High Prevalence of Biofilms on Retrieved Implants from Aseptic Pseudarthrosis Cases.

Recent literature has associated pseudarthrosis and pedicle screw loosening with subchronic infection at the pedicle of the vertebra. The positive culture results of a previous retrieval analysis show that such patients have a high frequency of bacterial contamination. The objective of this study is to visually capture the architecture of these undiagnosed infections, which have been described in other studies as biofilms on supposedly "aseptic" screw loosening. Explants from 10 consecutive patients undergoing revision spine surgery for pseudarthrosis were collected and fixed in glutaraldehyde solution. Each of these implants was imaged thoroughly by using scanning electron microscopy and x-ray spectroscopy to evaluate the architecture of the biofilm. Additionally, eight patient swabs from tissues around the implants were sent for cultures to assess bacterial infiltration in tissues beyond the biofilm. The implants were also analyzed using energy dispersive x-ray spectroscopy. The exclusion criteria included clinically diagnosed infection (current or previous) and/or mechanical failure of the implant due to falls/accidents. The study was successful in capturing the visual architecture of the biofilm on retrieved implants. A total of 77% of pseudarthrosis cases presented with loose pedicle screws, which were diagnosed by a preoperative computed tomography scan showing radiolucency along the screw track and were confirmed intraoperatively, and 72% of the cases showed biofilm on explants. In the absence of the clinical presentation of infection, impregnated bacteria could form a biofilm around an implant, and this biofilm can remain undetected via contemporary diagnostic methods, including swabbing. Implant biofilm is frequently present in "aseptic" pseudarthrosis cases.

Informations de copyright

Copyright © 2021 by The Japanese Society for Spine Surgery and Related Research.

Déclaration de conflit d'intérêts

Conflicts of Interest: AA is a consultant for Spinal Balance Inc., an editorial board member of Clinical Spine Surgery, and an editorial board member of Spine. VG received royalties from Paradigm Spine, Joimax, Globus Medical, Endosphere LLC, and Butterfly LLC and is a stockholder of Spinal Balance and Osteonovus. AA reports consultancy from Spinal Balance Inc., Editorial Board Membership from Clinical Spine Surgery, Editorial Board Membership from Spine, outside the submitted work; VG reports royalties from paradigm spine, Joimax, globus medical, endosphere LLC, butterfly LLC, Stock ownership from Spinal Balance, Osteonovus; JW reports royalties from Biomet, Seaspine, Amedica, Synthes, Investments/Options from Bone Biologics, Pearldiver, Electrocore, Surgitech, Board of Directors for North American Spine Society, AO Foundation, Cervical Spine Research Society, Society for Brain Mapping and Therapeutics, American Orthopaedic Association, Editorial Boards on Spine, The Spine Journal, Clinical Spine Surgery, Global Spine Journal, and Fellowship Funding (paid to institution) from AO Foundation; NA reports consultancy from Medtronic, Globus, GYS Tech, Spinal Balance, royalties from Medtronic, Elsevier, Globus, stocks from AF cell, Theracell, Atlas Spine, Paradigm spine, Bonovo, Medtronic, Globus, GYS Tech, Spinal Balance, SAB from Theracell, Globus, GYS Tech, Spinal Balance, speaker for DePuy Synthes, Stryker, and Editor for Gray's Anatomy; SG reports consultant for Benvenue Medical, Intrinsic Therapeutic, Magnifi Group, Medtronic, SI Bone, Spinal Kinetics, Institutional Support from DePuy (Johnson & Johnson), Globus, Synthes, royalties from DePuy (Johnson & Johnson), and stock from SI Bone & Spinal Kinetics. Rest of the coauthors have nothing to disclose.