F C Oner

University Medical Center Utrecht, Utrecht, Utrecht, Netherlands

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Publications (154)410.28 Total impact

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    ABSTRACT: Treatment and reconstruction of large bone defects, delayed unions and non-unions is challenging and has resulted in an ongoing search for novel tissue-engineered therapies. Bone morphogenetic protein-2 (BMP-2) gene therapy is a promising strategy to provide a sustained production of BMP-2 locally. Alginate polymer based non-viral gene therapy with BMP-2 plasmid DNA (pBMP-2) in constructs with multipotent mesenchymal stromal cells (MSCs) has resulted in prolonged gene expression and bone formation in vivo. To further translate this technology towards larger animal models, important issues remain to be investigated, such as the necessity of seeded cells as a target for gene therapy. For that purpose, a large animal-screening model in an orthotopic location, with fully separated chambers, was investigated. Four cylinder shaped implants were placed in the iliac crests of ten goats. Polycaprolactone tubes around each implant allowed bone ingrowth from the underlying bone and bone marrow and ensured separation of the experimental conditions. An empty tube showed low levels of spontaneous bone ingrowth and implantation of autologous bone indicated proper bone function with respect to remodeling and resorption. Control ceramic scaffolds were compared to scaffolds containing pBMP-2 either or not combined with seeded MSCs. Fluorochrome incorporation, evaluated at three, six and nine weeks and histomorphometry at twelve weeks after implantation revealed clear differences between the groups, with pBMP-2 combined with MSCs being most effective. BMP-2 protein was demonstrated in a variety of bone-residing cells through immunohistochemistry. Further analysis indicated that multinucleated giant cells might have an important role in transgene expression. Taken together, this work introduces a large animal model for studying bone formation at multiple sites simultaneously in an orthotopic location. The model appeared robust, showed no neighboring effects and demonstrated effectivity of combined cell-and gene therapy.
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    ABSTRACT: This project describes a morphology-based subaxial cervical spine traumatic injury classification system. Using the same approach as the thoracolumbar system, the goal was to develop a comprehensive yet simple classification system with high intra- and interobserver reliability to be used for clinical and research purposes. A subaxial cervical spine injury classification system was developed using a consensus process among clinical experts. All investigators were required to successfully grade 10 cases to demonstrate comprehension of the system before grading 30 additional cases on two occasions, 1 month apart. Kappa coefficients (κ) were calculated for intraobserver and interobserver reliability. The classification system is based on three injury morphology types similar to the TL system: compression injuries (A), tension band injuries (B), and translational injuries (C), with additional descriptions for facet injuries, as well as patient-specific modifiers and neurologic status. Intraobserver and interobserver reliability was substantial for all injury subtypes (κ = 0.75 and 0.64, respectively). The AOSpine subaxial cervical spine injury classification system demonstrated substantial reliability in this initial assessment, and could be a valuable tool for communication, patient care and for research purposes.
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    ABSTRACT: Study Design. Validation study.Objective. To investigate the most valid, reliable, and comprehensible response scale for spinal trauma patients to compare their current level of function and health with their pre-injury state.Summary of Background Data. In the context of a main project of the AOSpine Knowledge Forum Trauma to develop a disease specific outcome instrument for adult spinal trauma patients, the need to identify a response scale that uniquely reflects the degree to which a spine trauma patient has returned to his or her pre-injury state is crucial.Methods. In the first phase, three different question formats and three different response formats were investigated in a questionnaire, which was administered twice. Based on the results of the first phase, in the second phase a modified questionnaire was administered once to a second group of patients to investigate five different response formats: 0-10 Numeric Rating Scale (NRS-11), 0-100 Numeric Rating Scale (NRS-101), Visual Analog Scale (VAS), Verbal Rating Scale (VRS), and Adjective Scale (AS). All patients were interviewed in a semi-structured fashion to identify their preferences. Multiple statistical analyses were performed: test-retest reliability, internal consistency, and discriminant validity.Results. Twenty eligible patients were enrolled in the first phase and 59 in the second phase. The initial phase revealed the highest preference for one specific question format (60.0% and 86.7% after the first and second administration of the questionnaire, respectively). The second phase showed the VRS as the most preferred response format (35.6%). The semi-structured interviews revealed that overall, a subgroup of patients preferred a verbal response format (42.4%), and another group a numerical response format (49.1%). The statistical analysis showed good to excellent psychometric properties for all formats.Conclusions. The most preferred question and response formats were identified for use in a disease specific outcome instrument for spinal trauma patients.
