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Dive into the research topics where Maarten W. G. A. Bronkhorst is active.

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Featured researches published by Maarten W. G. A. Bronkhorst.


BMC Musculoskeletal Disorders | 2010

Primary hemiarthroplasty versus conservative treatment for comminuted fractures of the proximal humerus in the elderly (ProCon): A Multicenter Randomized Controlled trial

Dennis den Hartog; Esther M.M. Van Lieshout; Wim E. Tuinebreijer; Suzanne Polinder; Ed F. van Beeck; Roelf S. Breederveld; Maarten W. G. A. Bronkhorst; J. P. Eerenberg; Steven J. Rhemrev; W. Herbert Roerdink; Gerrit Schraa; Harm M. van der Vis; Thom P. H. van Thiel; Peter Patka; Stefaan Nijs; Niels W. L. Schep

BackgroundFractures of the proximal humerus are associated with a profound temporary and sometimes permanent, impairment of function and quality of life. The treatment of comminuted fractures of the proximal humerus like selected three-or four-part fractures and split fractures of the humeral head is a demanding and unresolved problem, especially in the elderly. Locking plates appear to offer improved fixation; however, screw cut-out rates ranges due to fracture collapse are high. As this may lead to higher rates of revision surgery, it may be preferable to treat comminuted fractures in the elderly primarily with a prosthesis or non-operatively. Results from case series and a small-sample randomized controlled trial (RCT) suggest improved function and less pain after primary hemiarthroplasty (HA); however these studies had some limitations and a RCT is needed. The primary aim of this study is to compare the Constant scores (reflecting functional outcome and pain) at one year after primary HA versus non-operative treatment in elderly patients who sustained a comminuted proximal humeral fracture. Secondary aims include effects on functional outcome, pain, complications, quality of life, and cost-effectiveness.Methods/DesignA prospective, multi-center RCT will be conducted in nine centers in the Netherlands and Belgium. Eighty patients over 65 years of age, who have sustained a three-or four part, or split head proximal humeral fracture will be randomized between primary hemiarthroplasty and conservative treatment. The primary outcome is the Constant score, which indicates pain and function. Secondary outcomes include the Disability of the Arm and Shoulder (DASH) score, Visual Analogue Scale (VAS) for pain, radiographic healing, health-related quality of life (Short-form-36, EuroQol-5D) and healthcare consumption. Cost-effectiveness ratios will be determined for both trial arms. Outcome will be monitored at regular intervals over the subsequent 24 months (1, 3 and 6 weeks, and 3, 6, 12, 18, and 24 months). Data will be analyzed on an intention to treat basis, using univariate and multivariable analyses.DiscussionThis trial will provide level-1 evidence on the effectiveness of the two mostly applied treatment options for three-or four part and split head proximal humeral fractures in the elderly. These data may support the development of a clinical guideline for treatment of these traumatic injuries.Trial registrationNetherlands Trial Register (NTR): NTR2040


BMC Musculoskeletal Disorders | 2011

Displaced midshaft fractures of the clavicle: non-operative treatment versus plate fixation (Sleutel-TRIAL). A multicentre randomised controlled trial

Sylvia A. Stegeman; Mireille de Jong; Cornelis F. M. Sier; Pieta Krijnen; Jan W. Duijff; Tom P. H. van Thiel; Piet Rijcke; Nicolaj M. R. Soesman; Tjebbe Hagenaars; Freek D. Boekhoudt; Mark R. de Vries; Gert R. Roukema; Andras F. K. Tanka; Jephta van den Bremer; Hub G. W. M. van der Meulen; Maarten W. G. A. Bronkhorst; Bart A. van Dijkman; Stephan W. A. M. van Zutphen; Dagmar I. Vos; N.W.L. Schep; Martin G. Eversdijk; Ger D. J. van Olden; Johan G. H. van den Brand; Robert Jan Hillen; J.P.M. Frolke; Inger B. Schipper

