骨科英文书籍精读（92）｜肘关节脱位（1）
DISLOCATION OF THE ELBOW
Dislocation of the ulno-humeral joint is fairly common – more so in adults than in children. Injuries are usually classified according to the direction of displacement. However, in 90% of cases the radioulnar complex is displaced posteriorly or posterolaterally, often together with fractures of the restraining bony processes.
Mechanism of injury and pathology
The cause of posterior dislocation is usually a fall on the outstretched hand with the elbow in extension. Disruption of the capsule and ligaments structures alone can result in posterior or posterolateral dislocation. However, provided there is no associated fracture, reduction will usually be stable and recurrent dislocation unlikely. The combination of ligamentous disruption and fracture of the radial head, coronoid process or olecranon process (or, worse still, several fractures) will render the joint more unstable and, unless the fractures are reduced and fixed, liable to redislocation.
Once posterior dislocation has taken place, lateral shift may also occur. Soft tissue disruption is often considerable and surrounding nerves and vessels may be damaged. Although certain common patterns of fracture-dislocation are recognized (based on the particular combination of structures involved), highenergy injuries do not necessarily follow any rules. A classic example is the so-called sideswipe injury which occurs, typically, when a car-driver’s elbow, protruding through the window, is struck by another vehicle.
The result is forward dislocation with fractures of any or all of the bones around the elbow; soft-tissue damage (including neurovascular injury) is usually severe.
Clinical features
The patient supports his forearm with the elbow in slight flexion. Unless swelling is severe, the deformity is obvious. The bony landmarks (olecranon and epicondyles) may be palpable and abnormally placed.
However, in severe injuries pain and swelling are so marked that examination of the elbow is impossible. Nevertheless, the hand should be examined for signs of vascular or nerve damage.
X-ray
X-ray examination is essential (a) to confirm the presence of a dislocation and (b) to identify any associated fractures. It is often only when the elbow is screened at the time of surgery that the full extent of the injury can be established.
---from 《Apley’s System of Orthopaedics and Fractures》
重点词汇整理：
restrain /rɪˈstreɪn/vt. 抑制，控制；约束；制止
provided/prəˈvaɪdɪd/conj. 假如，倘若v. 提供，给予（provide 的过去式和过去分词）
coronoid process or olecranon process冠突或鹰嘴突
Although certain common patterns of fracture-dislocation are recognized (based on the particular combination of structures involved), highenergy injuries do not necessarily follow any rules. 虽然确定了某些常见的骨折脱位模式(基于所涉及的特殊结构组合)，高能损伤并不一定遵循任何规则。
protrude /proʊˈtruːd/v. 伸出，突出；（动物）使（身体部位）突出
struck /strʌk/adj. 受罢工影响的v. 罢工；打击，撞击（strike 的过去式和过去分词）
百度翻译：
肘关节脱位
肱尺骨关节脱位相当常见，成人比儿童更常见。损伤通常按位移方向分类。然而，在90%的病例中，尺桡骨复合体后移或后外侧移位，常伴有限制性骨突骨折。
损伤机制与病理
造成后脱位的原因通常是伸直的手摔倒，肘关节伸直。仅囊膜和韧带结构的破坏可导致后外侧或后外侧脱位。然而，如果没有相关骨折，复位通常是稳定的，不太可能再脱位。桡骨头、冠状突或鹰嘴突韧带断裂和骨折（或更糟的是，多处骨折）的合并会使关节更加不稳定，除非骨折复位固定，否则容易再移位。
一旦发生后脱位，也可能发生侧移。软组织破裂通常相当严重，周围神经和血管可能受损。虽然骨折脱位的某些常见模式已被确认（基于所涉及的结构的特定组合），高能损伤并不一定遵循任何规则。一个典型的例子就是所谓的侧击伤，通常是当一个汽车司机的肘部从窗户伸出时，被另一辆车撞到。
其结果是肘关节周围的任何或全部骨骼向前脱位，软组织损伤（包括神经血管损伤）通常很严重。
临床特征
病人用肘关节支撑前臂，使其轻微弯曲。除非肿胀严重，否则畸形是明显的。骨标志物（鹰嘴和上髁）可以触摸到并且位置异常。
然而，在严重的伤害中疼痛和肿胀是如此
因为肘部检查是不可能的。然而，手部应该检查血管或神经损伤的迹象。
X射线
X光检查对于（a）确认是否存在脱位和（b）识别任何相关骨折至关重要。通常只有在手术时对肘关节进行检查，才能确定损伤的全部程度。