计算机辅助二维透视在经皮腰骶椎弓根螺钉置入术中的临床准确性。

Clinical accuracy of computer-assisted two-dimensional fluoroscopy for the percutaneous placement of lumbosacral pedicle screws.

机构信息

Division of Orthopaedics, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.

出版信息

Spine (Phila Pa 1976). 2011 Jan 1;36(1):84-91. doi: 10.1097/BRS.0b013e3181cbfd09.

DOI:10.1097/BRS.0b013e3181cbfd09

PMID:20595927

Abstract

STUDY DESIGN

Clinical case series.

OBJECTIVE

The primary objective of this study was to evaluate the clinical accuracy of computer-assisted two-dimensional fluoroscopy (2D-CAS) for the percutaneous placement of lumbosacral pedicle screws.

SUMMARY OF BACKGROUND DATA

Loss of visual anatomic landmarks and reduced tactile feedback increases the risk of pedicle screw misplacement by when using minimally invasive (MIS) percutaneous techniques. However, objective data on screw misplacement in this scenario is lacking.

METHODS

A MIS-2D-CAS technique (FluoroNav) was used for the placement of pedicle screws in 41 consecutive patients undergoing MIS-interbody instrumented fusion. Postoperative computerized tomography (CT) was obtained in all patients at 6 months after surgery and was evaluated by 3 observers. The relative position of the screw to the pedicle was graded regarding pedicle breach (I, no breach; II, <2 mm; III, 2-4 mm; IV, >4 mm), breach direction, vertebral body perforation and screw trajectory. Interobserver reliability of CT grading was assessed with kappa statistics.

RESULTS

A total of 161 screws were placed. No neurologic, vascular, or visceral injuries occurred. About 37 (23%) screws breached the pedicle. The majority (83.8%, 31/37) of breaches were graded II. There were 5 Grade III and 1 Grade IV breaches. Medial versus lateral breaches occurred in 30% (11/37) and 60% (22/37), respectively; 10% (4/37) of the breaches were superior. Overall, 8 (5%) vertebral body breaches occurred. Of the pedicle screws, 19 (12%) had trajectories that deviated from acceptable, with the majority being medial (16/19, 84%). Fluoroscopy time for screw placement was typically less than 20 seconds total per case. There was 1 clinically significant breach at L5 (III, medial) which resulted in a L5 radiculopathy. Kappa statistics showed excellent overall agreement between reviewers (k = 0.73-0.92; 90%-96% agreement).

CONCLUSION

The two-dimensional (2D) virtual fluoroscopy is a clinically acceptable option for percutaneous placement of pedicle screws. However, this technique requires cautious application and is particularly vulnerable to axial trajectory errors.

摘要

研究设计

临床病例系列。

目的

本研究的主要目的是评估计算机辅助二维透视（2D-CAS）在经皮腰骶椎椎弓根螺钉置入中的临床准确性。

背景资料总结

在使用微创经皮技术（MIS）时，视觉解剖标志的丧失和触觉反馈的减少会增加椎弓根螺钉放置不当的风险。然而，这种情况下螺钉放置不当的客观数据仍然缺乏。

方法

41 例接受 MIS 椎间融合内固定的患者采用 MIS-2D-CAS 技术（FluoroNav）进行椎弓根螺钉置入。所有患者均在术后 6 个月进行计算机断层扫描（CT）检查，并由 3 名观察者进行评估。根据椎弓根的破裂情况（I 级，无破裂；II 级，<2mm；III 级，2-4mm；IV 级，>4mm）、破裂方向、椎体穿孔和螺钉轨迹对螺钉与椎弓根的相对位置进行分级。采用 Kappa 统计评估 CT 分级的观察者间可靠性。

结果

共置入 161 枚螺钉。无神经、血管或内脏损伤发生。约 37 枚（23%）螺钉穿透椎弓根。大多数（83.8%，31/37）为 II 级破裂。有 5 例 III 级和 1 例 IV 级破裂。内侧与外侧破裂分别占 30%（11/37）和 60%（22/37），10%（4/37）的破裂位于上方。总体而言，8 例（5%）发生椎体破裂。19 枚（12%）螺钉的轨迹偏离可接受范围，其中大多数为内侧（16/19，84%）。每个病例的透视时间通常少于 20 秒。有 1 例 L5 螺钉（III 级，内侧）发生临床意义上的破裂，导致 L5 神经根病。Kappa 统计显示，观察者之间具有极好的总体一致性（k=0.73-0.92；90%-96%的一致性）。