British Columbia Medical Journal - November 2010

November 2010; 52:9
Pages 429-492
www.bcmj.org
Surgical interventions
The role of arthroscopy in the
treatment of degenerative joint
disease of the knee
Partial knee replacement
Total knee arthroplasty:
Techniques and results
Total hip arthroplasty:
Proust: Erik Paterson
Good guys: Russell Palmer
BCCDC: Antibiotic resistance
WorkSafeBC: Asbestosis
OSTEOARTHRITIS OF THE
HIP AND KNEE—PART 2

BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org430
contents
A R T I C L E S
OSTEOARTHRITIS OF THE HIP AND KNEE—PART 2
438 Guest editorial: Surgical interventions
B.A. Masri, MD
439 The role of arthroscopy in the treatment of degenerative
joint disease of the knee
Robert McCormack, MD
442 Partial knee replacement
Robert C. Schweigel, MD
447 Total knee arthroplasty: Techniques and results
Daniel H. Williams, MSc, FRCS, Donald S. Garbuz, MD, B.A. Masri, MD
455 Total hip arthroplasty: Techniques and results
R. Stephen J. Burnett, MD
O P I N I O N S
432 Editorials
Invasion of the body scanners, David R. Richardson, MD (432); The end of
an era, David B. Chapman, MD (433)
434 Comment
Determining fitness to drive: A troublesome task
Ian Gillespie, MD
435 Personal View
Re: Medical marijuana, Rielle Capler, MHA, Philippe Lucas, MA (435);
Dr Vroom responds, Willem R. Vroom, MD (436); CMPA position (436)
466 Good Guys
Russell Palmer: Forgotten champion, Angus Rae, MB
490 Back Page
Proust questionnaire: Erik T. Paterson, MD
30%
Cert no. SW-COC-002226
Established 1959
ON THE COVER: Part 2 of
our special series on OA of
the hip and knee focuses
on surgical interventions.
With the ongoing improve-
ment in outcomes and the
advent of predictable and
durable surgical technique,
younger patients are re-
questing the pain relief and
improved quality of life af-
forded by these operations.
Artwork by Jerry Wong.
ECO-AUDIT:
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November 2010
Volume 52• Number 9
Pages 429–492
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www.bcmj.org VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 431431
© British Columbia Medical Journal, 2010. All rights reserved. No part of this journal may be re-
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EDITOR
David R. Richardson, MD
EDITORIAL BOARD
David B. Chapman, MBChB
Brian Day, MB
Susan E. Haigh, MD
Lindsay M. Lawson, MD
Timothy C. Rowe, MB
Cynthia Verchere, MD
EDITOR EMERITUS
Willem R. Vroom, MD
MANAGING EDITOR
Jay Draper
PRODUCTION COORDINATOR
Kashmira Suraliwalla
EDITORIAL ASSISTANT
Tara Lyon
COPY EDITOR
Barbara Tomlin
PROOFREADER
Ruth Wilson
COVER CONCEPT & ART
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D E P A R T M E N T S
437 College Library
Best evidence: The tip of the information iceberg
Karen MacDonnell, Judy Neill
465 BC Centre for Disease Control
Your irresistible personal portrait: A way to reduce antibiotic resistance?
David M. Patrick, MD, Malcolm Maclure, ScD, Bill Mackie, MD, Rachel McKay, MSc
470 General Practice Services Committee
Divisions of Family Practice address community needs, improve care at
local level, Brian Evoy, PhD
472 In Memoriam
Dr Norman Wignall, Norman Wignall Jr.
472 Pulsimeter
New BC-wide surgery booking system (472); Online stroke information
(472); BC Genome Sciences Centre advances, Judy Hamill (473); BCPRA
education course for GPs, Michael Schachter, MD (473); Don Rix leadership
award announced (474); Call for nominations: BCMA and CMA special
awards (475); Signs of Stroke materials available for physicians, Susan
Pinton (479); Body Worlds and the Brain exhibition, Lloyd Oppel, MD (479)
476 WorkSafeBC
Asbestosis: A persistent nemesis, Sami Youakim, MD
477 Council on Health Promotion
Emergency departments: Are they considered a safe haven from prosecution
for impaired drivers involved in fatal or personal injury crashes?
Roy Purssell, MD, Luvdeep Mahli, Robert Solomon, LLB, Erika Chamberlain, LLB
480 Calendar
483 Classifieds
486 Advertiser Index
489 Club MD

D
oyouthinkit’snormalforyour
dentisttocheckyourprostate?”
I ask the new hygienist. “Be-
cause Dr Plaque checks mine every
time I come in.”
At this point, somewhat alarmed,
the hygienist glances at the last entry
in my chart, under which, while unat-
tended, I have written, “prostate nor-
mal.” After I explain my little joke to
theslightlycreeped-outyoungwoman,
all my appointments go pretty much
the following way.
“You haven’t had X-rays for a
while so we should do them.”
“Why?”
“Well, Dr Plaque likes to have
them done periodically to check on
things.”
“Well, then Dr Plaque can pay for
them.” I don’t think the dentist likes
me.
Imagine, doing a periodic X-ray to
check on things. This has always been
frowned upon in our profession. How-
ever,wearenowonthecrestofabrave
new scanning wave. Patients can pay
privately for almost any scan imagi-
nable. Then with the scans and reports
in hand they come to us for advice.
The problem is that nobody really
knows what to do with the results.
Randomized controlled trials that
investigate the impact of routine diag-
nostic imaging on mortality and mor-
bidity are scarce. So what does one do
with an otherwise healthy 50-year-old
man who pays privately for a coro-
nary CT that shows calcifications? Do
you order a stress test, exercise MIBI,
angiogram,orjustmonitorandencour-
age risk-factor modification (which is
what was prescribed prior to the scan
anyways)? How about tiny renal or
lung lesions? What about small cere-
bral ischemic changes? The list goes
on. Private companies are happy to do
the scans, but what is the next step?
Patients are signing up for virtual col-
onoscopies, ultrasounds, CTs, PET
scans, carotid dopplers, and more in
ever-increasing numbers.
Let’snotforgetmagneticresonance
imaging (MRI). Oh, how I hate those
three letters. It doesn’t seem to matter
what the patient’s problem is, eventu-
ally they always come to the conclu-
sion (based on the expert advice of
editorials
Invasion of the body scanners
their lawyer, spouse, parents, physio,
massage therapist, barista, or garden-
er) that they need an MRI just in case
something is being missed. This hap-
pens despite my explanation that an
MRI won’t aid in the diagnosis of their
ingrown toenail or make their obesity-
related back pain go away. I am con-
sidering purchasing a big magnet to
glide over people while I make a
humming noise. I will then give them
a stick drawing of the appropriate
injured area and bill them for a dis-
count MRI.
Technological advances are often
a good thing, but some rational judg-
ment must be applied. There is still
an art to practising medicine, an art
that can be intriguing, satisfying, and
alluring. I’m calling for the use of
good old common sense.Agood ques-
tion to ask is, “Is the management of
this patient likely to change depend-
ing on the outcome of this test?” If
not, don’t do it. If your patients remain
dissatisfied, send them to my newly
opened discount MRI clinic.
—DRR
“

W
e are approaching the end
of an era at our community
hospital. As you read this
line, you may be expecting a lament
on the death of the full-service family
physician. The family doctor who has
an office practice, hospital privileges,
does house calls, does palliative care,
delivers babies, and perhaps also does
ER work. The dinosaur that has previ-
ously been described in these pages,
and whose imminent demise has been
much lamented. This would be a rea-
sonable thought.
It may also be reasonable to expect
an essay on the demise of the commu-
nity hospital. I expect that this may
happen soon in the new era of “pro-
gram management.” The new buzz-
words in our health authority seem to
be carving our once unified hospital
into separate silos of health care deliv-
ery. Our interdependent departments
such as obstetrics, pediatrics, anesthe-
sia, and surgery are being managed
and directed by individuals who are
not on site full-time because they have
too much on their plates and have to
manage and direct multiple hospital
sites and programs.
But, alas no. I am going on about
the imminent loss of an indispensible
person at our hospital, our medical
staff secretary who for approximately
the past 17 years has been doing her
job with amazing dedication. Unfor-
tunately, she is retiring and her posi-
tion is not going to be filled.
I must be getting old. I find myself
reflecting more and more about how
things used to be. I am becoming one
of the When we generation. You know
who you are. You start sentences with
When we, such as, “When we started
at this hospital…” It is true.
When I started at my hospital 20
years ago, I applied for hospital privi-
leges through the medical staff secre-
tary. It was the medical staff secretary
who organized my pager for me, as
well as the multiple replacements I
have needed over the years. She
reminded me that my annual dues
were overdue, as was my annual reap-
plication for hospital privileges. The
medical staff secretary took minutes
at our medical staff meetings (and
many other committee meetings); she
coordinated our on-call schedules and
notified others of the changes that we
seemed to make so frequently. The
medical staff secretary updated our
hospital’s physician directory, an
indispensible tool for us and our office
staff. She was the “go to” person at
our hospital when one had a question
or a problem. She coordinated weekly
educationsessionsforphysicians.Our
medical staff secretary managed our
medical staff bank accounts and
administered the scholarships our
hospital medical staff gives to worthy
medical students each year.
Herjobdescriptionhasbeenchang-
ed by the hospital administration. She
editorials
The end of an era
is no longer supposed to be doing the
things she has done for the medical
staff for the last 17 years. She has out-
lasted every other secretary in the hos-
pital. She has gone above and beyond
on many occasions, quietly and effi-
ciently. She is due to retire shortly.
The glue that holds our hospital’s
medical staff together is about to be
dissolved.
By the time we realize what we
have lost, it will be too late. From one
dinosaur to another: Have a well-
deserved retirement, Marcy. You have
certainly earned it. We will all miss
you. It won’t be same around here any
more. —DBC
Linda Berti
604.291.2266
1.877.311.2266
lindab@cartergm.com
4550 Lougheed Hwy
Burnaby, BC
ALL makes and models!
(Honda, BMW, GM, Ford, Subaru, etc.)
Lowest prices.
No need to negotiate
Quick and convenient.
Over the phone, by email or in person
Car shopping that’s stress free.
The glue that holds our
hospital’s medical staff
together is about to
be dissolved.

