Departments of Biomedical Engineering, Orthopaedic Surgery, and Physical Medicine and Rehabilitation, Cleveland Clinic, 9500 Euclid Avenue, ND20, 44195 Cleveland, Ohio, USA.
J Orthop Res. 2011 Dec;29(12):1951-6. doi: 10.1002/jor.21468. Epub 2011 May 23.
Carpal tunnel mechanics is relevant to our understanding of median nerve compression in the tunnel. The compliant characteristics of the tunnel strongly influence its mechanical environment. We investigated the distensibility of the carpal tunnel in response to tunnel pressure. A custom balloon device was designed to apply controlled pressure. Tunnel cross sections were obtained using magnetic resonance imaging to derive the relationship between carpal tunnel pressure and morphological parameters at the hook of hamate. The results showed that the cross-sectional area (CSA) at the level of the hook of hamate increased, on average, by 9.2% and 14.8% at 100 and 200 mmHg, respectively. The increased CSA was attained by a shape change of the cross section, displaying increased circularity. The increase in CSA was mainly attributable to the increase of area in the carpal arch region formed by the transverse carpal ligament. The narrowing of the carpal arch width was associated with an increase in the carpal arch. We concluded that the carpal tunnel is compliant to accommodate physiological variations of the carpal tunnel pressure, and that the increase in tunnel CSA is achieved by increasing the circularity of the cross section.
腕管力学与我们对腕管中正中神经受压的理解有关。隧道的顺应特性强烈影响其力学环境。我们研究了隧道对隧道压力的可扩展性。设计了一种定制的气球装置来施加受控压力。使用磁共振成像获得腕管横截面，以得出在钩骨水平的腕管压力与形态参数之间的关系。结果表明，在 100 和 200mmHg 时，钩骨水平的横截面积（CSA）分别平均增加了 9.2%和 14.8%。CSA 的增加是通过横截面的形状变化实现的，显示出更大的圆形度。CSA 的增加主要归因于由横向腕韧带形成的腕弓区域的面积增加。腕弓宽度的变窄与腕弓的增加有关。我们得出结论，腕管具有顺应性，可适应腕管压力的生理变化，并且通过增加横截面的圆形度来增加隧道 CSA。
