寰枢椎椎弓根螺钉术中复位固定融合术治疗陈旧性齿状突骨折并寰枢椎脱位

Surgical treatment with atlantoaxial pedicle screws for reduction of atlantoaxial dislocation caused by old odontoid fracture

中文关键词:  陈旧性齿状突骨折  寰枢椎脱位  椎弓根螺钉  内固定  复位

英文关键词:Old odontoid fracture  Atlantoaxial dislocation  Screw  Fixation  Reduction

中文摘要:

  【摘要】 目的：总结应用后路寰枢椎椎弓根螺钉术中提拉复位固定植骨融合术治疗陈旧性齿状突骨折并寰枢椎脱位的疗效。方法：2007年1月~2010年1月收治21例陈旧性齿状突骨折并寰枢椎脱位患者，男13例，女8例；年龄13~68岁，平均38.5岁。患者均有不同程度的枕颈部疼痛和活动受限，均伴有神经功能障碍，ASIA分级：B级2例，C级13例，D级6例；JOA评分4～14分，平均8.3分。根据Anderson和D′Alonzo分型，Ⅱ型骨折17例（81%），Ⅲ型骨折4例（19%）。MRI检查示18例患者有不同程度的脊髓受压，7例脊髓受压节段髓内出现T2加权像高信号改变。均为寰椎前脱位，术前均进行颅骨牵引术，15例（71.4％）可部分复位，6例（28.6％）不可复位。术前寰齿间距（atlanto-dens interval，ADI）9～15mm，平均12.3mm。均采用后路寰枢椎椎弓根螺钉术中提拉复位固定和植骨融合术，随访观察患者临床症状和神经功能改善情况，影像学检查寰枢椎复位和植骨融合情况。结果：患者均顺利完成手术，术中均未发生椎动脉和脊髓损伤。共置入84枚寰枢椎椎弓根螺钉，术后X线片及三维CT检查3枚寰椎椎弓根螺钉内倾角偏小，螺钉部分穿破椎动脉孔内侧壁，椎动脉造影未见椎动脉损伤；1枚寰椎椎弓根螺钉内倾角过大，螺钉部分穿破椎管内侧壁，未出现新的神经损伤症状；其余螺钉位置满意。术后颈椎CT及MRI显示寰枢椎序列重建满意，齿状突区域脑脊液线清晰，脊髓无压迫，ADI为2～4mm，平均2.8mm。患者均获随访，随访时间6～36个月，平均20个月，术后6个月随访时3例患者的ASIA分级无改变，其余患者的神经功能明显改善，ASIA分级：C级3例，D级10例，E级8例； JOA评分为10～17分，平均14.6分，平均改善率为81.2%。1例患者植骨块有部分吸收，其余患者均在术后6个月获得骨性融合，融合率为95.2％；随访期间未发现螺钉松动、移位、断裂和寰枢椎再移位、失稳现象。结论：应用寰枢椎椎弓根螺钉术中提拉复位技术治疗陈旧性齿突骨折并寰枢椎脱位可获得良好的临床效果。

英文摘要:

  【Abstract】 Objectives: To summarize the clinical results of the posterior atlantoaxial pedicle screw-rod internal fixation with its intraoperative reduction and fusion in treatment of old odontoid fracture combined with unreducible atlantoaxial dislocation.　Methods: Twenty-one(8 females, 13 males) patients with an average age of 38.5(13-68) years at the time of injury between January 2007 and January 2010 were studied. The patients had various degrees of occipital neck pain, limited mobility and associated with neurological dysfunction. Degree B in 2 cases, degree C in 13 cases and degree D in 6 cases were assessed by the ASIA impairment scale. Japanese Orthopaedic Association(JOA) scores before operation were recorded from 4 to 14(mean, 8.3). Cervical spinal cord compression was showed by MRI examination in 18 patients, and intramedullary T2-weighted high signal change was found by MRI in 7 patients. All patients had anterior atlantoaxial dislocation, and underwent skull traction before operation. Fifteen cases were partially reduced(71.4%), and 6 not reduced at all(28.6％). The preoperative atlanto-dens interval(ADI) was from 9mm to 15mm(average 12.3mm). Patients were treated with posterior atlantoaxial pedicle screw-rod internal fixation with its intraoperative reduction and fusion. All patients were assessed clinically for neurologic recovery, atlantoaxial reduction and bone graft fusion. Results: No intraoperative vertebral artery injury and spinal cord injury were noted． A total of 84 pedicle screws was inserted. Postoperative CT reconstruction showed that 4 screw malpositions were noted， 3 of which penetrated lateral pedicle cortex but no vertebral artery injury confirmed by vertebral angiography, 1 penetrated medial pedicle cortex but no symptom of nerve root injury was found. 80 screws were sited completely in pedicle. All 21 patients were followed up for an average of 20 months(range, 6-36 months). Postoperative cervical spine CT and MRI showed that the sagittal cervical spine alignment was restored，cerebral spinal fluid line was clear in the odontoid process area and no spinal cord compression was found. The postoperative ADI was reduced to 2-4mm(average 2.8mm). Six months after surgery, all patients except 3 were substantially improved with degree C in 3 cases, degree D in 10 cases and degree E in 8 cases. JOA scores after operation were recorded from 10 to 17(mean, 14.6). The overall improvement rate was 81.2% on average. Solid bony fusion was achieved in 20 patients at 6 months after operation, but partial absorption of the bone graft occurred in one case. The rate of fusion was 95.2％, with no loosening, displacement, instability or breakage of the screws. Conclusions:　Good clinical results can be achieved by the posterior atlantoaxial pedicle screw-rod internal fixation with its intraoperative reduction and solid fusion.