后路钉棒内固定系统在不稳定性枢椎骨折治疗中进钉点与固定方式的选择

背景：上颈椎后路钉棒内固定过程中,放置寰椎侧块螺钉技术是关键。目的：总结后路钉棒内固定系统在不稳定性枢椎骨折治疗中的进钉点位置。方法：2007-01/2010-12采用Vertex颈椎后路钉棒内固定系统治疗不稳定性枢椎骨折19例,男12例,女7例,年龄21~75岁,平均49.5岁。采用寰椎侧块螺钉及枢椎椎弓根螺钉内固定6例,寰椎侧块、单侧枢椎椎弓根及颈3侧块螺钉内固定3例,寰椎侧块、双侧枢椎椎弓根及颈3侧块螺钉内固定1例,枢椎椎弓根及颈3侧块螺钉内固定9例,内固定过程中均行后侧椎板间植骨融合。结果与结论：19例患者全部获得随访,随访时间7~43个月。患者骨折复位满意,骨折端均获得愈合,植骨部位融合率达到100%,未出现断钉、断棒等现象,未发生颈髓及椎动脉等医源性损伤。该方法治疗不稳定性枢椎骨折创伤小,固定可靠,作者根据临床经验,对螺钉进钉点的位置总结如下：①对于寰椎侧块进钉点选择在侧块中点稍偏外、椎弓的下方1/3处,进针方向为向内、上分别稍倾斜约10°,5°。②枢椎椎弓根进钉点选择在枢椎上下关节面间、下关节正中垂线的中点,进针方向为向内、上分别倾斜15°~20°,25°。③第三颈椎侧块进钉点选择在侧块中心点内侧2mm,进针方向为向外、上倾斜20°~25°。

The clinical efficacy of application of posterior screw internal fixation system in instable axis fractures

BACKGROUND： During posterior screw-rod internal fixation of upper cervical spine, placement of atlas lateral mass screw is the key technology. OBJECTIVE： To summarize entrance point for screw insertion of posterior screw-rod internal fixation system in instable axis fractures. METHODS： From January 2007 to December 2010, nineteen patients with instable axis fractures, including 12 males and 7 females, with an average age of 49.5 years （range, 21-75 years）, were treated with Vertex posterior screw-rod internal fixation. Atlas lateral masses screw and axis pedicle screw were performed in 6 cases for internal fixation. Atlas lateral masses screw, single axis pedicle screw and neck 3 lateral masses screw were performed in 3 cases for internal fixation. Atlas lateral masses screw, double axis pedicle screws and neck 3 lateral masses screw were performed in 1 case for internal fixation. Axis pedicle screw and neck 3 lateral masses screw were performed in 9 cases for internal fixation. Fusion technique was performed in all cases. RESULTS AND CONCLUSION： Nineteen patients were followed up from 7 to 43 months. All cases had satisfactory reduction and healing in the positions of axis fractures, fusion rate in the positions of bone grafts was 100%. There were no screw and rod breakage, and no iatrogenic injury of spinal cord and vertebral artery happened. The method for the treatment of instable axis fractures is little trauma and reliable fixation. The authors according to clinical experiences, entrance point for screw insertion are summarized as follows： ①The entrance point of atlas lateral masses screw is slightly outer side in the lateral mass midpoint, at the bottom 1/3 of vertebral arch. Direction of needle is inward and upward slightly tilted about 10° and 5°. ②The entrance point of axis pedicle screw is between the upper and lower articular surface of axial, the midpoint of the middle vertical line of subtalar joint. Direction of needle is inward and upward slightly tilted about 15°-20° and 25°. ③The entrance point of neck 3 lateral masses screw is 2 mm inside of lateral mass center. Direction of needle is inward and upward slightly tilted about 20°-25°.