A
s long ago as 1999, the Sup-
reme Court of Canada decid-
ed in the case of Terry Gris-
mer to instruct all motor vehicle
licensing authorities to make fitness-
to-drive decisions on the basis of
functional capacity, not simply by
diagnosis, as had been done previous-
ly. Mr Grismer was the operator of a
mining truck and wanted to continue
his employment after a stroke pro-
duced a homonymous hemianopsia
that eliminated most of his left-side
peripheral vision in both eyes. Al-
though, sadly, Mr Grismer died while
the human rights legal challenge was
making its way through subsequent
levels of court, his estate pursued the
matter to this conclusion.
In our province, the Office of
the Superintendent of Motor Vehicles
(OSMV) then began a consultation
process and planned for the publica-
tion of a new BC Guide in Determin-
ing Fitness to Drive to replace the
1997 edition. After a long consulta-
tion period, in which many doctors
volunteered their time, the new edi-
tion was published online in July
2010. It was always the intention to
also publish a condensed and user-
friendly guide for physicians, as the
full edition was aimed more toward
the needs of regulators. This task has
now been delayed until at least 2011,
with no announced plan for medical
editing and consultation.
At the time of this writing, the
BCMA does not know when and how
the new Guide will be implemented.
ThefirstreadingofBill14–TheMotor
VehicleAmendmentAct, 2010, in part
21, provided for government to set out
by regulation the medical conditions
or functional impairments that oblige
a physician or other health profes-
sional to report.
Doctors can feel uncomfortable
balancing the mobility needs of a
patient against the potential risk to
public and patient safety when con-
sidering whether and what to report.
In my experience, a lot of the risk is
related to the driver’s level of insight.
A “safe enough driver” is aware of
any cognitive limitations and has the
judgment and willingness to adapt his
or her driving to these limitations. The
most dangerous situations are those in
which the driver denies or minimizes
the reduction in his or her functional
capacity and makes no accommoda-
tion for it.
When facing such complex deci-
sions it has been very helpful for BC
physicians to know they could contact
a medical consultant employed by the
OSMV. The OSMV used to have two
part-time medical consultants on staff.
For the past 10 years, Dr John Mc-
Cracken provided this valuable serv-
ice; however, his contract was not to
be renewed. The BCMA and the Col-
lege of Physicians and Surgeons of
BC have jointly written to the OSMV
to highlight this concern and request a
meeting. With the demographics of an
aging population and more crowded
roadways this is a time that we need
more medical consultation available
—not less.
Meanwhile,DriveABLEisthetest
that the OSMV has contracted with
the BC Automobile Association to
provideobjectiveinformationtoassist
in decision making when there is
a concern about cognitive function.
The OSMV is also proposing to use
SIMARD-MD, a brief pencil-and-
paper test, to assist health care pro-
viders in rapid screening of patients.
This approach has been used in a lim-
ited way inAlberta. We await the start
of a proposed pilot study in BC.
Functional capacity is much more
than the score on a test—without a
mechanism for meaningful and trust-
ed consultation we run the risk of even
more rigidity in fitness to drive deter-
minations than existed when only
diagnosis was used.
The BCMA’s Board of Directors
was kept regularly informed during
the preparation of the OSMV’s cur-
rent Guide, but the BCMA was never
advised of plans to discontinue the
role of medical consultant or the use
of medical appeals. We need to find a
way to address this social and medical
issue together and not lose many years
of medical “corporate memory” and a
spirit of collaboration, as we move
ahead.
—Ian Gillespie, MD
BCMA President
Determining fitness to drive: A troublesome task
comment

Re: Medical
marijuana
W
hile Health Canada has
delegated responsibility to
physicians to recommend
the use of cannabis for access to their
legal program, it has clearly abdicated
its responsibility to educate doctors to
ensure their medical opinion is more
informed than that of DrVroom [Med-
ical marijuana. BCMJ 2010;52:329].
As a result, Dr Vroom is not alone
is his lack of knowledge about the
medical use of cannabis. During our
many years working and conducting
research at both the British Columbia
Compassion Club Society and the
Vancouver Island Compassion Soci-
ety, we have heard the other side of
doctor-patientdynamicthatDrVroom
describes.
Many patients report having an
extremely difficult time obtaining
support from their physicians for the
use of this medicine, or even dis-
cussing this legitimate health option.
This deeply affects the doctor-patient
relationship, causing patients unnec-
essary stress and creating an atmos-
phere of shame and distrust. Sadly,
many patients find themselves in the
role of having to educate their doctors.
Cannabis is a legal therapy option
officially sanctioned by the federal
government.Itisnotaphysician’srole
to decide what is or isn’t a medicine,
but rather to discuss the suitability of
treatment options on a case-by-case
basis.Inapreviouseditorial,DrVroom
stated,“Iamnotafraidtokeepanopen
mind about remedies I know nothing
about, but I research their scientific
evidence.”1 DrVroomseemstobemak-
ingan exception for medical cannabis.
Thousands of peer-reviewed sci-
entific studies have been published on
the use of cannabis to treat many dif-
ferent conditions and symptoms—as
personal view
Letters for Personal View are welcomed.
They should be double-spaced and less
than 300 words. The BCMJ reserves the
right to edit letters for clarity and length.
Letters may be e-mailed (journal@bcma
.bc.ca), faxed (604 638-2917), or sent
through the post.
MARKET LOSS RECOVERY GROUPMARKETT LOSS RECOV Y GROUPRVE
Continued on page 436

both symptom relief for conditions
like chronic pain and to slow disease
progression. For starters, we suggest
that Dr Vroom might check out the
Canadians for Safe Access (CSA)
research page (http://safeaccess.ca/
research/), or consider attending an
upcoming accredited course by the
Canadian Consortium for the Investi-
gation of Cannabinoids (www.ccic
.net/registeronline).
—Rielle Capler, MHA
—Philippe Lucas, MA
Co-founders, Canadians
for Safe Access
Reference
1. Vroom WR. Naturopath prescribing: The
hill to die on. BC Med J 2009;51:101.
Dr Vroom responds
Ms Capler and Mr Lucas are correct
about my lack of knowledge of mari-
juana pharmacology. Their recom-
mended web site has, unfortunately,
not educated me any further.
The whole crux of my editorial
was to acknowledge that I have no
knowledge about all of the actions of
the 60-plus cannabinoids contained in
a joint, nor of their potency or con-
centration. That makes endorsing, let
alone prescribing, a substance such as
this problematic for me. I pointed out
that the only legal way to access mar-
ijuana is by the recognized indications
contained in the Health Canada Form
B1andpalliativesituations.MsCapler
and Mr Lucas maintain that it is not
for physicians to decide what is or
isn’t medicine. Maybe so, but there
are many medicines that I won’t pre-
scribe. And that is my right. Just
because Health Canada has created
“medical marijuana” as an escape
from advocacy group pressure doesn’t
mean that I have to accept their prob-
lem as now being mine.
Marijuana has an excellent reputa-
tion for being a recreational drug. I am
sure that, some day, research will lead
us to completely understand all of its
actions. Perhaps we may even see it
legitimized for recreational use. In
the meantime call it “experimental
marijuana,” “research marijuana,” or
“palliative marijuana”—anything but
“medical marijuana.”
—WRV
CMPA position
WhenweaskedfortheCanadianMed-
ical Protective Association’s position
on the topic of prescribing marijuana,
Luce Lavoie, the director of commu-
nications at the CMPA, directed us to
their statement entitled, “Marijuana
for medical reasons: The Medical
Declaration form,” originally pub-
lished October 2001, revised Septem-
ber 2009. Here is the introduction:
“Marijuana is not approved for use
as a drug in Canada. Health Canada
states that “no marijuana product has
been issued a notice of compliance”
and notes that indications, safety and
risks have not been adequately stud-
personal view
“MCI takes care of everything
without telling me how to
run my practice”.
Toronto – Calgary – Vancouver
MCI Medical Clinics Inc.
MCI means freedom:
I remain independent
Continued from page 435

ied and the appropriate dosage is
unclear.
“Many regulatory authorities
(Colleges) have considered these
facts. Some have stated clearly that
physicians should not support an
application for the medical use of
marijuana, while others have cho-
sen to simply remind their mem-
bers of the importance of evidence-
based medicine and the lack of
evidence about the benefits and
risks of this substance.
“However, patients who believe
that marijuana is effective for treat-
ing certain symptoms from which
they suffer can apply to Health
Canada for authorization to pos-
sess and use marijuana under the
Marijuana Medical Access Regu-
lations (the Regulations). Those
Regulations require the applicant
(patient) to submit two declara-
tions, one of which is the appli-
cant’s and the other a Medical Dec-
laration signed by the applicant’s
medical practitioner.”
The full statement is available
at www.cmpaacpm.ca/cmpapd04/
docs/resource_files/infosheets/20
09/com_is09103-e.cfm.
—ED
personal view
By BC physicians, for BC physicians
GPAC clinical practice guidelines are
now available in iPod Touch and
iPhone format — FREE!
This free application contains over 30 clinical practice guidelines in
abridged format. It serves as a condensed, portable companion to the
full clinical practice guidelines found at www.BCGuidelines.ca, where over
50 guidelines are available in a range of formats. Download app from:
http://itunes.apple.com/us/app/bc-guidelines/id377956292?mt=8
I
ncorporatinghigh-qualityevidence
into clinical decision making re-
quiressystematicsearching,apprais-
ing, and synthesizing of the literature.
Performing these complex and time-
consuming tasks on a regular basis
is beyond reasonable expectations
for busy physicians, so using existing
sources of evidence-based informa-
tion, particularly systematic reviews,
is helpful. Unlike traditional narrative
reviews that are generally written by a
few authors who subjectively select
literaturetocommentonabroadtopic,
systematic reviews tend to be pro-
duced by a team that endeavors to
search the literature on a narrow clin-
ical question in an unbiased and repro-
duciblemannerandanalyzethesearch
results according to explicit criteria.
Two initiatives of note that produce
carefully synthesized and appraised
systematic reviews are Clinical Evi-
dence from BMJ Publishing Group
and the Cochrane Collaboration. Both
tendtofocusonthebenefitsandharms
of clinical interventions.
ClinicalEvidence,createdin1999,
summarizessystematicreviews,RCTs,
and observational studies, and states
college library
Best evidence: The tip of the information
iceberg
the current view on what is known and
unknown about specific aspects of
disease management. Conveniently,
patient leaflets on general topics sup-
plement the more precisely focused
systematic reviews. Clinical Evidence
is both a stand-alone publication as
well as a component of BMJ Point of
Care. The Cochrane Collaboration, a
distinctandindependentorganization,
has been producing the Cochrane
Database of Systematic Reviews since
1993. The Collaboration is not-for-
profit, funded by agencies such as
universities, charities, and personal
donations. Like Clinical Evidence,
Cochrane reviews tend to focus on the
risks and benefits of therapeutic inter-
ventions. Both of these resources are
available for free to all College mem-
bers at www.cpsbc.ca/library.
In addition the College Library
offers workshops on identifying and
effectively searching high-quality
medical evidence, and we are also
happy to arrange one-on-one learning
sessions with College members.
—Karen MacDonell, Judy Neill
Librarians/Co-Managers, College of
Physicians and Surgeons of BC Library

