术中CT导航在脊柱侧凸后路胸椎椎弓根螺钉植入术中的应用

APPLICATION OF INTRAOPERATIVE CT NAVIGATION IN POSTERIOR THORACIC PEDICLE SCREW PLACEMENT FOR SCOLIOSIS PATIENTS

目的探讨术中CT导航在脊柱侧凸后路胸椎椎弓根螺钉植入术中的应用价值。方法回顾分析2009年10月-2011年12月行脊柱后路矫形融合术的46例胸弯脊柱侧凸患者临床资料,比较术中CT导航下(A组,21例)和传统C臂X线机下徒手(B组,25例)植入胸椎椎弓根螺钉的准确性和安全性。两组患者性别、年龄、脊柱侧凸类型、累及节段、主胸弯Cobb角等一般资料比较,差异均无统计学意义(P>0.05),具有可比性。A、B组各植入胸椎椎弓根螺钉273枚及308枚。采用Modi等方法,通过术中CT扫描对椎弓根螺钉位置分级,计算两组在上胸椎(T1～4)、中胸椎(T5～8)、下胸椎(T9～12)和整个胸椎(T1～12)的准确植钉率、安全植钉率和潜在危险植钉率。结果 A组整个胸椎的准确植钉率(93.4%)、安全植钉率(98.9%)均显著高于B组(83.8%、92.5%),潜在危险植钉率(1.1%)显著低于B组(7.5%),比较差异均有统计学意义(P<0.05)。两组上、中、下胸椎的准确植钉率、安全植钉率和潜在危险植钉率比较,差异均无统计学意义(P>0.05)。根据CT评估结果将潜在危险植钉重新植钉或去除。术后3 d根据神经系统体检评定两组均无神经功能缺失发生。结论与传统C臂X线机下徒手植钉技术相比,术中CT导航可提高胸椎椎弓根螺钉植入的准确性和安全性,可在术中发现危险螺钉并及时去除或修正,保障手术安全。

Objective To investigate the application value of intraoperative CT navigation in posterior thoracic pedicle screw placement for scoliosis patients. Methods Between October 2009 and December 2011, 46 patients with scoliosis were treated with thoracic pedicle screw placement under intraoperative CT navigation in 21 cases （group A） or under C-arm fluoroscopy in 25 cases （group B）. There was no significant difference in age, gender, type of scoliosis, involved segment, and Cobb angle of main thoracic curve between 2 groups （P 〉 0.05）. A total of 273 thoracic pedicle screws were placed in group A and 308 screws in group B. The pedicle screw position evaluated and classified by intraoperative CT images according to the Modi et al. method; and the accurate rate, the safe rate, and the potential risk rate of pedicle screws were calculated on the upper thoracic spine （T1-4）, the middle thoracic spine （T^-8）, the lower thoracic spine （T9-12）, and the entire thoracic spine （T^-~2）. The accuracy and security of thoracic pedicle screw placement were compared between 2 groups. Results On the entire thoracic spine, the accurate rate of group A （93.4%） was significantly higher than that of group B （83.8%）, the safe rate of group A （98.9%） was significantly higher than that of group B （92.5%）, showing significant differences between 2 groups （P 〈 0.05）. However, the potential risk rate of group B （7.5%） was significantly higher than that of group A （1.1%） （P 〈 0.05）. On the upper, the middle, and the lower thoracic spines, there was no significant difference in the accurate rate, the safe rate, and the potential risk rate of pedicle screws between 2 groups （P 〉 0.05）. According to CT evaluation results, the potential risk pedicle screws were revised or removed during operation. The patients of 2 groups had no neurological deficits through physical examination of nervous system at 3 days after operation. Conclusion Intraoperative CT navigation can improve the accuracy and security of posterior thoracic pedicle screw placement and it can ensure the safety of operation by finding and promptly removing or revising the potential risk pedicle screws.