寰枢椎后路三种组合固定技术治疗寰枢关节不稳的临床评估

Clinical evaluation of three types of combined posterior atlantoaxial internal fixation techniques for treatment of atlantoaxial instability

目的 评估寰枢椎后路三种组合固定技术治疗C1～2不稳的临床疗效和应用价值.方法 2002年8月至2008年3月,采用不同方法治疗寰枢关节不稳68例.（1）采用寰枢椎后路椎弓根螺钉技术治疗32例,其中AndersonⅡ型齿状突骨折20例（陈旧骨折7例,新鲜骨折13例）,Ⅲ型新鲜齿状突骨折6例,寰椎横韧带断裂4例,先天性游离齿突并寰枢椎不稳2例;（2）采用经寰椎后弓椎弓根螺钉联合枢椎椎板螺钉固定治疗20例,其中AndersonⅡ型齿状突骨折伴寰枢关节向后脱位8例,向前脱位4例,齿状突骨折不愈合2例,Ⅲ型齿状突骨折伴寰枢关节不稳3例,寰枢关节前脱位伴横韧带断裂3例;（3）对16例创伤性寰枢椎不稳经牵引已达复位的可复型及经口前路松解后牵引复位的难复型寰枢椎脱位患者,采用经颈后路Apofix椎板夹和C1～2关节突螺钉内固定联合自体髂骨植骨治疗.结果 （1）采用寰枢椎后路椎弓根螺钉技术治疗32例患者共置入寰枢椎椎弓根螺钉120枚,其中有3例在置入寰椎椎弓根螺钉时,因后弓细小发生破裂,改用寰椎侧块固定.术中无一例发生脊髓和椎动脉损伤.术后CT显示2例一侧枢椎椎弓根螺钉部分进入椎动脉孔,另1例枢椎螺钉偏内致椎弓根内侧皮质破裂,均无症状,未发现与螺钉有关的神经血管损伤并发症.32例患者均获随访6～42个月,平均26个月.术后JOA评分13.2～16.8分,平均14.8分.无内固定松动或断钉现象,均已达到骨性融合.（2）采用寰椎经后弓椎弓根螺钉联合枢椎椎板螺钉固定治疗20例患者共置入枢椎椎板螺钉32枚,枢椎椎板螺钉位于椎板中,无偏斜.术中无一例发生脊髓和椎动脉损伤.20例随访6～14个月,平均11.2个月.术后X线片未见明显颈椎不稳、无内固定松动或断钉现象,均获得了良好的骨性愈合.（3）16例难复型寰枢椎脱位患者症状均有所改善,无神经症状加重表现.无神经血管损伤等并发症发生.16例随访8～26个月,平均16个月,所有患者在3～6个月均获得骨性融合.术后脊髓功能改善优5例,良8例,有效2例,无变化1例,无加重患者.内置物无松动、断裂.结论 寰枢椎后路三种组合固定技术是治疗上颈椎疾患的有效方法,具有固定牢固、固定节段短和三维固定的优点,在临床应用可根据患者的具体病情组合固定.

Objective To assess clinical curative effect of three types of combined posterior atlantoaxial internal fixation techniques in treatment of atlantoaxial instability. Methods The study involved 68 patients with atlantoaxial instability treated with different fixation techniques from August 2002 to March 2008. （ 1 ） Transpedicular fixation was performed in 32 patients including 20 patients with Anderson Ⅱ odontoid fractures （seven with old odontoid fracture and 13 with fresh fractures）, six with type Anderson Ⅲ fresh odontoid fractures, four with disrupt of transverse ligament of the atlas and two with congenital loose odontoid process combined with atlantoaxial instability. （2） Transpedicular internal fixation with screws of atlas incorporating C2 laminar screws was performed in 20 patients with upper cervical injury including eight with type Ⅱ odontoid process fractures combined with atlantoaxial backward dislocation,four with type Ⅱ odontoid process fractures combined with atlantoaxial forward dislocation, two with nonunion of odontoid process fractures, three with type Ⅲ odontoid process fractures combined with atlantoaxial unsteadiness and three with atlantoaxial dislocation combined with disrupt of transverse ligament of atlas. （3）A total of 16 patients with traumatic atlantoaxial instability, reducible atlantoaxial dislocation and irreducible atlantoaxial dislocation were treated with four-point internal fixation technique using autologous iliac bone grafts. Results （1） A total of 120 screws were implanted in 32 patients, with no spinal cord or vertebral artery injury after surgery. Atlas lateral mass fixation was adopted in three patients because of broken posterior arch of the atlas. Postoperative CT showed that two screws were inserted into the vertebral artery hole and that one screw was inserted medially into the spinal canal and caused medial correx rupture, but both with no clinical symptoms. All 32 patients were followed up for 6-42 months （ average 26 months）, which showed solid fusion in all patients. The postoperative JOA scores ranged from 13.2 points to 16.8 points （average 14. 8 points）. （2） Thirty-two screws were implanted in 20 patients,with no spinal cord or vertebral artery injury. The patients were followed up for mean six months （ range 6-14 months）. Postoperative X-ray showed sound bone fusion, with no cervical instability, loosening or breakage of the screws. （3） The symptoms of all the patients were improved at different degrees, with no neurological deterioration or severe complications, such as nerve blood vessel injury. All 16 patients were followed up for 8-26 months （ average 16 months）, which showed bony fusion in all patients at 3-6 months after surgery. The spinal cord function was improved markedly in five patients, good in eight, mild in two but unchanged in one. Conclusions Three types of combined posterior atlantoaxial internal fixation techniques have advantages of rigid, short-segmental and three-dimensional fixation and hence are effective methods for treatment of upper cervical injuries. The combination mode can be varied according to specific condition of the patients.