X线三维导航系统辅助经寰枢关节螺钉固定治疗寰枢椎不稳

Posterior C1-C2 transarticular screw fixation for atlantoaxial instability assisted by intraoperative 3- dimensional fluoroscopy-based navigation

目的探讨术中x线三维导航系统辅助经寰枢关节螺钉固定治疗寰枢椎不稳定的可行性、疗效和适应证。方法回顾性分析北京积水潭医院脊柱外科2005年11月至2012年10月收治的寰枢椎不稳定患者58例。所有患者均在术中x线三维导航辅助下行后路寰枢关节螺钉内固定术。术前复位良好且不需要减压的患者行经皮微创手术。术中观察寰枢椎复位情况，记录手术时间、出血量及术后神经血管并发症情况。术后CT将螺钉分为3类，判断螺钉置入精确性。所有患者至少随访3个月，对患者颈部局部症状（VAS评分）及神经状况改善情况（Nuriek脊髓功能分级）进行评估，x线片评价植骨融合情况。结果51例患者行开放手术，7例患者行经皮微创手术。共置入经寰枢关节螺钉111枚．其中5例患者仅单侧置入螺钉。平均手术时间（202．2±54．2）min、平均出血量（412．6±281．2）ml。术中x线三维导航手术在手术时间及出血量上同传统透视徒手手术相似。微创手术同开放手术在手术时间及出血量上无显著性差异。所有螺钉置入位置满意，无并发症发生。未完全复位的患者其手术效果与完全复位患者无差异。术后3个月随访，所有患者颈部局部症状均有明显改善，VAS评分由术前（4．5±1．3）分降低至（0．7±0．8）分；Nufiek脊髓功能分级由术前（2．4±1．1）级改善至（0．6±1．0）级；植骨已融合。结论术中x线三维导航辅助经寰枢关节螺钉治疗寰枢椎不稳定安全可行，结合微创手术能够在保证螺钉精确性的同时达到微创治疗的目的。

Objective To assess the feasibility, efficacy and indication of posterior C1-C2 transarticular screw fixation for atlantoaxial instability assisted by intraoperative 3-dimensional fluoroscopy- based navigation. Methods From November 2005 to October 2012, 58 patients with at｜antoaxial instability underwent posterior C1-C2 transarticular screw fixation assisted by intraoperative 3-dimensional fluoroscopy- based navigation. Those with excellent atlantoaxial reduction and no need for decompression underwent pereutaneously minimally invasive procedures. Operative duration, blood loss volume, reduction of atlantoaxial joints and postoperative neurovascular complications were recorded. Screw positions were studied by postoperative computed tomography （CT） and divided into 3 categories. The follow-up period was at least 3 months. Local symptoms （ assessed by visual analogue scale （ VAS ） score ） , neurological conditions （Nurick classification） and bone graft fusion were evaluated. Results Among them, the procedure was either open surgery （ n = 51 ） or percutaneously minimally invasive surgery （ n = 7 ）. A total of 111 screws were placed satisfactorily. Five patients underwent only unilateral C1-C2 transarticular screw fixation. No severe complications were encountered. The mean operative duration was 202. 2 ± 54. 2 minutes and the average volume of blood loss 412. 6 ± 281.2 ml. And the values were comparable to those for the traditional fluoroscopy-guided free-hand procedures. No statistical significance existed between open and percutaneously minimally invasive procedures in operative duration, blood loss volume and precision of screw placement. The patients with incompletely reduced C1-C2 dislocation had comparable clinical outcomes with those with complete reduction. After a 3-month follow-up, all of them showed significant improvements of localsymptoms. VAS score decreased from 4. 5± 1.3 preoperatively to 0. 7 ± 0. 8 postoperatively while the Nurick classification improved from 2.4 ± 1.1 to 0. 6 ± 1.0. And bone graft fusion was satisfactory. Conclusions Posterior C1-C2 transarticular screw fixation for atlantoaxial instability assisted by intraoperative 3- dimensional fluoroscopy-based navigation is both feasible and safe. Combined with minimally invasive techniques, this procedure may achieve greater precision and minimal invasion.