Research Agenda

The Netherlands Orthopaedic Association (NOV), revised her Orthopaedic Research Agenda including her top priorities regarding Health Care Evaluation. In this new orthopaedic research agenda 2019-2022 we address unanswered questions. The focus is on addressing uncertainties about the effects of a treatment (healthcare evaluation) but also innovation is included.
Orthopaedics keeps people moving, from young to old, that is the mission of the Netherlands Orthopaedic Association (NOV). Based on this principle, the NOV encourages its members to provide orthopaedic care that is of excellent scientific quality, that is effective and that is offered with compassion. Furthermore, the NOV explicitly included in its strategic plan that orthopaedic care should be evaluated and developed further based on the outcomes of scientific research with an international appeal. In this context, the project “Health Care Evaluation Orthopaedics” was started to create an inventory of where evaluation of care is necessary in order to guarantee an even better quality of care for the patient based on scientific substantiation.
At the moment, many recommendations in guidelines have a low level of scientifically substantiated evidential value. As it is not always possible to substantiate all procedures with level I-II evidence-based methods, there is room for improvement from the patient’s perspective, which would clarify the added care value for him or her. The project “Health Care Evaluation Orthopaedics” resulted in an agenda prioritised unanswered questions from the daily practice of the patient and the orthopaedic surgeon. Scientific research is then the method to obtain answers to these questions. These scientific insights result in improved insights in the various diagnostic and treatment pathways, which enables the patient and the doctor to make a better choice.

For more information in English on the topic Health Care Evaluation in the Netherlands we recommend the Advisory Report Health Care evaluation – From project to process. A product of the Health Care Evaluation Steering committee 2016, Federation of Medical Specialists, The Netherlands.

We also published an English summary of the approach/methodology and our prioritised unanswered questions 2015-2018.

Would you like more information on the prioritised questions or are you interested in collaboration on one of the topics, please contact the research coordinator of the Netherlands Orthopaedic Association: CORE@orthopeden.org or call +31 (0)73 700 34 10

Health care evaluation questions

Adolescent idiopathic scoliosis (AIS): is standard radiological follow-up necessary? If so, at which frequency?
Prioritised 13x (10x NOV member, 3x patient representative)
There is no recent guideline for this subject.


Approximately 2-3% of children in the Netherlands aged between 10 and 18 years has adolescent idiopathic scoliosis (AIS). Both the conservative and the surgical treatment are usually followed up by conventional X-ray imaging. There is no scientific evidence to support this follow-up. At the moment, this young population is frequently exposed to (X-ray) examinations. It is not known how frequently and for what length of time this follow-up is required to confirm progression or post-operative complications (1). In addition, the question remains whether this follow-up using X-ray imaging is necessary, or whether there are suitable alternatives. Based on the currently available experimental research, alternatives could include an ultrasound examination (2).
  1. Dunn J, Henrikson NB, Morrison CC, Blasi PR, Nguyen M, Lin JS. Screening for Adolescent Idiopathic Scoliosis: Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2018 Jan 9;319(2):173-187.
  2. Brink RC, Wijdicks SPJ, Tromp IN, Schlösser TPC, Kruyt MC, Beek FJA, Castelein RM. A reliability and validity study for different coronal angles using ultrasound imaging in adolescent idiopathic scoliosis. Spine J. 2018 Jun;18(6):979-985.
Reduced distal radius fractures: lower rates of secondary fracture dislocation following treatment with a circular cast than with a plaster splint?
Prioritised 12x (10x NOV member, 2x stakeholder)
Is linked to the guideline on Distal Radius Fractures


