有鉤骨鉤基部撮影における撮影体位の検討

摘要

有鉤骨は，掌側部から突き出した大型の鈞状突起にちなんで名づけられた，手根骨を構成する骨のーつである.その役割は，手根管の尺側壁を形成しているため，有鉤骨鉤近傍を走行する尺骨神経·尺骨動脈を保護し，短小指屈筋·小指対立筋の起始部として存在している.%The hamate bone, one of the carpal (wrist) bones, has a large uncinate process protruding from the palm side. In sports such as golf and tennis, the hamate bone can break if is subjected to a high external force, such as from the handle of a racquet or club. At our hospital we take X-ray images of the hamate bone from two directions: an axial image through the carpal tunnel and an image at the base of the hamate hook (conventional method). While the conventional method makes it easy to create images of the base of the hamate hook, the patient may suffer pain during image-taking because the hamate bone is pulled to cause radial flexion. We therefore investigated a method of imaging that would create three-dimensional computed tomography (3DCT) images of the base of the hamate hook in which the patient would only have to only rotate the wrist externally and elevate the forearm without any radial flexion. Our results suggest that it is possible to obtain images of the base of the hamate hook as clear as those acquired using the conventional method with the patient in a comfortable and painless position taking images at an external rotation angle of 50.3° and a forearm elevation angle of 20.3°.