BackgroundThe traditional view that the vast majority of midshaft clavicular fractures heal with good functional outcomes following non-operative treatment may be no longer valid for all midshaft clavicular fractures. Recent studies have presented a relatively high incidence of non-union and identified speciic limitations of the shoulder function in subgroups of patients with these injuries.AimA prospective, multicentre randomised controlled trial (RCT) will be conducted in 21 hospitals in the Netherlands, comparing fracture consolidation and shoulder function after either non-operative treatment with a sling or a plate fixation.Methods/designA total of 350 patients will be included, between 18 and 60 years of age, with a dislocated midshaft clavicular fracture. The primary outcome is the incidence of non-union, which will be determined with standardised X-rays (Antero-Posterior and 30 degrees caudocephalad view). Secondary outcome will be the functional outcome, measured using the Constant Score. Strength of the shoulder muscles will be measured with a handheld dynamometer (MicroFET2). Furthermore, the health-related Quality of Life score (ShortForm-36) and the Disabilities of Arm, Shoulder and Hand (DASH) Outcome Measure will be monitored as subjective parameters. Data on complications, bone union, cosmetic aspects and use of painkillers will be collected with follow-up questionnaires. The follow-up time will be two years. All patients will be monitored at regular intervals over the subsequent twelve months (two and six weeks, three months and one year). After two years an interview by telephone and a written survey will be performed to evaluate the two-year functional and mechanical outcomes. All data will be analysed on an intention-to-treat basis, using univariate and multivariate analyses.DiscussionThis trial will provide level-1 evidence for the comparison of consolidation and functional outcome between two standardised treatment options for dislocated midshaft clavicular fractures. The gathered data may support the development of a clinical guideline for treatment of clavicular fractures.Trial registrationNetherlands National Trial Register NTR2399


BMC Musculoskeletal Disorders | 2010

Functional treatment versus plaster for simple elbow dislocations (FuncSiE): a randomized trial

Jeroen de Haan; Dennis den Hartog; Wim E. Tuinebreijer; Gijs I. T. Iordens; Roelf S. Breederveld; Maarten W. G. A. Bronkhorst; Milko M. M. Bruijninckx; Mark R. de Vries; Boudewijn J. Dwars; Denise Eygendaal; Robert Haverlag; Sven Meylaerts; Jan-Willem R. Mulder; Kees J. Ponsen; W. Herbert Roerdink; Gert R. Roukema; Inger B. Schipper; Michel A. Schouten; Jan Bernard Sintenie; Senail Sivro; Johan G. H. van den Brand; Hub G. W. M. van der Meulen; Tom P. H. van Thiel; Arie B. van Vugt; Egbert J. M. M. Verleisdonk; Jos P. A. M. Vroemen; Marco Waleboer; W. Jaap Willems; Suzanne Polinder; Peter Patka

BackgroundElbow dislocations can be classified as simple or complex. Simple dislocations are characterized by the absence of fractures, while complex dislocations are associated with fractures. After reduction of a simple dislocation, treatment options include immobilization in a static plaster for different periods of time or so-called functional treatment. Functional treatment is characterized by early active motion within the limits of pain with or without the use of a sling or hinged brace. Theoretically, functional treatment should prevent stiffness without introducing increased joint instability. The primary aim of this randomized controlled trial is to compare early functional treatment versus plaster immobilization following simple dislocations of the elbow.Methods/DesignThe design of the study will be a multicenter randomized controlled trial of 100 patients who have sustained a simple elbow dislocation. After reduction of the dislocation, patients are randomized between a pressure bandage for 5-7 days and early functional treatment or a plaster in 90 degrees flexion, neutral position for pro-supination for a period of three weeks. In the functional group, treatment is started with early active motion within the limits of pain. Function, pain, and radiographic recovery will be evaluated at regular intervals over the subsequent 12 months. The primary outcome measure is the Quick Disabilities of the Arm, Shoulder, and Hand score. The secondary outcome measures are the Mayo Elbow Performance Index, Oxford elbow score, pain level at both sides, range of motion of the elbow joint at both sides, rate of secondary interventions and complication rates in both groups (secondary dislocation, instability, relaxation), health-related quality of life (Short-Form 36 and EuroQol-5D), radiographic appearance of the elbow joint (degenerative changes and heterotopic ossifications), costs, and cost-effectiveness.DiscussionThe successful completion of this trial will provide evidence on the effectiveness of a functional treatment for the management of simple elbow dislocations.Trial RegistrationThe trial is registered at the Netherlands Trial Register (NTR2025).