    Spine 02/2015; DOI:10.1097/BRS.0000000000000852 · 2.45 Impact Factor
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    ABSTRACT: International web-based survey. To identify the most relevant aspects of human function and health status from the perspective of health care professionals involved in the treatment of spinal trauma patients. There is no universally accepted outcome instrument available that is specifically designed or validated for spinal trauma patients, contributing to controversies related to the optimal treatment and evaluation of many types of spinal injuries. Therefore, the AOSpine Knowledge Forum Trauma aims to develop such an instrument using the International Classification of Functioning, Disability, and Health (ICF) as its basis. Experts from the 5 AOSpine International world regions were asked to give their opinion on the relevance of a compilation of 143 ICF categories for spinal trauma patients on a 3-point scale: "not relevant," "probably relevant," or "definitely relevant." The responses were analyzed using frequency analysis. Possible differences in responses between the 5 world regions were analyzed with the Fisher exact test and descriptive statistics. Of the 895 invited AOSpine International members, 150 (16.8%) participated in this study. A total of 13 (9.1%) ICF categories were identified as definitely relevant by more than 80% of the participants. Most of these categories were related to the ICF component "activities and participation" (n = 8), followed by "body functions" (n = 4), and "body structures" (n = 1). Only some minor regional differences were observed in the pattern of answers. More than 80% of an international group of health care professionals experienced in the clinical care of adult spinal trauma patients indicated 13 of 143 ICF categories as definitely relevant to measure outcomes after spinal trauma. This study creates an evidence base to define a core set of ICF categories for outcome measurement in adult spinal trauma patients.Level of Evidence: N/A.
    Spine 01/2015; 40(2):E91-E96. DOI:10.1097/BRS.0000000000000684 · 2.45 Impact Factor
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    Spine 01/2015; DOI:10.1097/BRS.0000000000000824 · 2.45 Impact Factor
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    ABSTRACT: En bloc sacrectomy is a demanding surgical procedure to remove tumors from the sacrum. Comprehensive data on readmissions for complications endured months to years after initial discharge are scant. The purpose of this study is to present the long-term complications, readmissions and secondary interventions for patients having undergone en bloc sacrectomy. Patients were included if en bloc sacrectomy and follow-up were conducted in the authors institution. Correspondence from all specialties involved in the treatment of patients was retrieved. Predefined parameters were scored and assigned to five distinct phases: diagnostic phase; surgery; postoperative period to 1 year after surgery; second year after surgery until follow-up and last follow-up. Sixteen patients underwent anterior-posterior en bloc sacrectomy for a locally aggressive tumor (n = 2); malignant tumor (n = 13) or solitary metastasis (n = 1). The type of resection was low (n = 1); middle (n = 3); high (n = 4); total (n = 3) and hemisacrectomy (n = 5). The median surgical duration was 12.7 h and median blood lost was 12 l. A total of 73 major complications (average per patient 5; median 4; range 0-12) were recorded and 73 secondary interventions (average per patient 5; median 5; range 0-11) were performed in the first year postsurgery. From the second year until follow-up complications and secondary interventions markedly decreased. At final follow-up (65-266 months), considerable morbidity was found for the eleven patients still alive. En bloc sacrectomy is a procedure with a high rate of major complications, regardless of tumor histology, often necessitating readmissions and secondary interventions. Long-term survival is associated with considerable morbidity and extensive preoperative counseling should be conducted to discuss the risks and outcome of the procedure.
    European Spine Journal 12/2014; DOI:10.1007/s00586-014-3729-5 · 2.47 Impact Factor
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    ABSTRACT: To present a unique case of multilevel vertebral osteomyelitis after Lemierre syndrome.
    European Spine Journal 09/2014; DOI:10.1007/s00586-014-3576-4 · 2.47 Impact Factor
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    ABSTRACT: To develop a bio-assay for measuring long-term bioactivity of released anti-inflammatory compounds and to test the bioactivity of celecoxib (CXB) and triamcinolone acetonide (TA) released from a new PLGA-based microsphere platform.
