British Columbia Medical Journal - November 2010


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British Columbia Medical Journal - November 2010

  1. 1. November 2010; 52:9 Pages 429-492 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: Techniques and results Proust: Erik Paterson Good guys: Russell Palmer BCCDC: Antibiotic resistance WorkSafeBC: Asbestosis OSTEOARTHRITIS OF THE HIP AND KNEE—PART 2
  2. 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: Environmental benefits of using recycled paper Using recycled paper made with post- consumer waste and bleached without the use of chlorine or chlorine compounds results in measurable environmental benefits. We are pleased to report the following savings. 1399 pounds of post-consumer waste used instead of virgin fibre saves: • 8 trees • 760 pounds of solid waste • 837 gallons of water • 1091 kilowatt hours of electricity (equivalent: 1.4 months of electric power required by the average home) • 1382 pounds of greenhouse gases (equivalent: 1119 miles traveled in the average car) • 6 pounds of HAPs, VOCs, and AOX combined • 2 cubic yards of landfill space November 2010 Volume 52• Number 9 Pages 429–492 Enter to Win an iPad from
  3. 3. 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- produced, stored in a retrieval system, or transmitted in any form or by any other means—elec- tronic, mechanical, photocopying, recording, or otherwise—without prior permission in writing from the British Columbia Medical Journal. To seek permission to use BCMJ material in any form for any purpose, send an e-mail to or call 604 638-2815. The BCMJ is published 10 times per year by the BC Medical Association as a vehicle for continuing medical education and a forum for association news and members’opinions. The BCMJ is distributed by second-class mail in the second week of each month except January and August. Prospective authors should consult the “Guidelines forAuthors,” which appears regularly in the Jour- nal, is available at our web site at, or can be obtained from the BCMJ office. Statements and opinions expressed in the BCMJ reflect the opinions of the authors and not nec- essarily those of the BCMA or the institutions they may be assoicated with. The BCMA does not as- sume responsibility or liability for damages arising from errors or omissions, or from the use of information or advice contained in the BCMJ. The BCMJ reserves the right to refuse advertising. Subscriptions Single issue ................................................................................................................................$8.00 Canada per year........................................................................................................................$60.00 Foreign (surface mail)..............................................................................................................$75.00 Postage paid at Vancouver, BC. Canadian Publications Mail, Product Sales Agreement #40841036. Return undeliverable copies to BC Medical Journal, 115-1665 West Broadway, Vancouver, BC V6J 5A4; tel: 604 638-2815; e-mail: US POSTMASTER: BCMJ (USPS 010-938) is published monthly, except for combined issues Janu- ary/February and July/August, for $75 (foreign) per year, by the BC MedicalAssociation c/o US Agent- Transborder Mail 4708 Caldwell Rd E, Edgewood, WA 98372-9221. Periodicals postage paid at Puyallup, WA. USA and at additional mailing offices. POSTMASTER: Send address changes to BCMJ c/o Transborder Mail, PO Box 6016, Federal Way, WA 98063-6061, USA. #115–1665 West Broadway, Vancouver, BC, Canada V6J 5A4 Tel: 604 638-2815 or 604 638-2814 Fax: 604 638-2917 E-mail: Web: contents Advertisements and enclosures carry no endorsement of the BCMA or BCMJ. 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 Peaceful Warrior Arts DESIGN AND PRODUCTION Olive Design Inc. PRINTING Mitchell Press ADVERTISING OnTrack Media Tel: 604 375-9561 302–70 E. 2nd Ave. Vancouver, BC V5T 1B1 ISSN: 0007-0556 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
  4. 4. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org432 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 “
  5. 5. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 433 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 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.
  6. 6. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org434 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
  7. 7. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 435 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, faxed (604 638-2917), or sent through the post. MARKET LOSS RECOVERY GROUPMARKETT LOSS RECOV Y GROUPRVE Continued on page 436
  8. 8. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org436 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 ( 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
  9. 9. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 437 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 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, where over 50 guidelines are available in a range of formats. Download app from: 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 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
  10. 10. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org438 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
  11. 11. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 439 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.
  12. 12. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org440 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.
  13. 13. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 441 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.
  14. 14. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org442 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. Partial 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.
  15. 15. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 443 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 Partial knee replacement 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
  16. 16. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org444 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. Partial 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
  17. 17. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 445 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. Partial knee replacement 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.
  18. 18. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org446 Partial 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.
  19. 19. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 447 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: Techniques and results 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.
  20. 20. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org448 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.
  21. 21. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 449 Total knee arthroplasty: Techniques and results 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.
  22. 22. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org450 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 Total knee arthroplasty: Techniques and results
  23. 23. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 451 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- Total knee arthroplasty: Techniques and results The patient is mobilized, fully weight bearing in the majority of cases, as soon as the gross effects of the anesthetic have worn off.
  24. 24. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org452 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- Total knee arthroplasty: Techniques and results 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.
  25. 25. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 453 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. References 1. The Norwegian Arthroplasty Register. Report 2006. eng (accessed 15 August 2009). 2. The Australian National Joint Replace- Total knee arthroplasty: Techniques and results Survivorship rates in obese patients were not significantly lower than in patients who were not obese at 10 years follow-up.