BMC Musculoskeletal Disorders | 2011

A hinged external fixator for complex elbow dislocations: A multicenter prospective cohort study

Niels W. L. Schep; Jeroen de Haan; Gijs I. T. Iordens; Wim E. Tuinebreijer; Maarten W. G. A. Bronkhorst; Mark R. de Vries; J. Carel Goslings; S. John Ham; Steven J. Rhemrev; Gert R. Roukema; Inger B. Schipper; Jan Bernard Sintenie; Hub G. W. M. van der Meulen; Tom P. H. van Thiel; Arie B. van Vugt; Egbert J. M. M. Verleisdonk; Jos P. A. M. Vroemen; Philippe Wittich; Peter Patka; Esther M.M. Van Lieshout; Dennis den Hartog

BackgroundElbow dislocations can be classified as simple or complex. Simple dislocations are characterized by the absence of fractures, while complex dislocations are associated with fractures of the radial head, olecranon, or coronoid process. The majority of patients with these complex dislocations are treated with open reduction and internal fixation (ORIF), or arthroplasty in case of a non-reconstructable radial head fracture. If the elbow joint remains unstable after fracture fixation, a hinged elbow fixator can be applied. The fixator provides stability to the elbow joint, and allows for early mobilization. The latter may be important for preventing stiffness of the joint. The aim of this study is to determine the effect of early mobilization with a hinged external elbow fixator on clinical outcome in patients with complex elbow dislocations with residual instability following fracture fixation.Methods/DesignThe design of the study will be a multicenter prospective cohort study of 30 patients who have sustained a complex elbow dislocation and are treated with a hinged elbow fixator following fracture fixation because of residual instability. Early active motion exercises within the limits of pain will be started immediately after surgery under supervision of a physical therapist. Outcome will be evaluated at regular intervals over the subsequent 12 months. The primary outcome is the Quick Disabilities of the Arm, Shoulder, and Hand score. The secondary outcome measures are the Mayo Elbow Performance Index, Oxford Elbow Score, pain level at both sides, range of motion of the elbow joint at both sides, radiographic healing of the fractures and formation of periarticular ossifications, rate of secondary interventions and complications, and health-related quality of life (Short-Form 36).DiscussionThe outcome of this study will yield quantitative data on the functional outcome in patients with a complex elbow dislocation and who are treated with ORIF and additional stabilization with a hinged elbow fixator.Trial RegistrationThe trial is registered at the Netherlands Trial Register (NTR1996).


Journal of Trauma-injury Infection and Critical Care | 2013

Single-nucleotide polymorphisms in the Toll-like receptor pathway increase susceptibility to infections in severely injured trauma patients.

Maarten W. G. A. Bronkhorst; Nicole D. A. Boyé; Miranda A.Z. Lomax; Rolf H.A.M. Vossen; Jan Bakker; Peter Patka; Esther M.M. Van Lieshout

BACKGROUND Sepsis and subsequent multiple-organ failure are the predominant causes of late mortality in trauma patients. Susceptibility and response to infection is, in part, heritable. Single-nucleotide polymorphisms (SNPs) in Toll-like receptor (TLR) and cluster of differentiation 14 (CD14) genes of innate immunity may play a key role. The aim of this study was to assess if SNPs in TLR/CD14 predisposed trauma patients to infection. METHODS A prospective cohort of trauma patients (age 18–80 years; injury severity score [ISS] ≥ 16) admitted to a Level I trauma center between January 2008 and April 2011 was genotyped for SNPs in TLR2 (T-16934A and R753Q), TLR4 (D299G and T399I), TLR9 (T-1486C and T-1237C), and CD14 (C-159T) using high-resolution melting analysis. Association of genotype with prevalence of positive culture findings (gram positive, gram negative, fungi), systemic inflammatory response syndrome (SIRS), sepsis, septic shock, and mortality was tested with &khgr;2 and logistic regression analysis. RESULTS Genotyping was performed for 219 patients, of whom 51% developed positive culture findings in sputum, wounds, blood, or urine. SIRS developed in 64%, sepsis in 36%, and septic shock in 17%. The TLR2 T-16934A TA genotype increased the risk of a gram-positive infection (odds ratio, 2.816; 95% confidence interval, 1.249–6.348; p = 0.013) and SIRS (odds ratio, 2.386; 95% confidence interval, 1.011–5.632; p = 0.047). Trends were noted for TLR9 and CD14 SNPs but did not reach statistical significance. Sepsis and septic shock were unrelated to any of the SNPs studied. CONCLUSION Aberrant functioning of the TLR/CD14 pathway of innate immunity changes the risk of infectious complications in severely injured trauma patients. Of the seven SNPs studied, the TLR2 T-16934A increased the risk, the TLR9 T-1486C SNPs may decrease the risk, and TLR4 variation seemed unrelated to outcome. Early genotyping may prove to be helpful in the future in identifying polytraumatized patients at risk for infectious outcome. LEVEL OF EVIDENCE Prognostic and epidemiologic study, level II.


