骨科英文书籍精读（100）｜肱骨外髁骨折（1）
FRACTURES OF THE LATERAL CONDYLE
The lateral condylar (or capitellar) epiphysis begins to ossify during the first year of life and fuses with the shaft at 12–16 years. Between these ages it may be sheared off or avulsed by forceful traction.
Mechanism of injury and pathology
The child falls on the hand with the elbow extended and forced into varus. A large fragment, which includes the lateral condyle, breaks off and is pulled upon by the attached wrist extensors. Sometimes there is a compression, rather than avulsion, mechanism of injury. The fracture line usually runs along the physis and into the trochlea; less often it continues through the medial epiphysis and exits through the capitulatrochlear groove. It crosses the growth plate and so is a Salter Harris Type IV injury. In severe injuries the elbow may dislocate posterolaterally; the condyle is ‘capsized’ by muscle pull and remains capsized while the elbow reduces spontaneously.
The extent of this injury is often not appreciated. Because the condylar epiphysis is largely cartilaginous, the bone fragment may look deceptively small on x-ray. Displacement can be quite marked due to muscle pull. The fracture is important for two reasons: (a) it may damage the growth plate and (b) it always involves the joint. Early recognition and accurate reduction are therefore essential if a poor outcome is to be avoided.
---from 《Apley’s System of Orthopaedics and Fractures》
重点词汇整理：
epiphysis /i'pifisis/n. 骺；脑上体；松果体
metaphysi 干骺端
ossify /ˈɑːsɪfaɪ/vt. 使硬化；使骨化；使僵化vi. 骨化；硬化；僵化
fuse /fjuːz/n. 保险丝，熔线；导火线，雷管v. 融合
avulse/ə'vʌls/v. 抽出；撕裂，撕脱
trochlea /'trɒklɪr/n. [解剖] 滑车
groove /ɡruːv/n. [建] 凹槽，槽；最佳状态；惯例vt. 开槽于vi. 形成沟槽
capsize/ˈkæpsaɪz/vt. 倾覆（特指船）；翻覆；弄翻vi. 翻；倾覆；翻覆
appreciate /əˈpriːʃieɪt/vt. 欣赏；感激；领会；鉴别vi. 增值；涨价
deceptively /dɪˈseptɪvli/adv. 看似；不像看上去那么；比实际更显得
百度翻译：
外侧髁骨折
外侧髁（或小头）骨骺在第一年开始骨化，12-16岁时与骨干融合。在这两个年龄段之间，它可能会被切断或被强力牵引撕裂。
损伤机制与病理
孩子摔倒在手上，肘部伸直，被迫内翻。一大块碎片，包括外侧髁突，折断后被附在手腕上的伸肌拉着。有时损伤机制是压迫，而不是撕脱。骨折线通常沿着身体延伸并进入滑车；较少的情况下，它会继续穿过内侧骨骺，并穿过头滑车沟。它穿过生长板，所以是Salter Harris IV型损伤。在严重的损伤中，肘关节可能后外侧脱臼；髁突在肌肉牵引下“倾覆”并保持倾覆状态，同时肘关节会自行减少。
这种伤害的程度往往不被重视。因为髁状突骨骺主要是软骨组织，所以在x光片上，骨头碎片可能看起来很小。由于肌肉拉伤，位移会很明显。骨折很重要，有两个原因：（a）它可能损伤生长板；（b）它总是累及关节。因此，如果要避免不良结果，早期识别和准确的复位至关重要的。