Juni 2015, Vol. 22, Nummer 2. Nederlands Tijdschrift. rthopaedie. voor. Officieel orgaan van de Nederlandse Orthopaedische Vereniging

Juni 2015, Vol. 22, Nummer 2

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TRIATHLON A DECADE OF FUNCTION

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The Triathlon ® Single Radius Design influences patient outcome¹ ² ³ ,

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At Stryker we are convinced of the link between implant design and patient functional outcome. That’s why every one of the 1,000,000 plus Triathlon TKA knees implanted worldwide since 2004 features the patented single radius design. To hear more about the Triathlon knee system please speak to your local Stryker Representative.

¹ David F Hamilton, Richard Burnett, Colin R Howie, James T Patton, Matthew Moran, A. Hamish Simpson, Paul Gaston Implant design influences patient outcome after total knee arthroplasty. A PROSPECTIVE DOUBLE-BLIND RANDOMISED CONTROLLED TRIAL. Bone Joint J 2015;97-B:64–70 2.Cook et al. Functional Outcomes Used to compare Single Radius and Multiradius of Curvature Designs in Total Knee Arthroplasty. J Knee Surg 2012;25:249–254 3. Scott et al. Five-year survivorship and patient-reported outcome of the Triathlon single-radius total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. © 2015 Stryker Corporation. Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: Stryker, Triathlon. All other trademarks are trademarks of their respective owners or holders. A surgeon must always rely on his or her own professional clinical judgment when deciding whether to use a particular product when treating a particular patient. Stryker does not dispense medical advice and recommends that surgeons be trained in the use of any particular product before using it in surgery. The information presented is intended to demonstrate the breadth of Stryker product offerings. A surgeon must always refer to the package insert, product label and/or instructions for use before using any Stryker product. Products may not be available in all markets because product availability is subject to the regulatory and/or medical practices in individual markets. Please contact your Stryker representative if you have questions about the availability of Stryker products in your area.

TRIATH-AD-3

oorwoord Normaliter schrijft de hoofdredacteur een stuk over de inhoud van deze editie van het tijdschrift of een meer algemeen stuk over de toestand in de wereld. In dit voorwoord wil ik u graag meenemen naar de 11 mei editie van de Annals of Medical Care, waarin Atul Gawande schreef over een artikel dat de lawine aan zorg beschreef die patienten fysiek, psychisch en financieel benadeelde (http://www.newyorker.com/ magazine/2015/05/11/overkill-atul-gawande). Dit stuk raakte mij dusdanig dat ik mij deze keer wil laten verleiden tot een vorm van plagiaat en zal dus ook enkele passages citeren: “The researchers called it “low-value care.” But, really, it was no-value care. They studied how often people received one of twenty-six tests or treatments that scientific and professional organizations have consistently determined to have no benefit or to be outright harmful. Their list included doing an EEG for an uncomplicated headache (EEGs are for diagnosing seizure disorders, not headaches), or doing a CT or MRI scan for low-back pain in patients without any signs of a neurological problem (studies consistently show that scanning such patients adds nothing except cost), or putting a coronary-artery stent in patients with stable cardiac disease (the likelihood of a heart attack or death after five years is unaffected by the stent).”

Zou deze onnodige zorg ook in ons land en binnen ons vak bestaan? U kent vast ook die mensen waarbij een scopie van de knie werd verricht bij reeds bestaande radiologisch zichtbare afwijkingen, waarbij een scopische Neerplastiek werd uitgevoerd omdat de patient toch reele klachten had of waarbij de spondylodese werd verricht vanwege aanhoudende rugklachten bij discopathie. De vraag die Atul Gawande zich stelt en die ik ook wanhopig probeer te beantwoorden is de volgende: Waarom doen wij als dokters deze bewezen ineffectieve ingrepen terwijl wij natuurlijk weten van de stand van de wetenschap omtrent deze genoemde ingrepen? Is het de verwachting die de patient reeds heeft voor binnenkomst in de spreekkamer? Hebben we te goede diagnostische hulpmiddelen en zien we meer dan vroeger? Heeft het te maken met verlegenheid: we moeten toch iets doen tenslotte?

Juni 2015, Vol. 22, Nummer 2

Inhoud Voorwoord Taco Gosens

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Gains from the national implant registry go beyond quality control - a case report about its contribution in forensic sciences Tim A.E.J. Boymans, Martijn G. Schotanus, Eduard S. Krijgsman, Pieter B.J. Tilman and Emil H. van Haaren

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Dynamic splint for treatment of the dislocated hip in developmental displacement of the hip: a four-year evaluation Marijn J. Warners, Dirk P. ter Meulen, Jan D. Visser and Patrick G.M. Maathuis

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Dislocations of double mobility cups in compliant and non-compliant patients Bas de Hartog, Tom Wetzels, Paul C. Rijk and Peter F. Doorn

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Is MRI sensitive and specific enough in detecting cartilaginous lesions in the patellofemoral compartment after patellar dislocation? Navin Gurnani, Valerie G. Niehe, Emile G. Coerkamp and Ewoud R.A. van Arkel

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Clear instructions reduce missing responses in pen-and-paper collected Patient Reported Outcome Measures: A randomized study Loes W.A.H. van Beers, Vanessa A.B. Scholtes, Margot van Wermeskerken, Olvert A. Berkhemer and Rudolf W. Poolman

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Van de Vereniging

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“The virtuous patient is up against long odds, however. One major problem is what economists call information asymmetry. In 1963, Kenneth Arrow, who went on to win the Nobel Prize in Economics, demonstrated the severe disadvantages that buyers have when they know less about a good than the seller does. His prime example was health care. Doctors generally know more about the value of a given medical treatment than patients, who have little ability to determine the quality of the advice they are getting. Doctors, therefore, are in a powerful position. We can recommend care of little or no value because it enhances our incomes, because it’s our habit, or because we genuinely but incorrectly believe in it, and patients will tend to follow our recommendations.”

Dat zet je toch aan het denken, nietwaar? Blijkbaar dringen de levels of evidence maar lastig door in de spreekkamer: het gaat waarschijnlijk meer om het level of confidence waarmee de arts de patient het probleem uitlegt. Dr. Taco Gosens, hoofdredacteur

i Voor sommige artikelen is additioneel

materiaal beschikbaar op de website www.ntv-orthopaedie.nl, waaronder kleurenfoto’s en/of videobeelden. Deze artikelen zijn herkenbaar aan de volgende pictogrammen: Kleurenfoto's Videobeelden

Quick Response (QR) codes worden gebruikt voor een directe link naar het proefschrift. Hiervoor heeft u een smartphone en een QR code reader app nodig.

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Nederlands Tijdschrift voor

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Vol 22 jun ’15

REDACTIE Dr. Taco Gosens, hoofdredacteur Dr. Harmen B. Ettema Dr. Wouter L.W. van Hemert Dr. Hans (J).G.E. Hendriks Dr. Loes Janssen Dr. Job L.C. van Susante CORRECTOREN Mw. Sue Morrenhof-Atkinson REVIEWERS Dr. Bart J. Burger Mw. Geke A.W. Denissen Dr. Peter J. Emans Gert Jan P. Geysen Dr. Taco Gosens Olav P. van der Jagt Dr. Edwin J.P. Jansen Dr. J. Wim Morrenhof Mw. Dr. Marieke Ostendorf Dr. Hans (J.)A. van der Sluijs

UITGEVER & REDACTIESECRETARIAAT Serendipity Publishing Dorpsweg 81 1676 GE Twisk Telefoon: 0651-174410 E-mail: [email protected] Richtlijnen voor Auteurs www.ntv-orthopaedie.nl OPLAGE & FREQUENTIE 1.550 exemplaren, verschijnt elk kwartaal ABONNEMENTEN Het Nederlands Tijdschrift voor Orthopaedie wordt gratis toegezonden aan alle leden van de Nederlandse Orthopaedische Vereniging. Abonnementen Beneluxlanden  64,91 per jaar (excl. 6 % BTW). COPYRIGHT © 2015 NOV & Serendipity Publishing ISSN 1 380-653X

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Nederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

De Nederlandse Orthopaedische Vereniging werd op 1 mei 1898 in Amsterdam opgericht. De Vereniging heeft als doel: - Het bevorderen van studie en het verbreiden van kennis van de conservatieve en operatieve orthopedie onder artsen. - Het behartigen van de sociale belangen van de artsen die de orthopedie uitoefenen, zowel binnen de vereniging als daar buiten. Het Nederlands Tijdschrift voor Orthopaedie is het officiële orgaan van de Nederlandse Orthopaedische Vereniging. Het heeft ten doel de leden van de Vereniging en andere geïnteresseerden te informeren over ontwikkelingen op orthopedisch gebied, waarbij zowel klinische als fundamentele aspecten worden belicht. Deze doelstelling wordt verwezenlijkt in de vorm van oorspronkelijke artikelen, editorials en verslagen van wetenschappelijke vergaderingen, met name die van de NOV. Naast verenigingsnieuws wordt ook aandacht besteed aan recent verschenen literatuur en proefschriften. Voorts worden congressen, symposia en workshops op het gebied van de orthopedie aangekondigd. Beweringen en meningen, geuit in de artikelen en mededelingen in deze publikatie, zijn die van de auteur(s) en niet (noodzakelijkerwijs) die van de redactie. Grote zorgvuldigheid wordt betracht bij de samenstelling van de artikelen. Fouten (in de gegevensverwerking) kunnen echter niet altijd voorkomen worden. Met het oog hierop en omdat de ontwikkelingen in de medische wetenschap snel voortschrijden, wordt de lezer aangeraden onafhankelijk inlichtingen in te winnen en/of onderzoek te verrichten wat betreft de vermelde diagnostische methoden, doseringen van medicijnen, enz. De redactie wijst elke verantwoordelijkheid of aansprakelijkheid voor (de juistheid van) dergelijke gegevens van de hand en garandeert noch ondersteunt enig produkt of enige dienst, geadverteerd in deze publikatie, noch staat de redactie garant voor enige door de vervaardiger van dergelijke produkten gedane bewering. Conform de richtlijnen van de Inspectie voor de Gezondheidszorg (sectie reclametoezicht) zijn reclame-uitingen voor en productinformatie van receptgeneesmiddelen door farmaceutische bedrijven in het Nederlands Tijdschrift voor Orthopaedie alleen gericht op personen die bevoegd zijn om de betreffende geneesmiddelen voor te schrijven.

Gains from the national implant registry go beyond quality control - a case report about its contribution in forensic sciences i www.ntv-orthopaedie.nl/boymans2202/

Tim A.E.J. Boymans, Martijn G. Schotanus, Eduard S. Krijgsman, Pieter B.J. Tilman and Emil H. van Haaren Rapid and correct identification of victims from accidents, crimes or disasters is of crucial importance for the investigation team and the relatives. Medical devices such as joint prostheses and pacemakers implanted in the victim can accelerate this process. Complete and accurate registration of these implants on a large scale is therefore a prerequisite. In this case-report we discuss the additional advantages of a national registry for implants in the field of forensic sciences.