The question is whether repositioned distal radius fractures in patients of all ages - treated with a circular cast instead of a splint - exhibit lower rates of secondary fracture dislocation, resulting in lower rates of surgery, fewer complications and lower costs.
Twenty percent of all fractures are localised in the distal radius (1). Dislocated distal radius fractures are usually reduced in the Accident and Emergency department and immobilised by a cast on the forearm. This forearm cast is applied either as a circular cast, or as a splint. The Guideline on Distal Radius Fractures does not state a preference for either casting method (2). A recent survey revealed that a splint is fitted in 69% of Dutch hospitals and a circular cast in 31% of Dutch hospitals.
Reduced distal radius fractures exhibit secondary fracture dislocation in 36% of the patients (3). In the past, a second attempt to reduce the fracture often took place, but nowadays surgery is more commonly performed. A previous study with inclusion of 72 patients revealed that the position of the fracture is maintained more effectively by a circular cast than by a plaster splint (4). Better evidence is required to answer this unanswered question.
Whilst this health care evaluation query - use of a circular cast - aims to prevent secondary dislocation of a repositioned distal radius fracture in patients of all ages, the ongoing DART study (SEENEZ) aims to answer the question about what is the best treatment of secondary dislocated intra-articular distal radius fractures in patients over the age of 65 years.
  1. MacIntyre NJ, Dewan N. Epidemiology of distal radius fractures and factors predicting risk and prognosis. J Hand Ther 2016;29(2):136-45.
  2. Nederlandse Vereniging voor Heelkunde (NVvH). Richtlijn distale radius fracturen: diagnostiek en behandeling. Utrecht. 2010.
  3. Jung HW, Hong H, Jung HJ, Kim JS, Park HY, Bae KH, Jeon IH. Redisplacement of Distal Radius Fracture after Initial Closed Reduction: Analysis of Prognostic Factors. Clin Orthop Surg 2015;7(3):377-82.
  4. Wik TS, Aurstad AT, Finsen V. Colles' fracture: dorsal splint or complete cast during the first 10 days? Injury 2009;40(4):400-4. Antwoord
Dislocations of the proximal interphalangeal joint: does functional follow-up treatment result in improved functioning and fewer symptoms than treatment with buddy tape?
Prioritised 7x (5x NOV member, 1x patient representative, 1x stakeholder)
Is linked to the guideline on Hand Fractures (NVvH, draft)


The use of buddy taping compared to an extension block splint for PIP dislocation was examined in a randomised study. Immediate exercising of the fingers in buddy tape yielded at least comparable results to immobilisation of the fingers (1). Therefore, the working group specified the question to compare buddy taping to immediate exercising.

This question has a high priority, because dislocations of the proximal interphalangeal (PIP) joint belong to the most common hand injuries. This can cause chronic pain, stiffness, deformities and premature arthritis (2). Being able to prevent this results in reduced invalidity for the patient and lower costs for absenteeism from work.
The treatment of PIP dislocations is not clear-cut and varies from surgical repair of the volar plate to immediate exercise without protection. Previous studies have compared various methods and immobilisation periods in a (quasi) randomised manner. These were included in a Cochrane review. The conclusion was that there is insufficient evidence to determine the best treatment for PIP dislocations (3).
Another study involving patients with a PIP dislocation compared immediate exercise with immobilisation. This quasi-randomised study with moderate follow-up found no difference between both groups (4).
In conclusion, the time is ripe for a well-designed study in which patients with a PIP dislocation are randomised between immediate exercise and treatment with buddy tape.
  1. Paschos NK, Abuhemoud K, Gantsos A, Mitsionis GI, Georgoulis AD. Management of proximal interphalangeal joint hyperextension injuries: a randomized controlled trial. J Hand Surg Am. 2014 Mar;39(3):449-54.
  2. Freiberg A, Pollard BA, Macdonald MR, Duncan MJ. Management of proximal interphalangeal joint injuries. Journal of Trauma‐Injury Infection & Critical Care. 1999;46(3):523‐8.
  3. Chalmer J, Blakeway M, Adams Z, Milan SJ. Conservative interventions for treating hyperextension injuries of the proximal interphalangeal joints of the fingers. Cochrane Database Syst Rev. 2013 Feb 28;(2):CD009030.
  4. Norregaard O, Jakobsen J, Nielsen KK. Hyperextension injuries of the PIP finger joint. Comparison of early motion and immobilization. Acta Orthopaedica Scandinavica. 1987;58:239‐40.
Hip dysplasia (DDH): whether or not to use hip splinting treatment for children with mild Graf Type II hip dysplasia?
Prioritised 23x (19x NOV member, 4x patient representative)
Is linked to the guidelines:
1. JGZ – hip dysplasia, 2018
2. Hip dysplasia, under development


