Department of Spine Surgery, The First Bethune Hospital, Jilin University, Changchun, China.
Spine (Phila Pa 1976). 2013 Apr 15;38(8):E504-12. doi: 10.1097/BRS.0b013e3182880065.
Applied anatomical study and clinical application.
To design and optimize the method of cervical pedicle screw placement for cervical vertebrae C3-C5, and to test it in clinical applications.
Most of the anatomical studies on cervical pedicle screw placement previously published focused on the lower cervical vertebrae. Clinically, it is much more difficult to place C3, C4, and C5 screws than C6 and C7 screws; therefore, anatomical measurements of C3-C5 pedicles and design of an appropriate screw placement method are required.
A total of 20 cervical vertebrae specimens were prepared, and bilateral pedicle screws were manually inserted for C3-C5. The intersection of the horizontal line through the midpoint of the transverse process root and the vertical line through the mediolateral third of the superior articular process was used as the entry point. The screws were inserted along the axis of the pedicle, with the axis of the screw coinciding with that of the pedicle. The specimens were truncated along the horizontal or sagittal plane of the pedicle, and a variety of measurements were made to determine appropriate screw type and placement. Finally, this screw fixation technique was applied in clinical situations with the placement of 26 C3 screws, 26 C4 screws, and 38 C5 screws.
Pedicular height was larger than pedicular width for the same segment of C3-C5, and pedicular width of the different segments did not significantly vary. The lengths of the screw channels for C3-C5 screw placement were similar. The transverse angles of C3-C5 segments displayed a decreasing trend, whereas the vertical angles did not. In all clinical cases, all screws were properly within the pedicles examined using postoperative computed tomography scan. Only 1 C3 screw penetrated the medial cortex and slightly entered the spinal canal, but no clinical symptoms occurred.
The intersection of the horizontal line through the midpoint of the transverse process root and the vertical line through the mediolateral third of the superior articular process represents a superior frame of reference for the entry point for C3-C5 pedicle screw fixation. Clinically, we recommend the transverse angles to be 90° for C3 and 80° for C4 and C5, and the vertical angles to be 70° for C3-C5. We found that screws with a diameter of 3.5 mm and length of 20 mm or 22 mm to be safe, objective, and reliable.
应用解剖学研究和临床应用。
设计并优化颈椎 C3-C5 椎弓根螺钉置入方法，并进行临床应用测试。
以往发表的大多数颈椎椎弓根螺钉置钉的解剖学研究都集中在下颈椎。临床上，C3、C4 和 C5 螺钉的置钉难度明显大于 C6 和 C7 螺钉，因此需要对 C3-C5 椎弓根进行解剖学测量并设计合适的螺钉置入方法。
共准备 20 个颈椎标本，手动置入双侧 C3-C5 椎弓根螺钉。以横突根中点与上关节突中外 1/3 连线的水平线与矢状面交点作为进钉点，螺钉沿椎弓根轴线方向置入，使螺钉轴线与椎弓根轴线重合。将标本沿椎弓根的水平或矢状面截断，进行各种测量，以确定合适的螺钉类型和置入方法。最后，将这种螺钉固定技术应用于临床，共置入 26 枚 C3 螺钉、26 枚 C4 螺钉和 38 枚 C5 螺钉。
C3-C5 同一节段的椎弓根高度大于宽度，不同节段的椎弓根宽度无明显差异。C3-C5 螺钉置钉通道长度相似。C3-C5 节段的横突角呈递减趋势，而垂直角无明显变化。所有临床病例术后均行 CT 扫描，所有螺钉均恰位于椎弓根内。仅 1 枚 C3 螺钉穿透内侧皮质并轻度进入椎管，但无临床症状。
以横突根中点与上关节突中外 1/3 连线的水平线与矢状面交点作为进钉点，为 C3-C5 椎弓根螺钉固定提供了一个理想的参考框架。临床上，我们建议 C3 的横突角为 90°，C4 和 C5 的横突角为 80°，C3-C5 的垂直角为 70°。我们发现直径为 3.5mm、长度为 20mm 或 22mm 的螺钉安全、客观、可靠。
