Mogk Jeremy P M, Keir Peter J
Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA.
Clin Biomech (Bristol). 2009 Nov;24(9):708-15. doi: 10.1016/j.clinbiomech.2009.05.012. Epub 2009 Aug 4.
Deviated wrist postures have been linked to carpal tunnel syndrome development, yet the effect of posture on carpal tunnel volume remains unclear. The purposes of this study were (i) to evaluate the effect of boundary definitions on tunnel volume estimates in neutral and non-neutral (30 degrees flexion, 30 degrees extension) wrist postures and (ii) to develop a biomechanical wrist simulation to predict posture-related changes in tunnel volume.
Two carpal tunnel volume measures were calculated using (i) ulnar bony landmarks and (ii) radial and ulnar bony landmarks identified directly from magnetic resonance imaging (MRI) scans. A third volume measure combined computerized tunnel reconstructions with modelled bone surfaces to calculate an anatomically landmarked volume. Six individual simulations were then generated to predict volume in the flexed and extended postures based on individual carpal bone motions.
Boundary definitions influenced the absolute volume in each posture and the relative changes between postures. Relative to fully reconstructed volumes, radial and ulnar landmarked volumes were 15-25% larger across postures (681 (SD 467) mm(3); P=0.01), while the ulnar-only landmarked volumes were 10-20% smaller (562 (343) mm(3); P<0.01). Simulation predicted volumes were not significantly different from the reconstructed anatomically landmarked volumes, with less inter-individual variability between postures compared to MRI-based volumes.
Comparison of volume measures indicated the importance of capturing posture-related changes in the orientation of the proximal and distal tunnel boundaries, and revealed potential sources of error associated with volume reconstruction. Simulations can enable changes in tunnel dimensions to be related to bone movements throughout a range of motion.
手腕姿势异常与腕管综合征的发生有关，但姿势对腕管容积的影响尚不清楚。本研究的目的是：（i）评估边界定义对中立位和非中立位（30度屈曲、30度伸展）手腕姿势下腕管容积估计值的影响；（ii）开发一种生物力学手腕模拟模型，以预测与姿势相关的腕管容积变化。
使用（i）尺侧骨性标志和（ii）直接从磁共振成像（MRI）扫描中识别出的桡侧和尺侧骨性标志，计算两种腕管容积测量值。第三种容积测量方法是将计算机化的腕管重建与模拟的骨表面相结合，以计算具有解剖学标志的容积。然后基于个体腕骨运动生成六个个体模拟模型，以预测屈曲和伸展姿势下的容积。
边界定义影响每个姿势下的绝对容积以及姿势之间的相对变化。相对于完全重建的容积，在所有姿势下，桡侧和尺侧标志的容积大15%-25%（681（标准差467）mm³；P=0.01），而仅使用尺侧标志的容积小10%-20%（562（343）mm³；P<0.01）。模拟预测的容积与重建的具有解剖学标志的容积无显著差异，与基于MRI的容积相比，姿势间个体差异较小。
容积测量的比较表明，捕捉近端和远端腕管边界方向上与姿势相关的变化很重要，并揭示了与容积重建相关的潜在误差来源。模拟可以使腕管尺寸的变化与整个运动范围内的骨运动相关联。