DDH occurs in 1 out of every 1,000 live births. In the Netherlands, 1 to 4% of infants develops DDH before the age of 6 months (1). Inadequate treatment of DDH can result in pain, invalidity and/or early onset hip arthritis in adulthood. By contrast, mild DDH can develop into a normal hip joint spontaneously.
DDH is diagnosed by means of ultrasound examination before the age of 9 months, using the Graf classification (2). This unanswered question concerns mild Graf Type 2 DDH. There is no international consensus for the treatment of this group.
The NOV Working Group on Paediatric Orthopaedics has over the past year developed a uniform treatment flow chart for the treatment of DDH during the first year of life. The observation that mild DDH can develop into a normal hip joint without treatment, but with accurate follow-up, requires further investigation. The NOV has started a project group to answer this question. The NOV will further elaborate this question together with the Radiological Society of the Netherlands, Physicians for Youth Healthcare in the Netherlands (AJN) and the Association for Abnormal Hip Development (VAH).
  1. Boere-Boonekamp MM, Konijnendijk AAJ, Broerse A, Deurloo JA, Lanting CI. JGZ-richtlijn Heupdysplasie (Developmental Dysplasia of the Hip, DDH). Leiden/Enschede/Utrecht: TNO/UniversiteitTwente/NCJ; 2018.
  2. Sakkers R, Pollet V. The natural history of abnormal ultrasound findings in hips of infants under six months of age. J Child Orthop. 2018 Aug 1;12(4):302-307.
Patients with a total hip prosthesis, 5 years after the operation: which frequency of clinical and/or radiological follow-up is required?
Prioritised 6x (4x NOV member, 2x patient representative)
Is linked to the guideline on Total Hip Prosthesis


