Mechanical performance of cervical intervertebral body fusion devices: A systematic analysis of data submitted to the Food and Drug Administration
Institution:
1. U.S. Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA;2. University of Maryland, College Park, College Park, MD 20742;3. Engineering Center for Orthopaedic Research Excellence, Department of Bioengineering and Orthopaedic Surgery, Colleges of Engineering and Medicine, University of Toledo, Toledo, OH, 43606, USA;1. U.S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Applied Mechanics, Silver Spring, MD 20993, USA;2. U.S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Device Evaluation, Division of Orthopedic Devices, Silver Spring, MD 20993, USA;3. Walter Reed National Military Medical Center, Department of Orthopaedic Surgery, Bethesda, MD 20889, USA;2. University of Kansas School of Medicine, Kansas City, KS, United States;3. University of Toledo, Toledo, OH, United States
Abstract:
Cervical intervertebral body fusion devices (IBFDs) are utilized to provide stability while fusion occurs in patients with cervical pathology. For a manufacturer to market a new cervical IBFD in the United States, substantial equivalence to a cervical IBFD previously cleared by FDA must be established through the 510(k) regulatory pathway. Mechanical performance data are typically provided as part of the 510(k) process for IBFDs. We reviewed all Traditional 510(k) submissions for cervical IBFDs deemed substantially equivalent and cleared for marketing from 2007 through 2014. To reduce sources of variability in test methods and results, analysis was restricted to cervical IBFD designs without integrated fixation, coatings, or expandable features. Mechanical testing reports were analyzed and results were aggregated for seven commonly performed tests (static and dynamic axial compression, compression-shear, and torsion testing per ASTM F2077, and subsidence testing per ASTM F2267), and percentile distributions of performance measurements were calculated. Eighty-three (83) submissions met the criteria for inclusion in this analysis. The median device yield strength was 10,117 N for static axial compression, 3680 N for static compression-shear, and 8.6 N m for static torsion. Median runout load was 2600 N for dynamic axial compression, 1400 N for dynamic compression-shear, and ±1.5 N m for dynamic torsion. In subsidence testing, median block stiffness (Kp) was 424 N/mm. The mechanical performance data presented here will aid in the development of future cervical IBFDs by providing a means for comparison for design verification purposes.
