Mechanical performance of lumbar intervertebral body fusion devices: An analysis of data submitted to the Food and Drug Administration
Institution:
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;1. H. Lee Moffitt Cancer Center & Research Institute, NeuroOncology Program and Department of Neurosurgery and Orthopedics, University of South Florida, College of Medicine, Tampa, FL 33612, USA;2. Dept of Mechanical Engineering, University of South Florida, Tampa, FL 33620, USA;3. Dept of Chemical & Biomedical Engineering, University of South Florida, Tampa, FL 33620, USA;1. Office of Health Technology-6: Office of Orthopedic Devices, Office of Product Evaluation and Quality, CDRH | Food and Drug Administration, White Oak, Bldg 66, Rm 4450, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA;2. DHT6B: Division of Spinal Devices, OHT6: Office of Orthopedic Devices, Office of Product Evaluation and Quality, CDRH | Food and Drug Administration, White Oak, Bldg. 66, 10903 New Hampshire Avenue, Silver Spring, MD, USA;3. OHT6: Office of Orthopedic Devices, Office of Product Evaluation and Quality, CDRH | Food and Drug Administration, White Oak, Bldg 66, Rm 4444, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA;4. Department of Orthopedics and Rehabilitation, University of Wisconsin Hospital and Clinics, 600 Highland Ave, Madison, WI 53792, USA;5. Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA;6. Department of Orthopedics, Spencer Fox Eccles School of Medicine, University of Utah, University Orthopaedic Center, 590 Wakara Way, Salt Lake City, UT 84108, USA;7. Jupiter Medical Center, Palm Beach, Florida 33458, USA;8. Department of Orthopaedic Surgery, Johns Hopkins University, 601 North Caroline St Suite 5223, Baltimore, MD 21287-0882, USA;9. Mayo Clinic, 200 1st St SW, Rochester, MN, USA;10. Bioengineering Department, University of Toledo, 2801 W. Bancroft St, Toledo, OH 43606, USA
Abstract:
Lumbar intervertebral body fusion devices (L-IBFDs) are intended to provide stability to promote fusion in patients with a variety of lumbar pathologies. Different L-IBFD designs have been developed to accommodate various surgical approaches for lumbar interbody fusion procedures including anterior, lateral, posterior, and transforaminal lumbar interbody fusions (ALIF, LLIF, PLIF, and TLIF, respectively). Due to design differences, there is a potential for mechanical performance differences between ALIF, LLIF, PLIF, and TLIF devices. To evaluate this, mechanical performance and device dimension data were collected from 124 Traditional 510(k) submissions to the FDA for L-IBFDs cleared for marketing from 2007 through 2016. From these submissions, mechanical test 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. The Kruskal-Wallis test and Wilcoxon signed-rank test were used to determine if device type (ALIF, LLIF, PLIF, TLIF) had a significant effect on mechanical performance parameters (static testing: stiffness and yield strength; dynamic testing: runout load; subsidence testing: stiffness Kp]). Generally, ALIFs and LLIFs were found to be stiffer, stronger, and had higher subsidence resistance than PLIF and TLIF designs. These results are likely due to the larger footprints of the ALIF and LLIF devices. The relative mechanical performance and subsidence resistance can be considered when determining the appropriate surgical approach and implant for a given patient. Overall, the mechanical performance data presented here can be utilized for future L-IBFD development and design verification.