    Pharmaceutical Research 08/2014; DOI:10.1007/s11095-014-1495-z · 3.95 Impact Factor
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    ABSTRACT: Bone defect healing is highly dependent on the simultaneous stimulation of osteogenesis and vascularization. In bone regenerative strategies, combined seeding of multipotent stromal cells (MSCs) and endothelial progenitor cells (EPCs) proves their mutual stimulatory effects. Here, we investigated whether stromal cell-derived factor-1α (SDF-1α) stimulates vascularization by EPCs and whether SDF-1α could replace seeded cells in ectopic bone formation. Late EPCs of goat origin were characterized for their endothelial phenotype and showed to be responsive to SDF-1α in in vitro migration assays. Subsequently, subcutaneous implantation of Matrigel plugs that contained both EPCs and SDF-1α showed more tubule formation than constructs containing either EPCs or SDF-1α. Addition of either EPCs or SDF-1α to MSC-based constructs showed even more elaborate vascular networks after 1 week in vivo, with SDF-1α/MSC laden groups showing more prominent interconnected networks than EPC/MSC laden groups. The presence of abundant mouse specific CD31/PECAM-1 expression in these constructs confirmed ingrowth of murine vessels and discriminated between angiogenesis and vessel networks formed by seeded goat cells. Importantly, implantation of EPC/MSC or SDF-1α/MSC constructs resulted in indistinguishable ectopic bone formation. In both groups, bone onset was apparent at week 3 of implantation. Taken together, we demonstrated that SDF-1α stimulated the migration of EPCs in vitro and vascularization in vivo. Furthermore, SDF-1α addition was as effective as EPCs in inducing the formation of vascularized ectopic bone based on MSC seeded constructs, suggesting a cell replacement role for SDF-1α. These results hold promise for the design of larger cm-scale cell free vascular bone grafts.
    Stem Cells and Development 07/2014; 23(24). DOI:10.1089/scd.2013.0560 · 4.20 Impact Factor
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    ABSTRACT: Human fully upright ambulation, with fully extended hips and knees, and the body's center of gravity directly above the hips, is unique in nature, and distinguishes humans from all other mammalians. This bipedalism is made possible by the development of a lordosis between the ischium and ilium; it allows to ambulate in this unique bipedal manner, without sacrificing forceful extension of the legs. This configuration in space introduces unique biomechanical forces with relevance for a number of spinal conditions. The aim of this study was to quantify the development of this lordosis between ischium and ilium in the normal growing and adult spine and to evaluate its correlation with the well-known clinical parameter, pelvic incidence.
    European Spine Journal 05/2014; 23(7). DOI:10.1007/s00586-014-3358-z · 2.47 Impact Factor
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    ABSTRACT: Timely vascularization is essential for optimal performance of bone regenerative constructs. Vascularization is efficiently stimulated by vascular endothelial growth factor (VEGF), a substance with a short half-life time. This study investigates the controlled release of VEGF from gelatin microparticles (GMPs) as a means to prolong VEGF activity at the preferred location within 3D bioprinted scaffolds, and the effects on subsequent vascularization. Release of VEGF from GMPs was continuous for 3weeks during in vitro studies, and bioactivity was confirmed using human endothelial progenitor cells (EPCs) in migration assays. Traditional and real-time migration assays showed immediate and efficient EPC migration in the presence of GMP-released VEGF, indistinguishable from VEGF-solution that was added to the medium. Matrigel scaffolds containing EPCs and VEGF, which was released either in a fast or sustained fashion by application of GMPs, were investigated for their in vivo vasculogenic capacity. Implantation in subcutaneous pockets in nude mice for one week demonstrated that vessel formation was significantly higher in the VEGF sustained-release group compared to the fast release group. In addition, regional differences with respect to VEGF release were introduced in 3D bioprinted EPC-laden scaffolds and their influence on vasculogenesis was investigated in vivo. The different regions were retained and vessel formation occurred analogous with the results seen in the Matrigel plugs. We conclude that GMPs are suitable to generate sustained release profiles of bioactive VEGF, and that they can be used to create defined differentiation regions in 3D bioprinted heterogeneous constructs, allowing a new generation of smart scaffold design. The prolonged presence of VEGF led to a significant increase in scaffold vascularization when applied in vivo.
