颈椎椎弓根螺钉误置的临床特征分析

The clinical features of cevical spine pedicle screw malposition

中文关键词:  颈椎椎弓根螺钉  误置  并发症  特征

英文关键词:Cervical pedicle screw  Misplacement  Complication  Feature

中文摘要:

  【摘要】 目的：观察颈椎椎弓根置钉的准确性，分析螺钉误置的临床特征。方法：32例施行颈椎椎弓根置钉手术患者，男22例，女10例；年龄25~74岁（51.5±13.6岁）。颈椎骨折/脱位16例，颈椎后纵韧带骨化8例，颈椎多节段椎间盘突出1例，颈椎管内肿瘤7例（神经鞘瘤3例，脊膜瘤3例，室管膜瘤1例）。术前进行颈椎CT三维重建，确定椎弓根螺钉的进钉点，并测量椎弓根的内倾角、矢状面角度及直径、长度等参数；术中在C型臂X线机透视辅助下置入椎弓根螺钉；术后复查颈椎CT观察椎弓根螺钉位置，按照Lee等的方法判断椎弓根螺钉位置准确性：0级，螺钉未穿破椎弓根；1级，螺钉穿破椎弓根<25%的螺钉直径；2级，螺钉穿破椎弓根>25%，但<50%的螺钉直径；3级，螺钉穿破椎弓根>50%的螺钉直径。2级和3级判为螺钉误置，分析椎弓根螺钉误置的特点；观察血管神经损伤等并发症情况。结果：32例患者中因术中置钉困难更改为侧块螺钉3枚，改为寰椎椎板钩1枚，共置入颈椎椎弓根螺钉147枚（上颈椎40枚，中下颈椎107枚），椎弓根螺钉位置0级53枚，1级67枚，2级17枚（上颈椎2枚，下颈椎15枚），3级10枚（上颈椎1枚，下颈椎9枚）。椎弓根螺钉总误置率为18.3%（2级+3级）；外侧壁穿破17枚，下壁5枚，上壁4枚，内侧壁1枚。上颈椎椎弓根螺钉的误置率（7.5%）显著低于中下颈椎（22.4%）（P<0.05）；椎弓根外侧壁穿破率（11.5%）高于上壁（2.7%）、下壁（3.4%，）及内侧壁（0.7%）（P均<0.01）。5例患者6枚螺钉术中椎弓根钉道攻丝后活动性出血，予骨蜡封堵及置入螺钉后即止血，无血肿或脑缺血梗死并发症。3例患者术后出现上肢神经根刺激症状，予颈椎制动、神经营养治疗，分别于术后1个月、3个月、4个月好转。结论：颈椎椎弓根螺钉误置率较高，但相关并发症较少；穿破椎弓根外侧壁多于内侧壁、上壁或下壁；中下颈椎椎弓根螺钉的误置率高于上颈椎。

英文摘要:

  【Abstract】 Objectives: To evaluate the accuracy of cervical spine pedicle screw(CPS) insertion, and to explore the features of pedicle screw misplacement. Methods: Thirty-two patients stabilized by CPS were included. The cervical disorders included cervical fracture/dislocation(16 cases), ossification of posterior longitudinal ligament(8 cases), multiple cervical intervertebral disc herniation(1 case), neurilemoma(3 cases), spinal meningioma(3 cases) and ependymoma(1 case). Pre- and post-operative computed tomography(CT) scanning and multiple-planner reconstruction were used to determine the relevant parameters(entry point, the angle, the diameter and the length of pedicle) and accuracy of the CPS insertion. And the accuracy was classified according to Lee′s classification criterion: grade 0, no perforation; grade 1, perforation less than 25%; grade 2, perforation more than 25% but less than 50%; grade 3, perforation more than 50%. Grade 2 and 3 were regarded as misplacement. The pedicle screw placement was under the guidance of C-arm fluoroscopy. The features of screw misplacement were observed. Clinical outcome was assessed in all cases. Results: Among thirty-two patients, three lateral mass screws and one C1 laminar hook were used to replace preoperative planned pedicle screws. One hundred and forty-seven CPS were placed(40 screws in C1-C2, 107 screws in C3-C7), including 53 screws with grade 0, 67 screws with grade 1, 17 screws with grade 2(2 screws in C1-C2, 15 screws in C3-C7), and 10 screws with grade 3(1 screw in C1-C2, 9 screws in C3-C7). The total misplacement rate was 18.3%(grade 2 and 3, 27/147): 17 screws perforated lateral wall, 5 screws perforated inferior wall, 4 screws perforated superior wall, and 1 screw perforated medial wall. Pedicle screw perforation rate in C1-C2(7.5%, 3/40) was statistically less than that in C3-C7(22.4%, 24/107)(P<0.05). The rate of lateral wall perforation(11.5%) was statistically higher than that of superior wall(2.7%), inferior wall(3.4%) and medial wall(0.7%)(P<0.01), respectively. Bleeding from pedicle trajectory was found in 6 pedicles of 5 patients and was filled with bone-wax before pedicle screw insertion. Three patients complained postoperative radicular pain on the upper limb and relieved after restriction of cervical motion and neurotrophic medicine administration. No other complications were found. Conclusions: Misplacement of CPS occurs frequently, but relevant complications are scarce. Lateral wall perforation is more frequent than whtat of medial, superior or inferior wall. The incidence of pedicle screw perforation in C3-C7 is more than that in C1-C2.