I
n the first part of this two-part
theme issue, we discussed the
etiology, diagnosis, and nonoper-
ative treatment of osteoarthritis
(OA). While the majority of patients,
particularlythosewithsmalljointOA,
respond to nonoperative treatment,
surgical treatment is required in an
increasing proportion of patients with
large joint OA. With the ongoing im-
provements in outcomes and with the
advent of very predictable and durable
surgical technique, younger patients
with OA are requesting the pain relief
and the improved quality of life
afforded by these operations.
Hips and knees continue to be the
joints most commonly affected and
requiring surgical intervention. His-
torically, hip and knee joint replace-
ment were reserved for older patients,
and it was not uncommon to hear
patients complaining that they were
deniedsurgerybecausetheywere“too
young.” In the past, with the limited
durability of joint replacement, that
was a reasonable strategy to protect
patients from failed joint replacement
down the road. Today, however, tech-
niques for first-time joint replacement
have improved so significantly that
we can offer joint replacements with
predictable longevity, with fewer
complications, and with less severe
failures. Moreover, revision surgical
techniques have also improved to the
point where even when joint replace-
ments fail, they can be predictably
reconstructed in the majority of
patients.
Inthearticlesthatfollow,webegin
with an overview by Dr McCormack,
who describes the role of arthroscopy
in early OAof the knee. Because knee
OA often presents with isolated dis-
ease in one of the three compartments
of the knee, we continue with Dr
Schweigel’s discussion of partial knee
replacement. DrWilliams, Dr Garbuz,
and I then consider total knee replace-
ment. We finish with Dr Burnett’s
article about hip replacement and
resurfacing.
With the increasing success of hip
and knee replacement, demand will
continue to increase. It is my hope that
the articles in this two-part theme
issue will put the topic of hip and knee
osteoarthritis in perspective. I am
extremely grateful for the contribu-
tions of the various authors who have
done an excellent job of summarizing
this vast topic in a clear and concise
manner.
—B.A. Masri, MD, FRCSC
Professor and Head
Department of Orthopaedics
University of British Columbia
Guest editorial: Osteoarthritis of
the hip and knee, Part 2:
Surgical interventions
Guest editorial
Dr B.A. Masri

ABSTRACT: Degenerative joint dis-
ease is a common cause of knee
symptoms and disability. The indica-
tion to proceed to surgery is usually
the failure of standard nonsurgical
treatments. Despite the success of
joint replacement surgery, many cli-
nicians choose to avoid this large,
complex surgery if a minimally inva-
sive ambulatory procedure can allow
a patient to improve function and
quality of life. This has led to the fre-
quent use of arthroscopy to treat
degenerative joints, especially knee
joints. While a “scope” does qualify
as minimally invasive, it is still im-
portant to consider the ratio of risks
to benefits and the efficacy of arthro-
scopic debridement for degenera-
tive joint disease of the knee.
T
he impact of osteoarthritis
on the health care system is
significant and continues to
growasourpopulationages.
As there is no cure for degenerative
joint disease (DJD), medical interven-
tions have focused on symptom con-
trol. Unfortunately, none of the non-
operative measures are universally
successful and some have significant
risks. A minimally invasive day-care
procedure that improves patient func-
tion and delays more extensive recon-
struction is appealing. Arthroscopy is
the most commonly performed ortho-
paedic procedure, one often associat-
ed with knee ligament reconstruction
and treatment of meniscal tears. In
addition, some estimates suggest that
over 500 000 arthroscopies are per-
formed in North America each year
for the treatment of degenerative joint
disease.1 Recent studies have ques-
tioned the role of this procedure in the
treatment of osteoarthritis, and there
is a general consensus that it has been
overused in the past. The goal of this
article is to address the role of arthro-
scopic surgery in patients who have
degenerative joint disease in the knee.
Proposed benefits
It has been proposed that arthroscopic
lavage (wash out) of the knee joint can
improve patient status by washing out
inflammatory cytokines, cartilage frag-
ments, and other debris from the joint.
Formal joint debridement has also
been reported to improve patient
status by smoothing off unstable flaps
of articular cartilage and possibly
improving the weight distribution of
the remaining articular cartilage.2
On the one hand, if there is an
unstable meniscal fragment that is
causing mechanical symptoms, such
as locking, pain with sudden turns, or
sharp intermittent pain, an arthrosco-
py can address that component of the
patient’s symptoms by trimming the
unstable fragment. On the other hand,
it is difficult to quantify the benefit of
arthroscopic repair of the arthritic
knee given the inability during arthro-
scopy to actually perform biological
resurfacing in the face of diffuse
degenerative changes and the ex-
tremely variable course of DJD.
Recent studies
Most of the orthopaedic studies re-
garding the role of arthroscopy in the
treatment of DJD are of low quality
and suffer from the same shortcom-
ings seen in many other areas of med-
icine: variable selection criteria, incon-
sistent outcome measures, different
surgical techniques, and publication
The role of arthroscopy in the
treatment of degenerative joint
disease of the knee
Recent studies question the benefits of arthroscopic debridement for
managing patients with osteoarthritis affecting a weight-bearing joint.
Robert McCormack, MD, FRCSC
Dr McCormack is an associate professor in
the Department of Orthopaedics at the Uni-
versity of British Columbia.

attention because patients were ran-
domized to one of three arms: arthro-
scopic lavage, arthroscopic debride-
ment, or sham operation. The patients
were assessed by a blinded independ-
ent assessor and the key finding was
that there was no significant differ-
ence in pain or function between the
sham operation and either of the
arthroscopic surgery groups. As inter-
esting as the results were, the design
of the trial also captured a lot of atten-
tion.Theplaceboeffectofsurgerywas
neutralized by giving the patients in
the sham operation an anaesthetic and
creating the standard arthroscopic
portals, without performing any sur-
gery inside the knee.
The Moseley study created a furor
among orthopaedic arthroscopists.
Many criticized the design of the
study and the fact that all subjects
were males (in a female-dominated
disease) and all came from a Veterans
Affairs hospital (equivalent to work-
ers’ compensation patients). There
were concerns that the patients had
more severe disease than average and
that the authors used a nonvalidated
outcome measure. Nevertheless, sev-
eral societies, including the American
Rheumatological Association, came
out with position statements that
arthroscopy did not have a role in the
treatment of osteoarthritis.
This controversy spawned further
trials in a number of centres, and re-
cently a prospective randomized clin-
ical trial from the University of West-
ern Ontario was published, again in
the New England Journal of Medi-
cine.6 This Canadian trial by Kirkley
and colleagues randomized patients to
optimal medical treatment or optimal
medical treatment plus arthroscopic
debridement. The researchers defined
the grade of arthritis more precisely
and ensured that limb malalignment
was not significant. The patients in
both groups had similar age, BMI, and
length of follow-up. Importantly, the
researchers excluded patients with
significant meniscal tears that were
causing mechanical symptoms. The
primary outcome was the validated,
disease-specificWOMAC score.7 The
bottom line is that the trial addressed
most of the criticisms of the Moseley
trial. Interestingly, at 2 years follow-
up, the WOMAC scores were not sta-
tistically different (P = .22) and with
an absolute difference of less than 1%
that did not meet the threshold of a
clinically significant difference.
Significance of findings
What do these findings mean to the
clinician? Degenerative joint disease
of the knee ( ) is common and
familyphysiciansoftendecidetoorder
an MRI to assess the joint. Since the
same degenerative process affecting
the articular cartilage also affects the
menisci, it is not surprising that most
of these patients also have a degener-
ative tear of the meniscus ( ).
Unfortunately, the patient and physi-
cian frequently focus on the MRI
results and forget clinical correlation.
When there are significant degenera-
tive changes most of the symptoms
are related to the underlying degener-
ation. Asymptomatic meniscal tears
are very common in this clinical situ-
ation and meniscal resection does not
address the main pain generators. As
the Moseley and Kirkley trials show,
when there is significant degenera-
tion, arthroscopic debridement inclu-
ding resection of degenerative menis-
cal tears ( ) does not lead to
improvementinpatientoutcomes,and
may in fact lead to more rapid deteri-
oration.
The one caveat to this is that the
presence of significant mechanical
symptoms (locking, significant catch-
ing, or instability secondary to a torn
meniscus or loose body) is different
from isolated joint line pain. These
Figure 3
Figure 2
Figure 1
The role of arthroscopy in the treatment of degenerative joint disease of the knee
bias. Through the 1980s and 1990s a
variety of case reviews reported a rea-
sonable rate of improvement with
simple lavage or joint debridement in
knees affected by osteoarthritis. The
success rates ranged from 40% to
75%.2 As might be expected, the ben-
efits of simple lavage were, at best,
transient and one small prospective
randomized trial found that arthro-
scopic lavage was no more effective
than closed needle lavage of the joint.3
The evidence supporting arthro-
scopic debridement was somewhat
better, but improvement was frequent-
ly of short duration and studies show-
ed that orthopaedic surgeons were
actually poor at predicting which
patients would improve.4 In 2002 this
technique came under close scrutiny
when the results of a prospective ran-
domized trial by Moseley and col-
leagues was published in the New
England Journal of Medicine.5 This
trial captured a tremendous amount of
Figure 1. Anteroposterior weightbearing
radiograph showing degenerative joint
disease of the knee, particularly in the
medial compartment.