    Journal of Controlled Release 04/2014; DOI:10.1016/j.jconrel.2014.04.007 · 7.26 Impact Factor
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    ABSTRACT: Although radiotherapy is effective in achieving pain relief in most patients, it is not completely understood why some patients respond well to radiotherapy and others do not. Our hypothesis was that metastatic bone pain, if predominantly caused by mechanical instability of the spine, responds less well to radiotherapy than metastatic bone pain caused by local tumor activity. Recently, the Spinal Instability Neoplastic Score (SINS) was proposed as a standardized referral tool for non-spine specialists in order to facilitate early diagnosis of spinal instability. To investigate the association between spinal instability as defined by the SINS and response to radiotherapy in patients with spinal metastases. A retrospective matched case-control study in an academic tertiary referral center, conducted according to the STROBE guidelines. Thirty-eight patients with spinal metastases who were retreated after initial palliative radiotherapy from January 2009 to December 2010 were matched to 76 control patients who were not retreated. Radiotherapy failure as defined by retreatment (radiotherapy, surgery, conservative) after palliative radiotherapy for spinal metastases. Radiotherapy planning CT scans were scored by a blinded spine surgeon according to the SINS criteria. The association between SINS and radiotherapy failure was estimated by univariate and multivariate conditional logistic regression analysis. No funding was received and no conflicts of interest exist. Median SINS was 10 (range 4-16) for cases and 7 (range 1-16) for controls. The SINS was significantly and independently associated with radiotherapy failure (adjusted odds ratio, 1.3; 95% confidence interval, 1.1-1.5; p = 0.01). This study shows that a higher spinal instability score increases the risk of radiotherapy failure in patients with spinal metastases, independent of performance status, primary tumor and symptoms. These results may support the hypothesis that metastatic spinal bone pain, predominantly caused by mechanical instability, responds less well to radiotherapy than pain mainly resulting from local tumor activity.
    The spine journal: official journal of the North American Spine Society 04/2014; DOI:10.1016/j.spinee.2014.03.043 · 2.80 Impact Factor
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    ABSTRACT: Evaluation of recurrences, complications and function at mid-term follow-up after curettage for sacral giant cell tumor (GCT). We retrospectively studied all 26 patients treated for sacral GCT in the Netherlands (from 1990 to 2010). Median follow-up was 98 (6-229) months. All patients underwent intralesional excision, 21 with local adjuvants, 5 radiotherapy, 3 IFN-α, 1 bisphosphonates. Functional outcome was assessed using Musculoskeletal Tumor Society (MSTS) score. Statistics were performed with Kaplan-Meier, Cox regression, log rank and Mann-Whitney U. Recurrence rate was 14/26 after median 13 (3-139) months and was highest after isolated curettage (4/5). Soft tissue masses >10 cm increased recurrence risk (HR = 3.3, 95 % CI = 0.81-13, p = 0.09). Complications were reported in 12/26 patients. MSTS was superior in patients without complications (27 vs. 21; p = 0.024). Recurrence rate for sacral GCT was highest after isolated curettage, indicating that (local) adjuvant treatment is desired to obtain immediate local control. Complications were common and impaired function.
    European Spine Journal 03/2014; DOI:10.1007/s00586-014-3263-5 · 2.47 Impact Factor
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    ABSTRACT: Polyetheretherketone (PEEK) cages have been widely used in the treatment of lumbar degenerative disc disorders, and show good clinical results. Still, complications such as subsidence and migration of the cage are frequently seen. A lack of osteointegration and fibrous tissues surrounding PEEK cages are held responsible. Ceramic implants made of silicon nitride show better biocompatible and osteoconductive qualities, and therefore are expected to lower complication rates and allow for better fusion.Purpose of this study is to show that fusion with the silicon nitride cage produces non-inferior results in outcome of the Roland Morris Disability Questionnaire at all follow-up time points as compared to the same procedure with PEEK cages. This study is designed as a double blind multi-center randomized controlled trial with repeated measures analysis 100 patients (18-75 years) presenting with symptomatic lumbar degenerative disorders unresponsive to at least 6 months of conservative treatment are included. Patients will be randomly assigned to a PEEK cage or a silicon nitride cage, and will undergo a transforaminal lumbar interbody fusion with pedicle screw fixation. Primary outcome measure is the functional improvement measured by the Roland Morris Disability Questionnaire. Secondary outcome parameters are the VAS leg, VAS back, SF-36, Likert scale, neurological outcome and radiographic assessment of fusion. After 1 year the fusion rate will be measured by radiograms and CT. Follow-up will be continued for 2 years. Patients and clinical observers who will perform the follow-up visits will be blinded for type of cage used during follow-up. Analyses of radiograms and CT will be performed independently by two experienced radiologists. In this study a PEEK cage will be compared with a silicon nitride cage in the treatment of symptomatic degenerative lumbar disc disorders. To our knowledge, this is the first randomized controlled trial in which the silicon nitride cage is compared with the PEEK cage in patients with symptomatic degenerative lumbar disc disorders.Trial registration: NCT01557829.
