title: Appraisal of evidence base for introduction of new implants in hip and knee replacement: a systematic review of five widely used device technologies.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Systematic review of clinical trials, comparative observational studies, and registries for comparative effectiveness and safety of five implantable device innovations.
  
  
  METHODS
  PubMed (Medline), Embase, Web of Science, Cochrane, CINAHL, reference lists of articles, annual reports of major registries, summaries of safety and effectiveness for pre-market application and mandated post-market studies at the US Food and Drug Administration.
  
  
  METHODS
  The five selected innovations comprised three in total hip replacement (ceramic-on-ceramic bearings, modular femoral necks, and uncemented monoblock cups) and two in total knee replacement (high flexion knee replacement and gender specific knee replacement). All clinical studies of primary total hip or knee replacement for symptomatic osteoarthritis in adults that compared at least one of the clinical outcomes of interest (patient centred outcomes or complications, or both) in the new implant group and control implant group were considered. Data searching, abstraction, and analysis were independently performed and confirmed by at least two authors. Quantitative data syntheses were performed when feasible.
  
  
  RESULTS
  After assessment of 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. Comparative evidence per device innovation varied from four low to moderate quality retrospective studies (modular femoral necks) to 56 studies of varying quality including seven high quality (randomised) studies (high flexion knee replacement). None of the five device innovations was found to improve functional or patient reported outcomes. National registries reported two to 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 occurrence 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).
  
  
  CONCLUSIONS
  We did not find convincing high quality evidence supporting the use of five substantial, well known, and already implemented device innovations in orthopaedics. Moreover, existing devices may be safer to use in total hip or knee replacement. 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.
authors.affiliation: Patient Centered Comparative Effectiveness Program and US Food and Drug Administration Medical Device Epidemiology Science and Infrastructure Center, Department of Public Health, Weill Cornell Medical College, New York, NY 10065, USA Department of Orthopaedics, Leiden University Medical Center, 2300 RC Leiden, Netherlands Office of Surveillance and Biometrics, Center for Devices and Radiological Health, FDA, Silver Spring, MD 20993, USA.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Nieuwenhuijse
authors.affiliation: Department of Orthopaedics, Leiden University Medical Center, 2300 RC Leiden, Netherlands.
authors.forename: R G H H
authors.initials: RG
authors.lastname: Nelissen
authors.affiliation: Walaeus Library, Leiden University Medical Center, 2300 RC Leiden, Netherlands.
authors.forename: J W
authors.initials: JW
authors.lastname: Schoones
authors.affiliation: Patient Centered Comparative Effectiveness Program and US Food and Drug Administration Medical Device Epidemiology Science and Infrastructure Center, Department of Public Health, Weill Cornell Medical College, New York, NY 10065, USA Office of Surveillance and Biometrics, Center for Devices and Radiological Health, FDA, Silver Spring, MD 20993, USA ars2013@med.cornell.edu.
authors.forename: A
authors.initials: A
authors.lastname: Sedrakyan
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000401:mortality; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000401:mortality; D004812:Epidemiologic Methods; D005260:Female; D006622:Hip Prosthesis / Q000592:standards*; D006801:Humans; D062069:Inventions; D007720:Knee Prosthesis / Q000592:standards*; D008297:Male; D061214:Patient Safety; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular / Q000502:physiology; D012086:Reoperation / Q000706:statistics & numerical data; D017678:Sex Distribution