Altorfer Franziska C S, Kelly Michael J, Loggia Giuseppe, Avrumova Fedan, Zhu Jiaqi, Campbell Gracyn, Chazen J Levi, Tan Ek T, Lebl Darren R
Department of Spine Surgery, Hospital for Special Surgery, New York, NY.
University Spine Center Zürich, Balgrist University Hospital, University of Zürich, Zürich, Switzerland.
Spine (Phila Pa 1976). 2025 Oct 1;50(19):E397-E403. doi: 10.1097/BRS.0000000000005366. Epub 2025 Apr 16.
Cadaveric study.
To assess the feasibility and accuracy of robotic positioning of thoracic pedicle screws based on magnetic resonance imaging (MRI).
Robotic-assisted navigation (RAN) has demonstrated enhanced precision in thoracic pedicle screw placement. Currently, preoperative computer tomography (CT) scanning is required, exposing patients to radiation-a particular concern for younger patients undergoing multilevel fusion surgery. CT-like three-dimensional (3D)-MRI sequences may offer a radiation-free alternative, but their application in thoracic pedicle screw placement remains unexplored.
CT-like 3D-MRI scans of the thoracic spine were obtained in two human cadaveric specimens. A RAN system was employed to plan and guide 48 pedicle screws (bilateral screws in thoracic vertebrae T1-T12) using these MRI scans. Following the placement of the pedicle screws, post-procedure CT scans were obtained to evaluate the accuracy of screw positioning. Accuracy was assessed by comparing the actual placement to the pre-procedure plan (difference in millimetres) and via the Gertzbein-Robbins scale (GRS).
A total of 48 thoracic pedicle screws were inserted robotically in two human specimens (T1-T12 bilaterally). Post-procedure CT scan evaluations revealed that all screws achieved an acceptable grade on the GRS (A or B). Specifically, 87.5% of the screws were classified as grade A and 12.5% were classified as grade B. The median deviations from the planned trajectory were 0.4 mm in the axial (IQR: 0.0; 1.2 mm) and 0.05 mm in the sagittal (IQR: -0.3; 0.3 mm) planes.
This cadaveric study demonstrates that MRI-based RAN can accurately guide thoracic pedicle screw placement. The findings suggest MRI-based RAN could provide a radiation-free alternative for thoracic spine instrumentation, particularly beneficial for pediatric and adolescent patients.
尸体研究。
评估基于磁共振成像（MRI）的胸椎椎弓根螺钉机器人定位的可行性和准确性。
机器人辅助导航（RAN）已在胸椎椎弓根螺钉置入中显示出更高的精度。目前，需要术前计算机断层扫描（CT），这会使患者暴露于辐射下——这对于接受多级融合手术的年轻患者来说尤其令人担忧。类似CT的三维（3D）-MRI序列可能提供无辐射的替代方案，但它们在胸椎椎弓根螺钉置入中的应用仍未得到探索。
对两具人体尸体标本进行了类似CT的胸椎3D-MRI扫描。使用这些MRI扫描，采用RAN系统规划和引导48枚椎弓根螺钉（T1-T12胸椎双侧螺钉）。在置入椎弓根螺钉后，进行术后CT扫描以评估螺钉定位的准确性。通过将实际置入情况与术前计划进行比较（以毫米为单位的差异）并通过Gertzbein-Robbins量表（GRS）来评估准确性。
在两具人体标本（双侧T1-T12）中机器人共置入了48枚胸椎椎弓根螺钉。术后CT扫描评估显示，所有螺钉在GRS上均达到可接受等级（A或B）。具体而言，87.5%的螺钉被归类为A级，12.5%被归类为B级。与计划轨迹的中位数偏差在轴向为0.4毫米（四分位间距：0.0；1.2毫米），在矢状面为0.05毫米（四分位间距：-0.3；0.3毫米）。
这项尸体研究表明，基于MRI的RAN可以准确地引导胸椎椎弓根螺钉置入。研究结果表明，基于MRI的RAN可为胸椎脊柱内固定提供无辐射的替代方案，对儿科和青少年患者尤其有益。
