Inherent stiffness of three different posterior transpedicular fixation instrumentation. A mechanical comparative study

Autor: Dimosthenis Mavrilas, Georgios Petsinis, Panagiotis Korovessis, Despina D. Deligianni
Rok vydání: 2007
Předmět:
Zdroj: European Journal of Orthopaedic Surgery & Traumatology. 17:553-560
ISSN: 1432-1068
1633-8065
DOI: 10.1007/s00590-007-0241-1
Popis: Instrumented lumbar fusion with posterior pedicle screw systems enhances fusion rate. Although rigid pedicle-screw instrumentation increases fusion rate, recently many adverse effects have been reported in lumbar spinal fusion augmented with rigid instrumentation. This study compares static, non-destructive mechanical “in vitro” properties of three different systems [segmental contouring system (SCS), Claris and Twinflex], to investigate the inherent stiffness of these devices. Forty-eight identical lumbar synthetic models, each including three vertebral bodies and intervertebral discs, were instrumented with each of the three instrumentations Twinflex, Claris and SCS. Constructs with instrumented vertebrae as well as non-instrumented models were used in this study. The constructs underwent non-destructive static torsional and compressive-bending loading. Rigid instrumentation provided the highest torsional and compression stiffness. Torsional stiffness differed significantly (P Claris > Twinflex). Compressive stiffness also demonstrated statistically significant (P Claris, SCS > Twinflex). Both Claris and Twinflex provided similar compressive stiffness. In torsion, all three instrumentations equally reduced at 80% the amount of relative torsional displacement between adjacent instrumented vertebrae (P
Databáze: OpenAIRE
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