Altorfer Franziska C S, Kelly Michael J, Avrumova Fedan, Burkhard Marco D, Sneag Darryl B, Campbell Gracyn, Chazen Joseph L, Tan Ek T, Lebl Darren R
Department of Spine Surgery, Hospital for Special Surgery, 523 East 72nd Street, New York, NY, USA; University Spine Center Zürich, Balgrist University Hospital, University of Zürich, Zürich, Switzerland.
Department of Spine Surgery, Hospital for Special Surgery, 523 East 72nd Street, New York, NY, USA.
Spine J. 2025 May;25(5):1035-1041. doi: 10.1016/j.spinee.2024.10.020. Epub 2024 Nov 2.
Preoperative imaging for lumbar spine surgery often includes magnetic resonance imaging (MRI) for soft tissues and computer tomography (CT) for bony detail. While CT scans expose patients to ionizing radiation, whereas MRI scans do not. Emerging MRI techniques allow CT-like 3-dimensional (3D) visualization of bony structures, potentially removing the need for ionizing radiation from CT scans.
This study aims to explore the accuracy of robot-assisted lumbar pedicle screw placement based on preoperative CT-like 3D MRI as the data source for robotic registration.
Human cadaveric study.
CT-like 3D MRI scans of the lumbar spine were acquired in ten human cadavers. A robotic navigation platform was used to plan and navigate pedicle screw placement based on the CT-like 3D MRI. Postoperative CT scans assessed the accuracy of screw positioning compared to preoperative planning based on the Gertzbein-Robbins scale (GRS) and by direct measurement (mm).
A total of 100 lumbar pedicle screws were robotically placed in ten cadavers (L1 through L5 bilaterally) based on CT-like 3D MRI. On postoperative CT evaluation, 99.0% of the positioned screws achieved an acceptable grade on the GRS (Grade A: n=89 or Grade B: n=10), with 89.0% classified as Grade A and 10.0% as Grade B. Meaning that 89.0% of screws were fully contained within the pedicle (GRS A), and 10% had a minor cortical breach <2 mm (GRS B). The median deviation from the planned trajectory was 0.2 mm (axial IQR: 0.1 to 0.5 mm; sagittal: IQR: 0.1 to 0.4 mm), in both axial and sagittal planes.
This study showed that image registration of CT-like 3D MRI for robotic-assisted spine surgery is technically feasible and that accurate pedicle screw placement can be achieved without preoperative CT. Each CT-like 3D MRI was successfully registered for robotic navigation.
The results suggest that CT-like 3D MRI has the potential to be a radiation-free alternative for preoperative planning and navigation in lumbar spine instrumentation procedures.
腰椎手术的术前成像通常包括用于软组织的磁共振成像（MRI）和用于骨骼细节的计算机断层扫描（CT）。CT扫描会使患者暴露于电离辐射，而MRI扫描则不会。新兴的MRI技术可实现类似CT的骨骼结构三维（3D）可视化，有可能不再需要CT扫描中的电离辐射。
本研究旨在探讨基于术前类似CT的3D MRI作为机器人配准数据源的机器人辅助腰椎椎弓根螺钉置入的准确性。
人体尸体研究。
对10具人体尸体进行了腰椎类似CT的3D MRI扫描。使用机器人导航平台基于类似CT的3D MRI规划和导航椎弓根螺钉置入。术后CT扫描根据Gertzbein-Robbins量表（GRS）并通过直接测量（毫米）评估螺钉定位的准确性，与术前规划进行比较。
基于类似CT的3D MRI，在10具尸体（双侧L1至L5）中总共机器人置入了100枚腰椎椎弓根螺钉。术后CT评估显示，99.0%的定位螺钉在GRS上达到可接受等级（A级：n = 89或B级：n = 10），其中89.0%为A级，10.0%为B级。这意味着89.0%的螺钉完全位于椎弓根内（GRS A），10%有小于2毫米的轻微皮质突破（GRS B）。轴向和矢状面与计划轨迹的中位偏差均为0.2毫米（轴向四分位间距：0.1至0.5毫米；矢状面：四分位间距：0.1至0.4毫米）。
本研究表明，用于机器人辅助脊柱手术的类似CT的3D MRI图像配准在技术上是可行的，并且无需术前CT即可实现准确的椎弓根螺钉置入。每个类似CT的3D MRI均成功用于机器人导航配准。
结果表明，类似CT的3D MRI有可能成为腰椎脊柱器械手术术前规划和导航的无辐射替代方法。
