Project Description

The Zimmer Persona® system includes an AR Sizer, Broach Handle, Slap Hammer, Sizing Plate Handle, Tibial Resection System and Femoral Provisional Inserter/Extractor Handle that are used during total knee replacement surgery. Metaphase was involved throughout the extensive user centered development process to ensure that the ergonomics and design of each instrument addressed the complex user requirements for this physically demanding procedure.

  • On-Site Observational Research – Metaphase team observed total knee replacements at Rush University Medical Center in Chicago to identify human factors opportunities and interviewed surgeons about key pain points within the procedure.
  • Material Friction Study – Experts at Metaphase conducted an internal research study to determine what material and level of texture provide the optimal friction with a gloved hand. This study led Zimmer away from soft touch silicone, which were popular in other surgical instruments at the time, because it provided inferior traction in a wet surgical environment when compared against stainless steel with a heavy bead blasting. The result of this testing led to a proprietary surface finish which also reduces glare in the surgical environment.
  • Design Development & Cadaver Lab Usability Testing – Metaphase designers leveraged findings to optimize the ergonomics of the instrument grips and strategically placed cut outs on the instrument handles to reduce weight and therefore surgeon fatigue. Functional protypes of instruments designed by Metaphase were developed by Zimmer. Key opinion leaders (KOLs) were recruited to test the instruments in a cadaver lab and provide feedback to optimize the instrument designs.
  • Human Factors Validation Testing – Metaphase experts worked with Zimmer to develop the research protocol for the Human Factors Validation Testing (sometimes called Summative Usability Testing). Metaphase recruited surgeons, moderated interviews, and lead the analysis and reporting. Metaphase provided documentation for the design history files as well as the Human Factor report from the Validation Testing to support Zimmer’s FDA submission in the US as well as international regulatory agencies.