骨科英文书籍精读（127）｜腕关节损伤（2）
Imaging
X-rays are the key to diagnosis. There are three golden rules:
· Accept only high-quality films
· If the initial x-rays are ‘normal’, treat the clinical diagnosis
· Repeat the x-ray examination 2 weeks later.
Initially three standard views are obtained: anteroposterior and lateral with the wrist neutral, and an oblique ‘scaphoid’ view. If these are normal and clinical features suggest a carpal injury, further views are obtained: anteroposterior x-rays with the wrist first in maximum ulnar and then in maximum radial deviation, and an anteroposterior view with the fist clenched.
The examiner should be familiar with the normal x-ray anatomy of the carpus in all the standard views, so that he or she can visualize a three-dimensional picture from the two-dimensional, overlapping images of the carpal bones.
In the anteroposterior x-rays note the shape of the carpus, whether the individual bones are clearly outlined and whether there are any abnormally large gaps suggesting disruption of the ligaments. The scaphoid may be fractured; or it may have lost its normal bean shape and look squat and foreshortened, sometimes with an inner circular density (the cortical ring sign) – features of an end-on view when the bone is hyper- flexed because of damage to the restraining scapholunate ligament. The lunate is normally quadrilateral in shape, but if it is dislocated it looks triangular.
In the lateral x-ray the axes of the radius, lunate, capitate and third metacarpal are co-linear, and the scaphoid projects at an angle of about 45 degrees to this line. With traumatic instability the linked carpal segments collapse (like the buckled carriages of a derailed train). Two patterns are recognized: dorsal intercalated segment instability (DISI), in which the lunate is torn from the scaphoid and tilted backwards; and volar intercalated segment instability (VISI), in which the lunate is torn from the triquetrum and turns towards the palm; the capitate shows a complementary dorsal tilt. There may be a flake fracture off the back of a carpal bone (usually the triquetrum).
Special x-ray studies are sometimes helpful: a carpal tunnel view may show a fractured hook of hamate, and motion studies in different positions may reveal a subluxation. A radioisotope scan will confirm a wrist injury although it may not precisely localize it.
MRI is sensitive and specific (especially for detecting undisclosed fractures or Kienböck’s disease), but unless very fine cuts are taken it may miss TFCC and interosseous ligament tears.
---from 《Apley’s System of Orthopaedics and Fractures》
重点词汇整理：
clenched./klentʃt/adj. 紧握的
squat /skwɑːt/v. 蹲坐；蹲举；擅自占用；霸占adj. 矮胖的；矮而宽的
foreshortened /fɔ:'ʃɔ:rtnd/缩短的
cortical /ˈkɔːrtɪkl/adj. 皮质的；[生物] 皮层的；外皮的
ligament韧带
quadrilateral /ˌkwɑːdrɪˈlætərəl/n. 四边形adj. 四边形的
axes /ˈæksɪz/n. 轴线；轴心；坐标轴（axis 的复数）；斧头（axe 的复数）
capitate /ˈkæpəˌteɪt/adj. 头状花序的头状骨
derailed /dɪˈreɪld/v. [铁路] 出轨（derail的过去式）adj. （火车）出轨的
triquetrum /trai'kwetrʌm/adj. 三棱的；三角的；；三角骨
flake /fleɪk/n. 小薄片，碎片；古怪的人；搁架；坚硬石片；（卷绳或盘索的）一圈v. 剥落，将……剥落；
hamate,/ˈheɪmeɪt/n. 钩骨adj. 钩状的，具钩的
radioisotope /ˌreɪdioʊˈaɪsətoʊp/n. [核] 放射性同位素
fine cuts精细的切面
interosseous /,intər'ɔsiəs/adj. 骨间的；小腿骨间的；前臂骨间的
百度翻译：
成像
X光是诊断的关键。有三条黄金法则：
·只接受高质量影片
·如果最初的x光片“正常”，治疗临床诊断
·2周后重复x光检查。
最初获得三个标准视图：前后和侧腕中立，以及一个倾斜的“舟状骨”视图。如果这些都是正常的，并且临床特征表明腕关节有损伤，可以进一步观察：手腕先在最大尺侧，然后是最大桡侧偏斜的前后位x光片，握拳的前后位。
检查者应熟悉腕骨在所有标准视野下的正常x线解剖，以便他或她能够从二维重叠图像中看到三维图像腕骨。
在前后位的x光片中，注意腕骨的形状，是否有明显的骨线突出，是否有任何异常大的间隙表明韧带断裂。舟状骨可能骨折；或者它已经失去了正常的豆形，看起来又矮又短，有时有一个内圆形的密度（皮质环征）——这是由于约束性舟骨月骨韧带受损而导致骨骼过度弯曲时出现末端的特征。月骨的形状通常是四边形的，但如果错位，它看起来是三角形的。
在侧位x线上，桡骨、月骨、头状骨和第三掌骨的轴线是共线的，舟状骨与这条线成45度角。伴随着创伤性的不稳定，相连的腕关节会塌陷（就像脱轨列车的扣合车厢）。有两种模式：背侧夹层节段不稳定（DISI），月骨从舟骨上撕裂并向后倾斜；掌侧夹层节不稳定（VISI），月骨从三角肌上撕裂并转向手掌；头状体显示完全的背侧倾斜。腕骨（通常是三角肌）背面可能有片状骨折。
特殊的x光检查有时是有帮助的：腕管视图可以显示钩状钩断裂，不同位置的运动研究可能显示半脱位。放射性同位素扫描可以确认腕关节损伤，尽管不能精确定位。
磁共振成像是敏感和特异的（特别是用于检测未披露的骨折或基因博克病），但除非进行非常精细的切口，否则可能会漏掉TFCC和骨间韧带撕裂。