacements are now being recorded.
During the last two decades of the 20th century the designs of total knee prostheses used for primary knee replacement converged towards a bicondylar unconstrained replacement with a polyethylene bearing or insert contained between the femoral and tibial components. These prostheses are classified as either cruciate retaining, where the posterior cruciate ligament is preserved, or posterior stabilised, where the posterior cruciate ligament is removed (fig 3).w10 The posterior stabilised type of prosthesis incorporates a central peg and cam mechanism, theoretically allowing for a greater range of flexion while maintaining anteroposterior stability. Both designs have their advocates and advantages but provide similar long term results.
Fig 3 Posterior stabilised total knee replacement, with resurfacing of patella
Consensus has still not been reached in some areas of total knee replacement. For example, resurfacing of the patella with a patellar button is practised routinely, selectively, or not at all. The use of a mobile rather than a fixed bearing theoretically reduces contact stresses and therefore wear of the polyethylene (a major cause of osteolysis and aseptic loosening) and provides a better range of motion and functional outcome, although this has not been substantiated to date.21 A major UK multicentre health and technology assessment trial, due for completion in 2011, is looking at these and other contentious issues in knee replacement.
Another ongoing debate concerns the timing of knee replacement surgery. Support is increasing for the view that good results can be obtained in relatively early stages of osteoarthritis, and that there is little advantage in waiting until the patient is in extremis.22 Symptoms do not always seem to correlate with the radiological degree of osteoarthritis,w11 so that a patient with severe symptoms but only moderate radiological changes may none the less merit referral.
As part of informed consent for total knee replacement, patients need to be made aware of potential risks, to both their knee and their general health (table). Complications from total knee replacement have been reported in 5% of patients and 8% of knees.23 More specifically, deep infection occurs in between 0.5% and 1.5% of patients. The incidence of asymptomatic deep vein thrombosis in the perioperative period is high—as much as 50% in some studies. The extent of symptomatic deep vein thrombosis or pulmonary embolism is much lower, around 1% to 3%.23 The risk of death from total knee replacement is around 0.5% within the first 90 days of the procedure.w12
View this table:
[in this window]
[in a new window]
Potential complications of surgery for total knee replacement
Additional educational resources
Arthritis Research Campaign (www.arc.org.uk/about_arth/)—A review of the diagnosis and management of osteoarthritis of the hip and knee and guidelines for referral to specialists
British Orthopaedic Association (www.boa.ac.uk)—A consensus statement from the British Orthopaedic Association and British Association for Surgery of the Knee on best practice in total knee replacement
Robertsson O, Knutson K, Lewold S, Lidgren L. The Swedish Knee Arthroplasty Register 1975-1997. An update with special emphasis on 41,223 knees operated on in 1988-1997. Acta Orthop Scand 2001;71: 503-13[ISI]
Information for patients
Arthritis Research Campaign (www.arc.org.uk/about_arth/)—Booklet on undergoing knee replacement surgery; part of a comprehensive website providing detailed information for patients and healthcare professionals
Arthritis Care (www.arthritiscare.org.uk)—Provides a range of information booklets, runs self management courses, and helps patients access local care groups run by volunteers
American Academy of Orthopaedic Surgeons (orthoinfo.aaos.org)—Detailed information on osteoarthritis of the knee, total knee replacement, and rehabilitation
The American National Library of Medicine and the Patient Education Institute (www.nlm.nih.gov/medlineplus/tutorials/k ... 49101.html)—Information focusing on knee replacement
Predictable long term side effects of total knee replacement include difficulty squatting or kneeling, numbness lateral to the scar, and mechanical noises, or "clunking," from the prosthesis.
Strong evidence shows that most patients experience a reduction in pain and improved function after total knee replacement, quantified by specific outcome measures, or "knee scores."24 However, around half of revision knee replacements occur in the first two to four years after the primary operation. A risk factor for revision shown by the Swedish knee registry was young age at the time of primary surgery.20 Although total knee revision generally improves function, the overall complication rate is significantly greater, at about 26%.23 In one study, an eighth of patients who underwent a revision required re-revision due to complications. These data underpin the reluctance of orthopaedic surgeons to carry out total knee replacements in younger patients, particularly if alternative treatments can, albeit temporarily, control their symptoms.
