骨科英文书籍精读（74）｜肱骨近端骨折（1）
FRACTURES OF THE PROXIMAL HUMERUS
Fractures of the proximal humerus usually occur after middle age and most of the patients are osteoporotic, postmenopausal women. Fracture displacement is usually not marked and treatment presents few problems. However, in about 20 percent of cases there is considerable displacement of one or more fragments and a significant risk of complications due to bone fragility, damage to the rotator cuff and the prevailing co-morbidities. Deciding between operative and nonoperative treatment can be very difficult.
Mechanism of injury
Fracture usually follows a fall on the out-stretched arm – the type of injury which, in younger people, might cause dislocation of the shoulder. Sometimes, indeed, there is both a fracture and a dislocation.
Classification and pathological anatomy
The most widely accepted classification is that of Neer (1970) who drew attention to the four major segments involved in these injuries: the head of the humerus, the lesser tuberosity, the greater tuberosity and the shaft. Neer’s classification distinguishes between the number of displaced fragments, with displacement defined as greater than 45 degrees of angulation or 1cm of separation. Thus, however many fracture lines there are, if the fragments are undisplaced it is regarded as a one-part fracture; if one segment is separated from the others, it is a two-part fracture; if two fragments are displaced, that is a three-part fracture; if all the major parts are displaced, it is a four-part fracture. Furthermore, a fracture-dislocation exists when the head is dislocated and there are two, three or four parts. This grading is based on x-ray appearances, although observers do not always agree with each other on which class a particular fracture falls into.
---from 《Apley’s System of Orthopaedics and Fractures》
重点词汇整理：
postmenopausal /,postmɛnə'pɔzəl/adj. （妇女）绝经后的
prevailing /prɪˈveɪlɪŋ/adj. 流行的；一般的，最普通的；占优势的；盛行很广的v. 盛行，流行（prevail的现在分词形式）；获胜
co-morbidities副发病变 /mɔːrˈbɪdəti/
n. 发病率；病态；不健全
百度翻译：
肱骨近端骨折
肱骨近端骨折通常发生在中年以后，大多数患者是骨质疏松的绝经后妇女。骨折移位通常不明显，治疗也很少出现问题。然而，在大约20%的病例中，一个或多个碎片有相当大的移位，并且由于骨骼脆弱、肩袖损伤和常见的共病，有很大的并发症风险。在手术治疗和非手术治疗之间作出决定是非常困难的。
损伤机制
骨折通常发生在伸直的手臂摔倒后，这种损伤在年轻人中可能会导致肩关节脱位。有时，确实，既有骨折也有脱位。
分类与病理解剖
最广泛接受的分类是Neer（1970）的分类，他提请注意与这些损伤有关的四个主要部分：肱骨头、小结节、大结节还有肱骨干。Neer的分类区分了移位碎片的数量，位移定义为大于45度的角度或1cm的分离。因此，无论有多少条断裂线，如果碎片未移位，则视为一部分骨折；如果一部分与其他部分分离，则为两部分骨折；如果两个碎片移位，则为三部分骨折；如果所有主要部分移位，则为四部分骨折。此外，当头部脱臼，有两个、三个或四个部分时，就会出现骨折脱位。这种分级是基于x光表现的，尽管观察者并不总是一致认为某一特定骨折属于哪一类。