锁骨骨折手术安全性分区的MRI影像解剖学研究

Magnetic resonance imaging applied in safety division for clavicular fracture surgery

目的 通过MRI影像解剖学方法研究锁骨骨折手术安全性分区。方法 用核磁共振对13例志愿者锁骨邻近结构进行矢状位和冠状位图像采集。分别测量锁骨下静脉、臂丛神经束移行至锁骨下方时在锁骨投影A点和B点至胸锁关节的距离，以确定具体位置。同时测量钻孔安全深度和安全角度。结果 A点对应的体表标志为锁骨中内1／3交点（M点）；B点对应的体表标志为锁骨全长中点（N点）。将锁骨依据手术安全性分区进行如下划分，Ⅰ区为危险区：sJ点（胸锁关节）到M点；Ⅱ区为相对危险区：M点到N点；Ⅲ区为相对安全区：N点到CP’点（喙突在锁骨投影）；Ⅳ区为安全区：CP’点到AJ点（肩锁关节）。从Ⅰ区至Ⅳ区钻孔安全深度和安全角度数值依次递增。结论 研究锁骨手术安全性分区，可以有效避免手术时的锁骨下神经血管束损伤，降低术中风险。

Objective To define safety divisions through magnetic resonance imaging （MRI） for the clavicular fracture surgery. Methods The sagittal and coronal MRI of the adjacent structures of the clavicles in 13 patients were obtained. The distance from the projection point A of subclavian vein on clavicle to the sternoclavicular joint and the distance from the projection point B of brachial plexus on clavicle to the sternoclavicular joint were measured to determine the specific anatomic markers. The depths and angles for safe drilling were also measured. Results The surface landmark for point A was at the medial 1/3 intersection （point M） of the clavicle and that for B was at the midpoint （point N） of the clavicle. According to the surface landmarks, the safe divisions were defined as follows： Division Ⅰ （dangerous） covers from the sternoclavicular joint to point M; Division Ⅱ （relatively dangerous） is located between Point M and Point N; Division Ⅲ （relatively safe） is located from Point N to the projection point of coraeoid process on clavicle （Point CP＇）; Division Ⅳ （safe） spreads between Point CP＇ to the acromioclavicular joint. The depths and angles for safe drilling increased gradually from Division Ⅰ to Division Ⅳ. Conclusion In treatment of clavicular fractures, the safety divisions can help surgeons effectively avoid damaging nenrovascular bundles during plating and reducing surgical risks significantly.