| Summary: | 博士 === 國立成功大學 === 醫學工程研究所碩博士班 === 98 === Abstract
Functionally, the spine mainly supports the body axis and transmits the weight of the trunk to the lower limbs. It surrounds and protects the spinal cord and provides attachment for the ribs, and ligaments and muscles of the neck and back to allow physiologic mobility and activities of daily living. In an individual with a normal spine, the spine performs these functions without injury to bones, soft tissues, or neurologic structures. Because of improvement and development of the medical technology, the dramatic increase of aged population and associated osteoporosis has lead to increased patients with spinal trauma and related spinal disorder. In 2002, the America National Osteoporosis Foundation reported that there are over 500,000 vertebral fractures annually, and more than one fourth of American women older than 65 years of age suffer from vertebral fractures. In 2006, the Taiwan Department of Health reported that 12.5% of aged male and 20% of aged female suffer from vertebral fracture due to osteoporosis.
Currently pedicle screw instrumentation is frequently used for spinal reconstruction, fixation, correction and coupling decompression in spinal trauma and related spinal disorder surgery. However, the conventional screw is unable to provide enough screw-bone interface strength for osteoporotic cancellous bone, and complications resulting from loosening or failure of the implant remain a significant clinical problem.
For patients with osteoporosis and sustaining spinal trauma and related spinal disorder, the purpose of study is to design and develop a new bone cement anchoraged thoracolumbar pedicle screw to enhance the interface strength and shear strength after screw inserting into vertebra body, and to improve the fixation stability and reduce the postoperative complications due to screw loosening and displacement.
The specific aims are divided into three stages: (1) design and develop a novel bone cement anchoraged thoracolumbar pedicle screw through applying computer-aided engineering to enhance the interfacial strength between screw and osteoporotic bone; (2) investigate bone cement distribution patterns and pullout strength for pedicle screws inserted into sawbones empirically; (3) employ finite element method to analytically simulate the pullout strength of bone cement anchoraged pedicle screws for validation.
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