Pedicle screw-based posterior dynamic stabilisation of the lumbar spine: in vitro cadaver investigation and a finite element study |
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| Authors: | T Oktenoglu A Kiapour AF Ozer I Lazoglu T Kaner |
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| Institution: | 1. VehbiKoc Foundation American Hospital, Nisantasi, Istanbul, Turkey;2. Departments of Bioengineering and Orthopedic Surgery, E-CORE, University of Toledo, Toledo, OH, USA;3. Department of Neurosurgery, Koc University, Rumelifeneri Yolu, 34450 Istanbul, Turkey;4. Department of Mechanical Engineering, Koc University, Rumelifeneri Yolu, 34450 Istanbul, Turkey;5. Department of Neurosurgery, Istanbul Medeniyet University, Istanbul, Turkey |
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| Abstract: | Pedicle screw-based dynamic constructs either benefit from a dynamic (flexible) interconnecting rod or a dynamic (hinged) screw. Both types of systems have been reported in the literature. However, reports where the dynamic system is composed of two dynamic components, i.e. a dynamic (hinged) screw and a dynamic rod, are sparse. In this study, the biomechanical characteristics of a novel pedicle screw-based dynamic stabilisation system were investigated and compared with equivalent rigid and semi-rigid systems using in vitro testing and finite element modelling analysis. All stabilisation systems restored stability after decompression. A significant decrease in the range of motion was observed for the rigid system in all loadings. In the semi-rigid construct the range of motion was significantly less than the intact in extension, lateral bending and axial rotation loadings. There were no significant differences in motion between the intact spine and the spine treated with the dynamic system (P>0.05). The peak stress in screws was decreased when the stabilisation construct was equipped with dynamic rod and/or dynamic screws. |
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| Keywords: | dynamic pedicle screw-based system spine biomechanics lumbar spine cadaver investigation finite element modelling |
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