At the moment, approximately 28,000 total hip prostheses are fitted each year (1). The current guideline on Total Hip Prosthesis recommends routine follow-up by an orthopaedic surgeon (2). However, in the past 15 years of guideline development, it has not been possible to answer the question about the desired follow-up for total hip prostheses after 5 years based on scientific evidence. The research into this topic is limited both in quantity and generalisability (3-8). In addition, there appears to be significant practice variation and the outside world (insurance companies, Healthcare Institute) is demanding standpoints. In addition to the frequency of the long-term follow-up after a total hip prosthesis, there are more questions about this follow-up. Examples include: is a “return if experiencing symptoms” policy sufficient? Is a combination of PROMs and X-ray sufficient? And which health care professional should see the patient? (9-11)
  1. LROI-rapportage
  2. Richtlijn Totale heupprothese
  3. Hendricks TJ, Chong ACM, Cusick RP. The Cost of Routine Follow-Up in Total Joint Arthroplasty and the Influence of These Visits on Treatment Plans. Kans J Med. 2018 Aug 30;11(3):59-66.
  4. Kingsbury SR, Dube B, Thomas CM, Conaghan PG, Stone MH. Is a questionnaire and radiograph-based follow-up model for patients with primary hip and knee arthroplasty a viable alternative to traditional regular outpatient follow-up clinic? Bone Joint J. 2016 Feb;98-B(2):201-8.
  5. Silverwood R, Lawton R, Barnett K, Finlayson D: Is long-term follow-up after uncomplicated primary total hip arthroplasty necessary? Orthopaedic Proceedings. 2012;94B(supp XXXIX):176.
  6. Hacking C, Weinrauch P, Whitehouse SL, Crawford RW, Donnelly WJ. Is there a need for routine follow-up after primary total hip arthroplasty? ANZ J Surg. 2010;80(10):737–40.
  7. Robinson S, Varhol R, Bell C, Quirk F, Durrington L. HealthPathways: creating a pathway for health systems reform. Aust Health Rev. 2015;39(1):9–11.
  8. Waring S, Reynolds B, Schoch P, Thomson A, Williams S, Page R. Improved access orthopaedic joint replacement review clinic. ANZ J Surg. 2015;85(Suppl. 1):81–8.
  9. Haddad FS, Ashby E, Konangamparambath S. Should follow-up of patients with arthroplasties be carried out by general practitioners? J Bone Joint Surg Br. 2007;89(9):1133–4.
  10. Marsh JD, Bryant DM, MacDonald SJ, Naudie DD, McCalden RW, Howard JL, Bourne RB, McAuley JP. Feasibility, effectiveness and costs associated with a web-based follow-up assessment following total joint arthroplasty. J Arthroplast. 2014;29(9):1723–8.
  11. Large KE, Page CJ, Brock K, Dowsey MM, Choong PF. Physiotherapy-led arthroplasty review clinic: a preliminary outcomes analysis. Aust Health Rev. 2014;38(5):510–6.
Post-operative hip and knee prosthesis patients: which patients do/do not require thrombosis prophylaxis?
Prioritised 34x (28x NOV member, 3x patient representative, 3x stakeholder)
Is linked to the guidelines:
1. Total hip prosthesis
2. Total knee prosthesis
3. Anti-thrombotic policy (NIV)


Patients receiving a total hip or knee prosthesis are at risk of post-operative thrombosis (2.5% - 3.5%). Due to the large number of operations performed in the Netherlands (28,000 primary THP and 24,000 primary TKP annually (1)), approximately 1,650 patients will develop thrombosis every year. On the other hand, the incidence is also decreasing as a result of the rapid post-operative mobilisation and new treatment techniques.

Thrombosis is associated with significant mortality and morbidity and 30% of all patients will suffer a recurrence within 5 years. Prevention - by means of thrombosis prophylaxis - is therefore of vital importance. However, this also poses a risk of bleeding.

A lot of preliminary work has been performed since the prioritisation of the research question in 2015. This made it clear that a trial to study the duration of thrombosis prophylaxis is currently not relevant. A staggered approach is required to answer the aforementioned question. First, we need to distinguish between low-risk and high-risk patients for the development of thrombosis. Next, different thrombosis prophylaxis strategies can be used for these two patient groups. An example: the low-risk group receives a lower dose of thrombosis prophylaxis and for a shorter period, whilst the high-risk group receives (potentially) a higher dose of thrombosis prophylaxis for a longer period. This reduces the duration of anticoagulant treatment and the risk of complications - such as bleeding - for the majority of all patients, as well as the incidence of thrombosis.
In order to identify the low-risk and high-risk patients, the TRiP study was started in recent years as an initial phase to answering this question.
  1. LROI-rapportage
Hip or knee prosthesis patients: does the return to work improve with a referral to the occupational health physician?
Prioritised 19x (13x NOV member, 4x patient representative, 2x stakeholder)
Is linked to the guidelines 1. Total hip prosthesis and 2. Total knee prosthesis