Several authors have been frustrated by the search for evidence on precise indications for total knee replacement.23 w13 Important progress has been made since the 1980s, particularly in the formulation of knee scoring systems. Some would argue, however, that more careful consideration now needs to be given to the influence of patient characteristics and timing of surgery on the outcome of total knee replacement.
Evolving techniques
Minimal incision approach
A minimal incision approach to unicompartmental knee replacement has become popular, and excellent results have been shown. Modifications have now been made to some total knee replacement systems to allow a minimally invasive approach. Encouraging results have been reported for blood loss, length of hospital stay, and accuracy of implantation.25 Longer term outcome studies are required before this technique can be established more widely.
Image guidance
Computer navigation or "image guidance" in total knee replacement is currently more widely used in Europe and Australia than in the United Kingdom. A variety of systems are available, some of which require data from computed tomograms or magnetic resonance imaging scans before surgery. The technique involves the attachment of infrared beacons or transmitters to specific anatomical landmarks, the surgical instruments, and cutting blocks. Infrared cameras sited around the patient enable the computer to track the position of the instruments relative to the patient's knee. This system may provide a greater degree of accuracy during surgery, particularly for positioning the prosthetic components. The effect of this new technology on the outcome, complications, and survivorship of total knee replacement needs long term evaluation. As more simple, user friendly image guidance systems develop, they will increasingly be combined with minimally invasive surgical techniques and may evolve to be the optimum technique for total knee replacement surgery.
A patient's perspective
I'm 47 and work as a reprographics manager running three university print departments, so I'm always on my feet. I've suffered with osteoarthritis of the right knee for 10 years, but in the last four months the pain became much worse. Walking 100 yards was agonising. Stairs were impossible. The pain stopped me sleeping, so it was affecting my social life too.
I was admitted for a total knee replacement. This was my first operation so I was very nervous. I had a general anaesthetic and knew nothing about the op until I came round. The first 24 hours were uncomfortable, but I had control over the amount of painkiller I required by pressing a button. On the second day I was made to get up, bend the knee a little, and walk a few steps with a frame. The next day I walked to the corridor. After four days I was using crutches to walk up and down the corridor and stairs. I went home after seven days.
It's now five months since my operation. I've just returned home from a holiday in Spain where I managed to walk three miles along the beach. I'm totally pain free and have returned to work. I feel 100% better, can sleep well, and can continue with my life!
Martin Reid
--------------------------------------------------------------------------------
References w1-w13 are on bmj.com
See also p 1216
Contributors: SG and AF jointly developed the idea for this article. SG carried out the literature search and wrote the first draft. AF carried out a detailed review of the draft and further changes. AF is the guarantor.
Competing interests: None declared.
References
Top
Introduction
Sources and selection criteria
Non-operative treatment
Surgical intervention
References
Felson DT. Epidemiology of hip and knee osteoarthritis. Epidemiol Rev 1988;10: 1-28.[ISI][Medline]
Dieppe P, Brandt K. What is important in treating osteoarthritis? Whom should we treat and when should we treat them? Rheum Dis Clin North Am 2003;29: 687-716.[ISI][Medline]
Walker-Bone K, Javaid K, Arden N, Cooper C. Medical management of osteoarthritis. BMJ 2000;321: 936-40.[Free Full Text]
Raynauld JP, Buckland-Wright C, Ward R, Choquette D, Haraoui B, Martel-Pelletier J, et al. Safety and efficacy of long-term intraarticular steroid injections in osteoarthritis of the knee: a randomized, double-blind, placebo-controlled trial. Arthritis Rheum 2003;48: 370-7.[CrossRef][ISI][Medline]
Leopold SS, Redd BB, Warme WJ, Wehrle PA, Pettis PD, Shott S. Corticosteroid compared with hyaluronic acid injections for the treatment of osteoarthritis of the knee. A prospective, randomized trial. J Bone Joint Surg Am 2003;85-A: 1197-203.[Medline]
Medical Services Advisory Committee. Intra-articular viscosupplementation for treatment of osteoarthritis of the knee. Canberra, Australia: MSAC Application 1045:88; 2003.