    BMC Musculoskeletal Disorders 02/2014; 15(1):57. DOI:10.1186/1471-2474-15-57 · 1.90 Impact Factor
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    ABSTRACT: Polyetheretherketone (PEEK) cages have been widely used during the past decade in patients with degenerative disorders of the cervical spine. Their radiolucency and low elastic modulus make them attractive attributes for spinal fusion compared with titanium and bone graft. Still, limitations are seen such as pseudoarthrosis, subsidence, and migration of the cages. Limited evidence on the clinical outcome of PEEK cages is found in the literature other than noncomparative cohort studies with only a few randomized controlled trials. To assess the clinical and radiographic outcome of PEEK cages in the treatment of degenerative disc disorders and/or spondylolisthesis in the cervical spine. Systematic review of all randomized controlled trials and prospective and retrospective nonrandomized comparative studies with a minimum follow-up of 6 months and all noncomparative cohort studies with a long-term follow-up of more than 5 years. The primary outcome variable was clinical performance. Secondary outcome variables consisted of radiographic scores. The MEDLINE, EMBASE, and Cochrane Library databases were searched according to the Preferred Reporting Items of Systematic reviews and Meta-Analyses statement and Meta-analysis Of Observational Studies in Epidemiology guidelines. No conflict of interest reported. No funding received. A total of 223 studies were identified, of which 10 studies were included. These comprised two randomized controlled trials, five prospective comparative trials, and three retrospective comparative trials. Minimal evidence for better clinical and radiographic outcome is found for PEEK cages compared with bone grafts in the cervical spine. No differences were found between PEEK, titanium, and carbon fiber cages. Future studies are needed to improve methodology to minimize bias. Publication of lumbar interbody fusion studies needs to be promoted because differences in clinical and/or radiographic scores are more likely to be demonstrated in this part of the spine.
    The spine journal: official journal of the North American Spine Society 12/2013; DOI:10.1016/j.spinee.2013.08.030 · 2.80 Impact Factor
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    ABSTRACT: When used to fixate traumatic thoracolumbar burst fractures, pedicle screw constructs may fail in the presence of severe vertebral body comminution as the intervertebral disc can creep through the fractured endplates leading to insufficient anterior column support. Balloon-assisted endplate reduction (BAER) and subsequent calcium phosphate cement augmentation may prevent this event by restoring the disc space boundaries. The results of the first studies using BAER after pedicle screw fixation are encouraging showing good fracture reduction, few complications and minimal loss of correction at two years of follow up. To present the clinical and radiological outcome of twenty patients treated for traumatic thoracolumbar burst fractures with pedicle screws and BAER after a minimum of six years follow up. Prospective trial. Twenty consecutive neurologically intact adult patients with traumatic thoracolumbar burst fractures were included. Radiological parameters (wedge/Cobb angle on plain radiographs and midsagittal anterior/central vertebral body height on MRI scans) and patient reported parameters (EQ-5D and Oswestry Disability Index) were used. All patients had previously undergone pedicle screw fixation and BAER with calcium phosphate cement augmentation. The posterior instrumentation was removed approximately 1,5 years after index surgery. Radiographs were obtained preoperatively, postoperatively, after removal of the pedicle screws and at final follow up (minimum six years posttrauma). MRI scans were obtained preoperatively, one month after index surgery and one month after pedicle screw removal. Health questionnaires were filled out during the last outpatient visit. The pedicle screw instrumentation was removed uneventfully in all patients and posterolateral fusion was observed in every case. The mean wedge and Cobb angle converged to almost identical values (5,3 and 5,8 degrees respectively) and the midsagittal anterior and central endplates were reduced to approximately 90% and 80% of the estimated preinjury vertebral body height respectively; this reduction was sustained at follow up. Patient reported outcomes showed favorable results in 79% of the patients. One patient required (posterior) reoperation due to adjacent osteoporotic vertebral body collapse after pedicle screw removal. Balloon-assisted endplate reduction is a safe and low-demanding adjunct to pedicle screw fixation for the treatment of traumatic thoracolumbar burst fractures. It may help achieve minimal residual deformity and reduce the number of secondary (anterior) procedures. Despite these positive findings, one in five patients experienced daily discomfort and disability.