Case On a Wednesday morning in the fall of 2014 a woman got hit by a train and passed away immediately. Unfortunately, the victim was not carrying anything that could facilitate identification. The impact of the train on the woman’s body was of such severity that identification based on recognition was not possible. Besides body parts the investigation team found components of two total hip prostheses on and alongside the railway track (Figure 1). They appeared to be two cementless stems of the brand Stryker, type ABG-2 size 5, two 28mm cobaltchrome heads (one with neck length 0 and the other with neck length +4), one cementless cup of the brand Stryker, type ABG size 52mm (provided with

Figure 1. Overview of the accident site. Source: Geert Roeloffs, forensic investigator, Police district Limburg. T.A.E.J. Boymans, MD1, resident in orthopaedic surgery, M.G. Schotanus, MSc1, movement scientist, E.S. Krijgsman, MD2, forensic doctor, P.B.J. Tilman, MD1, orthopaedic surgeon, E.H. van Haaren, MD, PhD1, orthopaedic surgeon 1 Orbis Medisch Centrum Sittard, Sittard-Geleen, The Netherlands 2 GGD Zuid-Limburg, Sittard-Geleen, The Netherlands

Figure 2. The components of the two total hip prostheses that were implanted in the victim and eventually lead to identification.

two additional fixation spikes) and one cementless cup of the brand Stryker, type Trident size 56mm. Both cups had a poly-ethylene insert (Figure 2). The forensic investigation team contacted our department of orthopaedic surgery. The components found at the injury site were recognized as frequently used prostheses in our clinic and were possibly implanted by our team, however, years before the Dutch Arthroplasty Register (Landelijke Registratie Orthopedische Implantaten, LROI) was set up, which occurred in 2007. By consulting our own registry of operations we were able to draw up a list of patients meeting the above mentioned combination of prosthesis types. Eventually, there was only one patient with the exact combination of these eight components implanted. The serial numbers of the components in the concerned patient’s medical file corresponded precisely with those on the components found on the site of the accident. It pointed out that the victim was a 66-year-old lady living in the area of the accident. Nederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

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Gains from the national implant registry go beyond quality control - a case report about its contribution in forensic sciences

Discussion

Vol 22 jun ’15

Identification of victims from accidents, crimes and disasters is an important and contemporary matter. This is not only demonstrated by the abovementioned case, but also by the airplane disaster with flight MH17 last summer. During the identification procedure of these victims again it became clear how difficult and challenging this process can be.1-3 In the case of multiple victims with ‘known’ identity (for example using a list of passengers) one speaks of a ‘closed population investigation’ (e.g. MH17). By contrast, an ‘open population investigation’ involves completely unknown victims (e.g. the abovementioned case), leaving the investigation team with less clues about the possible identity.4-5 Because our team of orthopaedic surgeons registered all joint prostheses in a (selfdeveloped) database since 2003, we were able to provide a decisive clue in a very difficult open population investigation. Luck was on our side given the fact that the combination of prosthesis types and sizes only appeared once in this database. Regular identification techniques Identification using fingerprints, dental profiles and DNA-investigation is the golden standard.6 These techniques have proven to lead to successful identification in many cases, yet they are not always applicable for example in case of severe burning or mutilation. Identification of an unknown victim using DNA-investigation is time consuming, expensive and requires an existing DNA-profile of the victim in a database. In case of a closed population investigation a DNA-profile of the victim can be matched with a DNA-profile of family members. However, also DNA-investigation is not always possible, in particular not in case of advanced decomposition or severe carbonization due to burning. Comparing radiographs of body parts of the victim is likewise only useful in case of a closed population when the investigators have some presumption of the identity of the victim.4,6 The role of medical implants in the identification process The presence of an implant gives additional information about the victim: 1) there was a disease or medical condition which made an implant necessary; 2) the victim had access to the sources needed to obtain this implant; 3) depending on the kind of implant this could be a clue for the age of the victim.4 In addition, implants are often made of metal alloys (e.g. joint prostheses, osteosyntheses and pacemakers) and therefore able to withstand be-

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ing damaged in (high-impact) accidents or burnings.6 Furthermore, the presence of one or more implants without a unique code can offer a rich amount of information that could accelerate identification. The combination of sizes of joint prosthesis (like the abovementioned case), the position of osteosynthesis material and the length and orientation of screws combined with their anatomical location can be very directive in the identification process.4-6 The role of a national implant registry Experience shows that deficiencies or imperfections can become apparent during the life span of an implant. Two recent examples are the PIP breast implants and the metal-on-metal hip implants. The minister of Health, Welfare and Sports declared to investigate the possibilities for a national registry of orthopaedic, cardiologic, plastic and gynaecologic implants in March 2014. The main function of this implant registry is traceability, which means the ability to trace back an implant to the hospital and finally to the individual patient. This will serve identification of all patients with a certain type of implant in case unexpected side effects start to occur frequently in a population. Current situation regarding existing implant registries The scientific associations of the medical specialties orthopaedic surgery, cardiology, plastic surgery and gynaecology have all started to register (a part of) their implants. The Dutch Arthroplasty Register (LROI) is a digital quality registry founded by the Netherlands Orthopaedic Association (NOV) in 2007 and aims to warrant implant traceability. This registry not only contains hip and knee prostheses but also shoulder, elbow and ankle implants. Materials used for osteosynthesis are not yet registered. In 2013 all health facilities using orthopaedic implants participated in LROI-registry, leading to a national completeness of 98% for hip arthroplasty and 96% for knee arthroplasty.8,9 The National Cardiovascular Data Registry (NCDR) was founded by the Netherlands Society of Cardiology (NVVC) and contains registries of pacemakers and implantable cardioverter defibrillators (ICDs). The national coverage of the cardiologic registry is approximately 85%.7 The Dutch Institute Clinical Auditing (DICA) foundation has been appointed by the Netherlands Society for Plastic Surgery (NVPC) to establish a national registry for breast implants (Dutch Breast Implant Registry (DBIR)).7 The Dutch Society of Obstetrics and Gynaecology

Hoogwaardigheid in moderne cementeringstechniek

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PAL

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Gains from the national implant registry go beyond quality control - a case report about its contribution in forensic sciences

(NVOG) uses a mandatory national registration of all synthetic material (in particular meshes) used for prolapse surgery since May 2014.10

Vol 22 jun ’15

Areas of concern regarding the current forms of registration The completeness of the most advanced registries (i.e. LROI and NCDR) are high (96% and 85% respectively) but not yet 100%. In case of the LROI a reason for this could be the fact that not all of the hemi-hip arthroplasties performed by trauma surgeons are being registered yet. In September 2013, an agreement was made between the NOV and the Dutch Society of Trauma Surgery (NVT) stating that the NVT will also register all implants in the LROI . A legal mandate would facilitate this.7 Furthermore, correct use of definitions (both indication and prosthesis type), structural registration and digitalization of data by only a small amount of persons as well as frequent checks between the number of performed operations and the number of procedures registered, will improve the completeness even further.11 Patient data often registered includes name, date of birth and the (institute specific) patient number. The encrypted personal identification number (BSN) is mainly used by cardiology and orthopaedics, but less consistent by plastic surgery.7 The codes printed on implants are mainly the sizes and type numbers but rarely a unique identification number. The Food and Drug Administration (FDA) were obliged to use the Unique Device Identification (UDI) number for all medical devices in 2013. This unique code will augment the traceability of each individual implant further. The European Union (EU) adopted this proposal and will implement it gradually.7 Finally, the way the registration is performed deserves attention. In many institutions and health care facilities the actual registration of patient and/or implant data is done manually, possibly leading to errors, in particular in case of long series of numbers and letters. A uniform barcode system (such as the UDI number) in combination with barcode scanners will reduce the amount of errors considerably.7 Conclusion Complete and correct registration of all implants is not only a prerequisite for improved traceability in case of quality issues, but can also play a crucial role in the identification of victims from accidents, crimes and disasters. A national implant registry containing unique data from the patient (e.g. en-

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crypted personal identification number) and the implant (e.g. unique device identification number), registered in an automated way using barcode scanners, and stored on a central database is therefore an essential instrument. Disclosure statement Nothing to disclose. This article was reviewed by the editor-in-chief and one deputy-editor, and it underwent open review by two outside experts. The deputy-editor reviewed each revision of the article, and it underwent a final review by the editor-inchief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and the language corrector.

References 1. Stoker E, Thijssen W. ‘Mooi, denk ik: man met kroon en implantaten’. Volkskrant 8 september 2014. 2. Stoker E, Thijssen W. ‘Jullie zoon is geïdentificeerd’. Volkskrant 8 november 2014. 3. Vliegramp MH17: Hoe worden de lichamen van slachtoffers geïdentificeerd? http://www.rijksoverheid.nl/ onderwerpen/vliegramp-mh17/vraag-en-antwoord/ hoe-worden-de-lichamen-van-slachtoffers-geidentificeerd.html, geraadpleegd op 10 december 2014. 4. Wilson RJ, Bethard JD, DiGangi EA. The use of orthopedic surgical devices for forensic identification. J Forensic Sci. 2011;56:460-9. 5. Matoso RI, De Novaes Benedicto E, De Lima SHR, Prado FB, Daruge E, Daruge E Jr. Positive identification of a burned body using an implanted orthopedic plate. Forensic Science International. 2013;229:168.e1-5. 6. Durão CH, Pinto R, Ribeiro C, Vieira D. Importance of a national arthroplasty register for identification by medical examiner. Rev Bras Orthop. 2012;47:651-5. 7. Van de Laar CWE, Van Berkel JJ, De Jong C, Hermsen SA, De Bruijn ACP, Janssen SWJ. Registratie van implantaten in Nederland. Inventarisatie en pilot. RIVM Rapport 2014-0089. Bilthoven: Rijksinstituut voor Volksgezondheid en Milieu; 2014. 8. Van Steenbergen LN, et al. LROI Rapportage 2013: zicht op kwaliteit & veiligheid. ’s Hertogenbosch: Nederlandse Orthopaedische Vereniging en Stichting LROI; 2014. 9. Van Steenbergen LN, Denissen GAW, Spooren A, Van Rooden SM, Van Oosterhout FJ, Morrenhof JW, Nelissen RGHH. More than 95% completeness of reported procedures in the population-based Dutch Arthroplasty Register. External validation of 311,890 procedures. Acta Orthopaedica. 2015;86(4):1-8. doi:10.3109/17453 674.2015.1028307 10. Nota Gebruik van kunststof materiaal bij prolapschirurgie. Versie 2.1. Utrecht: Nederlandse Vereniging voor Obstetrie en Gynaecologie; 2014. 11. Denissen G. Registratieoptimalisatie voor maximale kwaliteit LROI. NTVO. 2014;21(3):92-93.

Dynamic splint for treatment of the dislocated hip in developmental displacement of the hip: a four-year evaluation i www.ntv-orthopaedie.nl/warners2202/

Marijn J. Warners, Dirk P. ter Meulen, Jan D. Visser and Patrick G.M. Maathuis Background: Developmental displacement of the hip (DDH) in newborns is commonly treated with the Pavlik harness. The dynamic splint was developed in 1985 and has proven efficacy in treating DDH in newborns. Since 2001 the dynamic splint is also used for DDH with dislocation. Complications of this treatment are generally negligible. A severe complication though is avascular Necrosis (AVN) of the hip. This complication can manifest during the first years after treatment. Purpose: This study evaluates the 4 year results of dynamic splint treatment on concentric reduction of the dislocated hip in DDH and the incidence of AVN. Methods: A consecutive series of 16 patients with DDH and dislocation treated with the dynamic splint between 2001 and 2004 was retrospectively evaluated. The severity of dislocation before treatment and the degree of concentric reduction after treatment were classified according to the position of the femoral head in relation with the PerkinsOmberdanne/Hilgenreiner line. The degree of dysplasia at follow-up was measured using the Center-Edge Angel (CEA). AVN after treatment was classified with the Kalamchi/MacEwen classification. Results: Thirteen hips (81%) were successfully reduced by the dynamic splint. Three hips remained dislocated and required closed reduction and casting under general anaesthesia. After reduction eight hips did not require any additional treatment. Eight required additional brace treatment due to residual dysplasia. Two patients (13%) in this second group developed radiographic signs of AVN, one was classified as type I the other as type II. Conclusion: Based on the results of this study the dynamic splint seems both a safe and effective treatment for DDH with dislocation. The hips with persisting dislocation after initial treatment achieved successful reduction after additional treatment. According to radiographic measurements none of the hips were dysplastic at final follow-up. None of the hips, solely treated with the dynamic splint, developed AVN. Two patients with residual dysplasia and dislocation after initial dynamic splint treatment showed mild AVN at four year follow-up.