mechanical problems are more pre-
dictably improved with arthroscopic
resection of the torn meniscus or loose
body. However, it is important to
remember that there may well be
residual symptoms, secondary to the
underlying DJD. The role of the pri-
mary care physician is to educate
patients that significant degenerative
changes are not helped by an arthro-
scopic “clean out.”
A second caveat is that occasion-
ally there is an indication for a diag-
nostic arthroscopy in a degenerative
joint, to better define the extent of
damage or to determine the role of
other procedures such as realignment
osteotomies or unicompartmental
arthroplasty. This may also apply to
patients whose symptom severity is
out of keeping with the radiographic
evidence.Thepatientcanhavechanges
that appear mild on plain radiographs
but when examined arthroscopically
prove to be more severe with large
focal defects in articular cartilage.
Even if arthroscopic debridement
offers a small benefit, this needs to be
balanced against the risks of the pro-
cedure.Complications,includingdeep
venous thrombosis and pulmonary
embolism, are not to be underestimat-
ed and have ranged in some series
from 7% to 31%, with a higher preva-
lence in older patients.8
Conclusions
Recent high-quality trials suggest that
in the absence of mechanical symp-
toms, arthroscopic debridement of the
knee has a very limited role to play
when managing significant degenera-
tive joint disease.
Competing interests
None declared.
References
1. Owings MF, Kozak LJ. Ambulatory and
inpatient procedures in the United
States, 1996. National Center for Health
Statistics.VitalhealthStat13(139).1998.
2. Calvert GT, Wright R. The use of arthro-
scopy in the athlete with knee osteoarth-
ritis. Clin Sports Med 2005;24:133-152.
3. Chang, RW, Falconer J, Stulberg SD, et
al.Arandomized,controlledtrialofarthro-
scopic surgery versus closed-needle joint
lavage for patients with osteoarthritis of
the knee. Arthritis Rheum 1993;36:289-
296.
4. Dervin GF, Stiell IG, Rody K, et al. Effect
ofarthroscopicdebridementforosteoarth-
ritis of the knee on health-related quality
of life. J Bone Joint Surg Am 2003;85A:
10-19.
5. Moseley JB, O’Malley K, Petersen N, et
al. A controlled trial of arthroscopic sur-
gery for osteoarthritis of the knee. New
Engl J Med 2002;347:81-87.
6. Kirkley A, Birmingham TB, Litchfield RB,
et al. A randomized trial of arthroscopic
surgery for osteoarthritis of the knee.
New Engl J Med 2008;359:1097-1107.
7. Bellamy N, Buchanan WW, Goldsmith
CH, et al. Validation study of WOMAC: A
health status instrument for measuring
clinically important patient relevant out-
comes to antirheumatic drug therapy in
patients with osteoarthritis of the hip or
knee. J Rheumatol 1988;15:1833-1840.
8. Sherman OH, Fox JM, Snyder SJ, et al.
Arthroscopy—“no-problemsurgery.”An
analysis of complications in two thou-
sand six hundred and forty cases: J Bone
Joint Surg Am 1986;68:256-265.
The role of arthroscopy in the treatment of degenerative joint disease of the knee
Figure 2. MRI showing degenerative tear of the medial meniscus.
Degenerative joint disease can also be seen in the medial
compartment.
Figure 3. An intraoperative arthroscopic view showing loss of
articular cartilage in the medial femoral condyle along with a
degenerative medial meniscal tear.

ABSTRACT: Partial knee replace-
ments have come into and out of
favor over the past 60 years. There
has been renewed interest in partial
knee replacements in the armamen-
tarium for arthritic knees due to
increasingly good results. Partial
knee replacements include the uni-
condylar knee replacement and the
patellofemoral arthroplasty. These
partial knee replacements are indicat-
ed for specific, isolated arthritic por-
tions of the knee joint—specifically
the medial, lateral, or patellofemoral
portion of the joint. In carefully
selected patients outcomes are com-
parable to the results of total knee
replacements. Patient selection and
meticulous surgical technique are
likely the key to a good result in a par-
tial knee replacement.
P
artial knee replacements
are a form of knee arthro-
plasty that doesn’t replace
the entire knee (the femoral
condyles, tibial plateau, and patella).
These surgical interventions include
the patellofemoral arthroplasty and
the more common unicondylar knee
arthroplasty. Both procedures have
been available since the 1950s and
may be options for patients who have
osteoarthritis in one compartment of
the knee, do not have specific con-
traindications for these more conser-
vative procedures, and who have
failed to benefit from nonoperative
management of their osteoarthritis.
Unicondylar knee
arthroplasty
In the past, unicondylar knee replace-
ments fell out of favor primarily be-
cause of the surgical technique of the
time, which made conversion to a full
knee replacement difficult. However,
with the advent of minimally invasive
approaches for unicondylar knee
replacement, there has been renewed
interest in this procedure over the past
decade.
A unicondylar knee replacement
( ) consists of a metal compo-Figure 1
nent that goes on the femoral condyle,
and another component that goes on
the tibial side. The tibial component
can be metal-backed with a fixed-
bearing or mobile-bearing polyethyl-
ene bearing surface, or it can be an all-
polyethylene fixed-bearing cemented
component. There is no evidence that
one approach is better than another.
The rationale for considering a
unicondylar knee arthroplasty is that
it is a more conservative operation
with faster recovery, less resection of
bone, conservation of the cruciate lig-
aments, and potentially better func-
tion. In addition, conversion to a total
knee replacement down the road is
simple using modern techniques, with
outcomes similar to a primary knee
replacement. When appropriate, par-
tial knee arthroplasty can be thought
of as a time-buying operation.
In addition, a unicondylar knee
replacement is an alternative to other
invasive procedures such as a high
tibial osteotomy or a total knee
replacement.
The last decade has seen renewed interest in unicondylar knee
arthroplasty and patellafemoral arthroplasty for patients with
osteoarthritis affecting one compartment of the knee.
Robert C. Schweigel, MD, FRCSC
Dr Schweigel is a clinical instructor in the
Department of Orthopaedics at the Univer-
sity of British Columbia.

Patient selection
Careful patient selection is needed to
get the best possible results. This re-
quires a thorough history and physical
examination.
The history should include specif-
ic questions about the knee to deter-
mine whether there was a gradual
onset of pain or whether there was a
specific incident (i.e., trauma) that
caused the problem. This is particu-
larly important because anterior cru-
ciate ligament deficiency is a con-
traindication for a unicondylar knee
replacement. When considering a uni-
condylar knee replacement, the loca-
tion of the pain is very important. It
must be localized to only one com-
partmentoftheknee.Foramedialuni-
condylar knee replacement, the pain
has to be medial and the patient has to
be able to point to the medial side of
the knee as the site of the pain. For a
lateral unicondylar knee replacement,
which is much less common as the
results are less predictable than a
medialunicondylarkneereplacement,
the pain has to be lateral. For either a
lateral or medial unicondylar knee
replacement, the presence of substan-
tial patellofemoral pain is a con-
traindication. In addition, the pain has
to be of sufficient magnitude and to
interfere with activities of daily living
to warrant surgical intervention. It is
important to ensure that all reasonable
attempts at medical management have
been exhausted before considering
any surgical procedure.
Indications
Kozinn and Scott have outlined several
classic indications and contraindica-
tions for unicondylar knee replace-
ment.1 Indications include the diagno-
sis of unicondylar osteoarthritis or
osteonecrosis in either the medial or
lateral compartment of the knee. Ini-
tially, Kozinn and Scott stipulated that
patient age had to be greater than 60
years and weight had to be less than
82 kg. There had to be minimal pain at
rest and low demand of activity. The
ideal range of motion was an arc of
flexion of 90 degrees with a contrac-
ture of less than 5 degrees. The angu-
lar deformity had to be less than 15
degrees and be passively correctible
to neutral at the time of operation.
Specific contraindications to a uni-
condylar knee arthroplasty identified
by Kozinn and Scott included the
diagnosis of an inflammatory arthri-
tis, age younger than 60 years, high
patientactivitylevel,painatrest(which
may indicate an inflammatory com-
ponent), and patellofemoral pain or
exposed bone in the patellofemoral or
opposite compartment at the time of
the surgery. Asymptomatic chondro-
malacia in the patellofemoral joint
was not necessarily a contraindication.
More recently, some of these indi-
cations have been expanded. Various
authors have reported good results in
patients younger than 60 years2 and in
obese patients with BMIs over 30.3
Generally it is felt that both of the
cruciate ligaments have to be intact to
perform a unicondylar knee arthro-
plasty. Again however, studies have
suggested that a medial compartment
unicondylar arthroplasty is possible
in an ACL-deficient knee in certain
Figure 1. (A) Anteroposterior radiograph showing a medial unicondylar knee replacement. (B) Lateral radiograph showing a medial
unicondylar knee replacement. Radiographs courtesy of Dr Bas Masri.
A B

circumstances;4 still, most surgeons
will not perform a unicondylar knee
replacement on a patient with a histo-
ry of torn ACL, and the presence of
a torn ACL should be considered a
contraindicationtoaunicondylarknee
replacement.
In summary, in addition to well-
localized pain with no patellofemoral
involvement, the indications for a uni-
condylar knee replacement include
the following:
• Range of motion of no less than
110 degrees with no more than a 5-
degree flexion deformity.
• Acorrectable varus on valgus defor-
mityofnomorethan5degreesofvar-
us or 15 degrees of valgus, with the
correctability of the deformity to be
determined on physical examination.
• An intact anterior cruciate ligament.
• Osteoarthritis localized to either the
lateralormedialcompartment,keep-
ing in mind that the vast majority of
unicondylar knee replacements are
medial.
• For some fixed-bearing tibial compo-
nentdesigns,aweightlimitof114kg.
Based on the above, it is clear that
not every patient with knee osteo-
arthritis is a candidate for a unicondy-
lar knee replacement, and the final
decision is up to the orthopaedic sur-
geon. Typically, only 10% to 20% of
patients undergoing knee replacement
are candidates for unicondylar knee
arthroplasty.
Results
It is difficult to sort out the results for
unicondylar knee arthroplasty, as
there are different types of unicondy-
lar knee arthroplasties. Additionally,
it is difficult to distinguish between
medial side versus lateral side proce-
dures with respect to outcomes. Fur-
thermore, one has to compare the
results of a unicondylar knee replace-
ment with other options such as a high
tibial osteotomy and a standard total
knee replacement. Again, various au-
thors have reported varying degrees
of success with unicondylar knee
arthroplasty. Recently authors have
reported 96% survival of the implant
at a 10-year follow-up and excellent
or good outcome in 92% of patients.5
Most recently Newman and col-
leagues6 compared unicondylar knee
replacement with total knee replace-
ment in a prospective randomized
control trial. This report stated that the
15-year survivorship for a unicondy-
larkneereplacementwascloseto90%
compared with 80% for a total knee
replacement. Additionally, the report
stated that the unicondylar knee
replacements had more “excellent”
results and a better range of motion
compared with the total knee replace-
ment. Registry data, however, such as
the Swedish Knee Replacement Reg-
istry, have shown a higher reoperation
rate for unicondylar knee replace-
ment, with the main reason for revi-
sion being progression of the arthritis.
The results for revision of a unicondy-
lar knee replacement to a full knee
replacement are similar to the results
for a primary total knee replacement,
and even though unicondylar knee
replacements may not last as long, the
outcome of revision is better than that
of a revision of total knee replacement.
Figure 2: (A) Anteroposterior radiograph showing a patellofemoral replacement. (B) Lateral radiograph showing a patellofemoral replacement.
Radiographs courtesy of Dr Bas Masri.
A B

