Gürkan Yavuz, Sarisoy Hasan Tahsin, Cağlayan Ciğdem, Solak Mine, Toker Kamil
Department of Anesthesiology, Kocaeli University Hospital, Kocaeli, Turkey.
Agri. 2009 Oct;21(4):149-54.
We studied the influence of patient positioning on the visibility of the sciatic nerve during ultrasound (US) examination in the popliteal region.
Using a linear broad band 7-12 MHz frequency probe, US examination of 24 sciatic nerves was performed by a blinded operator to obtain the best possible image at the level of the popliteal crease (PC) and at 4 and 8 cm above the PC in the prone position. Examinations were performed in neutral prone (Group N), with a silicone roller under the foot (Group R) and in "figure of four" (Group FOF) positions. "Figure of four" position was described as: the leg to be examined is flexed and abducted to allow the foot to rest on the ankle of the contralateral leg. A visibility score for the sciatic nerve was established as follows: Score I: Nerve is identified, but borders are not clear. Score II: Nerve is identified. Borders of the nerve are clearly distinguished from the surrounding structures. Three or less fascicles are visible. Score III: Nerve is identified. Borders of the nerve are clearly distinguished from the surrounding structures. Four or more fascicles are visible.
The distance of nerve division from the PC was 6.9+/-1.6 cm. A higher visibility score was obtained in Group FOF (2.6+/-0.6 vs 1.7+/-0.8) at the PC and at 4 cm (2.3+/-0.5 vs 1.6+/-0.8) and 8 cm (2.3+/-0.7 vs 1.4+/-0.7) above the PC, compared to Group N (p<0.001).
"Figure of four" position improves the visibility of the sciatic nerve and may have clinical impact.
我们研究了患者体位对腘窝区超声（US）检查时坐骨神经可视性的影响。
使用线性宽带7 - 12 MHz频率探头，由一名不知情的操作人员对24条坐骨神经进行US检查，在俯卧位时分别在腘横纹（PC）水平以及PC上方4 cm和8 cm处获取尽可能好的图像。检查分别在中立俯卧位（N组）、脚下垫硅胶滚轴（R组）和“4字”位（FOF组）进行。“4字”位描述为：待检查的腿屈曲并外展，使脚置于对侧腿的脚踝上。坐骨神经的可视性评分如下：I级：可识别神经，但边界不清楚。II级：可识别神经。神经边界与周围结构明显区分。可见3个或更少的束状结构。III级：可识别神经。神经边界与周围结构明显区分。可见4个或更多的束状结构。
神经分支距PC的距离为6.9±1.6 cm。与N组相比，FOF组在PC处、PC上方4 cm（2.3±0.5 vs 1.6±0.8）和8 cm（2.3±0.7 vs 1.4±0.7）处获得了更高的可视性评分（2.6±0.6 vs 1.7±0.8）（p<0.001）。
“4字”位可提高坐骨神经的可视性，可能具有临床意义。