Introduction Developmental displacement of the hip (DDH) is defined as an abnormal formation of the acetabulum in which the femur head is not held firmly in the underdeveloped socket. The most severe form of DDH induces subluxation or luxation. In these cases the femoral head is dislocated outside the confines of the inadequately formatted acetabulum.1 In The Netherlands the incidence of DDH in new-borns is estimated at 3.7% and the incidence of hip dislocations at 0.4%.2 In the mid 20th-century Arnold Pavlik developed a harness for treatment of hip dislocations in young infants which is still considered as the gold standard.3,4 However, difficulties have been enDrs. M.J. Warners1, Drs. D.P. ter Meulen2, Prof. dr. J.D. Visser1, Dr. P.G.M. Maathuis1 1 Department of Orthopaedic Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands 2 Department of Orthopaedic Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands Corresponding author: M.J. Warners Email: [email protected]

countered with its usage. Therefore in 1985 the dynamic splint for the treatment of DDH was developed.5 It combines the dynamic features of the Pavlik harness with the user-friendliness of the Camp abduction splint (Figure 1). This splint showed to be just as effective as the Pavlik harness, and obtained concentric reduction in 80 to 90% of patients.5 In both orthotic devices the femoral head is reduced gently by the weight of the legs, positioning the hip in flexion and abduction, which leads to reduc-

Figure 1. The dynamic splint with hinges that permit abduction, flexion within predetermined limits and rotation. Nederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

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Vol 22 jun ’15

Aequalis Ascend Flex TM

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This convertible shoulder system is an update of the Aequalis system by keeping proven key principles of the 3rd generation and Reversed prosthesis! Proximal bone preserving geometry due to the curved design which avoids supraspinatus damaging Female taper for easy access to prepare the glenoïd Reduction of notching with 145° inclination without instability Reduce lateralization of the humerus due to the offset tray

Marijn J. Warners, Dirk P. ter Meulen, Jan D. Visser and Patrick G.M. Maathuis

tion and stabilization.6 Extreme passive abduction however can compromise vascularisation of the femoral head which can lead to avascular necrosis (AVN), a severe complication in the treatment of DDH. When the Pavlik harness straps are properly adjusted the prevalence of AVN is negligible.7 The dynamic splint reduces inappropriate use and increases parental compliance, which is mandatory for successful treatment.8 Eighty-one percent of the parents of children treated with the splint are positive about the user-friendliness. Furthermore the dynamic splint showed to be successful in the treatment of DDH and the incidence of AVN was similar.5,8 This study has a four-year follow-up because radiographic changes may only manifest several years after treatment.9 The dynamic splint has proven efficacy in the treatment of isolated DDH. The aim of this study is to evaluate the results of dynamic splint treatment on concentric reduction of the dislocated hip in DDH and the incidence of AVN. Materials and Methods After approval from our institutional review board, dynamic splint treatment was retrospectively evaluated for patients with DDH and a dislocation who were treated at the University Medical Center Groningen between 2001 and 2004. Inclusion criteria were: (1) DDH with dislocation diagnosed using either ultrasound or AP X-Rays, (2) age between 3-7 months at start of treatment, (3) radiographic evaluation at initial diagnosis, directly after splint treatment and after a period of at least 3 years. Exclusion criteria were: (1) Chromosomal abnormalities, (2) neurological syndromes, (3) prior treatment for hip dysplasia, (4) or a need for surgical reduction. Sixteen patients met these inclusion and exclusion criteria. Three patients were excluded due to a surgical intervention (Pemberton osteotomy), 3 patients were excluded due to a lack of radiographic follow-up. Patients were initially treated with the dynamic splint in order to achieve closed reduction. The dynamic splint could only be adjusted properly if the hips were able to abduct with 40°. The splint was worn 24 hours a day. During treatment patients were regularly seen at the outpatient clinic. After 2 weeks reduction was evaluated using X-Rays . In case of persistent dislocation patients underwent closed reduction under general anaesthesia and casting for a period of three months. If reduction was stable but dysplasia remained, dynamic splint treatment was continued for children aged 3-12 months. Children of ambulatory age (1-2 years) were treated with a Hilgenreiner brace.6

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Radiographs were analysed at three time-points: (T1) initial diagnosis, (T2) after treatment and (T3) after a period of 3-5 years. At diagnosis (T1) and directly after treatment (T2) the degree of dysplasia was measured with the acetabular index (ACI) and subsequently the degree of dysplasia was staged using the criteria of Tönnis and Brunken.10 At mid-term follow-up (T3) the Center-Edge Angle (CEA) was added, because the capital femoral epiphysis achieved full ossification.11 The degree of dislocation was assessed using the Perkins-Omberdanne line.12 This line, drawn perpendicular to the Hilgenreiner line creates four quadrants. The hip is subluxated when the capital femoral epiphysis is located lateral to the Perkins line but is still below the Hilgenreiners line. A hip is luxated when the capital femoral epiphysis is above this line.12 At T3 the degree of avascular necrosis (AVN) was classified by the Kalamchi/MacEwen classification that differentiates four types of AVN.13 Measurements were done by a radiologist and were repeated by a research-fellow familiar with the subject. In case of variability between observers the senior author was consulted. Statistical Analysis Statistical analysis was performed using Stata (StataCorp. 2011. Stata Statistical Software: Release 12. College Station, TX: StataCorp LP.). Descriptive statistics were used to characterize the study population. Categorical variables were described as percentages and continuous variables were expressed as means and standard deviations (SD) (parametric data) or median and interquartile range (IQR) (non-parametric data). Associations between dichotomous data were tested with the Chi-square test and categorical data were compared using the Chi-square test for trend; Fisher’s correction was used when necessary. Continuous variables were estimated by using a Mann-Whitney U for nonparametric data. Differences were considered statistically significant when p < 0.05. Results Complete follow-up was available for 16 patients. All 16 patients had a one-sided dislocation of the hip. The average age of the study population was 4.5 months (SD 1). All patients were female. Thirteen patients (81%) had a right-sided DDH with dislocation. Nine hips (56%) were luxated and 7 were subluxated as classified using the PerkinsOmberdanne line. The severity of hip dysplasia, classified according to Tönnis en Bruncken, showed mild dysplasia in 7 cases (44%) and severe dysplasia in 9 cases (46%). There was no relation between Nederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

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Dynamic splint for treatment of the dislocated hip in developmental displacement of the hip: a four-year evaluation

Vol 22 jun ’15

Figure 2. X-Ray of a 8-year old girl with a right-sided avascular necrosis stage II according to the Kalamchi and MacEwen classification.

Figure 3. X-Ray of a 20-months old girl with failure of growth of the left ossific nucleus within 1 year after treatment, classified as AVN stage I according to the Kalamchi and MacEwen.

the severity of dysplasia and the type of luxation (p=0.34). Thirteen hips (81%) were successfully reduced after use of the dynamic splint. Three hips remained dislocated and required closed reduction and casting under general anaesthesia. Of the 13 patients who had successful reduction after initial dynamic splint treatment, 8 hips (50%) did not require additional treatment. The other five required a Hilgenreiner brace due to residual dysplasia. Of the 3 patients that needed closed reduction and casting under anaesthesia 2 needed additional treatment because of residual dysplasia with additional bracing. Patients were treated for an average duration of 6.5 months (SD 2, range 3-10). At final follow-up (median 45 months, IQR: 39-57) none of the hips remained dislocated. The radiographic evaluation showed an improvement of the ACI although one hip remained mildly dysplastic according to the criteria of Tönnis and Brunken. The average CEA of the affected hips was 35° (SD 4, 28-43). None were below 19°, which is the lowest normal value (Fredensborg N 1976). Two patients (13%) developed radiological signs of AVN at T3 according to the Kalamchi/MacEwen classification. One of these patients was staged with grade 2 AVN, and had closed reduction and casting after failed dynamic splint treatment (Figure 2.) The other patient was staged as grade 1 (Figure 3.). The degree of AVN of the other patient was staged as grade 1 (Figure 3.). Both patients with AVN had been treated with a Hilgenreiner brace due to residual dysplasia. There was no relationship between the severity of dysplasia or dislocation and the oc-

currence of AVN (p=1, p=0.175). Patients with AVN were not treated for a longer period of time (4.2 SD 1 vs. 6.9 SD 2, p=0.94).

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Discussion Treatment of DDH with the dynamic splint is widely accepted due to its safety, ease of use and good results5,8 Dysplasia has a wide range of severity. Although less common, sub- and dislocation of the femur head represent a more severe form.1 This study was set up to evaluate the results of dynamic splint treatment for patients with DDH and dislocation of the hip. Before interpreting the results of this retrospective study, the limitations must be pointed out. First of

Figure 4. X-Ray of the same girl as in fig. 3 with an improved acetabular and femoral head development, with no more signs of AVN 4 years after treatment.

Marijn J. Warners, Dirk P. ter Meulen, Jan D. Visser and Patrick G.M. Maathuis

all, the study consists of a limited number of patients. This however, can be expected because of the relatively low prevalence of DDH in combination with a dislocation.2 Another difficulty concerns the accuracy of the radiographic measurements, even though measurements were done by two observers to minimize measurement error. In addition, the radiographic classifications that were used to stage AVN have questionable reliability.14 Due to the retrospective nature of the study data was collected with a relative wide variation in time points and clinical findings were not uniformly documented. Ideally this study should have had a control group that was treated with the Pavlik bandage. Since surgery is an extra risk factor for AVN, patients in need of a Pemberton osteotomy were excluded. This might have influenced the success rates, although adding a surgical intervention could lead to equivocal interpretations.15 To diagnose AVN sufficient time should pass for clinical changes to become manifest. With the results of this study no conclusions can be drawn about the long-term follow-up. AVN however, may become radiographically apparent a few years after treatment. This four-year follow-up study should be sufficient in detecting the first radiographic signs of this severe complication.9 According to our study results, treatment with the dynamic splint results in a concentric reduction in 81% of the dislocated hips in DDH (T2). This is largely comparable with the results of Pavlik harness treatment for DDH with dislocations.6 At final follow-up (T3) none of the hips remained dislocated. None of the hips remained dysplastic at final follow-up (T-3) as measured with the ACI and CEA although additional treatment was needed in several cases. This is in accordance with prior results of dynamic splint treatment for DDH in non-dislocated hips.5 The combination of tight abduction and rigid immobilization, caused by either the Pavlik harness or the dynamic splint, can compromise vascularity, which eventually can cause AVN.16 Predictive factors for AVN include the severity of dislocation17, age at the time of treatment initiation18, male gender, bilateral dislocations, parental non-compliance and the duration of treatment.19 The hips with persisting dysplasia after initial treatment achieved successful reduction with additional procedures. In this group the incidence of AVN is largely comparable to the percentage of AVN after Pavlik treatment.16,20,21 It is notable that both patients in this study who developed AVN (13%) have had additional treatment. They started treatment at 5 months of age. At this relatively young age the ossific nucleus of the femur can be underdeveloped, which could be associated with an increased

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risk of AVN. Another risk factor with possible influence was the prolonged duration of treatment of patients in our study population compared with the duration of dynamic splint treatment for patients with isolated dysplasia in prior studies (6.7 months vs. 3.6 months).5,8 However, the patients in our study who developed AVN were not treated significantly longer than the other patients in our cohort. None of the patients who were solely treated with the dynamic splint developed signs of AVN during this study period.

jun ’15

Conclusion The main goal of this study was to evaluate the results of dynamic splint treatment for patients with DDH and dislocation. The hips with persisting dislocation after initial treatment achieved successful reduction with additional procedures. According to radiographic measurements none of the hips remained dysplastic at final follow-up. No signs of AVN developed in the hips solely treated with the dynamic splint. In the hips with persistent dysplasia or dislocation, the incidence of AVN is largely comparable to the percentages of AVN after Pavlik treatment. Based on the results of this study, the dynamic splint seems both a safe and effective treatment for DDH with dislocation. Author contributions Study concept and design: MJW, PGMM, and JDV. Acquisition of data: MJW and PGMM. Rating of radiographic images: MJW, DTM, PGMM, and JDV. Analysis and interpretation of data: MJW, DTM and PGMM. Drafting of the manuscript: MJW, DTM, PGMM, and JDV. Critical revision of the manuscript for important intellectual content: MJW, DTM, PGMM, and JDV. Approval of the final draft: all. Grant support No grant support. Disclosures One of the authors, Dr. Visser, receives royalties from the brace manufacturing company. The other authors have no disclosures. Writing assistance None. This article was reviewed by the editor-in-chief and one deputy-editor, and it underwent open review by two outside experts. The deputy-editor reviewed each revision of the article, and it underwent a final review by the editor-inchief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and the language corrector.