Complications
The complications after a unicondylar
knee replacement are similar to a total
knee replacement. These complica-
tions include inadequate pain relief,
deep venous thrombosis in 1% to 5%
of patients, infection in less than 1%
of patients, and unexplained pain
about the knee.
Late complications include loos-
ening of a component, subsidence of
the component, degeneration of the
other compartment resulting in pain,
infection, polyethylene wear, and pos-
sible dislocation of the polyethylene
component in a mobile-bearing knee
replacement.
Patellofemoral
arthroplasty
A patellofemoral replacement
( ) is indicated for the man-
agement of isolated osteoarthritis of
the patellofemoral joint. It has to be
clear that this form of partial knee
replacement is not indicated for pat-
ellofemoral pain in the absence of rad-
iographically proven osteoarthritis.
Patient selection
Patellofemoral arthritis occurs in up
to 9% of patients over the age of 40
and 15% of patients over 60.7 Most
patellofemoral pain or arthritis can be
treated with nonoperative measures
such as activity modification, physi-
cal therapy, analgesics, braces, and/or
injections. Patellofemoral arthroplas-
ty may be an option for patellofemoral
arthritis when other treatment modal-
ities have failed.
Patients with chondromalacia of
the patella have been treated with
arthroscopic debridement with limit-
ed success.8 A patellectomy has been
used in the past as well. Unfortunate-
ly, a patellectomy has its own set of
problems,whichincludelossofexten-
sion power and increased risk of arth-
ritis in the tibiofemoral compartment.
Figure 2
Indications
According to Lonner9 the indications
and contraindications for a patello-
femoral arthroplasty are isolated
patellofemoral osteoarthritis, post-
traumatic arthritis, or advanced chon-
dromalacia with eburnation on either
or both of the trochlear and patellar
surfaces. It is contraindicated in pa-
tients with medial or lateral joint line
pain or tibiofemoral arthritis or chon-
dromalacia. It is not felt to be appro-
priate for inflammatory arthritis or
crystalline arthropathy. It should be
used with extreme caution in a patient
who has a highly malaligned patello-
femoral articulation with a high Q
angle and is thus at risk for dislocation.
Results
The component for patellofemoral
arthroplasty consists of a metal troch-
lear component and a polyethylene
button that replaces the articular sur-
face of the patella. Good to excellent
results have been reported in short,
mid-term, and medium follow-up.
The results are reported as being 80%
to 90% good to excellent.9
Complications
The complications after a patello-
femoral arthroplasty include patellar
snapping and instability. Additionally
the standard complications for uni-
condylar knee arthroplasty can be
included. There can be ongoing res-
idual anterior knee pain and dys-
function. There can be subsidence,
polyethylenewear,orloosening.Long-
term arthritis in the tibiaofemoral
joint can also occur.
Conclusions
Partial knee replacements may be an
option for a select group of patients.
There is renewed interest in partial
knee replacements with recently re-
ported good long-term outcomes,
complications similar to total knee
replacement, and the fall-back option
of a conversion to a total knee replace-
ment. For the unicondylar knee, it is a
more conservative option with a fast
recovery, good functional outcome,
and is a possible good option to a high
tibial osteotomy or total knee replace-
ment. The unicondylar knee is most
commonly done for isolated medial
compartment osteoarthritis and has
very specific indications. The patello-
femoral arthroplasty is possibly indi-
cated in patients with isolated patello-
femoral arthritic pain. The limited
reports on the patellofemoral arthro-
plasty suggest very good results.
There is renewed interest in partial
knee replacements with recently reported
good long-term outcomes, complications
similar to total knee replacement, and the
fall-back option of a conversion to a
total knee replacement.

Competing interests
None declared.
References
1. Kozinn SC, Scott R. Unicondylar knee
arthroplasty. J Bone Joint Surg Am 1989;
71:145-150.
2. Pennington DW, Swienckowski JJ,
Lutes WB, et al. Unicompartmental knee
arthoplasty in patients sixty years of age
or younger. J Bone Joint Surg. 2003;85-
A:1968-1973.
3. Tabor OB Jr, Tabor OB, Bernard M, et al.
Unicompartmental knee arthroplasty:
Long-term success in middle-age and
obese patients. J Surg Orthop Adv
2005;14:59-63.
4. Christensen NO. Unicompartmental
prosthesis for gonarthrosis. A nine-year
series of 575 knees from a Swedish hos-
pital. Clin Orthop Relat Res 1991;
273:165-169.
5. Berger RA, Meneghini RM, Jacobs JJ, et
al. Results of unicompartmental knee
arthoplasty at a minimum of ten years
follow-up. J Bone Joint Surg Am 2005;
87:999-1006.
6. NewmanJ,PydisettyRV,AckroydC.Uni-
compartmental or total knee replace-
ment. The 15-year results of a prospec-
tive randomized controlled trial. J Bone
Joint Surg Br 2009;91:52-57.
7. Davies AP, Vince AS, Shepstone L, et al.
The radiological prevalence of patello-
femoral osteoarthritis. Clin Orthop Relat
Res 2002;402:206-212.
8. Federico DJ, Reider B. Results of isolat-
ed patellar debridement for patello-
femoral pain in patients with normal
patellar alignment. Am J Sports Med
1997;25:663-669.
9. Lonner JH. Patellofemoral arthroplasty.
In: Lotke PA, Lonner JH (eds). Master
techniques in orthpaedic surgery: Knee
arthroplasty.3rded.Philadelphia,PA:Lip-
pincott Williams and Wilkins; 2009:343-
359.

ABSTRACT: While osteoarthritis re-
mains the most common indication
for total knee replacement, the num-
ber of primary total knee arthroplas-
ties performed annually has increas-
ed exponentially over the last 55
years. Outcomes have improved
with the use of careful preoperative
assessment, a range of component
options, and operative technique
guided by clear surgical goals.
Informed consent of any patient con-
templating total knee arthroplasty
must be obtained by discussing the
risks and benefits and explaining that
between 80% and 85% of patients
are satisfied after the procedure.
M
ajor joint arthroplasty is
undoubtedly one of the
surgical success stories
of modern times. The
number of primary knee arthroplas-
ties performed annually increased
exponentially over the last half of the
20th century and increased between
16% and 44% during the first 5 years
of the 21st century.1,2 The history of
total knee arthroplasty began back
in 1860, when the German surgeon
Themistocles Gluck implanted the
first primitive hinge joints made of
ivory. Development really took off
following the introduction of the
Walldius hinge joint in 1951: initially
manufactured from acrylic and later,
in 1958, from cobalt and chrome.3
Unfortunately, this hinge joint suffer-
ed from early failure.
Intheearly1960s,JohnCharnley’s
cementedmetal-on-polyethylenetotal
hip arthroplasty inspired the develop-
ment of the modern total knee replace-
ment.4 Gunston, from the same centre
as Charnley, went on to design an
unhinged knee that replaced both the
medial and lateral sides of the joint
with separate condylar components.
Improvedbiomechanicsresultedfrom
the preserved intact cruciate and col-
lateral ligaments, which maintained
the stability of unlinked femoral and
tibial components, and a design that
allowedthecentreofrotationtochange
with flexion of the knee.5 The metal-
on-polyethylene condylar design—
completely replacing the femoral and
tibial articulating surfaces—was pur-
sued throughout the early 1970s at
centres across the world.6-11 The result
was an implant relying on component
geometry and soft tissue balance to
provide stability, with a large articu-
lating surface area to spread load and
minimize polyethylene wear. Incre-
mental improvements in component
materials, geometry, and fixation
continued throughout the 1970s and
1980s. More accurate sizing, the
option of patellafemoral replacement,
better instrumentation, and compo-
nents that allowed an increased range
of motion and a lower wear rate have
since been developed.
Unicompartmental knee arthro-
plasty developed in parallel with total
kneereplacementfromtheearlyefforts
Total knee arthroplasty:
Providing a patient with a pain-free, stable knee joint that will last a
long time can be achieved by focusing on five surgical goals.
Daniel H. Williams, MSc, FRCS (Tr & Orth), Donald S. Garbuz, MD, MPH, FRCSC, B.A.
Masri, MD, FRCSC
Dr Williams is a fellow in the Division of
Lower Limb Reconstruction and Oncology
in the Department of Orthopaedics at
the University of British Columbia. Dr Gar-
buz is an associate professor and head of
the Division of Lower Limb Reconstruction
and Oncology in the Department of Ortho-
paedics at UBC. Dr Masri is a professor and
head of the Department of Orthopaedics at
UBC.

