摘要
目的利用寰枢椎影像学测量建立寰椎侧块螺钉进钉安全区域并指导手术操作。方法30例形态正常的寰枢椎行CT薄层扫描和三维重建,置钉空间(SAS)定义为CT横断面上横突孔内缘切线与椎管切线这两条平行线间的距离,测量0°、10°内倾角的置钉空间值(分别为SAS1、SAS2)及置钉区域；CT测量13例患者术后的置钉位置。结果内倾0°时SAS1为(7．81±1．28)mm,内倾10°时SAS2则为(9．69±1．23)mm,两者差异有统计学意义(P＜0．01)；SAS1寰椎椎弓根中线至后正中线的距离与枢椎下关节突中线至后正中线的距离差异无统计学意义；当内倾角为10°时,SAS2中线在后弓的位点移至SAS1寰椎椎弓根中线位点外侧约2．0 mm处。13例患者共26枚寰椎侧块螺钉均准确置入,未穿破骨皮质、突入椎管内或损伤血管神经。结论寰椎侧块螺钉置钉存在安全区域,内倾10°时可以获得更宽的置钉空间。实施寰椎侧块螺钉固定术之前,需要对寰椎横断面CT图像等进行测量,确定置钉的安全区域。
Objective To investigate the safe region for screw fixation in atlas lateral mass by radiologic measurements to conduct the operative procedure. Methods The dimensions of the pedicles were determined in 30 patients with normal atlas by CT scan and three dimensional reconstruction images of the upper cervical spine. The space available for the screw （SAS） was defined as the perpendicular distance between two lines tangential to the spinal canal and the transverse foramen, respectively. SAS was evaluated at 0°（ SASI ） and 10°（SAS2） insertion angles. The location of screws in 13 cases of opera- tion were observed by CT scan images measurements of the cervical spine. Results SASI at 0° insertion angle was （7.81 ± 1.28） mm and SAS2 at 10° insertion angle was （9.69 ± 1.23） mm, with statistical difference （ P 〈0.01 ）. For SASI, the distance from the midline of pedicle to the midline of posterior arch and the distance from the center of C2 inferior articular process to the midline of posterior arch showed insignificant statistical difference. However, the entry point at the posterior arch of the midline of SAS2 was located at 2.0 mm lateral to the midline of ASAI. Twenty-six pedicle screws in 13 cases were inserted correctly, without cortex breakage, or nerve and vessel injury. Conclusions There is a safe region for screw fixation in atlas lateral mass. Wider space available for the screw can be acquired when transverse angle is 10°. It is necessary to confirm the safe region by using axial CT of atlas before screw fixation.
出处
《中华创伤杂志》
CAS
CSCD
北大核心
2006年第6期404-407,共4页
Chinese Journal of Trauma