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Dynamic splint for treatment of the dislocated hip in developmental displacement of the hip: a four-year evaluation

References

Vol 22 jun ’15

1. Weinstein SL, Mubarak SJ, Wenger DR. Developmental hip dysplasia and dislocation – Part 1. J Bone Joint Surg. 2003;85(9):1824-32 2. Boere-Boonekamp MM, Kerkhoff TH, Schuil PB, et al. Early detection of developmental dysplasia of the hip in The Netherlands: the validity of a standardized assessment protocol in infants. Am J Public Health. 1998;88:285–288 3. Grill F, Bensahel H, Canadell J, et al. The Pavlik harness in the treatment of congenital dislocating hip: report on a multicenter study of the European Paediatric Orthopaedic Society. J Pediatr Orthop. 1988;8(1):1-8 4. Pavlik A. The functional method of treatment using a harness with stirrups as the primary method of conservative therapy for infants with congenital dislocation of the hip. Clin Orthop Relat Res. 1957;281:4-10 5. Visser JD. Dynamic Splint for Treatment of Congenital Dysplasia of the Hip. Journal of Pediatric Orthopaedics. 1985;5(1):85-88 6. Weinstein SL, Mubarak SJ, Wenger DR. Developmental Hip Dysplasia and Dislocation Part II. J Bone Joint Surg Am, 2003;85(10):2024-2035 7. Kitoh H, Kawasumi M, Ishiguro N. Predictive factors for unsuccessful treatment of developmental dysplasia of the hip by the Pavlik harness. Journal of Pediatric Orthopaedics. 2009;29(6):552-7 8. Gerritsen N. 2004. De effectiviteit van de dynamische heupabductiebeugel bij het verkrijgen van concentrische reductie van de geluxeerde heup bij ontwikkelingsdysplasie. Manuscript Rijks Universiteit Groningen in samenwerking met Universitair Medisch Centrum Groningen 9. Malvitz TA and Weinstein SL. Closed reduction for congenital dysplasia of the hip. Functional and radiographic results after an average of thirty years. J bone Joint Surg. 1994;76A: 1777-1792 10. Tonnis D. Brunken D. Eine abrenzung normaler und pathologischer Huftplannendachwinkel zur Diagnose der Huftdysplasie. Arch Orthop Unfallchir. 1868;64:197 -228

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11. Greenspan A. Orthopedic Imaging: A Practical Approach. 4th Edition. Philadelphia, Lippincott Williams & Wilkins, 2004 12. Schuenke M, Schulte E, Schumacher U, Ross LM Lamperti ED and.Voll M. General Anatomy and Musculoskeletal System - Latin Nomencl. 1st Edition. Thieme Medical Publishers, 2010. 13. Kalamchi A, and MacEwen GD. Avascular necrosis following Treatment of Congenital Dislocation of the HIP. J Bone Joint Surg. 1980;62(6):876-88. 14. Roposch A, Wedge JH, and Riedl G. Reliability of Bucholz and Ogden Classiﬁcation for Osteonecrosis Secondary to Developmental Dysplasia of the Hip. Clin Orthop Relat Res. 2012;470(12):3499-505 15. Domzalski M, Synder M. Avascular necrosis after surgical treatment for development dysplasia of the hip. Int Orthop. 2004;28:65. 16. Salter RB, Kostiuk J, Dallas S. Avascular necrosis of the femoral head as a complication of treatment for congenital dislocation of the hip in young children: a clinical and experimental investiation. Can J Surg. 1969;12:44 17. Inoue T, Naito M, Nomiyama H. Treatment of developmental dysplasia of the hip with the Pavlik harness: factors for predicting unsuccessful reduction. Journal of Pediatric Orthopaedics. 2001;10:186-191 18. Senaran H, Bowen JR, Harcke HT. Avascular necrosis rate in early reduction after failed Pavlik harness treatment of developmental dysplasia of the hip. Journal of Pediatric Orthopaedics. 2007; 27:192–197 19. Hassan FA. Compliance of parents with regard to Pavlik harness treatment in developmental dysplasia of the hip. Journal of Pediatric Orthopaedics. 2009;18(3):111-5 20. Fujioka F, Terayama K, Sugimoto N, et al. Long-term results of congenital dislocation of the hip treated with the Pavlik harness. Journal of Pediatric Orthopaedics. 1995;15:747-752 21. Viere RG, Birch JG, Herring JA, et al. Use of the Pavlik harness in congenital dislocation of the hip. An analysis of failures of treatment. J Bone Joint Surg Am. 1990;72:238-244

Dislocations of double mobility cups in compliant and non-compliant patients i www.ntv-orthopaedie.nl/hartog2202/

Bas de Hartog, Tom Wetzels, Paul C. Rijk and Peter F. Doorn Recurrent dislocation of a total hip arthroplasty (THA) remains a complex and challenging problem in orthopedic surgery. The treatment plan for recurrent dislocations must be personalized depending on the cause of the dislocations and the habitus of the patient. One treatment option is the use of a double mobility cup. The Medical centre Leeuwarden has been using the Avantage® cup (Biomet®) for the treatment of recurrent dislocations after primary THA. The initial results suggest that the Avantage® cup is an acceptable treatment for recurrent dislocations. However, the ultimate success of the Avantage® cup appears to be dependent on successful patient education.

Introduction Recurrent dislocations of a Total Hip Arthroplasty (THA) can lead to anxiety in the patient, frustration for the treating surgeon and damage to the prosthesis itself. Additionally, there are the expenses of hospital admissions, physiotherapy and resources such as hip abduction braces; none of which can be underestimated. According to the literature the incidence of dislocations of THAs varies between 1-10%. Revision THAs have a greater risk of dislocation with the incidence reported as between 10-50%.1,2,3,4,5,6,7 Dislocation of a THA is roughly always caused by impingement, after which the head siphons itself out of the cup. Impingement can occur due to contact of the components of a THA itself, or due to contact with soft tissue or osseous components. There are several risk factors associated with recurrent dislocations. These risk factors can be subdivided into component or surgery related factors (a malposition of the femoral or acetabular component, posterolateral approach or capsule removal), soft tissue factors (soft tissue impingement, abductor muscle weakness, soft tissue tension problems, previous surgery, neuromuscular diseases, hip fractures as a primary or secondary cause for a THA) and patient related factors such as female patients and poorly compliant patients (eg patients who cannot understand or cannot keep to the early post operative hip instructions).5,8,9 Depending on the B. de Hartog, MD, resident Orthopedic surgery, T. Wetzels, MD, resident Orthopedic surgery, P.C. Rijk, MD, PhD, Orthopedic Surgeon, P.F. Doorn, MD, PhD, Orthopedic surgeon, Medisch Centrum Leeuwarden, The Netherlands Corresponding author: B. de Hartog, MD Email: [email protected]

cause of impingement, there are different treatment options. It is therefore essential to recognize and determine the cause of impingement. In the event of a primary dislocation, a closed reduction under anaesthesia or dormicum can be performed. After a primary or secondary dislocation the patient can be fitted with a hip abduction brace. In most cases, this, in combination with advice concerning ‘avoidable movements’ proves to be sufficient intervention and recurrent dislocations will be avoided. When a recurrent dislocation occurs, revision surgery is usually necessary. Over the last few years, the Orthopaedic Department of the Medical Centre of Leeuwarden has been using the Avantage® cup (Biomet®) to treat recurrent dislocations of THAs. The Avantage® cup has a double

Figure 1. Double mobility system, a 28 mm metal head articulates in a large diameter PE liner, which can articulate in a fixed metal shell.


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Dislocations of double mobility cups in compliant and non-compliant patients

Table 1. Patient characteristics Group Number

Vol 22 jun ’15

Age

Female

Follow up

Total

22

73 yr (57 – 90)

54,5%

3 yr (2d – 6,4 yr)

Revision dislocation

15

74 yr (58 – 90)

53,3%

3,2 yr (2d – 6,4 yr)

Revision high risk

4

71 yr (63 – 80)

75%

3,4 yr (0,9yr – 5,3 yr)

Primary high risk

3

65 yr (56 – 73)

33,3%

1,3 yr (57d – 2,7 yr)

mobility system. The design is based on a tripolar system where a normal sized metal head articulates in a polyethylene (PE) liner and this liner in turn articulates in a metal shell (figure 1). The basic idea of the design is that the extra mobility provided by the PE liner prevents impingement and also allows the patient to achieve a greater range of motion (ROM). In this study we will discuss the first results of the Avantage® cup in the Medical Centre of Leeuwarden. Material and Methods In this retrospective study we analysed 22 cases in which an Avantage® cup was used in the period between October 2005 and November 2010 in the Medical Centre Leeuwarden (see table 1 and 2 for patient characteristics and indications). Four different orthopedic surgeons treated the patients, and in all cases the posterolateral approach was used. The study population consists of 10 male and 12 female patients. The average age of the patients at the time of surgery was 73 years (5790 years). The mean follow up was 3 years (2 days – 6.4 years). Six patients were deceased and one patient had a revision of the Avantage® cup within one year of surgery. Two patients had a follow up of less than 1 month. One patient died 2 days after surgery due to a cause not related to the surgery, the other patient refused follow up after discharge from hospital. These 2 patients have not been used in the further analysis. The Avantage® cup was used primarily in 3 patients after a hip fracture, because of the expected increased risk of dislocations. Two of these patients had a cerebral ischemic stroke and were (partially) paralytic on the fractured side. One patient was a chronic alcoholic. In the remaining nineteen patients the Avantage® cup was used during revision surgery. Four had loosening of the cup and risk factors associated with recurrent dislocation. Fifteen patients had

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Table 2. Indication for use of Avantage® cup Group Number Revision for recurrent dislocations Revision in high risk patients

15

4 1/4 history of subluxation 1/4 severe dementia 1/4 large acetabular defect 1/4 undefined

Primary in high risk patients

3

2/3 cerebral ischemic stroke 1/3 chronic alcoholic

a history of recurrent dislocation of which fourteen were THAs and one was hemiarthroplasty. The average dislocation rate before revision surgery was 3 (2-6) In six of the fifteen revision cases the neck length was increased during revision surgery. One patient also had the femoral stem revised. The average time between primary and revision surgery was 4.7 years (2.1 days -18.9 years). In the case of one patient, the cup was implanted six months after removing an infected cup. Before the removal of the primary cup the patient suffered recurrent dislocations. Two of the nineteen patients were at risk of suffering recurrent dislocations as they were non-compliant. One patient was a chronic alcoholic and the other had severe Alzheimer’s Disease. There were no recorded complications relating to the implantation of the Avantage® cup. One patient died two days after surgery due to a pre-existing pulmonary disease.

Bas de Hartog, Tom Wetzels, Paul C. Rijk and Peter F. Doorn

Table 3. Dislocations of Avantage® cup Group Number (%) Revision recurrent dislocation, n=13(*) Revision high risk, n=4 Primary high risk, n=3

1 (7,7%) 0 (0%) 2 (66,7%)

(*) 2 exclusions due to short follow up

Results Despite adequate follow up, three of the twenty patients suffered a dislocation of the Avantage® cup (table 3). In two of these cases the Avantage® cup was placed primarily and in one case it was used in revision surgery due to recurrent dislocations. All three patients proved difficult to instruct. Two were chronic alcoholics and the other was partially paralysed on the operated side due to a cerebral ischemic stroke. In total there were five non-compliant patients and three had a dislocation of the Avantage® cup Discussion The initial results of our data suggest that the patients who might benefit from a double mobility system such as the Avantage® cup are those who suffer from recurrent dislocations that do not have a clear cause and those who have a high probability of dislocation. Dislocations after treatment with the Avantage® cup reoccurred in all the patients who were difficult to instruct. This study describes twenty-two patients, of which thirteen were treated with a double mobility system because or recurrent dislocation following primary total hip arthroplasty. All of the thirteen patients had a follow-up period of greater than four months. Only one of these patients had a dislocation of the Avantage® cup and this equates to a success rate of 92.3%. Five patients in our cohort proved non-compliant and three had a dislocation of the Avantage® cup. This is a success rate of only 40%. Non-compliancy in patients appears to be an important risk factor in determining if a dislocation will reoccur after the implantation of a double mobility system. It is acknowledged that determining who will be difficult to instruct in the hip rules cannot be quantified but in some cases there maybe justification in choosing a more secure system such

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as a constrained cup system. Another treatment option that can be considered for patients where compliancy is likely to be difficult (e.g. chronic alcoholics) is the creation of a girdlestone procedure. This will result in the patient having a disability but will often reduce pain and result in acceptable function. In the literature success rates (the prevention of re-dislocations) of 93-96,5% have been reported for the double mobility cup system during revision surgery.7,9,10,11,12 The success rate for the double mobility system when used in primary surgery is even better 99,6-100%.5,10 A success rate of 100% has been described by Guyen et al. The double mobility system was used in 163 patients, with a minimum of 1 risk factor for the occurrence of dislocations, after a mean follow up of 40 months. Notably the authors stated an age >75 years for a male and >70 years for a female as a risk factor. Of the 163 patients, 84,4% had a second risk factor for dislocations. These inclusion criteria must of course be taken into account when interpreting these results.5 The difference between the constrained cup system and the double mobility cup system is the extra security ring which secures the head to the cup. The obvious advantage of this is that it prevents dislocations; however it also increases the shear force between the fixed shell and the acetabulum. The increased stress between the cup and acetabulum could increase the risk of early cup loosening. A possible disadvantage of the double mobility system might be the increased PE wear due to the articulation between the PE liner and the shell. The increased PE wear could also lead to an increased incidence of early loosening.5,13,14 Thanks to the quality of the modern ultra-high molecular weight polyethylene and its resistance to wear, this problem might not become an issue. In vitro studies have shown that the mobility between the PE liner and the shell only occurs during the extremes of motion. The hypothesis is that, for this reason, there will be no significantly increased PE wear and osteolysis, due to the large diameter PE liner.15 In a study by Malik et al. which compared the incidence of osteolysis between normal cups and double mobility cups no significant difference was found.10 A wear analysis in ‘young and active’ patients has not been performed and should be conducted before a broader application of the Avantage® cup for primary placement can be justified.16 The main limitations of our study are the retrospective design and the small, heterogeneous populaNederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

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Vol 22 jun ’15

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Dislocations of double mobility cups in compliant and non-compliant patients

tion. Despite these two limitations, the results of the use of the Avantage® cup in revision surgery due to recurrent dislocations are promising. In contrast, the results in both primary and in revision surgery for non-compliant patients are disappointing. Disclosure statement There has been no conflict of interest of any kind while working on this manuscript. Vol 22 jun ’15

This article was reviewed by the editor-in-chief and one deputy-editor, and it underwent open review by one outside expert. The deputy-editor reviewed each revision of the article, and it underwent a final review by the editor-in-chief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and the language corrector.

