Title:
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In-vitro biomechanics of vertebroplasty
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Osteoporotic vertebral compression fractures are a major burden
worldwide. Percutaneous vertebroplasty is a recognised treatment option for
these fractures but there is conflicting evidence regarding the optimum amount
of cement to use and there is little evidence regarding the best surgical
approach to treating these fractures. Newer techniques are available which
expand on the basic premise of percutaneous vertebroplasty. This project
aimed to provide the basic science to answer the questions of cement fill,
approach and the use of modern adjuncts to traditional percutaneous
vertebroplasty. The first phase looked at approaches and cement fill and found
that a 30% fill via a unipedicular approach , gave the best biomechanical
outcome combined with the lowest theoretical risk and that the interaction
between the cement and the vertebral endplate was important for syength
restoration. Phase 2 expanded on the work carried out earlier in this study and
looked at the response to dynamic loading of augmented and unaugmented
vertebra. It reinforced the findings of phase 1 that 30% was the key figure and
the endplate-bolus interaction was key. Finally phase 3 took the work carried
out in the study so far and compared cavity creation vertebroplasty using a
contour osteotome with traditional balloon kyphoplasty in, a static loading
environment. It demonstrated equivocal strength restoration between the two
but with lower incidence of implant induced fracture in the contour group. The
culmination of this project provides guidelines for the effective use of cement
augmentation by percutaneous vertebroplasty as a method for restoring
strength post vertebral fracture in osteoporotic patients.
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