Static Evaluation of Pedicle Screw Spinal Constructs to the ASTM Standard: A Comparison of Multiple Test Laboratories

2011 ◽  
Vol 8 (9) ◽  
pp. 103492 ◽  
Author(s):  
David Spenciner ◽  
D. Spenciner ◽  
J. Graham ◽  
S. W. Dean
2017 ◽  
Vol 01 (04) ◽  
pp. 317-334
Author(s):  
Jan-Sven Jarvers ◽  
Ulrich Spiegl ◽  
Stefan Glasmacher ◽  
Christoph Heyde ◽  
Christoph Josten

Abstract Importance of Navigation Navigation and intraoperative imaging have undergone an enormous development in recent years. By using intraoperative navigation, the precision of pedicle screw implantation can be increased in the sense of patient safety. Especially in the case of complex defects or tumor diseases, navigation is a decisive aid. As a result of the constantly improved technology, the requirements for reduced radiation exposure and intraoperative control can also be met. The high costs of the devices can be amortized, for example by a reduced number of revisions. This overview presents the principles of navigation in spinal surgery and the advantages and disadvantages of the different navigation procedures.


2018 ◽  
Vol 1 (2) ◽  
pp. 2
Author(s):  
Chiung Chyi Shen

Use of pedicle screws is widespread in spinal surgery for degenerative, traumatic, and oncological diseases. The conventional technique is based on the recognition of anatomic landmarks, preparation and palpation of cortices of the pedicle under control of an intraoperative C-arm (iC-arm) fluoroscopy. With these conventional methods, the median pedicle screw accuracy ranges from 86.7% to 93.8%, even if perforation rates range from 21.1% to 39.8%.The development of novel intraoperative navigational techniques, commonly referred to as image-guided surgery (IGS), provide simultaneous and multiplanar views of spinal anatomy. IGS technology can increase the accuracy of spinal instrumentation procedures and improve patient safety. These systems, such as fluoroscopy-based image guidance ("virtual fluoroscopy") and computed tomography (CT)-based computer-guidance systems, have sensibly minimized risk of pedicle screw misplacement, with overall perforation rates ranging from between 14.3% and 9.3%, respectively."Virtual fluoroscopy" allows simultaneous two-dimensional (2D) guidance in multiple planes, but does not provide any axial images; quality of images is directly dependent on the resolution of the acquired fluoroscopic projections. Furthermore, computer-assisted surgical navigation systems decrease the reliance on intraoperative imaging, thus reducing the use of intraprocedure ionizing radiation. The major limitation of this technique is related to the variation of the position of the patient from the preoperative CT scan, usually obtained before surgery in a supine position, and the operative position (prone). The next technological evolution is the use of an intraoperative CT (iCT) scan, which would allow us to solve the position-dependent changes, granting a higher accuracy in the navigation system. 


Author(s):  
Anne E. Gattiker ◽  
Phil Nigh ◽  
Wojciech Maly

Abstract This article provides an analysis of a class of failures observed during the SEMATECH-sponsored Test Methods Experiment. The analysis focuses on use of test-based failure analysis and IDDQ signature analysis to gain insight into the physical mechanisms underlying such subtle failures. In doing so, the analysis highlights techniques for understanding failure mechanisms using only tester data. In the experiment, multiple test methods were applied to a 0.45 micrometer effective channel length ASIC. Specifically, ICs that change test behavior from before to after burn-in are studied to understand the physical nature of the mechanism underlying their failure. Examples of the insights provided by the test-based analysis include identifying cases where there are multiple or complex defects and distinguishing cases where the defect type is likely to be a short versus an open and determining if the defect is marginal. These insights can be helpful for successful failure analysis.


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