BMC Musculoskeletal Disorders | 2014

Surgery versus conservative treatment in patients with type A distal radius fractures, a randomized controlled trial

Monique M. J. Walenkamp; J. Carel Goslings; Annechien Beumer; Robert Haverlag; Peter A. Leenhouts; Egbert J. M. M. Verleisdonk; Ronald S. L. Liem; Jan Bernard Sintenie; Maarten W. G. A. Bronkhorst; Jasper Winkelhagen; Niels W. L. Schep

BackgroundFractures of the distal radius are common and account for an estimated 17% of all fractures diagnosed. Two-thirds of these fractures are displaced and require reduction. Although distal radius fractures, especially extra-articular fractures, are considered to be relatively harmless, inadequate treatment may result in impaired function of the wrist. Initial treatment according to Dutch guidelines consists of closed reduction and plaster immobilisation. If fracture redisplacement occurs, surgical treatment is recommended. Recently, the use of volar locking plates has become more popular. The aim of this study is to compare the functional outcome following surgical reduction and fixation with a volar locking plate with the functional outcome following closed reduction and plaster immobilisation in patients with displaced extra-articular distal radius fractures.DesignThis single blinded randomised controlled trial will randomise between open reduction and internal fixation with a volar locking plate (intervention group) and closed reduction followed by plaster immobilisation (control group). The study population will consist of all consecutive adult patients who are diagnosed with a displaced extra-articular distal radius fracture, which has been adequately reduced at the Emergency Department. The primary outcome (functional outcome) will be assessed by means of the Disability Arm Shoulder Hand Score (DASH). Secondary outcomes comprise the Patient-Rated Wrist Evaluation score (PRWE), quality of life, pain, range of motion, radiological parameters, complications and cross-overs. Since the treatment allocated involves a surgical procedure, randomisation status will not be blinded. However, the researcher assessing the outcome at one year will be unaware of the treatment allocation. In total, 90 patients will be included and this trial will require an estimated time of two years to complete and will be conducted in the Academic Medical Centre Amsterdam and its partners of the regional trauma care network.DicussionIdeally, patients would be randomised before any kind of treatment has been commenced. However, we deem it not patient-friendly to approach possible participants before adequate reduction has been obtained.Trial registrationThis study is registered at the Netherlands Trial Register (NTR3113) and was granted permission by the Medical Ethical Review Committee of the Academic Medical Centre on 01-10-2012.


Shock | 2015

Effects of sequence variations in innate immune response genes on infectious outcome in trauma patients: A comprehensive review

Maarten W. G. A. Bronkhorst; Peter Patka; Esther M.M. Van Lieshout

ABSTRACT Infectious complications, sepsis, and multiple organ dysfunction syndrome (MODS) remain important causes for morbidity and mortality in patients who survive the initial trauma. Increasing evidence suggests that genetic variants, particularly single nucleotide polymorphisms (SNPs), are critical determinants for interindividual differences in both inflammatory responses and clinical outcome in sepsis patients. Although the effect of SNPs on sepsis and MODS has been studied in many populations and diseases, this review aimed to summarize the current knowledge on the effect of SNPs on infectious complication specifically in trauma patients. A review of available literature was performed in PubMed database. The following genes have been studied in populations of trauma patients: CD14, HMGB1, IFNG, IL1A, IL1B, IL1RN, IL4, IL6, IL8, IL10, IL17F, IL18, MBL2, MASP2, FCN2, TLR1, TLR2, TLR4, TLR9, TNF, LTA, GR, MYLK, NLRP3, PRDX6, RAGE, HSPA1B, HSPA1L, HSP90, SERPINE1, IRAK1, IRAK3, VEGFA, LY96, ANGPT2, LBP, MicroRNA, and mtDNA. In this review, we discuss the genes of the Pattern Recognition Receptors, Signal Transducing Adaptor Proteins, and Inflammatory Cytokines of the innate immune system. A number of genetic variations have so far been studied in cohorts of trauma patients. Studies are often unique and numbers sometimes small. No definitive conclusions can be reached at this time about the influence of specific sequence variations on outcome in trauma patients.


