Department of Orthopedic Surgery, Shinshu University, School of Medicine, Matsumoto, Nagano, Japan.
Spine (Phila Pa 1976). 2010 Feb 1;35(3):347-52. doi: 10.1097/BRS.0b013e3181b77f0a.
Retrospective clinical study.
To assess the accuracy of multilevel registration for skip pedicle screw placement during image-guided, computer-assisted spine surgery, in the setting of adolescent idiopathic scoliosis (AIS).
Computerized frameless stereotactic image-guidance has been used recently to improve pedicle screw placement accurately and safety during spine surgery. Because of possible intervertebral motion and usual difference in patients' position between preoperative imaging and surgery, the imaging model and the surgically exposed spine may be significantly discordant. Consequently, current protocols suggested separate registration of each spinal level (single-level registration) before respective pedicle screw placement, a time-consuming process. Moreover, although multilevel registration for lumbar spine has been reported, and that for thoracic spine has not.
A total of 19 patients (1 male and 18 females; mean age, 13.9 years) with AIS who underwent multilevel registration for skip pedicle screw placement were included. Variables including surgical time, blood loss, preoperative and 2-year postoperative Cobb angle, correction rate, and postoperative screw position by computed tomography image were evaluated. Mean registration error after point merge and again after surface merge were recorded for each consecutive vertebra of each case.
Mean surgical time was 310 minutes (range, 168-420 min). Mean blood loss 1138 g (range, 300-2300 g). Cobb angle before operation and at 2 years postoperation was 62.4 degrees (43 degrees-100 degrees) and 21.6 degrees (9 degrees-42 degrees), respectively. Mean correction rate 66.2% (39.7%-84.5%). Total 265 screws were inserted with computed tomography-based navigation system. Pedicle violation was observed in only 4 screws (1.5%). No neurovascular complication occurred. After point merge, average Mean registration error of all cases was 1.69 +/- 0.52 mm, and after surface merge was 0.51 +/- 0.16 mm.
Multilevel registration may decrease operative time without compromising accuracy of pedicle screw placement afforded by this technique in the setting of AIS.
回顾性临床研究。
评估在青少年特发性脊柱侧凸（AIS）患者中，图像引导、计算机辅助脊柱手术中使用多层配准进行跳跃式椎弓根螺钉放置的准确性。
最近已经使用计算机化无框架立体定向图像引导来提高脊柱手术中椎弓根螺钉放置的准确性和安全性。由于可能存在椎间运动以及患者在术前成像和手术之间的体位差异，成像模型和手术暴露的脊柱可能存在显著差异。因此，目前的方案建议在每个椎弓根螺钉放置之前分别对每个脊柱节段进行单独注册（单节段注册），这是一个耗时的过程。此外，虽然已经报道了用于胸腰椎的多节段注册，但尚未报道用于胸椎的多节段注册。
共纳入 19 例 AIS 患者（1 例男性，18 例女性；平均年龄 13.9 岁），他们接受了跳跃式椎弓根螺钉放置的多层配准。评估了手术时间、出血量、术前和术后 2 年 Cobb 角、矫正率以及 CT 图像术后螺钉位置等变量。记录了每个病例每个连续椎体在点合并后的平均注册误差，以及在表面合并后的平均注册误差。
平均手术时间为 310 分钟（范围 168-420 分钟）。平均出血量为 1138g（范围 300-2300g）。术前和术后 2 年的 Cobb 角分别为 62.4°（43°-100°）和 21.6°（9°-42°）。平均矫正率为 66.2%（39.7%-84.5%）。共插入 265 枚螺钉，采用基于 CT 的导航系统。仅在 4 枚螺钉（1.5%）中观察到椎弓根侵犯。没有发生神经血管并发症。点合并后，所有病例的平均注册误差为 1.69±0.52mm，表面合并后为 0.51±0.16mm。
在 AIS 患者中，多层配准可以减少手术时间，同时不影响该技术提供的椎弓根螺钉放置准确性。
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