Impact of Implant Developers on Published Outcome and Reproducibility of Cohort-Based Clinical Studies in Arthroplasty

Department of Orthopaedic Surgery, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck, Austria.
The Journal of Bone and Joint Surgery (Impact Factor: 5.28). 12/2011; 93 Suppl 3(Supplement_3):55-61. DOI: 10.2106/JBJS.K.01108
Source: PubMed


The reproducibility of the results of cohort-based clinical studies of arthroplasty procedures by the average orthopaedic surgeon is a major issue involving the quality of the scientific literature. We compared the results of a comprehensive literature analysis with data from national arthroplasty registries to examine the influence of arthroplasty implant inventors on the outcomes published in peer-reviewed journals.
A structured review of the literature published in MEDLINE-listed journals was performed. A comparison of the average revision rates in the identified studies (adjusted for the number of arthroplasty cases and the duration of follow-up) with the registry data was then conducted.
Seventeen of the analyzed arthroplasty implants were developed in the United States. Studies by the developers of these implants often had a substantial influence on the published outcome. For approximately 50% of the implant systems analyzed, the average revision rate derived by combining all published studies showed a statistically significant and clinically relevant deviation from the revision rate derived from the arthroplasty registry data, which reflected the outcome in the average patient. For the majority of implants for which the revision rate calculated from the published clinical studies was very low compared with the rate calculated from the registry data, the developing institution accounted for 39% to 100% of the published outcome data for the implant. In contrast, the published results were usually reproducible in clinical practice if <25% of the published data were reported by the developers. Three of the nine arthroplasty implants developed in Europe showed a significant and clinically relevant difference between the revision rate derived from only the studies published by the developers and the rate calculated from the registry data. However, because of the considerably greater amount of data from independent studies that was typically available for the European implants than for the American implants, studies by the developer that deviated significantly from the registry data could usually also be identified as outliers by a meta-analysis of all published studies. A high proportion of the published data involving three of the European implants was reported by the inventors, but comparison with the registry data revealed that the average published revision rates for two of these three implants were reproducible in clinical practice.
The published results of the clinical studies involving many of the arthroplasty implants, especially implants developed in the United States, were highly influenced by reports from the center that developed the implant. This often had a substantial effect on the reproducibility of the outcome data. There appeared to be relevant differences between the medical research systems in Europe and the United States that also affected the reproducibility and applicability of the results for the average surgeon. Registry data can contribute substantial added value to an informed discussion of arthroplasty outcomes.

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    • "The same method is used in the British registry (patient time incidence rate), European Arthroplasty Register (EAR), and French SoFCOT THA registry ( [4] [5]. Despite these limitations, registries allow epidemiological and demographic studies, as well as comparisons of outcomes across implants and institutions within a country. "
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    ABSTRACT: The first nationwide orthopaedic registry was created in Sweden in 1975 to collect data on total knee arthroplasty (TKA). Since then, several countries have established registries, with varying degrees of success. Managing a registry requires time and money. Factors that contribute to successful registry management include the use of a single identifier for each patient to ensure full traceability of all procedures related to a given implant; a long-term funding source; a contemporary, rapid, Internet-based data collection method; and the collection of exhaustive data, at least for innovative implants. The effects of registries on practice patterns should be evaluated. The high cost of registries raises issues of independence and content ownership. Scandinavian countries have been maintaining orthopaedic registries for nearly four decades (since 1975). The first English-language orthopaedic registry was not created until 1998 (in New Zealand), and both the US and many European countries are still struggling to establish orthopaedic registries. To date, there are 11 registered nationwide registries on total knee and total hip replacement. The data they contain are often consistent, although contradictions occur in some cases due to major variations in cultural and market factors. The future of registries will depend on the willingness of health authorities and healthcare professionals to support the creation and maintenance of these tools. Surgeons feel that registries should serve merely to compare implants. Health authorities, in contrast, have a strong interest in practice patterns and healthcare institution performances. Striking a balance between these objectives should allow advances in registry development in the near future. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
    Orthopaedics & Traumatology Surgery & Research 12/2014; 101(1). DOI:10.1016/j.otsr.2014.06.029 · 1.26 Impact Factor
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    • "Recent reports on material safety concerns regarding hip arthroplasty (Godlee 2012, Smith et al. 2012) and publications on developer's bias regarding knee implants (Labek et al. 2011a, Pabinger et al. 2012) have led to concerns about the quality and reliability of studies on knee arthroplasties. Optimal quality of knee implants is therefore an important issue, which is reflected in the revision rate. "
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    ABSTRACT: Background and purpose: Recent reports on developer bias in unicondylar knee arthroplasty led to concerns about quality of publications regarding knee implants. We therefore compared revision rates of registry and non-registry studies from the beginning of knee arthroplasty up to the present. We assessed the time interval between market introduction of an implant and emergence of reliable data in non-registry studies. Material and methods: We systematically reviewed registry studies (n = 6) and non-registry studies (n = 241) on knee arthroplasty published in indexed, peer-reviewed international scientific journals. The main outcome measure was revision rate per 100 observed component years. Results and interpretation: For 82% of the 34 knee implants assessed, revision data from non-registry studies are either absent or poor. 91% of all studies were published in the second and third decade after market introduction. Only 5% of all studies and 1% of all revisions were published in the first decade. The first publications on revision rates of total knee arthroplasty (TKA) started 6 years after market introduction, and reliable data were found from year 12 onward in non-registry studies. However, in unicondylar knee arthroplasty (UKA) the first publications on revision rates could be found first 13 years after market introduction. Revision rates of TKA from non-registry studies were reliable after year 12 following market introduction. UKA revision rates remained below the threshold of registry indices, and failed to demonstrate adjustment towards registries. Thus, the superiority of registry data over non-registry data regarding outcome measurement was validated.
    Acta Orthopaedica 09/2014; 86(1):1-5. DOI:10.3109/17453674.2014.961119 · 2.77 Impact Factor
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    • "The lack of a national register is even more harmful in the United States because the arthroplasty surgery activity is intense and the sheer number of publications resulting from this activity has a significant influence throughout the world. The impact of the work of American inventors was revealed by the EAR team [28]. Overall, for implants developed in the USA, 48.2% of primary implantations and 47.1% of observed component years were reported by authors affiliated with the inventor(s). "
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    ABSTRACT: The goal of the Quality of Literature in Arthroplasty (QoLA) project launched in 2009 was to compare the implant results from clinical studies published in indexed scientific journals with those found in reference national registers. The potential biases in the chosen articles (country of origin, inventor involved in study, methodological quality) were systematically analyzed and the revisions per 100 observed component years (Revp100OCY) index was calculated. For a given implant, a differential factor greater than 3 between the Revp100OCY index for published series and the one from registers was considered as indicative of a potential selection (inventor) or publication (conflict of interest) bias. Although initially performed on English publications, this methodology was subsequently applied to French publications in the field of total hip arthroplasty (THA).
    Orthopaedics & Traumatology Surgery & Research 03/2013; 99(3). DOI:10.1016/j.otsr.2013.02.001 · 1.26 Impact Factor
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