References 1. Bourne RB, Mehin R. The dislocating hip. What to do, What to do. J Arthroplasty. 2004; 19(4): 111 – 114 2. Biedermann R, Tonin A, Krismer M, Rachbauer F, Eibl G, Stöckl B. Reducing the risk of dislocation after Total hip arthroplasty. The effect of orientation of the acetabular component. J bone joint surg (BR)87; 762 – 769, 2005 3. Morrey B. Results of reoperation for hip dislocation. The big picture. Clin Orthop relat res 2004; 429: 94-101 4. Parvizi J, Morrey B. Bipolar hip arthroplasty as a salvage treatment for instability of the hip. J bone joint surg 82; 1132 – 1139, 2000 5. Guyen O, Pibarot V, Vaz G, Chevillotte C, Carret J.P, Bejui-Hugues J. Unconstrained tripolar implants for primary total hip arthroplasty in patients at risk for dislocation. J Arthroplasty 2007;22:849-858 6. Williams Jr JT, Ragland PS, Clarke S. Constrained components for the unstable hip following total hip arthroplasty: a literature review. International orthopaedics 2007; 31: 273-277

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7. Langlais FL, Ropars M, Gaucher F, Musset T, Chaix O. Dual mobility cemented cups have low dislocation rates in THA revisions. Clin Orthop relat res 2008; 466: 389-395 8. Mansonis JL, Bourne RB. Surgical approach, abductor function, and total hip arthroplasty dislocation. Clin Orthop relat res. 2002 Dec; (405): 46-53 9. Guyen O, Pibarot V, Vaz G, Chevillotte C, Bejui-Hugues J. Use of a dual mobility socket to manage total hip arthroplasty instability. Clin Orthop Relat Res 2009; 567:465-472 10. Hailer NP, Weiss RJ, Stark A, Kärrholm. Dual-mobility cups for revision due to instability are associated with a low rate of re-revisions due to dislocation. 228 patients from the Swedish hip arthroplasty register. Acta orthopaedica 2012; 8(6):566-571 11. Philippot R, Adam P, Reckhaus M, Delangle F, Verdot F.X, Curvale G, Farizon F. Prevention of dislocation in total hip revision surgery using a dual mobility design. Orthopeadics & traumatology: surgery & research 2009; 95: 407-413 12. Boyer B, Philipot R, Geringer J, Farizon F. Primary Total hip arthroplasty with dual mobility socket to prevent dislocation: a 22-year follow-up of 240 hips. International Orthopaedics. (sicot) 2012; 36: 511-518 13. Cooke CC, Hozack W, Lavernia C, Sharkey P, Shastri S, Rothman R.H. Early failure mechanisms of constrained tripolar acetabular sockets used in revision total hip arthroplasty. J Arthroplasty 2003; 18: 827-833 14. Guyen O et al. Tripolar hip implant intermediate component motion analysis. Presented at the 51th Orthopaedic Research Society Annual Meeting, D.C Washington; 2005 15. Stulberg S.D. Duel mobility for chronic hip instability: a solution option. Orthopedics, 2010 Sep 7;33(9):637 16. Beaulé PE, Schmalzried TP, Udomkiat P, Amstutz HC. Jumbo femoral head for the treatment of recurrent dislocation following total hip replacement. J Bone Joint Surg Am, 2002;84-A(2):256-263

Is MRI sensitive and specific enough in detecting cartilaginous lesions in the patellofemoral compartment after patellar dislocation? Navin Gurnani, Valerie G. Niehe, Emile G. Coerkamp and Ewoud R.A. van Arkel Background: Cartilage or osteochondral injury after lateral patellar dislocation (LPD) is a well-known cause of anterior knee pain. The assessment of cartilage injury after LDP still remains under debate. Purpose: The objective is to compare the extent of cartilage damage after LDP using MRI and arthroscopy. Methods: This retrospective study included 31 knees which had undergone (recurrent) LDP. All patients were treated with a Medial Patellofemoral Ligament repair from 2008 to 2012. Our population ranged between the 18-42 years. Agreement in cartilage injury, sensitivities and specificities for the patellofemoral compartment were assessed with MRI. Results: The weighted kappa value for the agreement of patellofemoral cartilage injury after LDP was 0.24. Corpora libera showed a sensitivity of 66 percent and specificity of 89 percent; osteochondral defects, sensitivity 75 percent and specificity 89 percent; and avulsion fractures, sensitivity 60 percent and specificity 73 percent. Conclusion: A fair agreement of the cartilage injury after LDP between MRI and arthroscopy was observed in the patellofemoral compartment.

Introduction LPD represents 2-3 % of all knee injuries but accounts for as many as 9-16 % of injuries in young athletes with hemathrosis.1 Patients often present themselves in the emergency department with acute knee pain and hemathrosis.1,18 Spontaneous reduction frequently occurs after LDP before entering the hospital, which makes half of the patients clinically unsuspected. LPD may lead to bone, cartilage or soft tissue injury in the knee joint. The most prominent place due to its trauma mechanism is the medial dome of the patella and lateral condyle of the femur.1,18 Most orthopaedic surgeons treat the first injury conservatively with a brace unless there is an obvious osteochondral fracture with a loose intra-articular fragment.18 The major complication is recurrent dislocation of the patella, which is 17 % after primary LPD.2 If giving way symptoms still exist or recurrent dislocations occur, depending on the knee pathology, surgery is recommended.18 The predisposing factors for LPD are trochlear dysplasia, lateralisation of the tibial tuberositas and patella alta. The Medial Patellofemoral Ligament (MPFL) prevents patellar lateralisation when the knee is in slight flection and not articulating with the femoral trochlea.2,18 In 90 percent of traumatic LPD a (partial) rupture of the MPFL is expected.1,2,18 Drs. N. Gurnani, resident orthopaedic surgery, Drs. V.G. Niehe, radiologist, Drs. E.G. Coerkamp, radiologist, Dr. E.R.A. van Arkel, orthopaedic surgeon, Medisch Centrum Haaglanden, The Hague, The Netherlands Corresponding author: N. Gurnani Email: [email protected]

Based on several operative studies the incidence of chondral and osteochondral lesions after LDP ranged between 32-96 percent.5 Similarly, MRI studies have reported an incidence between 30-70 percent of chondral or osteochondral injury after LPD.5 It is also presumed that continuing patellar dislocation could lead to early osteoarthritis. Furthermore, a worsening of the articular cartilage was seen at a second-look arthroscopy 1.5-2 years after diagnosis of LDP.8,19 Recurrent patellar dislocations can deteriorate patellofemoral cartilage further. A 7-year nonoperative follow-up study demonstrated high frequencies of full thickness patellar (45%) and trochlear (31%) cartilaginous lesions, which were presumed to be a sign of developing osteoarthritis (OA).20 After a 13 year follow up patellofemoral OA was observed in 22 % of the patients, the highest frequency for patellofemoral pain or recurrent dislocation.21 An accurate assessment of the (osteo) chondral injury in the knee is compulsory for conservative or operative treatment after LDP. The literature reports a very wide incidence in detecting (osteo) chondral injury with MRI in patients after LDP.8 Therefore, the purpose of this study was to investigate whether MRI is an accurate method in detecting (osteo) chondral injury after LDP. We hypothesized MRI not to be accurate enough in detecting (osteo) chondral injury after (recurrent) LDP. Material and Methods We have retrospectively studied 31 knees that have undergone (recurrent) LDP. All had been treated with a MPFL repair from 2008 to 2012, ages ranging Nederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

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Is MRI sensitive and specific enough in detecting cartilaginous lesions in the patellofemoral compartment after patellar dislocation?

between 18-42 years. Patients were first treated with a brace if no intra-articular loose bodies were detected and were operated after conservative treatment with a brace failed. An additional tuberositas transposition was performed in 3 patients with a Tibial Tuberosity – Trochlear Groove distance (TT-TG) larger than 21mm or in athletes with high demand. The included patients were either seen in the emergency department or referred to our outpatient clinic with persistent anterior knee pain. MRI scans were obtained when the patient history included or suspected patellar dislocation and a positive apprehension sign. The TT-TG distance was calculated using CT scans. All the MRI scans were scored and graded by a musculoskeletal radiologist for patellofemoral (osteo) chondral injuries, corpora libera and avulsion fractures. Cartilage injury was graded by using the International Cartilage Repair Society (ICRS) classification.2 Grade 1, superficial lesions; grade 2, lesions extending to <50 percent of the cartilage depth; grade 3, defects >50 percent of the cartilage depth; grade 4 penetration of the subchondral bone. In cases with multiple cartilage defects in the patellofemoral compartment, the highest grade was documented. Avulsion fractures and corpora libera were scored if present, the size of the lesions were mentioned separately. Prior to MPFL repair, in all patients, arthroscopy of the effected knee was performed. The same orthopaedic surgeon performed all the operations. The ICRS classification was also used to classify the patellofemoral (osteo) chondral lesions in surgery.2 In cases with multiple cartilage injuries in the patellofemoral compartment the highest grade was documented. Corpora libera and avulsion fractures were scored if present, size was mentioned separately. The specificities and sensitivities of MRI for each grade of cartilage defects were calculated. This was also done for avulsion fractures, corpora libera and osteochondral defects. Weighted kappa values for multiple categories and their 95 percent confidence intervals were performed to assess agreement between arthroscopy and MRI. According to Landis en Koch, a kappa value of < 20 indicates poor agree-

ment, 0.21-0.40 indicates fair agreement, 0.41-0.60 indicates moderate agreement, and 0.81-1.0 indicate good agreement. Because all MRI scans were graded by the same radiologist and all the surgeries were done by the same orthopaedic surgeon no inter observer agreement was calculated. Results At arthroscopy, 9 patients (29 percent) were observed without cartilage injury after LDP, 3 patients (9 percent) with grade 1, 8 patients (26 percent) with grade 2, 7 patients (23 percent) with grade 3 and 4 patients (13 percent) with grade 4 in the patellofemoral compartment (table 1). Pre-operative MRI reported 18 patients (59 percent) with no cartilage injury after LDP, 2 patients (6 percent) with grade 2, 2 patients (6 percent) with grade 3, and 9 (29 percent) patients with grade 4. No patients were diagnosed with grade I cartilage injury. Exact agreement between MRI and arthroscopy was seen in 13 of the 31 patients (42 percent). The weighted kappa value calculated was 0.24 for the different grades of cartilage defects. Sensitivities, specificities, positive and negative predictive value are reported in table 3. The sensitivities, specificities, positive and negative predictive values of corpora libera, osteochondral defects and avulsion fractures are reported in table 4. Discussion Our study found a fair agreement between MRI and arthroscopy after LDP, with a kappa value of 0.24. Exact agreement was only seen in 42 percent. No grade I cartilage injury was seen using MRI, this might be caused by our limited scan sequence with fewer slices. The protocol did not include the axial plane, which could explain the missed diagnoses. Therefore, it was not possible to calculate the sensitivity and specificity for grade I. MRI missed the diagnosis in 18 patients (58 percent), the diagnoses was missed by 1 grade in 6 patients (19 percent),

Table 1. Findings at arthroscopy Cartilage defects at arthroscopy Number of patients ICRS Grade 0 - normal ICRS Grade 1 - nearly normal ICRS Grade 2 - abnormal ICRS Grade 3 – severely abnormal ICRS Grade 4 - severely abnormal, sub chondral bone

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9 3 8 7 4

Percentage 29 9 26 23 13

Navin Gurnani, Valerie G. Niehe, Emile G. Coerkamp and Ewoud R.A. van Arkel

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Table 2. Agreement assessment between MRI and arthroscopy of the knee after LDP MRI A’scopy

Chondral defects No injury

I

II

III

IV

Total

No injury Grade 1 Grade 2 Grade 3 Grade 4

9 (5.23) 2 3 3 1

0 0 (0) 0 0 0

0 0 1 (0.52) 1 0

0 0 0 1 (0.45) 1

0 1 4 2 2 (1.16)

9 3 8 7 4

Totaal

18

0

2

2

9

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Table 3. Sensitivity, specificity, positive and negative predictive value of MRI for chondral defects Chondral defects Sensitivity Specificity No injury Grade 1 Grade 2 Grade 3 Grade 4