    The spine journal: official journal of the North American Spine Society 12/2013; DOI:10.1016/j.spinee.2013.11.044 · 2.80 Impact Factor
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    ABSTRACT: Regenerative Medicine (RM) interventions, such as (stem) cell transplantation, scaffolds, gene transfer, and tissue engineering, are likely to change the field of orthopedics considerably. These strategies will significantly differ from treatments in current orthopedic practice, as they treat the underlying cause of disease and intervene at a biological level, preferably in an earlier stage. Whereas most of the RM interventions for orthopedics are still in the preclinical phase of research, the amount of clinical studies is expected to increase rapidly in the future. The debate about the challenging scientific and ethical issues of translating these innovative interventions into (early) clinical studies is developing. However, no empirical studies that have systematically described the attitudes, opinions, and experiences of experts in the field of orthopedic RM concerning these challenges exist. The aim of this study is to identify ethical issues which experts in the area of RM for musculoskeletal disorders consider to be relevant to address in order to properly translate RM interventions into (early) clinical studies. Study design/setting: In-depth qualitative interviews were conducted with 36 experts in the field, mainly spine surgeons and musculoskeletal scientists from the Netherlands and the United Kingdom(UK). A topic list of open questions, based on existing literature and pilot interviews, was used to guide the interviews. Data analysis was based on the constant comparative method, which means going back and forth from the data to develop codes, concepts and themes. Four ethical themes emerged from the interview data. First, the risks to study participants. Second, the appropriate selection of study participants. Third, setting relevant goal(s) for measuring outcome, varying from regenerating tissue to improving well-being of patients. Finally, the need for evidencebased medicine and scientific integrity, which is considered challenging in orthopedics. The overall attitude towards the development of RM was positive, especially since current surgical treatments for spine disorders lack satisfactory effectiveness. However, efforts should be taken to adequately address the ethical and scientific issues in the translation of RM interventions into clinical research. This is required to prevent unnecessary risks to study participants, to prevent exposure of future patients to useless clinical applications, as well as to prevent this young field from developing a negative reputation. Not only will the orthopedic RM field benefit from ethically and scientifically sound clinical studies, but the rise of RM also provides an opportunity to stimulate evidence-based practice in orthopedics and address hype- and profit driven practices in orthopedics.
    The spine journal: official journal of the North American Spine Society 10/2013; 14(6). DOI:10.1016/j.spinee.2013.10.016 · 2.80 Impact Factor
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    ABSTRACT: Histology is an important outcome variable in basic science and pre-clinical studies regarding intervertebral disc degeneration (IVD). Nevertheless, an adequately validated histological classification for IVD degeneration is still lacking and the existing classifications are difficult to use for inexperienced observers. Therefore the aim of this study was to develop and to validate a new histological classification for IVD degeneration. Moreover, the new classification was compared to the frequently used non-validated classification. The new classification was applied to human IVD sections. The sections were scored twice by 2 independent inexperienced observers, twice by 2 experienced IVD researchers and once by an pathologist. For comparison, the sections were also scored according to the classification described by Boos et al. by two experienced IVD researchers. Macroscopic grading according Thompson et al, glycosaminoglycan (GAG) content and age were used for validation. The new classification had an excellent intra- and a good inter-observer reliability. Intraclass Correlation Coefficients (ICC) were 0.83 and 0.74, respectively. Intra and inter-observer reliability were comparable for experienced and inexperienced observers. Statistically significant correlations were found between the new classification, macroscopic score, GAG content in the nucleus pulposus and age; Correlation coefficient (CC) 0.79, -0.62 and 0.68, respectively. The CCs of the Boos classification were all lower compared to the new classification. the new histological classification for IVD degeneration is a valid instrument for evaluating IVD degeneration in human IVD sections and is suitable for inexperienced and experienced researchers.
    Osteoarthritis and Cartilage 10/2013; 21(12). DOI:10.1016/j.joca.2013.10.001 · 4.66 Impact Factor

Publication Stats

3k Citations
410.28 Total Impact Points

Institutions

  • 1995–2014
    • University Medical Center Utrecht
      • • Department of Orthopedics
      • • Orthopedic Surgery
      Utrecht, Utrecht, Netherlands
    • Utrecht University
      • • Division of Orthopaedics
      • • Department of Clinical Sciences of Companion Animals
      Utrecht, Utrecht, Netherlands
  • 2011
    • Leiden University Medical Centre
      Leyden, South Holland, Netherlands
  • 2007
    • University of British Columbia - Vancouver
      • Department of Orthopaedics
      Vancouver, British Columbia, Canada
  • 2006
    • University of Toronto
      Toronto, Ontario, Canada
  • 2005
    • Thomas Jefferson University
      • Department of Orthopaedic Surgery
      Philadelphia, PA, United States
    • Radboud University Medical Centre (Radboudumc)
      Nymegen, Gelderland, Netherlands