of McKeever and Elliott in 1952.12
However, because the unicompartmen-
tal procedure replaces only the dis-
eased part of the joint with more nat-
uralkinematicsorjointmovement,13,14
the indications for its use are more
limited.
Indications and
preoperative assessment
Osteoarthritis, whether primary, post-
traumatic, or secondary to avascular
necrosis, osteochondritis, or sepsis, is
by far the most common indication for
total knee replacement. Inflammatory
arthritides make up the bulk of the
remaining indications. Diagnosis of
the underlying condition allows appli-
cation of appropriate nonoperative
treatment, while the functional impact
of disease upon the everyday life of
the patient determines the appropriate
timing of surgery. Mechanical symp-
toms—locking or giving way—may
be amenable to arthroscopic assess-
ment and treatment. The severity of
symptoms are assessed by noting
reduced walking distance, analgesic
use, and sleep disturbance. Ability to
climb stairs or inclines, use of walk-
ing aids or other orthotics, and exac-
erbating or relieving factors all build a
more detailed picture of disability.
Knee examination should include
assessment of gait, surgical scars, loc-
alized tenderness, active and passive
range of motion, limb alignment, co-
ronal and sagittal plane ligament sta-
bility, and neurovascular status of the
limb. Other pathology contributing to
symptoms should be excluded by
examination of the back, hip, foot, and
ankle of the same limb.
Up-to-date and serial (if available)
radiographs of the knee should in-
clude an anteroposterior view as well
as true lateral and skyline patello-
femoral views of the involved knee
together with full long leg views if
there is significant deformity, previ-
ous fracture, or previous osteotomy of
the femur or tibia. An anteroposterior
pelvis and lateral radiograph of the
ipsilateralhipshouldbesoughtifthere
are symptoms of groin pain or signs of
stiffness or pain on rotation of the hip.
Magnetic resonance imaging can be
used to assess for meniscal or liga-
mentous injury in appropriate cases,
but is generally not required for the
routine assessment of the painful
arthritic knee. Radiographs should
always be performed before MRI is
ordered; in many cases, the plain rad-
iographic findings will make MRI
unnecessary.
The option of total knee arthro-
plasty is typically discussed with pa-
tients at the point in their lives when
knee pain from arthritis is significant-
ly interfering with activities of daily
living. Informed consent requires a
full discussion of the risks and bene-
fits of surgery to ensure that patient
expectations are realistic. Generally,
between 80% and 85% of patients are
satisfied with their knee arthroplasty.
The most significant complication is
deep infection, which complicates
between 1% and 2% of operations and
mayrequirefurtherandrepeatedmajor
joint surgery. Arterial injury compli-
cates between 0.03% and 0.17% of
cases15 and peroneal nerve injury has
been reported in between 0.3% and
2.0% of patients.16 The 20-day post-
operative mortality rate of 0.2% is
increased above the age-matched pop-
ulation and is the same as that meas-
ured for total hip arthroplasty. The
mortality rate normalizes with the
age-matched population after the 70th
postoperative day.17 Mortality at 1
year following knee arthroplasty is
1.6%, which is half the mortality rate
oftheage-matchedpopulation,demon-
strating that total knee arthroplasty
patients are a highly select group.18
Operative technique
Preoperative radiographic templating
for knee arthroplasty, while not as cru-
cial as for hip arthroplasty, does indi-
cate the size and shape of the tibial
bone to be removed and the compo-
nent type and size that is likely to be
required. It is particularly important
in cases requiring the extremes of
implant size to ensure that all likely
sizes are available, in cases of severe
deformity, and in cases where there is
severe bone loss.
Components
Most orthopaedic supply companies
manufacture a range of implant de-
signs, from cruciate ligament retain-
ing ( ) and posterior stabilized
( ) implants that usually pro-
vide sufficient stability in the primary
setting, through to megaprotheses for
replacing tumor or bone.
The level of built-in constraint, or
stability,requiredbyakneeprostheses
depends upon whether the posterior
cruciate and collateral ligaments are
intact. If the posterior cruciate liga-
ment is compromised, as it is in most
rheumatoid knees, or there is fixed
Figure 2
Figure 1
Total knee arthroplasty: Techniques and results
Radiographs should
always be performed
before MRI is ordered;
in many cases, the
plain radiographic
findings will make
MRI unnecessary.

coronal plane or significant flexion
deformity, then the PCL is replaced
by a cam and post, the design of which
controls sagittal plane kinematics.
A larger post can provide additional
side-to-side/coronal plane stability
( ). If the medial collateral lig-
ament is compromised, a hinged pros-
thesis is chosen to further improve
coronal plane stability ( ). In-
evitably this puts greater strain upon
the hinge itself and produces increas-
ed shear stresses at the implant inter-
face with the bone. A rotating hinge
allows movement in the axial plane
between the polyethylene and tibial
surface, decreasing these stresses but
producing a secondary surface for the
generation of wear debris. Modular
femoral and tibial stems are added to
the resurfacing implants in this scen-
ario to increase the area of fixation,
spreading load and decreasing stress-
es at the implant bone interface.
Femoral or tibial stems of varying
lengths may also be added if there are
significant uncontained bone defects.
Generally, a contained bony defect
with an intact cortical rim or an uncon-
tained defect of less than 5 mm can be
filled with cement upon implantation.
Contained defects greater than 5 mm
with an intact cortical rim can be treat-
ed with morcelized impaction bone
allografting. Uncontained defects re-
quire shaping to accommodate the
metal wedges that are added to the
implant. Larger defects are not com-
monly encountered in the primary set-
ting, but when present may require
bulk bone allograft. The addition of a
femoral or tibial stem provides addi-
tional stability and protects supple-
mented defects, minimizing the risk
of long-term implant subsidence.
Surgical goals
The clinical aims of knee arthroplasty
are to provide the patient with a pain-
free, stable joint that will last a long
Figure 4
Figure 3
Figure 1. Cruciate ligament retaining
implant.
Figure 2. Posterior stabilized implant. The
presence of a post (arrow) distinguishes this
design from the cruciate ligament retaining
design in Figure 1, which has no such post.
Figure 3. Posterior stabilized implant
with larger post (arrow) for improving
coronal plane stability.
Figure 4. Hinged implant for improving
coronal plane stability. The hinge is linked
into the femoral component as indicated by
the arrow.

time.Toachievethis,thesurgicalteam
focuses on five surgical goals:
• Mechanical alignment of the limb.
The proximal tibia and the distal
femur are cut so that the mechanical
axis of the limb—from the centre of
the hip to the centre of the ankle
joint—passes through the centre of
the knee arthroplasty. This ensures
that forces are transmitted equally
through each side of the new joint,
optimizing the lifetime of the joint.19
Aligning the limb correctly also pro-
vides the correct starting platform
for achieving subsequent surgical
goals.
• Joint line preservation. The depth of
bone removed from the tibia and the
femur should be equal to the height
of the respective components that
are implanted. By taking out what is
to be put back in, the position of the
original joint line is preserved. This
optimizes the function of the liga-
ments and muscles acting upon the
knee.
• Soft tissue balance in the coronal
plane. Balancing the knee to varus
and valgus stress maintains equal
load transmission through each side
of the knee. Following many years
of disease, deformity in the coronal
plane can become fixed by contrac-
ture of soft tissues. Osteoarthritis
most commonly leads to a varus
deformity and tight medial soft tis-
sues, which are released in the fol-
lowing order to attain satisfactory
balance:
1. Medial osteophyte removal.
2. Proximal subperiosteal stripping
of the deep medial collateral lig-
ament.
3. Posteromedial capsular release.
4. PCLsacrifice requiring the use of
a posterior stabilized component.
5. Distal tibial periosteal stripping
of the MCL (avoiding complete
release and subsequent valgus
instability).
Rheumatoid arthritis or lateral
femoral condyle hypoplasia can lead
to a valgus deformity that requires the
following releases to attain satisfac-
tory balance:
1. Lateral osteophyte removal.
2. Subperiosteal dissection of the lat-
eral joint capsule.
3. Lateral patellofemoral ligament
release.
4. “Pie crusting” of the iliotibial band
if tight in extension.
5. Popliteus release if tight in flexion.
6. PCL sacrifice requiring the use of a
posterior stabilized component.
7. Lateral collateral ligament release
from its femoral insertion (avoid-
ing complete release and subse-
quent varus instability).
• Balance of the flexion and extension
gaps in the sagittal plane. This re-
sults in the knee maintaining stabil-
ity throughout its full range of mo-
tion.Flexioninstabilityoccurswhen
the gap between the tibia and the
femur is wider in flexion than in
extension and must be corrected to
ensure the patient is asymptomatic.
Recurvatum or extension beyond
0 degrees may result from a “loose”
extension gap. A “tight” flexion or
extension gap may restrict the full
range of flexion or extension. Loss
of full range of motion at either
extreme can be disabling. Loss of
full flexion can make stair and hill
climbing difficult. Loss of full ex-
tension makes complete lockout of
the knee impossible and requires
prolonged quadriceps muscle en-
gagement—which is tiring for the
patient—when standing in one spot.
A tibiofemoral gap consistent
throughout a full range of motion
can be achieved by using an appro-
priately sized tibial insert combined
with a femoral component implant-
ed in the correct position.
• Q angle correction. This is the angle
between the quadriceps and the
patella tendon and is a function of
the positioning of the tibial, femoral,
and, if used, patella component. In
particular the femoral component
requires appropriate positioning in
all three planes to allow the patella
to track correctly.
Each of these goals may not nec-
essarily be addressed in strict order
during surgery. Indeed, some of the
steps involved during the procedure
may address more than one goal at the
same time. For instance, sizing and
positioning the femur ensures balance
of the flexion and extension gaps as
well as creating a Q angle that affords
correct patella tracking. What is vital
is that every goal be considered in
order to produce a pain-free, stable
joint that will last a long time.
The operation
Following complete preoperative
assessment and planning to ensure
correct implant availability, a typical
total knee arthroplasty would proceed
as follows:
• Intravenous antibiotics are given
well before inflation of a proximal
thigh tourniquet to 300 mm Hg.
• The skin is prepped and draped to
allow an adequate midline longitu-
dinal incision to access the knee
joint, usually via a medial parapatel-
lar approach.
• Part of the anterior fat pad, remnants
of the medial and lateral menisci,
the anterior cruciate ligament and
the PCL (if a posterior stabilized
implant is to be used) are excised.
Osteophytes are excised and the
proximal medial soft tissues are
released to allow visualization of the
edge of the medial tibial plateau and
forward subluxation of the tibia in
full flexion and external rotation.
Further preliminary soft tissue re-
leases are performed at this stage as
appropriate.
• The tibia is cut at 90 degrees to its

