Spinal stabilization by an anterior vertebral body replacement is frequently used in patients suffering from destroyed vertebral bodies. The aim of this study was to analyse (i) the choice of endplate size and positioning of vertebral body replacements in daily patient care and (ii) if these factors have an influence on clinical and radiological outcomes.
Patients’ outcomes were analysed three years after vertebral body replacement implantation using the visual analogue scale spine score. Safe zones on the vertebral body endplates were defined. Overall endplate coverage and implant subsidence were evaluated by CT and X-ray. Compression tests were performed on 22 lumbar vertebral bodies to analyse endplates sizes’ influence on subsidence.
Mean coverage of the vertebral body’s superior and inferior endplates by the vertebral body replacement was 27.8% and 30.8%, respectively. Mean overlap of the safe zone by the implant was 49.8% and 40.6%. Mean subsidence was 1.1 ± 1.2 mm, but it did not have any effect on the outcome. In the compression tests, no significant difference (p = 0.468) was found between the two endplate sizes.
Coverage of vertebral body endplates and positioning of implants in the safe zone did not entirely comply with the given recommendations. The amount of endplate coverage had no influence on subsidence or long-term outcomes in daily patient care. On the other hand, correct positioning of the implant may influence its subsidence.
Copyright © 2020 Elsevier Ltd. All rights reserved.
About The Expert
Michael Kreinest
Sabine Kelka
Paul A Grützner
Sven Y Vetter
Philipp Kobbe
Miguel Pishnamaz
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