100 0 13 14 50

74 100 96 95 35

by 2 grades in 7 patients (23 percent), by 3 grades in 4 patients (13 percent) and by 4 grades in 1 patient (3 percent). We did not calculate any interobserver agreement because the same orthopaedic surgeon did all arthroscopies and one radiologist graded all the MRI scans. The study by Von Engelhardt et al5 reported kappa values ranging between the 0.60-0.83 for cartilage injury, which is higher than our findings. This might be due to their superior scan protocol with addition of the axial plane and thinner slices (3-4mm). Another study by Duc et al22 studied the pre-operative MRI scans with patients undergoing arthroscopic or open surgery of the knee joint. They compared cartilage injuries observed on the scans with injuries seen at surgery. A difference in kappa value was found, depending on the location of injury. A high kappa value (1.00) was found for de medial femur condyle, whereas the lowest kappa value (0.43) was reported at the medial tibial plateau. The study by Drape et al4 reported a kappa value of 0.84 in patients with osteoarthritis, with a different scan sequence. This is different to (osteo) chondral lesions arising from LDP but does support the high correlation between MRI and arthroscopy. Our findings are based on kappa values found in the patellofemoral compartment. A cross-sectional study by Engelhardt et al. consisting of 36 patients

Positive predictive Negative predictive value value 50 0 50 50 22

100 90 76 79 91

compared cartilage injuries of the knee on MRI with subsequent arthroscopy. They reported the poorest kappa value of 0.32 and 0.52 in the patellofemoral compartment8, in accordance with this study. A prospective comparative study by Friemert et al. in 195 patients assessed the sensitivity and specificity of chondral injuries. They reported fairly low sensitivities for the patellofemoral compartment 33- 68 percent, and specificities 96-99 percent.10 Detection of grade 1 and 2 injuries was poor, which is in accordance to our findings. In addition we also found poor detection in grade 3 injuries in the patellofemoral compartment. No cartilage injury after LDP at arthroscopy was detected best with MRI, a sensitivity of 100 percent and a specificity of 74 percent. This finding is in accordance with in the literature.8,14,10 Limitations in our study are that there was a long period of time between the MRI scan and the arthroscopic procedure. Another limitation was our scan sequence, which did include the axial plane. This might be the cause of underdiagnoses of cartilage injury with MRI, which was found in 11 of the 31 patients. Patients might have undergone recurrent LDP in that period which could increase the cartilage damage. Also avulsion fractures diagnosed with MRI are mostly located in the joint capsule, which were not seen when grading with arthroscopy. Nederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

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Is MRI sensitive and specific enough in detecting cartilaginous lesions in the patellofemoral compartment after patellar dislocation?

Table 4. Other outcomes between MRI and Arthroscopy Lesion Sensitivity Specificity Corpora libera Osteochondral defect Avulsion fracture Vol 22 jun ’15

66 75 60

89 89 73

Conclusion This study found a fair agreement (kappa value: 0.24) between MRI and arthroscopy in detecting cartilaginous injuries in the patellofemoral compartment after LDP. This finding is consistent with other studies reporting fair to moderate agreement in the patellofemoral compartment. The reported sensitivities and specificities are similar to the literature for the patellofemoral compartment. The difference in detection of injury relies on the many scan sequences, planes and slices. Our findings are based on a limited scan sequence with few patients. More comparative studies with different scan sequences are needed to assess the agreement, sensitivity and specificity of a MRI scan after patellar dislocation. Disclosure statement Nothing to disclose. This article was reviewed by the editor-in-chief and one deputy-editor, and it underwent open review by two outside experts. The deputy-editor reviewed each revision of the article, and it underwent a final review by the editor-inchief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and the language corrector.

References 1. Earhart C, Patel DB, White EA, Gottsegen CJ, Forrester DM, Matcuk GR Jr. Transient lateral patellar dislocation: review of imaging findings, patellofemoral anatomy, and treatment options. Emerg Radiol. 2013 Jan;20(1):11-23 2. Tigchelaar SJ, Koeter S, van Kampen A, Diagnosis and treatment of primary patellar dislocations (Article in Dutch) Ned. Tijd. Traumatologie 2007,nr. 3,30-99 3. Cameron ML, Briggs KK, Steadman JR. Reproducibility and reliability of the outerbridge classification for grading chondral lesions of the knee arthroscopically. Am J Sports Med. 2003 Jan-Feb;31(1):83-6 4. Drapé JL, Pessis E, Auleley GR, Chevrot A, Dougados M, Ayral X. Quantitative MR imaging evaluation of chondropathy in osteoarthritic knees. Radiology. 1998 Jul;208(1):49-55. 5. Von Engelhardt LV, Lahner M, Klussmann A, Bouillon B, Dàvid A, Haage P, Lichtinger TK. Arthroscopy vs. MRI for

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Positive predictive Negative predictive value value 40 50 30

96 96 90

a detailed assessment of cartilage disease in osteoarthritis: diagnostic value of MRI in clinical practice. BMC Musculoskelet Disord. 2010 Apr 20;11:75. 6. McNicholas MJ, Brooksbank AJ, Walker CM. Observer agreement analysis of MRI grading of knee osteoarthritis. J R Coll Surg Edinb. 1999 Feb;44(1):31-3. 7. Erickson SJ, Prost RW, Timins ME. The “magic angle” effect: background physics and clinical relevance. Radiology. 1993 Jul;188(1):23-5 8. Von Engelhardt LV, Raddatz M, Bouillon B, Spahn G, Dàvid A, Haage P, Lichtinger TK. How reliable is MRI in diagnosing cartilaginous lesions in patients with first and recurrent lateral patellar dislocations? BMC Musculoskelet Disord. 2010 Jul 5;11:149. 9. Acebes C, Roman-Blas JA, Delgado-Baeza E, Palacios I, Herrero-Beaumont G. Correlation between arthroscopic and histopathological grading systems of articular cartilage lesions in knee osteoarthritis. Osteoarthritis Cartilage. 2009 Feb;17(2):205-12. 10. Friemert B, Oberländer Y, Schwarz W, Häberle HJ, Bähren W, Gerngross H, Danz B. Diagnosis of chondral lesions of the knee joint: can MRI replace arthroscopy? A prospective study. Knee Surg Sports Traumatol Arthrosc. 2004 Jan;12(1):58-64. 11. Rodríguez-Merchán EC, Gómez-Cardero P. The outerbridge classification predicts the need for patellar resurfacing in TKA. Clin Orthop Relat Res. 2010 May;468(5):1254-7. 12. Broderick LS, Turner DA, Renfrew DL, Schnitzer TJ, Huff JP, Harris C. Severity of articular cartilage abnormality in patients with osteoarthritis: evaluation with fast spin-echo MR vs arthroscopy. AJR Am J Roentgenol. 1994 Jan;162(1):99-103. 13. Von Engelhardt LV, Lahner M, Klussmann A, Bouillon B, Dàvid A, Haage P, Lichtinger TK. Arthroscopy vs. MRI for a detailed assessment of cartilage disease in osteoarthritis: diagnosticvalue of MRI in clinical practice. BMC Musculoskelet Disord. 2010 Apr 20;11:75. 14. Harris JD, Brophy RH, Jia G, Price B, Knopp M, Siston RA, Flanigan DC. Sensitivity of magnetic resonance imaging for detection of patellofemoral articular cartilage defects. Arthroscopy. 2012 Nov;28(11):1728-37. 15. International Cartilage Grading Society http://www. cartilage.org/_files/contentmanagement/ICRS_evaluation.pdf 16. Bachmann GF, Basad E, Rauber K, Damian MS, Rau WS. Degenerative joint disease on MRI and physical activity: a clinical study of the knee joint in 320 patients. Eur Radiol. 1999;9(1):145-52.

Navin Gurnani, Valerie G. Niehe, Emile G. Coerkamp and Ewoud R.A. van Arkel

17. Sillanpää PJ, Mäenpää HM, Mattila VM, Visuri T, Pihlajamäki H. Arthroscopic surgery for primary traumatic patellar dislocation: a prospective, nonrandomized study comparing patients treated with and without acute arthroscopic stabilization with a median 7-year follow-up. Am J Sports Med. 2008 Dec;36(12):2301-9 18. Jain NP, Khan N, Fithian DC. A treatment algorithm for primary patellar dislocations. Sports Health. 2011 Mar;3(2):170-4. 19. Nomura E, Inoue M. Second-look arthroscopy of cartilage changes of the patellofemoral joint, especially the patella, following acute and recurrent patellar dislocation. Osteoarthritis Cartilage. 2005 Nov;13(11):1029-36

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20. Sillanpää PJ, Mäenpää HM, Mattila VM, Visuri T, Pihlajamäki H. Arthroscopic surgery for primary traumatic patellar dislocation: a prospective, nonrandomized study comparing patients treated with and without acute arthroscopic stabilization with a median 7-year follow-up. Am J Sports Med. 2008 Dec;36(12):2301-9 21. Mäenpää H, Lehto MU. Patellar dislocation. The long-term results of nonoperative management in 100 patients. Am J Sports Med. 1997 Mar-Apr;25(2):213-7 22. Duc SR, Koch P, Schmid MR, Horger W, Hodler J, Pfirrmann CW. Diagnosis of articular cartilage abnormalities of the knee: prospective clinical evaluation of a 3D water-excitation true FISP sequence. Radiology. 2007 May;243(2):475-82


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Clear instructions reduce missing responses in pen-and-paper collected Patient Reported Outcome Measures: A randomized study Loes W.A.H. van Beers, Vanessa A.B. Scholtes, Margot van Wermeskerken, Olvert A. Berkhemer and Rudolf W. Poolman Vol 22 jun ’15

Introduction: Patient Reported Outcome Measures (PROMs) gain importance in clinical orthopaedic research and patient care. In pen-and-paper administered PROMs, missing items may lead to loss of valuable data. In the current study we explored whether alternative application strategies might reduce the number of missing items using the Dutch Hip disability and Osteoarthritis Outcome Score (HOOS). Methods: Paper-based Dutch HOOS questionnaires were sent to 240 patients with osteoarthritis of the hip, who were on the waiting list for a total hip replacement. Three different versions were randomly sent: “Original” (the original Dutch HOOS); “Instructions” (the original Dutch HOOS with an additional instruction, emphasizing the need to fill out all items) and “No subheadings” (the original Dutch HOOS without subheadings). Results: The ‘Instructions’ group had the lowest number of missing items, the highest number of complete questionnaires and the highest number of useful (less than 50% missing items) questionnaires, compared to the ‘Original’ and ‘No subheadings’ groups. The ‘Instructions’ group had the lowest response rate compared to the other two groups. Conclusion: Adding clear instructions to the HOOS reduces the number of missing items. In this randomized study we further showed that non-response is a problem that should be challenged.

Introduction Patient Reported Outcome Measures (PROMs) gain importance in clinical orthopaedic research and patient care.1,2 In the Netherlands, the Dutch Orthopaedic Association (NOV) has given an advice regarding the use of PROMs for patients who undergo total hip replacement and most orthopaedic clinics use this guideline.3 Although healthcare providers prefer PROMs to be collected digitally, patients still prefer pen-and-paper.4 However, in pen-and-paper administered PROMs, a potential problem is that patients (non)randomly skip questions. This can result in missing items, which may lead to loss of valuable data. Although there are ways to statistically impute missing items, these procedures are complicated, time-consuming and potentially lead to invalid results. In addition, the majority of PROMs scoring instructions do not address the way to handle missing items. In the current study we explored whether alternative application strategies might reduce the L.W.A.H. van Beers MSc1, V.A.B. Scholtes PhD1, M. van Wermeskerken PhD2, O.A. Berkhemer 1, R.W. Poolman MD PhD 1 1 Department of Orthopaedic Surgery, Joint Research, Onze Lieve Vrouwe Gasthuis (OLVG), Amsterdam, The Netherlands 2 Institute of Psychology, Erasmus University Rotterdam, Rotterdam, The Netherlands Corresponding author: L.W.A.H. van Beers Email: [email protected]

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number of missing items using the Dutch Hip disability and Osteoarthritis Outcome Score (HOOS), a frequently used PROM in orthopaedic and osteoarthritis research.5 This PROM evaluates symptoms and functional limitations related to the hip joint and is considered reliable and valid.6,7 Our primary purpose was to evaluate whether an additional instruction, emphasizing the need to fill out all items, would reduce the number of missing items as compared to the original HOOS. The HOOS consists of five subscales, of which the subheadings might seem irrelevant for patients and therefore lead to missing items, therefore we also evaluated whether a version without these subheadings would yield less missing items compared to the original HOOS. Methods Paper-based, self-administered, Dutch HOOS questionnaires were sent to the home address of 240 patients with osteoarthritis of the hip. All patients were in expectation of a total hip replacement surgery at the Onze Lieve Vrouwe Gasthuis in Amsterdam,The Netherlands. No reminders were sent out. Patients were blinded for our hypothesis. Informed consent was waivered by the local ethical committee. Three different versions were randomly sent: ‘Original’ (the original Dutch HOOS); ‘Instructions’ (the original Dutch HOOS with the following additional instruction: “Thank you in advance for filling out this questionnaire. We know from experience that questions might be skipped, for instance because you have not performed these activities

Peer-to-peer educatieve evenementen en technieken verbinden medisch specialisten van over de hele wereld. Ontdek het zelf op: www.smith-nephew.com/education Supporting healthcare professionals for over 150 years

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Clear instructions reduce missing responses in pen-and-paper collected Patient Reported Outcome Measures: A randomized study

for a prolonged time. We would appreciate it if you would answer these questions with the most appropriate answer. If you skip questions, we can not process this questionnaire.” ) and ‘No subheadings’ (the original Dutch HOOS without subheadings). Response rates, number of missing items, percentage of complete (0% missing items) and useful (< 50% missing items per subscale8) questionnaires were compared. Analyses were performed for both the total group and the response group. Kruskal Wallis and Mann-Whitney U tests were used for continuous data; Pearson Chi-square test was used for dichotomous data (SPSS 18.0). Statistical significance was set at p<0.05 for response rates, and at p<0.008 for number of missing items, completeness and usefulness (Bonferoni correction for multiple testing). Sample size calculation resulted in n=52 per group to achieve 81% power to detect a difference between group proportions of 15%. We sent out 80 questionnaires per group.