mechanical axis using an extra-
medullary or intramedullary jig.
Tibial bone is removed from the
normal side of the joint to the same
depth—usually 10 mm—as the
height of the tibial component to be
implanted, with the aim of preserv-
ing the position of the original joint
line.
• The femoral intrameduallary canal
is entered and the appropriate jig
is used to cut the distal femur in
between 5 and 7 degrees of valgus
relative to the anatomical axis. This
ensures the bone is cut at 90 degrees
to the mechanical axis of the femur,
thus satisfying the first surgical
goal of knee arthroplasty. Femoral
boneisremovedtothesamedepth—
again, usually 10 mm—as the height
of the femoral component to be im-
planted, with the aim of preserving
the position of the original joint line.
• The extension gap is checked to
ensurea10-mmspacercanbeinsert-
ed. If it cannot, the tibia or femur, as
appropriate, are recut by an appro-
priate amount—usually 2 to 4 mm.
Overall alignment of the bony cuts
is checked to ensure the limb is
straight and the soft tissues balance
to varus and valgus stress. Further
adjustments of the bony cuts and
further soft tissue releases proceed
if required.
• The femoral size is measured (in
the anteroposterior and mediolateral
plane) and correct position of
the femoral cutting block in the
sagittal (anteroposterior transla-
tion), the coronal (mediolateral
translation), and axial plane (rota-
tion) is ensured.
• The posterior femoral condylar cut
is made to enable trialing of the 10-
mm spacer block at 90 degrees of
flexion to confirm that the flexion
gap matches the extension gap be-
tween the tibia and the femur.
• The remaining femoral bony cuts
are made to match the inside of the
femoral component, and a drill hole
is made in each condyle to accom-
modate the two femoral pegs.The
trial components are inserted with
the appropriate tibial spacer. The
patella is prepared if it requires
replacement, and is rechecked prior
to final implantation. The optimum
position of the tibial component is
marked and preparation of the tibial
keel is completed.
• The cancellous bone surface is clean-
ed and the real components cement-
ed with antibiotic-loaded cement.
Compressionisappliedwiththeknee
in extension through a trial insert.
Once the cement has hardened any
loose cement is removed and the
appropriate real polyethylene insert
is implanted.
• The tourniquet is released to con-
firm hemostasis. A single drain is
used and the retinacular-tendinous
layer is closed with interrupted sut-
ures.The subdermal tissues and skin
are closed and dressings applied.
Postoperative care
Two further intravenous doses of anti-
biotics are given to cover the first 24
hours. Low molecular weight heparin
or a similar suitable anticoagulant is
prescribed—according to patient risk
assessment—usually up until the 10th
day postoperatively to ensure optimal
thromboprophylaxis. The patient is
mobilized, fully weight bearing in the
majority of cases, as soon as the gross
effectsoftheanesthetichavewornoff.
Patients are encouraged to maximize
knee extension and flexion at every
stage of their recovery to ensure opti-
mal outcome. Exercises are commen-
ced to ensure full recovery of quadri-
ceps tone and strength and analgesia
is provided to ensure the best possible
results from physiotherapy. Discharge
from hospital is allowed when the
wound is dry and the patient is safe
ascending and descending stairs.
Sutures or skin clips are removed at
10 to 14 days. A walking aid may be
required for several weeks following
surgery. The literature supports driv-
ing from 8 weeks, so long as the pa-
tient is clear of opiod analgesia and
can perform an emergency stop.20 Fol-
low-up appointments are scheduled at
6 to 8 weeks, 1 year, 5 years, and every
subsequent fifth year thereafter. Earli-
er follow-up should be requested if
there is any sign of infection or other
significant concern. Over 85% of total
knee arthroplasty patients will recover
knee function following a general
rehabilitation protocol. The remain-
ing 15% of patients will have difficul-
The patient is mobilized, fully weight
bearing in the majority of cases, as
soon as the gross effects of the
anesthetic have worn off.

ty obtaining proper knee function sec-
ondarytosignificantpain,limitedpre-
operative motion, or the development
of arthrofibrosis. This subset of
patients will require a more specific
prolonged rehabilitation program that
may involve ongoing oral analgesia,
continued physical therapy, additional
diagnostic studies, and occasionally
manipulation. Controlling pain is the
mainstay of any such treatment plan.21
Results
The survivorship rate is the percent-
age of total knee arthroplasties that
have not been revised in any given
series of patients. It is generally the
most often quoted outcome in the joint
arthroplasty literature. Survivorship
is arguably the most useful outcome
when distinguishing between differ-
ent prosthetic designs and also helps
answer the patient question, “How
long will the knee last?”
The pioneers of total knee arthro-
plasty saw early failures that quickly
led to the use of more durable materi-
als, better fixation, and improved de-
sign.5-11 Published longer-term results
have shown markedly differing sur-
vivorship rates between more subtle
differences in arthroplasty design. In
a recent study looking at 3234 knee
arthroplasties performed between
survivorship rates of 100% at 10 years
are seen with the Miller-Galante II
knee, which was redesigned to solve
the high rate of patellofemoral compli-
cations seen with the Miller-Galante I
(which still had an 84.1% survivorship
rate at 10 years).28 Studies comparing
the results of different design options
manufactured by the same company
are now also available: the 10-year
Genesis knee results for the (posteri-
or) cruciate retaining knee reveal 97%
survival compared with the Genesis
posterior stabilized knee, which has
96%survival—aninsignificantdiffer-
ence.29 The results of unicompartmen-
tal knee arthroplasty have been as
good as total knee arthroplasty in pub-
lished individual series, with sur-
vivorship rates of 98% at 10 years.30,31
It is arguably the recent registry
data for newer generation knee im-
plants that apply most readily to the
average patient considering total knee
arthroplasty. The 8-year survivorship
rate for the eight most common knee
joints in current use in Norway is
between 89% and 95%1 and the 7-year
rate in Australia is 95.7%.2 Of note,
purely in terms of survival, these reg-
istries have found inferior results for
even the best-performing unicompart-
mental knee arthroplasties when these
are compared with total knee arthro-
plasty. The cumulative survival at 7
years for unicompartmental knees in
Australia is only 88.1% compared
with95.7%fortotalknees.1,2 Thismay
relate to issues of patient selection or
reflect the increased technical expert-
ise required for this procedure. Con-
version of unicompartmental knee
arthroplasty to total knee replacement
isrelativelystraightforward,soappro-
priate patients seeking a partial knee
replacement should not be discour-
aged by the slightly lower long-term
survivorship seen in registry data.
Several knee scores have been
developed to assess outcome follow-
1969 and 1995, 89% of the condylar
designs had survived 10 years and
between 78% and 89% had survived
15years.22 Survivorshiprates,however,
varied considerably among different
implant designs. The corresponding
rates for some, now discontinued,
designs in this same study were
between 43% and 63% at 10 years
and between 28% and 59% at 15
years.22 Further studies have confirm-
ed clinical survival of the total condy-
lar knee design of 94% at 15 years23
and between 77% and 91% at 21 to 23
years.24,25 For this reason the total
condylar design has endured. Perhaps
the best long-term published results
are for the Anatomic Graduated Con-
dylar (AGC) knee arthroplasty, the
success of which is attributed to a
straightforward design that utilizes
carefullymanufacturedmaterials.The
AGC knee has a published survivor-
ship rate of 98.9% in 4583 knees at 15
years26 and a rate of 97.8% in 7760
knees at 20 years—quite impressive
survivorship. The number of knees
that reach long-term follow-up in such
series are, however, often small; only
36 of the 7760 knees in this study
made it to the 20-year point.27
Medium-term follow-up is becom-
ing available on updated versions of
the total condylar design. Improved
Improved survivorship rates of 100% at
10 years are seen with the Miller-Galante II
knee, which was redesigned to solve the
high rate of patellofemoral complications
seen with the Miller-Galante I.