In the Netherlands, approximately 28,000 total hip prostheses (THP) and 24,000 total knee prostheses (TKP) are fitted annually (1). Estimates reveal that approximately a quarter of patients with a THP or TKP is in paid employment. These numbers will probably increase significantly in years to come. However, a substantial number of patients do not resume work after receiving a THP or TKP (2). Referral to the occupational health physician might improve the return to work. However, very little research has been performed on this subject to date. ZonMw (Efficiency Study, open round 2019, study into the cost-effectiveness of interventions) has however recently awarded a subsidy to the research group of Prof. J.R. Anema (VUMC). In this research, active referral - among others to an occupational health physician after TKP - forms part of the intervention that will be studied. The project carries the title: “Cost-effectiveness of a transmural integrated health care program for knee arthroplasty in the working population”. As this project overlaps to a certain extent with the ongoing CORE project “PaTIO”, these groups are working together closely.
  1. LROI-rapportage
  2. Tilbury C, Schaasberg W, Plevier JW, Fiocco M, Nelissen RG, Vliet Vlieland TP. Return to work after total hip and knee arthroplasty: a systematic review. Reumatolgy 2014;53(3):512-525.
Symptomatic flat-footedness: what is the effect of an orthotic?
Prioritised 13x (11x NOV member, 2x patient representative)
There is no guideline for this subject.


To date, no comparative research has been properly set up and performed to answer the simple question whether orthotics are effective in the treatment of symptomatic flat-footedness of children and/or adults.

Roughly 45% of children up to 4 years of age, 15% of older children (1) and 30% of adults over the age of 20 years (2,3) have flat feet. It is not known how many orthotics are fitted annually in the Netherlands. We do know that they last an average of 2 years and the costs are variable, but are usually around € 200. It is known that tailor-made orthotics are only better than “off the shelf” orthotics for certain foot conditions (hollow feet, hallux valgus with pain and juvenile idiopathic arthritis). There is no evidence of this for other indications. However, most orthotics (both off-the-shelf and tailor-made) are prescribed for flat feet (4).

A lot of research has been performed into the effect of orthotics “on something”; down to the smallest details. An example of this is: “Effects of orthopedic insoles on static balance of older adults wearing thick socks” (5). However, there are almost no comparative studies and if there are any, then they are of very moderate quality (6).
When working on this research question, attention should therefore be paid to the accurate determination of the primary endpoint and a control group; a challenge in itself!
  1. Evans AM, Rome K. A Cochrane review of the evidence for non-surgical interventions for flexible pediatric flat feet. Eur J Phys Rhabil Med. 2011 Mar;47(1):69-89.
  2. Pita-Fernandez S, Gonzalez-Martin C, Alonso-Tajes F, Seoane-Pillado T, Pertega-Diaz S, Perez-Garcia S, Seijo-Bestilleiro R, Balboa-Barreiro V. Flat Foot in a Random Population and its Impact on Quality of Life and Functionality. J Clin Diagn Res. 2017 Apr;11(4):LC22-LC27.
  3. Parvez Inamdar, Darshita Fatnani, Fatima Rajiwate, Bushra Shaikh, Bhakti Deshpande, Shehnila Shaikh, Bharat Ranka, Shagufa Dhansay. Prevalence of flat foot and high arched foot in normal working individuals using footprint method. Int J Physiother and Res. 2018; 6(3):2754-58
  4. Stolwijk NM. Feet4feet plantar pressure and kinematics of the healthy and painful foot (proefschrift). Nijmegen. 2014.
  5. Ma CZ, Wong DW, Wan AH, Lee WC. Effects of orthopedic insoles on static balance of older adults wearing thick socks. Prosthet Orthot Int. 2018 Jun;42(3):357-362.
  6. Hsieh RL, Peng HL, Lee WC. Short-term effects of customized arch support insoles on symptomatic flexible flatfoot in children: A randomized controlled trial. Medicine (Baltimore). 2018 May;97(20):e10655.
Low-grade cartilage tumours: is surgery necessary or not? RCT: MRI wait-and-see versus surgery.
Prioritised 10x (9x NOV member, 1x stakeholder)
There is no guideline for this subject.


The treatment of low-grade central cartilage tumours of the extremity (atypical cartilaginous tumours) varies per centre. Some centres opt for annual examinations and monitoring by X-ray and MRI and monitor these patients for 5-10 years sometimes. Other centres opt for a minimally invasive curettage of all cartilage tumours. There are no randomised studies comparing these treatment strategies.