Journal of Shoulder and Elbow Surgery | 2017

Reliability, validity, responsiveness, and minimal important change of the Disablities of the Arm, Shoulder and Hand and Constant-Murley scores in patients with a humeral shaft fracture

Kiran C. Mahabier; Dennis den Hartog; Nina Theyskens; M.H.J. Verhofstad; Esther M.M. Van Lieshout; P. Koen Bos; Maarten W. G. A. Bronkhorst; Milko M. M. Bruijninckx; Jeroen de Haan; P Ted Den Hoed; Martin G. Eversdijk; J. Carel Goslings; Robert Haverlag; Martin J. Heetveld; Albert J.H. Kerver; Karel A. Kolkman; Peter A. Leenhouts; Sven Meylaerts; Ron Onstenk; Martijn Poeze; Rudolf W. Poolman; Bas J. Punt; Ewan D. Ritchie; W. Herbert Roerdink; Gert R. Roukema; Jan Bernard Sintenie; Nicolaj M. R. Soesman; Maarten van der Elst; Frank H.W.M. Van der Heijden; Frits M. van der Linden

BACKGROUND The Disabilities of the Arm, Shoulder and Hand (DASH) and Constant-Murley scores are commonly used instruments. The DASH is patient-reported, and the Constant-Murley combines a clinician-reported and a patient-reported part. For patients with a humeral shaft fracture, their validity, reliability, responsiveness, and minimal important change (MIC) have not been published. This study evaluated the measurement properties of these instruments in patients who sustained a humeral shaft fracture. METHODS The DASH and Constant-Murley instruments were completed 5 times until 1 year after trauma. Pain score, Short Form 36, and EuroQol-5D were completed for comparison. Internal consistency was determined by the Cronbach α. Construct and longitudinal validity were evaluated by assessing hypotheses about expected Spearman rank correlations in scores and change scores, respectively, between patient-reported outcome measures (sub)scales. The smallest detectable change (SDC) was calculated. The MIC was determined using an anchor-based approach. The presence of floor and ceiling effects was determined. RESULTS A total of 140 patients were included. Internal consistency was sufficient for DASH (Cronbach α = 0.96) but was insufficient for Constant-Murley (α = 0.61). Construct and longitudinal validity were sufficient for both patient-reported outcome measures (>75% of correlations hypothesized correctly). The MIC and SDC were 6.7 (95% confidence interval, 5.0-15.8) and 19.0 (standard error of measurement, 6.9), respectively, for DASH and 6.1 (95% CI -6.8 to 17.4) and 17.7 (standard error of measurement, 6.4), respectively, for Constant-Murley. CONCLUSIONS The DASH and Constant-Murley are valid instruments for evaluating outcome in patients with a humeral shaft fracture. Reliability was only shown for the DASH, making this the preferred instrument. The observed MIC and SDC values provide a basis for sample size calculations for future research.


BMC Musculoskeletal Disorders | 2014

HUMeral Shaft Fractures: MEasuring Recovery after Operative versus Non-operative Treatment (HUMMER): a multicenter comparative observational study

Kiran C. Mahabier; Esther M.M. Van Lieshout; Hugo W. Bolhuis; P. Koen Bos; Maarten W. G. A. Bronkhorst; Milko M. M. Bruijninckx; Jeroen de Haan; Axel Deenik; Boudewijn J. Dwars; Martin G. Eversdijk; J. Carel Goslings; Robert Haverlag; Martin J. Heetveld; Albert J.H. Kerver; Karel A. Kolkman; Peter A. Leenhouts; Sven Meylaerts; Ron Onstenk; Martijn Poeze; Rudolf W. Poolman; Bas J. Punt; W. Herbert Roerdink; Gert R. Roukema; Jan Bernard Sintenie; Nicolaj M. R. Soesman; Andras K. F. Tanka; Edgar J. T. ten Holder; Maarten van der Elst; Frank H.W.M. Van der Heijden; Frits M. van der Linden


Lab on a Chip | 2014

Make it spin: individual trapping of sperm for analysis and recovery using micro-contact printing

Jean-Philippe Frimat; Maarten W. G. A. Bronkhorst; B. de Wagenaar; Johan G. Bomer; F. van der Heijden; A. van den Berg; Loes Irene Segerink

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Inger B. Schipper

Leiden University Medical Center

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Peter Patka

Erasmus University Rotterdam

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Dennis den Hartog

Erasmus University Rotterdam

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Jeroen de Haan

Erasmus University Rotterdam

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N.W.L. Schep

Academic Medical Center

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Niels W. L. Schep

Erasmus University Rotterdam

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Pieta Krijnen

Leiden University Medical Center

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