下颈椎椎弓根螺钉内固定技术在临床中的应用

Application of the pedicle screw in the subaxial cervical spine

目的 ：探讨下颈椎椎弓根螺钉内固定技术的临床应用。方法 ：对2011年9月至2013年7月行下颈椎椎弓根螺钉内固定的32例患者进行回顾性分析,男20例,女12例;年龄21-78岁,平均56.4岁。其中10例为创伤性颈髓损伤,9例为颈椎管内肿瘤,7例颈椎后纵韧带骨化症,6例多节段颈椎病。所有患者术前行X线、CT、MRI及椎动脉MRA等影像学检查,术后及随访时行X线片及CT平扫明确螺钉的位置情况。根据Lee等4级分类法评价置钉的准确性,创伤性患者行ASIA分级评价脊髓功能变化,非创伤性患者采用JOA评分评价神经功能改善情况。结果：32例患者成功置入144枚下颈椎椎弓根螺钉,术后CT显示,0级132枚,1级5枚,2级5枚,3级2枚。有12枚螺钉穿破椎弓根,其中8枚螺钉穿破椎弓根外侧皮质,2枚螺钉穿破椎弓根下侧皮质,穿破椎弓根内侧、上侧皮质螺钉各1枚。术后随访12-33个月,平均（21.0±1.5）个月,6例完全性颈髓损伤患者术后神经功能虽无恢复,但截瘫平面下降1-3个脊髓节段。4例不完全性颈髓损伤患者术后按ASIA损伤分级提高1-2级。22例非创伤性患者术后6个月JOA评分平均（15.9±0.6）分,较术前（11.5±0.8）分明显提高（P〈0.01）。所有患者未发现钉棒系统松动、断裂情况。结论：下颈椎椎弓根螺钉固定能提供优秀的三维稳定性。合理选择适应证,术前充分准备以及根据椎弓根形态个体化置钉可以最大限度的降低手术风险及手术并发症,值得临床应用推广。

Objective：To research the clinical application of lower cervical pedicle screw fixation procedure. Methods：From September 2011 to July 2013,32 patients underwent posterior pedicle screw rod system fixation were retrospective analyzed including 20 males and 12 females with an average age of 56.4 years old ranging from 21 to 78 years. Among them,10 patients were traumatic cervical spinal injury,9 patients were cervical spinal canal tumors,7 cases were posterior longitudinal ligament ossification of cervical vertebrae,6 cases were multiple segmental cervical spondylopathy. Preoperatively,X ray,computed tomography,magnetic resonance imaging and magnetic resonance angiography of the vertebral artery were performed in all patients. After the operation and during the follow up,X ray and computed tomography were performed to confirm the pedicle screw position. The accuracy of the pedicle screw placement was evaluated by 4 grades classification from Lee. The spinal cord function was assessed by ASIA impairment scale for traumatic patients and JOA score for non traumatic patients. Results：Totally 144 pedicle screws performed on 32 patients from C3 to C7involving 132 screws of grade 0,5 screws of grade 1,5 of screws grade 2 and 2 screws of grade 3 according to postoperative CT. There were 12 screws penetrating the pedicle cortex including 8 screws at lateral,2 screws at caudal,1 screw at medial and 1 screw at cranial. The follow-up time was 12 to 33 months with an average of（21.0±1.5） months. The spinal cord function was not improved in 6 complete cervical spinal cord injury patients,but their paraplegic level descended 1 to 3 segments. Four incomplete cervical spinal cord injury patients＇ ASIA impairment scale was increased by 1 to 2 grades in average. The JOA score of 22 atraumatic patients increased from preoperative 11.5±0.8 to 15.9±0.6 of postoperative at 6 months（P〈0.01）. There were no screw loosening,screw pullout and screw rod breakage. Conclusion：The lower cervical pedicle screw fixation can provide excellent 3D stability of the vertebral column. The operation risk and complication could be minimized by adequate preoperative evaluation for appropriate cases and individual pedicle screw placement. It deserved the clinical expansion.