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Spinal Instrumentation (spinal + instrumentation)

Distribution by Scientific Domains
Life Sciences50%

Selected Abstracts

Micro-computed tomography evaluation of vertebral end-plate trabecular bone changes in a porcine asymmetric vertebral tether

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2010
Jean-Michel Laffosse
Abstract We conducted a micro-CT analysis of subchondral bone of the vertebral end-plates after application of compressive stress. Thoracic and lumbar vertebral units were instrumented by carrying out left asymmetric tether in eleven 4-week-old pigs. After 3 months of growth, instrumented units and control units were harvested. Micro-CT study of subchondral bone was performed on one central and two lateral specimens (fixated side and non-fixated side). In control units, bone volume fraction (BV/TV), number of trabeculae (Tb.N), trabecular thickness (Tb.Th), and degree of anisotropy (DA) were significantly higher, whereas intertrabecular space (Tb.Sp) was significantly lower in center than in periphery. No significant difference between the fixated and non-fixated sides was found. In instrumented units, BV/TV, Tb.N, Tb.Th, and DA were significantly higher in center than in periphery. BV/TV, Tb.N, and Conn.D were significantly higher in fixated than in non-fixated side, while Tb.Sp was significantly lower. We noted BV/TV, Tb.N, and Tb.Th significantly lower, and Tb.Sp significantly higher, in the instrumented levels. This study showed, in instrumented units, two opposing processes generating a reorganization of the trabecular network. First, an osteolytic process (decrease in BV/TV, Tb.N, Tb.Th) by stress-shielding, greater in center and on non-fixated side. Second, an osteogenic process (higher BV/TV, Tb.N, Conn.D, and lower Tb.Sp) due to the compressive loading induced by growth on the fixated side. This study demonstrates the densification of the trabecular bone tissue of the vertebral end-plates after compressive loading, and illustrates the potential risks of excessively rigid spinal instrumentation which may induce premature osteopenia. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:232,240, 2010 [source]

Letter to the Editor: Ketamine and spinal instrumentation by Alain Borgeat

PEDIATRIC ANESTHESIA, Issue 12 2007
Article first published online: 1 NOV 200
No abstract is available for this article. [source]

Ketamine and spinal instrumentation

PEDIATRIC ANESTHESIA, Issue 11 2007
Alain Borgeat
No abstract is available for this article. [source]

Pedicle dimensions of the thoracic and lumbar vertebrae in the Greek population,,

CLINICAL ANATOMY, Issue 6 2005
Anastasios G. Christodoulou
Abstract The aim of this study is to understand the magnitude of the pedicle's diameters for the use of pedicle screw fixation in spinal instrumentation. Pedicle dimensions from T1 to L5 were measured in 16 whole human cadaver spines (eight women and eight men). The mean age at the time of death was 67.2 (range: 59,84 years). The external transverse, the external sagittal, and the internal transverse diameter pedicle widths were measured with electronic calipers both on the right and left pedicles. The widest external transverse diameter was at the L5 level with a mean of 13.61 mm (range: 10.29,16.20 mm). The narrowest external transverse pedicle diameter was at the T5 level with a mean of 5.09 mm (range: 4.10,6.88 mm). The widest external sagittal pedicle diameter was at the T11 level with a mean of 17.02 mm (range: 14.84,19.57 mm), while the narrowest one was at T1 level with a mean of 8.90 mm (range: 7.18,11.37 mm). The maximum internal transverse pedicle diameter was at the L5 level with a mean 8.95 mm (range: 7.10,11.21 mm), while the minimum was at the T5 level with a mean 3.90 mm (range: 3.10,4.82 mm). Statistical significant greater pedicle dimensions were found in males at multiple levels. Pedicle dimensions at the levels from T3 to T8 need preoperative evaluation with computed tomography before the insertion of pedicle screws with diameter more than 5 mm. Pedicles at T12 to L5 levels may accommodate screws of 7 mm diameter. Clin. Anat. 18:404,408, 2005. © 2005 Wiley-Liss, Inc. [source]