  26. 26. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org454 mentRegistry.Annualreport2008.www (acces- sed 15 August 2009). 3. Walldius B. Arthroplasty of the knee joint using an acrylic prosthesis. Acta Orthop Scand 1953;23:121-131. 4. CharnleyJ.Arthroplastyofthehip.Anew operation. Lancet 1961;1(7187):1129- 1132. 5. Gunston FH. Polycentric knee arthro- plasty. Prosthetic simulation of normal knee movement. J Bone Joint Surg Br 1971;53:272-277. 6. Ranawat CS. History of total knee replacement. J South Orthop Assoc 2002;11:218-226. 7. Coventry MB, Finerman GA, Riley LH, et al. A new geometric knee for total knee arthroplasty. Clin Orthop Relat Res 1972; 83:157-162. 8. Freeman MA, Swanson SA, Todd RC. Total replacement of the knee using the Freeman-Swanson knee prosthesis. Clin Orthop Relat Res 1973;(94):153-170. 9. Insall JF, Ranawat CS, Scott WN, et al. Total condylar knee replacment: Prelimi- nary report. Clin Orthop Relat Res 1976;149-154. 10. Ranawat CS, Shine JJ. Duo-condylar total knee arthroplasty. Clin Orthop Relat Res 1973;(94):185-195. 11. Townley C, Hill L. Total knee replace- ment. Am J Nurs 1974;74:1612-1617. 12. McKeever DC. The classic: Tibial plateau prosthesis 1960. Clin Orthop Relat Res 2005;440:4-8. 13. Goodfellow J, O’Connor J. The mechan- ics of the knee and prosthesis design. J Bone Joint Surg Br 1978;60-B:358-369. 14.Marmor L. The modular knee. Clin Orthop Relat Res 1973;(94)242-248. 15. Smith DF, McGraw RW, Taylor DC, et al. Arterial complications and total knee arthroplasty. J Am Acad Orthop Surg 2001;9:253-257. 16. Lonner JH, Lotke PA. Aseptic complica- tions after total knee arthroplasty. J Am Acad Orthop Surg 1999;7:311-324. 17. Lie SA, Engesaeter LB, Havelin LI, et al. Early postoperative mortality after 67,548 total hip replacements: Causes of death and thromboprophylaxis in 68 hos- pitals in Norway from 1987 to 1999. Acta Orthop Scand 2002;73:392-399. 18. National Joint Registry [for England and Wales 2007]. (ac- cessed 13 September 2010). 19. Fang DM, Ritter MA, Davis KE. Coronal alignment in total knee arthroplasty: Just how important is it? J Arthroplasty 2009; 24:39-43. 20. Spalding TJ, Kiss J, Kyberd P, et al. Driv- er reaction times after total knee replace- ment. J Bone Joint Surg Br 1994;76:754- 756. 21. RanawatCS,RanawatAS,MehtaA.Total knee arthroplasty rehabilitation protocol: What makes the difference? J Arthro- plasty 2003;18:27-30. 22. PradhanNR,GambhirAF,PorterML.Sur- vivorship analysis of 3234 primary knee arthroplasties implanted over a 26-year period: A study of eight different implant designs. Knee 2006;13:7-11. 23. Ranawat CS, Flynn WF Jr, Saddler S, et al. Long-term results of the total condy- lar knee arthroplasty. A 15-year survivor- ship study. Clin Orthop Relat Res 1993; (286)94-102. 24. Rodriguez JA, Bhende HF, Ranawat CS. Total condylar knee replacement: A 20- year followup study. Clin Orthop Relat Res 2001;(388)10-17. 25. Pavone VM, Boettner FM, Fickert SM, et al. Total condylar knee arthroplasty: A long-term followup. Clin Orthop Relat Res 2001;(388):18-25. 26. Ritter MA, Berend ME, Meding JB, et al. Long-term followup of anatomic gradu- ated components posterior cruciate- retaining total knee replacement. Clin Orthop Relat Res 2001;(388):51-57. 27. Ritter MA. The Anatomical Graduated Component total knee replacement: A long-term evaluation with 20-year sur- vival analysis. J Bone Joint Surg Br 2009;91:745-749. 28. Berger RA, Rosenberg AG, Barden RM, et al. Long-term followup of the Miller- Galante total knee replacement. Clin Total knee arthroplasty: Techniques and results Orthop Relat Res 2001;(388):58-67. 29. Laskin RS. The Genesis total knee pros- thesis: A 10-year followup study. Clin Orthop Relat Res 2001;(388):95-102. 30. Berger RA, Meneghini RM, Jacobs JJ, et al. Results of unicompartmental knee arthroplasty at a minimum of ten years of follow-up. J Bone Joint Surg Am 2005;87:999-1006. 31. Murray DW, Goodfellow JW, O’Connor JJ. The Oxford medial unicompartmen- tal arthroplasty: A ten-year survival study. J Bone Joint Surg Br 1998;80:983-989. 32. Baker PN, van der Meulen JH, Lewsey JF, et al. The role of pain and function in determining patient satisfaction after total knee replacement. Data from the National Joint Registry for England and Wales. J Bone Joint Surg Br 2007; 89:893-900. 33. Ranawat CS, Padgett DF, Ohashi Y. Total knee arthroplasty for patients younger than 55 years. Clin Orthop Relat Res 1989;(248)27-33. 34. Diduch DR, Insall JN, Scott WN, et al. Total knee replacement in young, active patients. Long-term follow-up and func- tional outcome. J Bone Joint Surg Am 1997;79:575-582. 35. Griffin FM, Scuderi GR, Insall JN, et al. Total knee arthroplasty in patients who were obese with 10 years followup. Clin Orthop Relat Res 1998;(356)28-33. 36. Gatha NM, Clarke HD, Fuchs RF, et al. Factors affecting postoperative range of motion after total knee arthroplasty. J Knee Surg 2004;17:196-202.
  27. 27. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 455 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: Techniques and results 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.
  28. 28. BC MEDICAL JOURNAL VOL. 52 NO. 9, NOVEMBER 2010 www.bcmj.org456 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.
  29. 29. VOL. 52 NO. 9, NOVEMBER 2010 BC MEDICAL JOURNAL 457 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