Figure 1.

Results

the HOOS leading to a total response rate of 70%. The response rate varied from 60% to 81.3% amongst the three groups. The response rate of the ’Instructions’ version was the lowest. We analyzed our data for both the total group and the response group (the group of patients that has returned the questionnaire). The results for the response group are described in this results section, the results for both groups are shown in table 1.

Response rate As shown in figure 1, a total of 168 patients returned

Missing items The ‘Instructions’ group had the lowest number of

Table 1. Overview of the number (and percentage) of complete and useful questionnaires displayed for each version of the questionnaire ‘Original N=54

‘Instructions’ N=47

‘No subheadings’ N=63

3.75 (5.85)

0.63 (1.38)**,***

3.54 (5.49)

Complete Questionnaires (% within groups) • Response group • Total group

26 (47.3%) 26 (32.5%)

38 (79.2%)**, *** 38 (47.5%)

27 (41.5%) 27 (33.8%)

Useful Questionnaires • Response group • Total group

42 (76.4%) 42 (52.5%)

47 (97.9%)**, *** 47 (58.8%)

52 (80%) 52 (65%)

55 (100%) 53 (96.4%) 54 (98.2%) 42 (76.4%)

48 (100%) 48 (100%) 48 (100%) 48 (100%)**,***

64 (98.5%) 64 (98.5%) 64 (98.5%) 52 (80%)

55 (100%)

47 (97.9%)

65 (100%)

Response group: mean number of missing items (standard deviation).

Response group: useful Subscales

Symptoms Pain ADL Sport / recreation Quality of Life

Complete = 0% missing items, useful = < 50% missing items per subscale * significant difference group ’Original’ – ‘No subheadings’ ** significant difference group ’Original’ – ‘Instructions’ *** significant difference group ’No subheadings’ – ‘Instructions’ Alpha is set at p=.0083

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p-value

** ***

** ***

p<.000 p<.000

p =.001 p <.000

**p=.001

***p=.004

**p<.000 ***p=.001 -

Loes W.A.H. van Beers, Vanessa A.B. Scholtes, Margot van Wermeskerken, Olvert A. Berkhemer and Rudolf W. Poolman

missing items: the mean number of missing items was almost 6 times less compared to ‘Original’ and ‘No subheadings’ groups. Completeness and usefulness The highest number of complete questionnaires was reached in the ‘Instructions’ group. A mean of 79% of the returned questionnaires were complete, which was nearly twice as high as the ‘Original’ (47%) and ‘No subheadings’ (42%) group. The highest number of useful questionnaires was also found in the ‘Instructions’ group. Nearly all (98%) of returned questionnaires in this group were useful, which was significantly more compared to ‘Original’ and ‘No subheadings’, which reached a maximum of 80%. When analyzing per subscale, only the subscale ‘sport/recreation’ within the ‘Instructions’ version has significant more usable questionnaires compared to ‘Original’ and ‘No subheadings’. However, when performing these analyses for the total group, no significant differences are found. Discussion This study showed that missing items are a serious problem for the use of PROMs in patients receiving total hip replacement. Adding clear instructions to the HOOS reduces the number of missing items. Our results showed that this addition significantly increases the number of complete and usable HOOS questionnaires with 32% and 22%, respectively. No significant differences were found between the ‘Original’ and ‘No subheadings’ versions. Removing subheadings is not helpful for reducing missing items or improving the number of complete or useful questionnaires. The guideline of the NOV, regarding the use of PROMs, contains the HOOS-PS.9 This is a shorter, 5 items, version of the HOOS. Although patients are more likely to complete a shorter questionnaire, the items which are most often missing (‘getting in/out of bath or shower’ and ‘running’) also exist in the HOOS-PS. For the HOOS-PS it is not possible to calculate a total score when one or more items are missing. Furthermore, most orthopaedic clinics add the optional Oxford Hip Score to their set of PROMs, increasing the total amount of questions a patient has to answer. When using a pen-and-paper version, adding a simple instruction is advisable to reduce the number of missing items, also when using the HOOS-PS. In this randomized study we further showed that non-response is a major threat. The ‘Instructions’ group has the lowest response rate, for which we do not have a proper explanation. The overall non-

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response was 30%, which has a large impact on the overall usefulness of the PROM. Since orthopaedic clinics and healthcare insurance companies have an increased interest in the use of PROM data, a main priority should be the problem of non-response and how to deal with this. Disclosure statement All authors have completed an ICMJE form for disclosure of potential conflicts of interest. No disclosures were reported in relation to this article. This article was reviewed by the editor-in-chief and one deputy-editor, and it underwent open review by two outside experts. The deputy-editor reviewed each revision of the article, and it underwent a final review by the editor-inchief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and the language corrector.

References 1. Franklin PD, Harrold L, Ayers DC. Incorporating Patient-reported Outcomes in Total Joint Arthroplasty Registries: Challenges and Opportunities. Clin Orthop 2013;471(11):3482-3488.. 2. Calvert M, Blazeby J, Altman DG, Revicki DA, Moher D, Brundage MD. Reporting of patient-reported outcomes in randomized trials: the CONSORT PRO extension. JAMA 2013;309(8):814-822. 3. Patient Reported Outcome Measures: Advies Nederlandse Orthopaedische Vereniging (NOV). http:// www.orthopeden.org/uploads/hH/xE/hHxEZWiUni1_ n1AQFZn4_Q/PROMs-Orthopedie-Advies-vastgesteldin-de-ALV-van-4-oktober-2012-NOV.pdf . 4-10-2012. Ref Type: Internet Communication 4. Keurentjes JC, Fiocco M, So-Osman C et al. Hip and knee replacement patients prefer pen-and-paper questionnaires: Implications for future patient-reported outcome measure studies. Bone Joint Res 2013;2(11):238-244. 5. Gossec L, Hawker G, Davis AM et al. OMERACT/OARSI initiative to define states of severity and indication for joint replacement in hip and knee osteoarthritis. J Rheumatol 2007;34(6):1432-1435. 6. Nilsdotter AK, Lohmander LS, Klassbo M, Roos EM. Hip disability and osteoarthritis outcome score (HOOS)-validity and responsiveness in total hip replacement. BMC Musculoskelet Disord 2003;30:4-10. 7. de Groot IB, Reijman M, Terwee CB et al. Validation of the Dutch version of the Hip disability and Osteoarthritis Outcome Score. Osteoarthritis Cartilage 2007;15(1):104109. 8. www.koos.nu . 2013. Ref Type: Internet Communication 9. Davis AM, Perruccio AV, Canizares M et al. The development of a short measure of physical function for hip OA HOOS-Physical Function Shortform (HOOS-PS): an OARSI/OMERACT initiative. Osteoarthritis Cartilage 2008;16(5):551-559.


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Summerclass Orthopedie gaat internationaal Na vier edities Summerclass Orthopedie is 2015 een tussenjaar naar een nieuwe, internationale opzet. “Er is behoefte aan en ruimte voor meer kruisbestuiving over de grenzen”, aldus een van de initiatiefnemers Rolf Bloem. De basisdoelstelling blijft gelijk: studenten proeven de orthopedie in al haar facetten.

Er is in de opleidingen geneeskunde en bewegingswetenschappen te weinig aandacht voor klachten aan het bewegingsapparaat en de rol van orthopedie, vindt Rolf Bloem van de vakgroep orthopedie bij de Reinier de Graaf Groep. “Wij vinden het belangrijk dat deze artsen en onderzoekers van de toekomst een juist beeld hebben van ons vak. Niet alleen omdat we graag zien dat de beste studenten optimaal gemotiveerd kiezen voor orthopedie als specialisatie, maar ook omdat zoveel specialismen direct of indirect met het bewegingsapparaat te

maken hebben. Aangezien het niet mogelijk is de opleidingen te veranderen, organiseren we sinds 2011 de Summerclass Orthopedie. Daarmee spijkeren we jaarlijks zo’n 125 studenten op een voor hen aantrekkelijke manier bij.” En hoe verleid je studenten tot het opofferen van drie dagen zomervakantie? “Dat doen we door goed naar ze te luisteren en door een gevarieerd programma te bieden: theorie, praktische workshops, sport en natuurlijk ook een feest”, zo somt Petra le Roy op, manager van de vakgroep orthopedie. “De Summerclass vindt plaats bij Lijm & Cultuur, een voormalige lijm- en gelatinefabriek in Delft. Die monumentale en industriële locatie draagt direct bij aan de informele en ontspannen sfeer. De vierde- tot zesdejaars studenten komen uit het hele land, en uit Vlaanderen, en de sprekers hebben verschillende achtergronden; ze nemen allemaal hun unieke ervaringen mee. Doordat de sfeer zo laagdrempelig is, pakken de deelnemers de mogelijkheid ook hun persoonlijke vragen te stellen; vragen die binnen de meer formele setting van een opleiding geen ruimte krijgen.” Specialistisch en breed Per editie richt de Summerclass zich op een orthopedisch subspecialisme, bijvoorbeeld ‘De heup’ of ‘Kinderorthopedie’; daarbinnen is de aanpak zo breed mogelijk. Le Roy: “We nodigen specialisten uit vanuit het hele land. Daarbij kijken we over de orthopedische grenzen heen, omdat dat in de praktijk ook veel vaker gaat en moet gebeuren.” Zo is de TU Delft al vanaf de eerste editie bij de Summerclass betrokken. “Dit blijkt voor de deelnemers, voor de TU Delft en voor ons van enorme meerwaarde te zijn. Het verruimt de blik en intensiveert de samenwerking.” De Summerclass werd al snel na de introductie door geheel orthopedisch Nederland omarmt. “We zijn trots op de steun die we krijgen van de NOV en vanuit de industrie en we zijn blij dat de Summerclass de rol vervult die we voor ogen hadden”, aldus Bloem. Hierbij refereert hij ook aan het NOV Strategisch Plan 2012-2016: “De Summerclass draagt direct bij aan het versterken van de maatschappelijke positie van de orthopedie.” Hier ligt ook de basis voor de nieuwe ontwikkeling. Nederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

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Internationaal Na vier edities staat er een stevig fundament, zowel inhoudelijk als organisatorisch. “Maar we merken dat een en ander onder druk staat”, vertelt Bloem. “De organisatie vraagt veel van onze vakgroep en de benodigde financiën, zo’n 40 – 45 duizend euro per editie, kunnen een knelpunt worden. Daarbij zien we inhoudelijk veel mogelijkheden om de Summerclass te internationaliseren.” Voor een gedegen interne reflectie, een analyse van kansen en mogelijkheden en vanwege interne ontwikkelingen (dit betreft de interne verhuizing van de vakgroep en de op handen zijnde fusie van de Reinier de Graaf Groep, HagaZiekenhuis en het LangeLand Ziekenhuis) is dit jaar een tussenjaar. “De kans is groot dat we definitief overstappen naar een tweejaarlijke cyclus”, aldus Bloem. “In ieder geval wil-

len we inhoudelijk een slag maken. Bijvoorbeeld met de Summerclass Tour. Daarbij konden de studenten de afgelopen jaren onder anderen Jan Verhaar, kolonel-arts Michiel van Haeff en Rien Heiboer vragen stellen. Hun expertise en ervaring zijn natuurlijk ook zeer interessant voor studenten uit andere landen. En specialisten vanuit internationaal gerenommeerde onderzoekscentra, universiteiten en ziekenhuizen kunnen de nieuwsgierigheid en motivatie van onze studenten prikkelen.” Zo groeit het Delfts initiatief uit tot een International Orthopaedic Summer School annex International Orthopaedic Festival. Gabriëlle Kuijer, communicatieadviseur NOV, [email protected]

LROI: indicatorenuitvraag afgerond met een uitstekend resultaat

gevuld. De overige kwaliteitsindicatoren konden de instellingen aanvullen in de online vragenlijst.

