Spine
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Comparative Study
The TRP2 allele of COL9A2 is an age-dependent risk factor for the development and severity of intervertebral disc degeneration.
Low back pain (LBP) and sciatica are usually caused by degenerative disc disease (DDD). Although they are common, the etiology of these conditions is poorly understood. A large population case-control study in the Southern Chinese was performed to study genetic risk factors to DDD. ⋯ This largest-ever population study using MRI to define DDD demonstrates for the first time that the Trp2 allele is a significant risk factor for the development and severity of degeneration. The association is age- dependent as it is more prevalent in some age groups than in others. The contrasting Trp allele frequencies between the Finns and the Chinese are the first indication that the genetic risk factors for DDD varies between ethnic groups.
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Comparative Study
Effects of charité artificial disc on the implanted and adjacent spinal segments mechanics using a hybrid testing protocol.
Finite element model of L3-S1 segment and confirmatory cadaveric testing were used to investigate the biomechanical effects of a mobile core type artificial disc (Charité artificial disc; DePuy Spine, Raynham, MA) on the lumbar spine. ⋯ The hybrid testing protocol is advocated because it better reproduces clinical observations in terms of motion following surgery, using pure moments. Using this approach, we found that the Charité artificial disc placement slightly increases motion at the implanted level, with a resultant increase in facet loading when compared to the adjacent segments, while the motions and loads decrease at the adjacent levels. However, in the load control mode that we believe is not that clinically relevant, there was a large increase in motion and a corresponding increase in facet loads, as compared to the intact.
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Comparative Study
Does anterior plating of the cervical spine predispose to adjacent segment changes?
In a human cadaveric model, the effects of plate supplementation on the mechanical behaviors of adjacent segments were investigated. ⋯ Intradiscal pressures and intervertebral motion at the adjacent levels are not significantly affected by the instrumented anterior fusion. The clinically observed degenerative change at adjacent segments in the cervical spine is more likely to be attributed to natural progression of the spondylotic process as opposed to biomechanical effect of the instrumentation or fusion.
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Comparative Study
The learning curve associated with thoracoscopic spinal instrumentation.
Consecutive case prospective radiographic and medical record review. ⋯ The learning curve associated with thoracoscopic spinal instrumentation appears to be acceptable. Significant differences were noted in operating time and percent curve correction after 28 cases. The complication rates remained stable throughout the surgeon's experience.
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Prospective trial. ⋯ The authors have developed a novel method of spinal stereotaxy using exact plastic copies of the spine manufactured using biomodeling technology. Biomodel spinal stereotaxy is a simple and accurate technique that may have advantages over frameless stereotaxy.