Kamal Robin N, Leversedge Fraser, Ruch David S, Mithani Suhail K, Cotterell Ilvy H F, Richard Marc J
Department of Orthopaedic Surgery, Stanford University, Redwood City, CA.
Department of Orthopaedic Surgery, Duke University, Durham, NC.
J Hand Surg Am. 2018 Nov;43(11):1038.e1-1038.e5. doi: 10.1016/j.jhsa.2018.03.016. Epub 2018 Apr 19.
This study defines the sigmoid notch view of the distal radius. Specifically, we tested the null hypothesis that there is no relationship between the subchondral stripe of bone seen on a sigmoid notch view of the distal radius and the articular surface of the sigmoid notch.
We used 44 wrist specimens for anatomic and fluoroscopic analysis. We measured the articular depth of the sigmoid notch from its deepest point and classified the shape of the sigmoid notch. We then placed a radiopaque marker at the nadir of the articular surface and quantified the fluoroscopic depth of the sigmoid notch. A sigmoid notch view, which was a tangential fluoroscopic view of the volar and dorsal lips of the sigmoid notch, was obtained. The relationship of the articular surface to the stripe of subchondral bone seen on this view, called the sigmoid stripe, was determined.
Anatomic analysis revealed sigmoid notch types with proportions similar to those in previous descriptions. The marker for the articular surface was superimposed or just ulnar to the sigmoid stripe in all specimens. In flat face and ski slope notches, this was coincident with the volar and dorsal lips of the sigmoid notch. In C- and S-type notches, there was a measurable distance from the articular surface marker to the edges of the bone of the volar and dorsal lips of the sigmoid.
The articular surface marker at the nadir of the sigmoid notch is always coincident or ulnar to the sigmoid stripe in the sigmoid notch view.
Surgeons can use the sigmoid notch view as a reliable method to (1) evaluate the integrity of the articular surface, (2) ensure hardware is not placed in the distal radioulnar joint, and (3) guide placement of volar locking plates in the coronal plane.
本研究定义桡骨远端的乙状切迹视图。具体而言，我们检验了以下零假设：在桡骨远端乙状切迹视图上看到的软骨下骨条纹与乙状切迹的关节面之间不存在关联。
我们使用44个腕关节标本进行解剖学和荧光透视分析。我们从乙状切迹的最深点测量其关节深度，并对乙状切迹的形状进行分类。然后我们在关节面的最低点放置一个不透射线的标记物，并对乙状切迹的荧光透视深度进行量化。获得了乙状切迹视图，即乙状切迹掌侧和背侧唇的切线荧光透视图。确定了关节面与在此视图上看到的软骨下骨条纹（称为乙状条纹）之间的关系。
解剖学分析显示乙状切迹类型的比例与先前描述的相似。在所有标本中，关节面的标记物与乙状条纹重叠或刚好位于其尺侧。在平面和滑雪坡切迹中，这与乙状切迹的掌侧和背侧唇重合。在C型和S型切迹中，从关节面标记物到乙状切迹掌侧和背侧唇骨边缘有可测量的距离。
在乙状切迹视图中，乙状切迹最低点的关节面标记物总是与乙状条纹重合或位于其尺侧。
外科医生可以将乙状切迹视图作为一种可靠的方法来（1）评估关节面的完整性，（2）确保硬件不放置在桡尺远侧关节内，以及（3）在冠状面引导掌侧锁定钢板的放置。
