胸椎椎弓根螺钉置入治疗胸椎骨折的准确性和安全性评价

The assessment of accuracy and safety of thoracic pedicle screw placement in the fracture of thoracic spine

目的探讨胸椎椎弓根螺钉置入技术治疗胸椎骨折的准确性和安全性。方法50例胸椎骨折患者术前均行脊柱标准俯卧位CT加密扫描,测量进针点、入钉点至椎体前缘的深度、进针角度和直径,根据测得数据确定椎弓根螺钉置入的深度和方向,术后再行脊柱X线片及CT加密扫描评价置钉的准确性和安全性。结果50例患者共置入240枚胸椎椎弓根螺钉,术后CT加密扫描和X线片观察到220枚(91.7%)螺钉完全在椎弓根皮质骨内;20枚(8.3%)螺钉发生错置,其中7枚(2.9%)螺钉偏外;5枚(2.1%)螺钉偏前外侧,有2枚(0.8%)螺钉靠近主动脉;3枚(1.3%)螺钉偏下;3枚(1.3%)螺钉直径过大导致椎弓根内壁膨胀内移;2枚(0.8%)螺钉误入椎管内。螺钉完全在椎弓根皮质内的百分比在不同的胸椎节段之间有显著性差异。结论术前CT扫描测量胸椎骨折患者椎弓根的有关数据可为术中准确置入螺钉提供重要参考依据。术中标准的X线透视指导和解剖标记定位是保证胸椎椎弓根螺钉准确置入的关键因素。术后CT加密扫描能准确地反映椎弓根螺钉位置偏差,并能反映椎弓根螺钉与相邻结构的位置和关系。螺钉发生错置多见于上胸椎。

Objective To investigate the accuracy and safety of pedicle screw placement in the fracture of thoracic spine. Methods On the basis of imaging for the fracture of thoracic spine of 50 cases, the screw prick point, angle, depth and diameter were measured and defined on the thoracic vertebrae pedicle by CT thin-slice scan in standard prone in all cases. The accuracy and safety of screws placement was evaluated with X-ray and CT thin-slice scan in all cases postoperative. Results Among of 240 thoracic pedicle screws that were inserted in 50 cases, 220 screws （91.7%） were fully contained within the cortical boundaries of the pedicle, 20 screws （ 8. 3% ） were misplaced, 7 screws （ 2. 9% ） laterally, 5 screws （2. 1% ） anterolateral and 2 （ 0. 8% ） of it demonstrated aortic abutment, 3 screws （ 1.3% ） caudad perforations of the pedicle,3 screws（ 1.3% ） expended the wall of the pedicle to inside, 2 screws （0. 8% ） were misplaced in vertebral canal according to X ray and CT thin-slice scan. When comparing screws in different part of thoracic, there was a significant difference. Conclusions Preoperative CT measuremently of the thoracic pedicle in the treatment of thoracic fracture can provide important data. It is important factors for thoracic pedicle screws that can be placed safety with guided by intraoperative fluoroscopic imaging and anatomic landmarks. CT thin-slice scan can evaluate accuracy misplace of thoracic pedicle screws, and show anatomic place surroundings of thoracic pedicle screws postoperative. More misplaced screws are seen proximally.