CLS影像园XCTMR.com

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Clinical History(临床病史): 35-year-old status post trauma. 35岁，男性，外伤CLS影像园XCTMR.com

Findings(影像所见): AP view of the left shoulder demonstrate marked internal rotation and impaction fracture of the humeral head. Axial view demonstrates posterior subluxation of the humeral head in the glenoid fossa and the impaction fracture of the humeral head.CLS影像园XCTMR.com

左肩关节正位显示肱骨头明显内旋和嵌入骨折。轴位显示位于关节窝内的肱骨头向后方半脱位并嵌入骨折。CLS影像园XCTMR.com

Diagnosis(诊断): Posterior dislocation with impaction fracture of the humeral head.CLS影像园XCTMR.com

肱骨头后脱位并嵌入骨折CLS影像园XCTMR.com

Discussion(讨论):CLS影像园XCTMR.com

后脱位很少见，多由于肩关节受到由前向后的暴力作用或在肩关节内收内旋位跌倒时手部着地引起。后脱位可分为肩胛岗下和肩峰下脱位、盂下脱位，肩关节脱位如在初期治疗不当，可发生习惯性脱位。CLS影像园XCTMR.com
Posterior dislocation of the shoulder is uncommon and constitutes less than 5% of shoulder dislocations. Posterior dislocation is usually the result of anterior to posterior directed trauma, but can be seen as the result of violent muscle contraction causing the humerus to rotate severely internally and adduct as is seen in convulsive seizures and electric shock.CLS影像园XCTMR.com

Radiographic signs of posterior dislocation include:CLS影像园XCTMR.com

Distortion of the elliptical area created by the overlapping humeral CLS影像园XCTMR.com
head and glenoid fossa on the AP view.CLS影像园XCTMR.com
A vacant glenoid cavity.CLS影像园XCTMR.com
>6 mm space separating humeral head and anterior rim of the glenoid.CLS影像园XCTMR.com
Fixed internal rotation of the humerusCLS影像园XCTMR.com
Impaction fracture of the humeral head, i.e., through line.CLS影像园XCTMR.com

Reference:CLS影像园XCTMR.com
Resnick D. Bone and Joint Imaging, 2nd Edition. CLS影像园XCTMR.com
W. B. Saunders, Philadelphia; 1996:1021-1026.CLS影像园XCTMR.com
Harris J, Harris W, and Novelline R. The Radiology ofCLS影像园XCTMR.com
Emergency Medicine, 3rd Edition. Williams and Wilkins, CLS影像园XCTMR.com
Baltimore; 1993:283-285.