Cynthia J Chang1, Mehdi Kazemzadeh-Narbat2. 1. Office of Product Evaluation and Quality, Center for Devices and Radiological Health, US Food and Drug Administration, US. 2. Office of Product Evaluation and Quality, Center for Devices and Radiological Health, US Food and Drug Administration, US Musculoskeletal Clinical Regulatory Advisers (MCRA), Washington DC, US.