410.Monteggia Fracture (Part III)
每天朗读一段医学影像学英语文章
The diagnosis can usually be made with AP and lateral radiographs of the forearm. If there is any uncertainty about involvement of the elbow, dedicated elbow radiographs should be obtained. The ulna fracture is usually obvious; however, radial head dislocations can be subtle. A line drawn along the long axis of the radius should bisect the capitellum. One can also use the fact that the radial head often dislocates in the direction of the fracture apex. The radial head should also be scrutinized for fracture, which is common in posterior radial head dislocation. In complex cases, CT can be used to detect additional injuries, such as coronoid process fractures. MRI can be considered to evaluate for ligamentous injury.
The most common acute complication is posterior interosseous nerve (PIN) palsy, which may be caused by either direct contusion (usually in the setting of a Bado Type 2 injury) or stretch injury from radial head dislocation. The PIN is a deep motor branch of the radial nerve that wraps around the neck of the radius and supplies the wrist extensors except the extensor carpi radialis longus. Symptoms include weakness upon extension of the thumb or fingers and pain with supination and pronation. When associated with stretch injury, symptoms often resolve with radiocapitellar joint reduction. Common long-term complications include chronic proximal radioulnar and radiocapitellar joint instability, delayed union, malunion, nonunion, and proximal radioulnar synostosis.
Notes：
1. bisect /baɪ'sekt/ /baɪ'sɛkt/ vt. 把…一分为二；把…二等分
2. capitellum /ˌkæpɪ'tɛləm/ /ˌkæpɪˈtɛləm/ n. (骨的)小头
3. scrutinize /ˈskru:tnˌaɪz/ /'skrutənaɪz/ vt. 仔细检查，详审
4. posterior interosseous nerve (PIN) palsy 骨间后神经麻痹
5. extensor /ɪk'stensə/ /ɪk'stɛnsɚ/ n. 伸肌
6. extensor carpi radialis longus 桡侧腕长伸肌
7. supination /ˌsju:pi'neiʃən/ /ˌsju:pi'neiʃən/ n. 反掌，反掌的姿势
8. pronation /prəu'neiʃən/ /prəu'neiʃən/ n. 手掌向下
9. synostosis /ˌsɪnɑs'tosɪs/ /ˌsɪnɑsˈtosɪs/ n. 骨性联接；骨结合
来源：每天朗读一段医学影像学英语文章
圈主
深圳市人民医院放射科副主任医师杨敏洁