骨科英文书籍精读（136）｜月骨脱位（1）
CARPAL DISLOCATIONS, SUBLUXATIONS AND INSTABILITY
The wrist functions as a system of intercalated segments or links, stabilized by the intercarpal ligaments and the scaphoid which acts as a bridge between the proximal and distal rows of the carpus. Fractures and dislocations of the carpal bones, or even simple ligament tears and sprains, may seriously disturb this system so that the links collapse into one of several well-recognized patterns (see Chapter 16).
LUNATE AND PERILUNATE DISLOCATIONS
A fall with the hand forced into dorsiflexion may tear the tough ligaments that normally bind the carpal bones. The lunate usually remains attached to the radius and the rest of the carpus is displaced backwards (perilunate dislocation). Usually the hand immediately snaps forwards again but, as it does so, the lunate may be levered out of position to be displaced anteriorly (lunate dislocation). Sometimes the scaphoid remains attached to the radius and the force of the perilunar dislocation causes it to fracture through the waist (trans-scaphoid perilunate dislocation).
Clinical features
The wrist is painful and swollen and is held immobile. If the carpal tunnel is compressed there may be paraesthesia or blunting of sensation in the territory of the median nerve, and weakness of palmar abduction of the thumb.
X-ray
Most dislocations are perilunate. In the antero-posterior view the carpus is diminished in height and the bone shadows overlap abnormally. One or more of the carpal bones may be fractured (usually the scaphoid and radial styloid). If the lunate is dislocated, it has a characteristic triangular shape instead of the normal quadrilateral appearance.
In the lateral view it is easy to distinguish a lunate from a perilunate dislocation. The dislocated lunate is tilted forwards and is displaced in front of the radius, while the capitate and metacarpal bones are in line
with the radius. With a perilunate dislocation the lunate is tilted only slightly and is not displaced forwards, and the capitate and metacarpals lie behind the line of the radius (DISI pattern); if there is an associated scaphoid fracture, the distal fragment may be flexed.
---from 《Apley’s System of Orthopaedics and Fractures》
重点词汇整理：
intercalated adj. 夹层的；插入的v. 插入
（intercalate的过去分词）；设置（闰
日、闰月等）
scaphoid /ˈskæfɔɪd/n. 舟状骨adj. 船状
的，船形的
styloid process /ˈstaɪˌlɔɪd/茎突
bind /baɪnd/n. 捆绑；困境；讨厌的事
情；植物的藤蔓vt. 绑；约束；装订；
包扎；凝固
The lunate usually remains attached to
the radius and the rest of the carpus is
displaced backwards (perilunate
dislocation). 月骨通常附着在桡骨上，
其余的腕关节向后移位(月骨周围脱位)
。注意此句中的and。
snap /snæp/n. 猛咬；劈啪声；突然折
断adj. 突然的vt. 突然折断，拉断；猛
咬；啪地关上vi. 咬；厉声说；咯嗒一
声关上
paraesthesia /ˌpærɪsˈθiːʒə/n. 感觉异常
；触觉异常
blunting /ˈblʌntɪŋ/v. （使）减弱；（使尖端、刀等）变钝（blunt 的现在分词）
territory /ˈterətɔːri/n. 领土，领域；范围；地域；版图
quadrilateral /ˌkwɑːdrɪˈlætərəl/n. 四边形adj. 四边形的
百度翻译：
腕关节脱位，半脱位和不稳定
腕关节的功能是一个中间节段或连接系统，由腕骨间韧带和舟状骨稳定，舟状骨充当腕关节近端和远端行之间的桥梁。腕骨的骨折和脱位，甚至是单纯的韧带撕裂和扭伤，都可能严重扰乱这一系统，使连接处塌陷成几种公认的模式之一（见第16章）。
月骨与月骨周围脱位
摔倒时，手被迫背伸，可能会撕裂通常束缚腕骨的坚韧韧带。月骨通常与桡骨相连，腕关节的其余部分向后移位（月骨周围脱位）。通常手784会立即再次向前猛击，但当它这样做时，月骨可能会被撬出位置，向前移动（月骨脱位）。有时舟状骨仍然附着在桡骨上，骨周脱位的力量使其穿过腰部骨折（经舟骨月骨周围脱位）。
临床特征
手腕疼痛肿胀，无法移动。如果腕管被压迫，可能会出现正中神经感觉异常或感觉迟钝，以及拇指掌外展无力。
X射线
大多数脱臼是月牙周围的。在前后视图中，腕骨高度降低，骨影异常重叠。一个或多个腕骨可能骨折（通常是舟状骨和桡骨茎突）。如果月牙错动，它的特征是三角形，而不是正常的四边形。
从侧面看，很容易区分月骨和月骨周围脱位。脱位的月骨向前倾斜，在桡骨前方移位，而头状骨和掌骨在一条直线上
以半径计算。月骨周围脱位时，月骨仅轻微倾斜，不向前移位，头状骨和掌骨位于桡骨线后面（DISI模式）；如果有相关的舟骨骨折，远端碎片可能会弯曲。