ingtotalkneearthroplasty.Thesetools
produce numbers that correspond to
excellent, good, fair, or poor outcome.
For example 92% of knees were as-
sessed as good or excellent in one
study, with 1.6% fair and 6.5% poor.23
Between 96% and 98% of knees were
assessed as good or excellent in anoth-
er study.29 However, more recently it
has been shown that the views of sur-
geons and their patients regarding the
outcome of surgical interventions do
not always correlate well—especially
with respect to function and pain.
Patient questionnaires are thought to
better assess patient outcome, and in a
recent study 81.8% of 8095 patients
were satisfied, 11.2% (906 of 8095)
were unsure, and 7.0% (566 of 8095)
were not satisfied with their new knee
joint.32
With regard to younger patients
under the age of 55 years, a survivor-
ship rate of 96% of 93 knees was
observed at 10 years,33 and of 90% of
108 knees at 18 years;34 94% of pa-
tients in the latter study had good or
excellent function and all but two
patients had improvement in their
activity score postoperatively. Fur-
thermore, 24% regularly participated
in activities such as tennis, skiing,
bicycling, or strenuous farm or con-
struction work.34 This suggests that
the traditional practice of withholding
knee replacement until patients are
over 65 or over is not warranted, and
replacement should proceed when
clinically appropriate.
It was traditionally thought that
obese patients do not fare as well as
normal-weight patients following
joint replacement. Postoperative out-
come scores for obese patients, how-
ever, were found to be comparable to
scores for patients who were not obese
in one recent study. Furthermore,
given the lower preoperative scores
measured in the obese group, the over-
all improvement was actually greater
than in the normal-weight group.
Additionally, survivorship rates in
obese patients were not significantly
lower than in patients who were not
obese at 10 years follow-up.35 There
was, however, a greater proportion of
lucent lines seen on the radiographs
around the implants of the obese
patients23,35 and in the morbidly obese
the complication rates are higher and
the implant survivorship rate is lower.
The final objective measure of
outcome perhaps most relevant to the
individual patient is range of flexion.
This has gradually improved from a
mean of 99 degrees23 to between 114
and 117 degrees with newer genera-
tion designs.29 Postoperative range of
motion largely depends on the preop-
erative range of motion. Generally,
what the patient has before the opera-
tion is what the patient can expect to
achieve after surgery and rehabilita-
tion.36 Patients seeking knee replace-
ment should be counseled that their
postoperative knee will not be “nor-
mal,” but it will feel and function
much better than their preoperative
arthritic knee.
Conclusions
Osteoarthritis remains the most com-
mon indication for total knee arthro-
plasty. Fortunately, technical devel-
opments over the last half century
have resulted in 10-year survivorship
rates of 90% and higher, and between
80% and 85% of patients have been
satisfied with their total knee replace-
ment. Further incremental improve-
ments in knee arthroplasty engineer-
ing, implant design, and material
science will continue to improve bear-
ing surface tribology, implant fixa-
tion, and implant longevity. These
advances will all help meet the main
surgical goals of total knee arthro-
plasty: to correct limb alignment, pre-
serve joint line position, balance the
soft tissues in the coronal plane, bal-
ance the flexion/extension gap in the
sagittal plan, and create a Q angle that
facilitates satisfactory patella track-
ing. Preoperative assessment and
planning will also help meet these
goals by ensuring patient expectations
are realistic and informed consent has
been obtained after a full discussion
of the risks and benefits of surgery.
Competing interests
None declared.
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ABSTRACT: Primary total hip arthro-
plasty has become one of the most
successful surgical procedures over
the past 50 years and is currently
performed worldwide with similar
techniques and excellent results.
Despite variations in technique and
implant selection, medium and long-
term outcome studies have demon-
strated over 90% implant survival at
15 to 20 years. Previous problems
with implant fixation have now been
reduced, and the focus has shifted
to the selection of improved bearing
surfaces to limit wear, hip replace-
ment options for younger patients,
and improved surgical and anesthet-
ic techniques. Current surgical ap-
proaches to the hip rely most often
on direct lateral or posterolateral
exposure. The most commonly uti-
lized bearing surface for both hip
replacement and hip resurfacing in
Canada is a metal (cobalt-chrome)
femoral head combined with a
second-generation cross-linked poly-
ethylene, combined with cementless
implant fixation. Alternative bear-
ings such as ceramic-on-ceramic
and metal-on-metal may be consid-
ered for hip replacement in younger
patients. Although it has not been
determined which surface will prove
best for younger patients in the long-
term, there is no question about the
benefits of total hip arthroplasty.
With current techniques, the results
are favorable, and patient satisfaction,
pain relief, and long-term implant
survival are excellent.
T
he current long-term suc-
cess of total hip replacement
(THR) surgery has led to the
observation by Coventry1
that “total hip replacement, indeed,
might be the orthopaedic operation of
the century.” The indications for THR
have expanded to such an extent that
this surgery is no longer performed
only in the elderly or in those with de-
bilitatinghippain,arthritis,andsevere
functional restrictions. Rather,THR is
now performed in younger and higher-
demand patients, with expectations,
quality-of-life measures, and inten-
tions to return to prior activity levels
that challenge surgical techniques and
implant design technology. The ad-
vantages of THR generally outweigh
the disadvantages ( ), and atten-
tion is now focused on improved fix-
ation of the implants, reduction in the
rates of failure, and development of
bearing surfaces to reduce long-term
wear and improve implant longevity.
Surgical exposure
Several surgical exposures are utiliz-
ed for THR. The two most common
Table
Total hip arthroplasty:
Younger, more active patients are now candidates for total hip re-
placement with the advent of improved implant fixation and new
low-wearing bearing surfaces.
R. Stephen J. Burnett, MD, FRCSC, Dipl ABOS
Dr Burnett is a consultant orthopaedic
surgeon in the Division of Orthopaedic Sur-
gery, Adult Reconstructive Surgery of the
Hip and Knee, Vancouver Island Health–
South Island.

exposures ( ) are the anterolat-
eral2 and the posterolateral approach-
es to the hip.3 Patients may also be
offered one of the newer techniques of
surgicalexposurereferredtoasmuscle-
sparing or minimally invasive. The
decision of which surgical exposure
to use will depend upon surgeon expe-
rience and preference, patient body
habitus (i.e., obesity), patient anatom-
ical factors, the location and type of
prior surgical incisions over the hip,
and implant selection. The most im-
portant factor to consider is surgeon
experience and preference.
The anterolateral exposure is an
abductor-splitting approach requiring
removalandrepairoftheanterior30%
to 40% of the gluteus medius and min-
imus. This approach may also be uti-
lized for revision THR surgery. Many
surgeons select this approach based
upon the potential for a reduced dislo-
cation rate. Disadvantages of the an-
terolateral approach include:
• An increase in limp due to splitting
oftheabductormuscle(alsolikelydue
Figure 1 to traction injury to anterior branch-
es of the superior gluteal nerve dur-
ing surgery). Often the limp is re-
ported as being asymptomatic, but
frequently it is a Trendelenburg gait.
• An increase in the formation of het-
erotopic bone within the abductor
muscles and anteriorly over the cap-
sule and greater trochanter.
• A greater incidence of trochanteric
complications (intraoperative frac-
ture, postoperative fracture, or es-
cape of the greater trochanter), and
trochanteric pain (often incorrectly
attributed to a diagnosis of tro-
chanteric bursitis), most likely due
to failure of the abductors to heal
following the repair.
• A tendency for the surgeon to insert
the femoral component angled from
anterior to posterior within the fem-
oral canal (i.e., nonanatomic femoral
component placement).
With the popularity of less inva-
sive surgery, the posterolateral expo-
sure has again gained prominence.
Disadvantages of the posterolateral
approach include:
• Perhaps a slightly higher risk of dis-
location, although with experience
this is minimized.
• The need for careful attention to
component orientation in order to
insert the implants in proper antev-
ersion.
InCanadabetween2008and2009,
the direct lateral approach (60%) and
posterolateral approach (36%) com-
bined for over 95% of all surgical
exposures.4 When minimally inva-
sive surgery for THR is performed, it
is most commonly performed using
one of these two approaches. Other
minimally invasive surgical approach
options include the two-incision ap-
proach,5,6 the anterolateral (Watson-
Jones) approach, and the direct ante-
rior (Hueter) approach.7 Often these
surgical approaches require the sur-
geon to change to a different OR
setup6 (i.e., one with a specialized
table, retractors, and lights, and access
to intraoperative X-ray) and to use an
implant he or she may be less familiar
Total hip arthroplasty: Techniques and results
Advantages
• Predictable immediate pain relief and
return to function.
• Predictable long-term implant survival.
• Low risks and few complications for
healthy patients.
• Contemporary bearing surfaces that
may reduce long-term wear.
• Multiple indications (osteoarthritis,
inflammatory arthritis, osteonecrosis,
posttraumatic hip conditions).
• Bone preservation options (hip
resurfacing, tapered femoral stems).
Disadvantages
• Prosthetic joint replacement limitations.
• Activity limitations (nonimpact only).
• Bearing surface wear in younger active
patients.
• Revision surgery complications (three to
five times higher than for primary THR).
• Major complications (infrequent).
Table. Advantages and disadvantages of
total hip replacement.
Figure 1. Common surgical exposures. (A) Anterolateral incision. This incision is centred
longitudinally over the greater trochanter and permits an abductor-splitting approach. (B)
Posterolateral incision. This approach is similar distally to the anterolateral, curving from the
tip of the greater trochanter slightly posteriorly, entering the hip posterior to the abductor
musculature.

with in order to make the procedure
feasible. While there may be a few
short-term advantages to minimally
invasive surgery, the early and mid-
term results have been associated with
significantly increased risks and sur-
gical complications,5 which have not
been seen in THR prior to the popu-
larity of these techniques. Thus, the
enthusiasm for minimally invasive
surgery has declined recently in favor
of surgery performed safely through
smaller incisions, and with the goal of
achieving an ideal implant orientation
and longevity. Computer-assisted
surgery (CAS) for total hip replace-
ment has gained popularity and is per-
formed in many centres. The advan-
tages and results of CAS have been
difficult to assess, and there does not
appear to be any significant advantage
to CAS at this time. The one area of
potential advantage is that CAS may
be useful in identifying “outlier”
acetabular component position/angu-
lation and leg length and hip offset
intraoperatively, which might help in
select situations, especially for sur-
geons with less experience perform-
ing THR and surgeons combining
CASwithminimallyinvasivesurgery.
The main disadvantage is increased
OR time and increased cost. Overall,
CAS has not been shown to be cost-
effective to date.
Implant fixation:
Cemented or cementless?
Both cemented and cementless fixa-
tion are currently utilized in THR sur-
gery, although there has been a trend
in North America toward cementless
implants over the past 10 years. Total
hip replacement implants typically
consist of the acetabular component
(which is fitted into the patient’s
native acetabular pelvic bone with or
without cement), the femoral compo-
nent (inserted down the femoral
canal), and the bearing surfaces (the
articulating aspects of the implant).
When describing fixation methods,
we are referring to the femoral and
acetabular components.
Acetabular component
implant fixation
The use of cemented acetabular com-
ponents has declined in recent years in
North America, although cemented
components are still used occasional-
ly in older and lower-demand patients.
When compared with cementless im-
plants, cemented acetabular compo-
nents have been associated with in-
creased rates of loosening at 10 to 20
years, especially in patients younger
than 50,8 when compared to cement-
less implants. Cementless acetabular
fixation was introduced to solve the
problem of loosening with cemented
acetabular cups. The most commonly
usedcompositeforcementlessacetab-
ular components is titanium alloy,
which is favorable for bone ingrowth.
Typically, a modular bearing surface
(the liner) is inserted into the inner
aspect of the acetabular component,
and locks into place via a mechanism
contained within the acetabular com-
ponent. The acetabular component
may accept bearing surfaces, including
liners made of polyethylene, ceramic,
or metal, to complete the acetabular
component composition ( ).
This modular bearing surface may be
exchanged in the future if wear or
other less common indications make
this necessary, leaving the intact
osseo-integrated acetabular compo-
nent in place. The long-term results of
cementless titanium acetabular fixa-
tion have been favorable. At a mini-
mum of 20 years, the implant survival
Figure 2
Total hip arthroplasty: Techniques and results
Figure 2. Cementless titanium acetabular
component. (A) The porous outer surface
permits bone ingrowth and the cluster holes
allow for adjunctive screw fixation. (B) The
polished inner surface with circumferential
locking mechanism accommodates a
modular acetabular bearing surface. The
modular acetabular liners available for this
component include: (C) Cross-linked
polyethylene. (D) Ceramic. (E) Metal.
A B
C D
E

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