Spine
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Comparative Study
The radiographic and imaging characteristics of porous tantalum implants within the human cervical spine.
Seven cadaveric cervical spines were implanted with a porous tantalum spacer and a titanium alloy spacer, and their radiographic and imaging characteristics were evaluated. ⋯ The material properties of titanium and porous tantalum cervical interbody implants contribute to their differential appearance in different imaging methods. The titanium implant appears to image best with computed tomography, whereas the porous tantalum implant produces less artifact than does the titanium implant on several magnetic resonance imaging sequences.
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Comparative Study
Anatomic considerations of anterior transarticular screw fixation for atlantoaxial instability.
Anatomic parameters of C1 and C2 were measured in 30 dried human cervical spines. Anterior transarticular C1-C2 screws were placed in 15 cadaveric spines. ⋯ An anterior transarticular atlantoaxial screw 15-25 mm long can be inserted with a lateral angulation of 5-25 degrees relative to the sagittal plane and a posterior angulation of 10-25 degrees relative to the coronal plane. Additionally, in C1-C2 anterior plate fixation screws 15 mm long could be anchored in the inferior facet of the C1, and screws 9-15 mm long could be anchored in the C2 vertebral body.
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Comparative Study
Predictive signs of discogenic lumbar pain on magnetic resonance imaging with discography correlation.
The correlation between discogenic lumbar pain and disc morphology was investigated by using magnetic resonance imaging and discography. ⋯ Although the lumbar intervertebral discs with posterior combined anular tears are likely to produce pain, the validity of these signs for predicting discogenic lumbar pain is limited.
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Comparative Study
A human cadaver model for determination of pathologic fracture threshold resulting from tumorous destruction of the vertebral body.
Thoracic vertebrae were subjected to compressive loads after drilling of the centrum to simulate destruction from metastatic tumorous involvement. ⋯ The vertebral strength index can be used to predict the strength of any thoracic vertebra. When compared with an idealized vertebral strength index based on the intact vertebral cross-sectional area and normal bone mineral density, a patient's actual vertebral strength index can be used as one of the criteria for prophylactic stabilization.