Iatrogenic vertebral fracture in ankylosed spine during liver transplantation: a case report and biomechanical study using finite element method

• Published in: European spine journal 2024-04, Vol.33 (4), p.1332-1339
• Main Authors: Huneidi, Maxime, Bailly, Nicolas, Farah, Kaissar, May, Adrien, Arnoux, Pierre-Jean, Fuentes, Stéphane
• Format: Article
• Language: English
• Subjects: Biomechanics; Decompression; Finite element method; Fractures; Iatrogenesis; Liver transplantation; Liver transplants; Mechanical properties; Medicine; Medicine & Public Health; Neurosurgery; Original Article; Osteoporosis; Patients; Sacrum; Spine; Surgical Orthopedics; Vertebrae
• ISSN: 0940-6719; 1432-0932
• DOI: 10.1007/s00586-023-08103-7

Purpose The occurrence of an iatrogenic vertebral fracture during non-spinal digestive surgery is an exceptional event that has not been previously documented. Our study aims to explain the occurrence of this fracture from a biomechanical perspective, given its rarity. Using a finite element model of the spine, we will evaluate the strength required to induce a vertebral fracture through a hyperextension mechanism, considering the structure of the patient's spine, whether it is ossified or healthy. Methods A 70-year-old patient was diagnosed T12 fracture during a liver transplantation on ankylosed spine. We use a finite element model of the spine. Different mechanical properties were applied to the spine model: first to a healthy spine, the second to a osteoporotic ossified spine. The displacement and force imposed at the Sacrum, the time and location of fractures initiation were recorded and compared between the two spine conditions. Results A surgical treatment is done associating decompression with posterior fixation. After biomechanical study, we found that the fracture initiation occurred for the ossified spine after a sacrum displacement of 29 mm corresponding to an applied force of 65 N. For the healthy spine it occurred at a sacrum displacement of 52 mm corresponding to an applied force of 350 N. Conclusion The force required to produce a type B fracture in an ankylosed spine is 5 times less than in a healthy spine. These data enable us to propose several points of management to avoid unexpected complications with ankylosed spines during surgical procedures. Level of evidence IV.