Innovation question

Can we use pre-intervention patient characteristics for better prediction of what the intervention outcome will be, for example for:
- patients who are eligible for treatment with hip/knee prosthesis;
- patients with (various) degenerative spinal conditions.
This question is a combination of three prioritised innovation questions:
  1. Can we use big data for better prediction of the treatment effect on pain and functionality, after insertion of a knee or hip prosthesis? Prioritised 27x (22x NOV member, 3x patient representative, 2x stakeholder)
  2. Which factors are essential for triage and therefore predictors of the treatment outcome (surgical/non-surgical) in patients with degenerative lower back problems? Prioritised 20x (17x NOV member, 1x patient representative, 2x stakeholder)
  3. Which factors are important for the selection of optimum surgical interventions for patients with degenerative deformities of the spine? Prioritised 10x (8x NOV member, 2x patient representative)
These three separate questions are actually modules that form part of the question What is the predictability of outcomes following orthopaedic intervention? Collaboration with other initiatives in this field is required to answer such a broadly formulated question. Collaboration to increase methodological knowledge is important: for example, how can we use big data, machine learning or other AI-like applications efficiently and responsibly, together with the existing knowledge and algorithms that have already been developed? We can use this knowledge in the future for other high-priority questions. This will result in a scientific orthopaedic network, aimed at predictive research. In the ideal situation, we can add new modules in the future.

The examples of hip and knee prostheses and degenerative lower spine conditions are relevant, because:
  1. In the Netherlands, approximately 28,000 total hip prostheses (THP) and 24,000 total knee prostheses (TKP) are fitted annually (1). The results of these surgeries are generally good. However, approximately 10-20% of people are not satisfied following a TKP/THP (2-5). However, a large proportion of the potential gain in satisfaction will not be achieved through innovations in implants or techniques. Therefore, this question focuses on improved selection of patients who are actually satisfied with the post-operative result. This is about prediction of the outcomes. Examples of possible predictors include coping style and expectations (6).
  2. Degenerative lower back problems are very common, have a high socio-economic impact and pose dilemmas for health care providers when selecting the optimum treatment strategy. Degenerative lower back problems are often multi-factorial in nature. This means that treatment focused on one specific component of the symptoms may have little effect, because other causal factors remain untreated. Clarity about the factors that are important for successful treatment could be useful in the better prediction of outcomes following different treatment strategies.
  3. The NOV has already initiated various projects in this field, including the LROI study (Van Rens Fonds) (7,8) There are also ongoing national and international studies that could contribute answers to this innovation question. The developments will be monitored within CORE.
  1. www.lroi-rapportage.nl
  2. Nilsdotter AK, Toksvig-Larsen S, Roos EM. Knee arthroplasty: are patients’ expectations fulfilled? A prospective study of pain and function in 102 patients with 5-year follow-up. Acta Orthop. 2009;80(1):55–61.
  3. Anderson JG, Wixson RL, Tsai D, Stulberg SD, Chang RW. Functional outcome and patient satisfaction in total knee patients over the age of 75. J Arthroplast. 1996;11(7):831–40.
  4. Baker PN, van der Meulen JH, Lewsey J, Gregg PJ. The role of pain and function in determining patient satisfaction after total knee replacement. Data from the National Joint Registry for England and Wales. J Bone Joint Surg Br. 2007;89(7):893–900.
  5. Gandhi R, Davey JR, Mahomed NN. Predicting patient dissatisfaction following joint replacement surgery. J Rheumatol. 2008;35(12):2415–8.
  6. Development of a preoperative prediction tool for pain and functional outcome after TKA using the Dutch Arthroplasty Register (LROI) data (lopend VRF onderzoek 2018)
  7. Influence of patient characteristics (case mix) on outcome of total hip and total knee arthroplasty; a dutch national joint registry study (lopend VRF onderzoek 2017)


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