Moseley JB, O'Malley K, Petersen NJ, Menke TJ, Brody BA, Kuykendall DH, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2002;347: 81-8.[Abstract/Free Full Text]
Fond J, Rodin D, Ahmad S, Nirschl RP. Arthroscopic debridement for the treatment of osteoarthritis of the knee: 2- and 5-year results. Arthroscopy 2002;18: 829-34.[Medline]
Hanssen AD, Stuart MJ, Scott RD, Scuderi GR. Surgical options for the middle-aged patient with osteoarthritis of the knee joint. Instr Course Lect 2001;50: 499-511.[Medline]
Naudie D, Bourne RB, Rorabeck CH, Bourne TJ. The install award. Survivorship of the high tibial valgus osteotomy. A 10- to -22-year follow up study. Clin Orthop 1999;367: 18-27.[Medline]
Billings A, Scott DF, Camargo MP, Hofmann AA. High tibial osteotomy with a calibrated osteotomy guide, rigid internal fixation, and early motion. Long-term follow-up. J Bone Joint Surg Am 2000;82-A: 70-9.
Murray DW, Goodfellow JW, O'Connor JJ. The Oxford medial unicompartmental arthroplasty: a ten-year survival study. J Bone Joint Surg Br 1998;80-B: 983-9.[CrossRef]
Svard UC, Price AJ. Oxford medial unicompartmental knee arthroplasty. A survival analysis of an independent series. J Bone Joint Surg Br 2001;83-B: 191-4.[CrossRef]
Brown A. The Oxford unicompartmental knee replacement for osteoarthritis. Issues Emerg Health Technol 2001;23: 1-4.[Medline]
Ackroyd CE, Newman JH. The Avon patellofemoral arthroplasty: two to five year results. J Bone Joint Surg Br 2003;suppl II: 162-3.
Mont MA, Haas S, Mullick T, Hungerford DS. Total knee arthroplasty for patellofemoral arthritis. J Bone Joint Surg Am 2002;84-A: 1977-81.[Medline]
Dixon T, Shaw M, Ebrahim S, Dieppe P. Trends in hip and knee joint replacement: socioeconomic inequalities and projections of need. Ann Rheum Dis 2004;63: 825-30.[Abstract/Free Full Text]
Ritter MA, Berend ME, Meding JB, Keating EM, Faris PM, Crites B. Long-term follow-up of anatomic graduated components posterior cruciate-retaining total knee replacement. Clin Orthop 2001;388: 51-7.[Medline]
Khaw FM, Kirk LM, Gregg PJ. Survival analysis of cemented press-fit condylar total knee arthroplasty. J Arthroplasty 2001;16: 161-7.[CrossRef][ISI][Medline]
Robertsson O, Knutson K, Lewold S, Lidgren L. The Swedish Knee Arthroplasty Register 1975-1997. An update with special emphasis on 41,223 knees operated on in 1988-1997. Acta Orthop Scand 2001;71: 503-13.[ISI]
Jacobs W, Anderson P, Limbeek J, Wymenga A. Mobile bearing vs fixed bearing prosthesis for total knee arthroplasty for post-operative functional status in patients with osteoarthritis and rheumatoid arthritis. Cochrane Database Syst Rev 2004(2): CD003130.
Gidwani S, Tauro B, Whitehouse S, Newman JH. Do patients need to earn total knee arthroplasty? J Arthroplasty 2003;18: 199-203.[CrossRef][ISI][Medline]
Kane RL, Saleh KJ, Wilt TJ, Bershadsky B, Cross WW III, MacDonald RM, et al. Total knee replacement. Rockville, MD: Agency for Healthcare Research and Quality, 2003. (Evidence report/technology assessment No 86.)
Callahan CM, Drake BG, Heck DA, Dittus RS. Patient outcomes following tricompartmental total knee replacement: a meta-analysis. JAMA 1994;271: 1349-57.[Abstract]
Tria AJ Jr, Coon Tm. Minimal incision total knee arthroplasty: early experience. Clin Orthop 2003;416: 185-90.[Medline]
(Accepted 13 August 2004)
Other related articles in BMJ:
Primary care
Acupuncture as a complementary therapy to the pharmacological treatment of osteoarthritis of the knee: randomised controlled trial.
Jorge Vas, Camila Méndez, Emilio Perea-Milla, Evelia Vega, María Dolores Panadero, José María León, Miguel Ángel Borge, Olga Gaspar, Francisco Sánchez-Rodríguez, Inmaculada Aguilar, and Rosario Jurado
BMJ 2004 329: 1216. [Abstract] [Abridged text] [Full text]
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