术前判别寰枢椎解剖类型对上颈椎后路置钉策略的意义

Individualized strategy for upper cervical surgery based on the identification of atlantoaxial anatomic variation

中文关键词:  寰枢椎脱位  解剖变异  个性化手术

英文关键词:Atlantoaxial dislocation  Anatomic variation  Individual surgery

中文摘要:

  【摘要】 目的：探讨术前判别寰枢椎解剖类型对上颈椎后路置钉策略的意义。方法：2012年3月~2015年10月对86例上颈椎疾病患者实施后路寰枢椎内固定手术，其中颅颈交界畸形合并寰枢椎脱位33例，创伤性寰枢椎脱位18例，寰枢椎椎管内肿瘤14例，寰枢椎结核合并寰枢椎脱位9例，类风湿关节炎合并寰枢椎脱位12例。在颈椎侧位X线片上测量寰椎后弓的高度，对后弓高度≥3.5mm的A型寰椎选择寰椎椎弓根螺钉固定，对后弓高度<3.5mm的B型寰椎选择寰椎椎板钩固定。CT薄层扫描测量枢椎椎动脉孔入口至枢椎椎管内壁的距离（a），数层法识别椎动脉孔球部开始出现的层数，计算e值（层数×层厚）；根据a、e值确定枢椎椎动脉孔的类型：a>4.5mm、e≥4.5mm为Ⅰ型，a≤4.5mm、e<4.5mm为Ⅱ型，a≤4.5mm、e≥4.5mm为Ⅲ型，a>4.5mm、e＜4.5mm为Ⅳ型；Ⅱ型选择枢椎椎板螺钉固定，Ⅰ、Ⅲ、Ⅳ型选择经椎弓根螺钉固定。结果：86例患者中，寰椎后弓A型146侧，B型26侧；枢椎椎动脉孔Ⅱ型32侧，Ⅰ、Ⅲ、Ⅳ型140侧。手术共置入寰椎椎板钩26枚，寰椎椎弓根螺钉146枚，枢椎椎板螺钉32枚，枢椎椎弓根螺钉140枚；施行寰椎椎弓根螺钉-棒-枢椎椎弓根螺钉内固定术（57例）、寰椎椎弓根螺钉-棒-枢椎椎板螺钉内固定术（16例）和寰椎椎板钩-棒-枢椎椎弓根螺钉内固定术（13例）三种类型的个性化内固定组合手术。手术均顺利完成，手术时间95~156min（130±25min），手术出血量105~188ml（150±35ml）。术后复查X线片显示寰枢椎均达到理想复位，随访8~18个月（13±5.5个月），末次随访CT检查结果显示，除1例寰椎椎板钩固定病例出现内固定松动外，其余患者均获得骨性融合。结论：术前应用影像技术对患者寰枢椎解剖类型进行综合判断并制定个性化的置钉策略和固定方式，有助于提高手术安全性。 【关键词】 寰枢椎脱位；解剖变异；个性化手术

英文摘要:

  【Abstract】 Objectives: To explore the individualized strategy for posterior atlantoaxial surgery based on the identification of atlantoaxial anatomic variation. Methods: Clinical data of 86 patients with upper cervical disorders who underwent posterior approach instrumentation from March 2012 to October 2015 in Guangzhou General Hospital of Guangzhou Military Command were analyzed retrospectively. There were 33 cases of atantoaxial dislocation with cranial-cervical junction malformation, 18 cases of traumatic atlantoaxial dislocation, 14 cases of atlantoaxial intraspinal tumor, 9 cases of atlantoaxial dislocation with upper cervical tuberculosis and 12 cases of atlantoaxial dislocation with rheumatoid arthritis. According to the height of posterior atlas arch(HPAA) in lateral X-ray radiography, atlas transpedicle screws were determined to place whether on not. When it was referred as type A atlas(HPAA≥3.5mm), atlantal pedicle screw fixation could be chosen, while atlas lamina hook could be used in patients with type B atlas(HPAA<3.5mm). Types of axial vertebral artery foramen were determined by value a(distance between the entrance of vertebral artery foramen and inner wall of axial canal) and value e(slice number when the bulb of vertebral artery foramen occurred × slice thickness) which obtained in thin slice CT scan. a>4.5mm and e≥4.5mm was type Ⅰ; a≤4.5mm and e＜4.5mm was type Ⅱ; a≤4.5mm and e≥4.5mm was type Ⅲ; a＞4.5mm and e＜4.5mm was type Ⅳ. Type Ⅱ axis chose lamina screws and other types of Ⅰ/Ⅲ/Ⅳ axis chose transpedicle screws. Results: There were 146 sides of type A and 26 sides of type B in atlas, 32 sides of type Ⅱ, 140 sides of type Ⅰ/Ⅲ/Ⅳ in axis. Then 26 atlas hooks, 146 atlas transpedicle screws, 32 axis lamina screws and 140 axis transpedicle screws were used. Therefore 3 types of instrumentation were performed in the study: atlas pedicle screw-rod-axis pedicle screw, atlas pedicle screw-rod-axis lamina screw, atlas hooks-rod-axis pedicle screw. The operation time was 95-156mins(average, 130±25mins), blood loss was 105-188ml(average, 150±35ml). Postoperative X-ray showed that all the patients got ideal reduction. The patients were followed up for 8 to 18 months(average, 13±5.5 months). The latest CT scan showed good bone fusion in 85 patients, except 1 patient with atlas hook loosening. Conclusions: For atlantoaxial dislocation, individualized strategy based on atlantoaxial anatomic variation in modern image techniques will be helpful to reduce surgical risk and improve the success rate of procedure.