Voor de allereerste keer zijn dit jaar alle kwaliteitsindicatoren heup en knie uitgevraagd via het indicatorenportaal in het LROI-dashboard. In een tripartiet-overeenkomst tussen de zorgverzekeraars, zorgverleners en patiënten zijn de kwaliteitsindicatoren op 1 november 2014 aangeboden bij het zorginstituut. Het doel van het vaststellen en gebruiken van deze kwaliteitsindicatoren is om informatie te verkrijgen over de medisch inhoudelijke kwaliteit van de zorg.

Alle instellingen zijn ontzettend druk in de weer geweest om alle gegevens over 2014 in te voeren in de LROI. Ook is er veel aandacht besteed aan de volledigheid van de records; vooral de variabelen BMI en BSN ontbraken nog wel eens. Al deze variabelen zijn in de afgelopen maand zoveel mogelijk aangevuld, wat resulteert in een overall volledigheid van de records van maar liefst 84 procent.

Tot 1 april 2015 konden alle orthopedische instellingen die heup- en knieprothesen plaatsen de indicatoren heup en knie via het indicatorenportaal in het LROI dashboard aanleveren. De kwaliteitsindicatoren die betrekking hebben op de LROI (en al in de LROI stonden) zijn in het portaal automatisch

Eerste wetenschappelijke publicatie uit de LROI is een feit In de Acta Orthopaedica (maart 2015) is het allereerste artikel van de LROI gepubliceerd. In dit artikel schrijft Liza van Steenbergen, epidemioloog bij de LROI, dat het register een compleetheid heeft bereikt van meer dan 95 procent. Ook de validiteit van het register is erg hoog; het percentage van missende of fout gecodeerde data is minder dan 0,5%. Een zo volledig register is onmisbaar bij het verbeteren van de kwaliteit van orthopedische zorg. Zo kan de tijd tussen het eerste implantaat en een eventuele vervanging worden berekend, en zijn de implantaten goed traceerbaar.

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Alle instellingen hebben de kwaliteitsindicatoren aangeleverd via het indicatorenportaal. Een uitstekend resultaat waar de orthopedie erg trots op mag zijn. Alle gegevens zijn inmiddels doorgeleverd aan het Zorginstituut Nederland. Van daaruit zijn ze verder verdeeld onder de individuele zorgverzekeraars. Het artikel van Liza van Steenbergen is de basis voor het verdere onderzoek in de LROI. Door de toevoeging van de eventuele overlijdensdatum van de patiënt aan het register (per september 2014) en een compleetheid van meer dan 95 procent, is de basis voor het berekenen van een betrouwbare survival van implantaten bereikt. Na het herzien van het wetenschappelijke reglement en het opstellen van nieuwe overeenkomsten met de ziekenhuizen, wordt het daarnaast voor wetenschappers ook mogelijk om data aan te vragen bij de LROI. Meer informatie hierover vindt u binnenkort op www.lroi.nl. Op deze website staat onder [Publicaties] een link naar het artikel in de Acta Orthopaedica.

Wetenschapsagenda Orthopedie: prioriteren Kwaliteit van Zorg Het project ‘Wetenschapsagenda Orthopedie’ inventariseerde waar een nog hogere kwaliteit bereikt kan worden door wetenschappelijke onderbouwing van behandelingen. Onderzoek naar de hieruit resulterende top 10 van kennishiaten zorgt voor meer bewijs voor effectieve behandeling; daarmee vormt deze eerste NOV-wetenschapsagenda de basis voor de continue kwaliteitscyclus van de orthopedie.

Voor veel aandoeningen bestaan verschillende behandelmogelijkheden. Zowel artsen als patiënten willen uit deze mogelijkheden de best passende optie kiezen. Om te bepalen welke behandeling in welke situatie het meest effectief is, is meer wetenschappelijk onderzoek nodig. Daarom startte in september 2014 een werkgroep van orthopeden1 met het project ‘NOV-wetenschapsagenda’. Kennishiaten in kaart De eerste stap van het project betrof een inventarisatie van kennishiaten en de wetenschappelijke onderbouwing van het dagelijks geneeskundig handelen in de orthopedie. Dit gebeurde via een analyse van NOV-richtlijnen en via een enquêtering van NOV-leden, NOV-werkgroepen en overige stakeholders, zoals patiëntenverenigingen en zorgverzekeraars. Kennishiaten waren bovendien deels al geïnventariseerd in het SEENEZ–project (Stimuleer Effectieve en Elimineer Niet Effectieve Zorg). Daarnaast hebben alle NOV-leden en overige stakeholders via e-mail een uitnodiging ontvangen voor deelname aan een digitale enquête om kennisvragen (hiaten) uit de dagelijkse praktijk aan te leveren. Dit leidde tot 136 kennishiaten. Samen met de kennishiaten van de overige stakeholders en uit de richtlijnanalyse zijn 286 kennishiaten geïnventariseerd. De werkgroep reduceerde deze lijst tot 132 kennishiaten. Deze grove selectie is gedaan op basis van: ontdubbelen; verwijderen van kennelijke individuele kennishiaten; verwijderen van kennishiaten waar al kennis van aanwezig is, maar die nog niet in een richtlijn is opgenomen (dit wordt doorgegeven aan de Commissie Kwaliteit); verwijderen van kennishiaten waar momenteel al onderzoek naar gedaan wordt; beoordeling op klinische relevantie en onderzoekbaarheid. Gezamenlijk prioriteren Omdat het niet mogelijk is om al deze 132 onderzoeksonderwerpen tegelijkertijd te onderzoeken, zijn deze tijdens een bijeenkomst op 17 maart jl. geprioriteerd. Deze prioritering vond plaats per deelgebied op basis van de volgende criteria: re-

levantie (ernst, prevalentie, kosten); urgentie; haalbaarheid van onderzoek en de impact op vakgebied/maatschappij. Deze prioriteringsbijeenkomst had ongeveer 60 deelnemers: orthopedisch chirurgen, VOCA-bestuur, wetenschappelijk onderzoekers en vertegenwoordigers van onder andere patiëntenverenigingen, zorgverzekeraars, het Nederlands Huisartsen Genootschap, de Nederlandse Internisten Vereniging (sectie ouderengeneeskunde), de Vereniging voor Sportgeneeskunde en het Koninklijk Nederlands Genootschap voor Fysiotherapie. Per deelgebied zijn de landelijke experts uitgenodigd om een goede onderbouwing van de prioriteringslijst te krijgen. Top 10 onderzoeksvragen De uit de bijeenkomst resulterende prioriteringslijst vormt de basis voor de NOV-wetenschapsagenda. De werkgroep beoordeelde deze lijst vervolgens op onderzoekbaarheid (zoals tijd, kosten aspect), haalbaarheid en maatschappelijke relevantie. Dit leidde tot deze definitieve top 10 onderzoeksvragen: 1. Wat is de duur en keuze van antistolling bij THP en TKP? 2. Antibiotica profylaxe bij prothesechirurgie – eenmalig of 24u? 3. Wat is de beste behandeling bij wondlekkage na totale knie- en heupprothese? 4. Ontwikkelen registratiesysteem: 1. Klompvoet; 2. DDH; 3. CP heup; 4. Idiopathische scoliose. 5. Wat is de effectiviteit van pre- en postoperatieve fysiotherapie bij THP en bij TKP? 6. Wat is de effectiviteit van stepped care versus usual care bij artrose van de knie? 7. Wat zijn effectieve indicatiegebieden voor heupartroscopie? Register ontwikkelen analoog aan LROI. 8. Wat is de optimale timing van een voorste kruisband reconstructie? 9. Wat is de beste behandeling van SAPS: bursectomie versus decompressie versus conservatief? 10. Welke injectie dosis verhouding en middelen is effectief bij de behandeling van knieartrose? De werkgroep heeft deze hoogst geprioriteerde onderzoeksvragen verder uitgewerkt en ze worden gebruikt voor het opzetten van toekomstige onderzoeksprogramma’s, researchnetwerken en kwaliteitsprojecten (zoals richtlijnen). Deze eerste NOV-wetenschapsagenda is de basis van een continue cyclus binnen de kwaliteitscyclus van de orthopedie. Het NOV-bestuur bewaakt, Nederlands Tijdschrift voor Orthopaedie, Vol 22, Nr 2, juni 2015

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ondersteunt en stimuleert de voortgang van de uitvoering. Voor de financiering van de geprioriteerde onderzoeken is beoogd gebruik te maken van reguliere subsidieaanvragen via het ZonMwprogramma DoelmatigheidsOnderzoek en andere mogelijke subsidiebronnen, zoals het Reumafonds en zorgverzekeraars via een nog in te richten ‘Shared Savings Fonds’. Rondom een onderzoeksaanvraag wordt een netwerk opgezet waarin meerdere maatschappen/vakgroepen en UMC’s kunnen participeren, zodat op korte termijn, met grote patiëntenaantallen onderzoeksvragen kunnen worden beantwoord (analoog aan het NVOG consortium 2.0). Het officiële rapport van de NOV-Wetenschapsagenda wordt tijdens de NOV Najaarsvergadering gepubliceerd. 1

Prof dr. Rob Nelissen (voorzitter), dr. Rudolf Poolman, dr. Gert Jan Geysen, dr. Koen Bos, dr. Peter Nolte, dr. Jos van Raaij, dr. Klaas van der Heijden,

Zorg voor beweging Jaarmagazine 2016: uw eigen magazine Zorg voor beweging Jaarmagazine is het magazine voor uw patiënten, voor het algemeen publiek en daardoor ook voor meer formele stakeholders. Het Jaarmagazine brengt de state of the art van de orthopedie naar de lezer en laat hem/haar de passie ervaren van de orthopedisch chirurg. De artikelen laten zien hoe breed orthopedie als specialisme is en hoe dit vakgebied zich ontwikkelt. Daarbij komen natuurlijk ook veel patiënten aan het woord; zij delen hun verhaal en hun ervaren kwaliteit van leven, ook als een volledig herstel niet haalbaar is gebleken.

U heeft de mogelijkheid om Zorg voor beweging Jaarmagazine 2016 uw eigen gezicht en inhoud mee te geven. Kies uit deze mogelijkheden: 1. Eigen Special en eigen omslag, 2. Alleen een eigen achterzijde, 3. Standaard luxe uitvoering, met ruimte voor een adressticker. Sneak preview inhoud 2016 - Uw eigen Special met 4 pagina’s eigen tekst en beeld; - Hoofdartikel, onder andere met medewerking van professor Erik Scherder en voormalig topvolleyballer Bas van de Goor; - Opmerkelijk orthopedie, onder andere over ‘passie voor sport’ en multidisciplinaire samenwerking;

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dr. Elgun Zeegers, dr. Taco Gosens. Met ondersteuning van: ir. Teus van Barneveld, directeur Kennisinstituut van Medisch Specialisten en Dieuwke Leereveld, MSc, junior adviseur Kennisinstituut van Medisch Specialisten (tevens auteur van dit artikel).

De prioriteringsbijeenkomst op 17 maart 2015: de prioritering vond plaats per deelgebied op basis van relevantie, urgentie, haalbaarheid van onderzoek en de impact op vakgebied/maatschappij.

- Patiëntportretten, onder andere van Richard Krajicek; - Een dag orthopedie; Opleiding; Kwaliteit; Ontwikkelingen; Columns; Stap voor Stap; Eponiem; Orthopedie door de jaren; Onder de loep; Innovatie; Infographic; Wat en wie in de orthopedie. Bestellen & gebruik Informatie over de kosten, rekenvoorbeelden, tips voor de invulling van uw Special en voor de verspreiding van uw oplage vindt u op de NOV-website, onder [Patiënteninformatie] [Campagne – info]. Heeft u belangstelling voor een Special? Vraag een vrijblijvende offerte. Kiest u voor een eigen achterzijde zonder Special? Tref nu de benodigde voorbereidingen voor de foto of voor de vormgeving. [email protected]

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Juni 2015, Vol. 22, Nummer 2. Nederlands Tijdschrift. rthopaedie. voor. Officieel orgaan van de Nederlandse Orthopaedische Vereniging

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