前后路联合手术治疗齿状突骨折畸形愈合伴难复性寰枢椎脱位

Anterior and posterior approach surgical treatment for irreducible atlantoaxial dislocation associated with odontoid malunion

目的:探讨经口前路松解齿状突部分切除与后路复位固定融合治疗齿状突骨折畸形愈合伴难复性寰枢椎脱位的疗效。方法:2008年1月～2011年1月我院共收治7例齿状突骨折畸形愈合致难复性寰枢椎脱位患者,男5例,女2例,年龄21～51岁,平均36.4岁。术前神经功能JOA评分为5～9分,平均7.3±2.1分;脊髓有效空间(space available for the cord,SAC)为4～12mm,平均8.34±3.68mm。均行经口前路松解、齿状突部分切除,一期后路寰枢椎椎弓根螺钉系统进一步提拉复位、固定、融合术,术后观察神经功能改善情况,并行X线、CT、MRI检查观察复位及植骨融合情况。结果:手术时间280～360min,平均310min。术中出血510～930ml,平均670ml。术中无脊髓神经损伤;1例术中置入枢椎椎弓根螺钉时损伤椎动脉,经原钉道拧入螺钉后完成止血,术后随访无椎动脉损伤的临床表现;1例术中置入寰椎椎弓根螺钉时寰椎后弓下壁破裂,未改变钉道,继续沿椎弓根方向置入螺钉,术后随访无寰枢椎的再失稳和移位。所有患者均获得满意复位。随访9～36个月,平均19.6个月。均在术后6个月获得骨性融合,随访期间未发现螺钉松动、移位、断裂,无寰枢椎再移位、失稳现象。末次随访时,JOA评分为11～15分,平均13.1±2.1分,与术前比较有统计学差异(P<0.05),改善率为78.8%～93.5%,平均87.4%;末次随访时的SAC为11～18mm,平均14.78±2.15mm,与术前比较明显增大(P<0.05)。结论:对于齿状突骨折畸形愈合伴难复性寰枢椎脱位患者,经口咽前路松解齿状突部分切除与后路复位固定融合术可获得好的复位效果,近期疗效满意。

Objectives： To explore the clinical efficacy of transoral release, limited odontoidectomy and posterior pedicle screw instrumentation for irreducible atlantoaxial dislocation associated with odontoid malunion. Methods： From January 2008 to January 2011, 7 cases suffering from irreducible atlantoaxial dislocation due to odontoid malunion underwent surgery in our hospital. There were 5 males and 2 females, with an average age of 36.4 years. The preoperative JOA score was 7.3±2.1（range, 5-9）, and the preoperative space available for the cord （SAC） was 8.34±3.68mm（range, 4-12mm）. All cases underwent one stage transoral release, limited odontoidectomy and posterior pedicle screw instrumentation. The clinical outcome was reviewed and the degree of reduction and bone fusion were assessed by X-ray, CT scan, three-dimensional CT reconstruction and MRI. Results： The average operative time was 310min（range, 280-360min）, and the average blood loss was 670ml（range, 510-930ml）. No spinal cord injury was noted. One case was complicated with vertebral artery injury when implanting C2 pedicle screw, but no symptoms was noted during follow-up. One case was complicated with rupture of C2 inferior wall when implanting C2 pedicle screw, but no instrument failure was noted during follow-up. All cases got complete atlantoaxial reduction, and all cases were followed up for an average of 19.6 months（range, 9-36 months）, and got bony fusion 6 months later. No instrument failure or recurrence of dislocation was noted. At final follow-up, the JOA score was 13.1±2.1（range, 11-15）, which showed significant difference compared with preoperative one（P〈0.05）, with an average improve rate of 87.4%（range, 78.8%-93.5%）. At final follow-up, the SAC was 14.78±2.15mm（range, 11-18mm）,which showed significant difference compared with preoperative one（P〈0.05）. Conclusions： For irreducible atlantoaxial dislocation due to odontoid malunion, transoral release, limited odontoidectomy and posterior pedicle screw instrumentation is reliable for short-term outcome.