Appearance 倒拿破仑帽征见于脊椎正位片第五腰椎(L5)和骶椎(S1)水平处。与骶椎重叠的骨质与倒置拿破仑帽的圆顶相似,而横突形成了渐缩的边缘。 图1 拿破仑帽 Explanation Spondylolisthesis is the anterior displacement of one vertebra with respect to another and frequently occurs at the lumbosacral junction. The inverted Napoleon’s 脊椎滑脱是一个椎体相对于另一个椎体向前脱位,常发生于腰骶关节。当严重的L5椎体(帽子的圆顶)滑脱并重叠于骶椎时,就会产生倒拿破仑帽征。 Notable disruption of any of stabilizing forces may result in depiction of the inverted Napoleon’s hat sign. Discussion Spondylolisthesis at the lumbosacral junction results from a loss of bone stability secondary to congenital defects of the L5 laminae, defects of the pedicles of the L5 inferior articular processes, or defects of the lamina of the sacral superior articular processes. The Newman classification describes the five types of spondylolisthesis: I, congenital or dysplastic; II, isthmic or spondylytic; III, degenerative; IV, traumatic; V, pathologic; and, an additional category established since the original Newman classification, VI, postsurgical. Isthmic, degenerative, and postsurgical causes are the most common types. 参考文献 1.Talangbayan L E. The inverted Napoleon's hat sign.[J]. Radiology, 2007, 243(2):603. 2.Eisenberg RL. Atlas of signs in radiology. Philadelphia,Pa: Lippincott, 1984. |
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