Medical Research: Why did you decide to study this topic?
Dr. Nieuwenhuijse : The introduction of new orthopaedic implants and related technologies has been the focus of major scientific and policy discussions since the failures of articular surface replacement and large head size metal-on-metal articulations in total hip replacement were brought to light. However, scientists and policy makers seem to “run out of steam,” and the momentum for change generated by these recent high profile failures is waning. The consequences of uncontrolled device introduction worldwide may not be fully recognised by the scientific community and there is a high likelihood that current practice regarding device innovations will not change much. As such, there is a need to investigate whether the problems associated with the articular surface replacement and large head size metal-on-metal articulation are isolated events or if there is a systemic problem affecting the introduction of a much wider range of implantable devices.
In this study, we systematically evaluate the evidence concerning the introduction of five substantial, innovative, relatively recent, and already widely implemented device technologies used in major total joint replacement to determine the evidence of effectiveness and safety for introduction of five recent and ostensibly high value implantable devices in major joint replacement to illustrate the need for change and inform guidance on evidence based introduction of new implants into healthcare.
Medical Research: What are the main findings of the study?
Dr. Nieuwenhuijse : From 10 557 search hits, 118 studies (94 unique study cohorts) met the inclusion criteria and reported data related to 15 384 implants in 13 164 patients. None of the five device innovations was found to improve functional or patient reported outcomes.
National registries reported 2-12 year follow-up for revision occurrence related to more than 200 000 of these implants. Reported comparative data with well established alternative devices (over 1 200 000 implants) did not show improved device survival. Moreover, we found higher revision rates associated with modular femoral necks (hazard ratio 1.9) and ceramic-on-ceramic bearings (hazard ratio 1.0-1.6) in hip replacement and with high flexion knee implants (hazard ratio 1.0-1.8).
Medical Research: Were any of the findings unexpected?
Dr. Nieuwenhuijse : Most notable was the widespread usage of these new innovations without either substantial research or convincing evidence of their benefit over existing alternative device solutions for the same conditions. Recent large scale failures of the articular surface replacement and large head size metal-on-metal articulations in total hip replacement have learned us that incremental device innovations can have a large impact on implant survival and patient safety. Since none of the five selected device innovations were safer than earlier alternative devices, we believe improved regulation and professional society oversight are necessary to prevent patients from being further exposed to these and future innovations introduced without proper evidence of improved clinical efficacy and safety. Innovation in itself is a good thing and should continue to be a major research and industry focus, but clinical introduction should follow a stepwise and controlled model preventing exposure of large numbers of patients to potentially inferior new devices.
Medical Research: What should clinicians and patients take away from your report?
Dr. Nieuwenhuijse : Introduction of new device innovations should follow a stepwise and controlled model preventing exposure of large numbers of patients to potentially inferior new devices. Clinicians should be hesitant to use new implants or device innovations when there is no or insufficient evidence of their improved benefit over existing devices, especially when data regarding safety and survival is not available. In that case, widespread usage is not recommended and only selective usage in study protocols is advised.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Nieuwenhuijse : Further research should focus on the problem of introducing new implants and device innovations without causing a slow uptake of beneficial device innovations or discourage the search for device improvement. This should include research into methods for reliable early implant evaluation, appropriate and relevant outcome measures and post market surveillance mechanisms.