Fasani-Feldberg Gregory, Kisinde Stanley, Lieberman Isador H
Scoliosis and Spine Tumor Center, Texas Back Institute, 6020 W. Parker Rd., Ste 200a, Plano, TX, 75093, USA.
Eur Spine J. 2025 May 27. doi: 10.1007/s00586-025-08951-5.
Pelvic fixation with S1 and S2 sacral alar-iliac screws (S1 & S2 AIs) in a stacked configuration can help to offset the exceedingly large forces across the lumbosacral junction in long spinal fusion constructs extending to the sacrum. Traditionally, these modalities of pelvic fixation have been heavily reliant on fluoroscopy and other intraoperative imaging for safe insertion through the sacral alar, the sacroiliac joint and into the narrow corridor of the wing of the ilium. However, recently, computer-assisted robotic guidance and its intraoperative re-registration function has allowed for safe and accurate placement, and intraoperative accuracy assessment of S1 & S2 AIs while minimizing additional radiation associated with fluoroscopic-guidance.
To review and report our experience with, and assess the intraoperative accuracy and feasibility of, robotic-guided S1AI and S2AI screws inserted in a stacked bedrock configuration as part of instrumented constructs aimed to achieve spinopelvic fusion.
STUDY DESIGN / SETTING: Retrospective Cohort study.
We evaluated the number of sacral spinopelvic fixation screws successfully implanted under robotic guidance and the deviation of the achieved screw trajectories from the pre-operatively planned trajectories. The presence and orientation of sacral alar-iliac cortical screw breaches and other intra- or postoperative complications directly related to placement of the stacked S1AI or S2AI implants were also evaluated.
We included all patients that underwent posterior instrumented spinal fusion up to the pelvis under computer-assisted robotic guidance with open bilateral sacroiliac joint fixation and fusion using S1 & S2 AIs from June 2022 to December 2024. Patients were excluded if the pelvic fixation was not applied in a stacked bedrock configuration. Patient demographics, intra-operative technical errors, complications and other surgical parameters, and any post-operative complications were reviewed and recorded. The data was collected from clinical charts in the electronic medical records system, radiologic images from PACS, and surgical details from operative notes. We also obtained intraoperative secondary registration images for assessment of accuracy, interpreted as the deviation (mm) of the achieved trajectories from the preoperatively planned trajectories in the coronal and sagittal planes, from the robotic planning software system.
51 patients (32 F & 19 M), mean age 66 (34-80) years, underwent placement of S1AI and S2AI screws under computer-assisted robotic guidance in a stacked bedrock configuration. The most common primary indication for instrumented spinopelvic fusion in these cases was scoliosis (degenerative scoliosis = 26, idiopathic scoliosis = 8), followed in descending order by degenerative spondylolisthesis [10] and kyphosis [7]. Robotic guidance was successful in all 204 screws (4 screws per patient). There was no significant difference in the length of implants inserted on either side of the pelvis, however, the mean length of the S1 AIs (80 mm) was significantly shorter than the S2 AIs (90 mm) [p = 0.005]. The overall mean accuracy in all planes was 2.05 ± 1.97 mm; larger values of proximal deviation were associated with similarly larger values of distal deviation. The mean deviation of the revision screws was greater (3.5 ± 2.16) than that of newly inserted screws (1.72 ± 1.30) [p-value = 0.003]. There were no complications directly related to the robotic-guided placement of the screws. 11 iliac cortical breaches - 5 each through the lateral and medial cortices, and one through the inferior cortex - were identified in 10 patients on post-operative CT images but with no further clinical consequences as they only invaded the bulk masses of the surrounding mm.
Robotic-guided placement of S1 and S2 AI implants in a stacked bedrock configuration for spinopelvic fixation and fusion is feasible with clinically acceptable results. Secondary registration and intra-operative accuracy assessment of screw placement may help to avoid the need for revision surgery related to misplacement of these implants.
采用S1和S2骶骨翼-髂骨螺钉（S1 & S2 AI）以堆叠形式进行骨盆固定，有助于抵消在延伸至骶骨的长节段脊柱融合结构中，腰-骶关节处过大的作用力。传统上，这些骨盆固定方式在经骶骨翼、骶髂关节并进入髂骨翼狭窄通道安全置入螺钉时，严重依赖透视及其他术中成像技术。然而，近来计算机辅助机器人导航及其术中重新注册功能，已能实现S1 & S2 AI螺钉的安全、准确置入以及术中准确性评估，同时将与透视引导相关的额外辐射降至最低。
回顾并报告我们在机器人引导下，以堆叠基岩形式置入S1AI和S2AI螺钉作为器械化结构一部分以实现脊柱-骨盆融合的经验，并评估其术中准确性及可行性。
研究设计/地点：回顾性队列研究。
我们评估了在机器人引导下成功植入的骶骨-脊柱-骨盆固定螺钉数量，以及实际螺钉轨迹与术前规划轨迹的偏差。还评估了骶骨翼-髂骨皮质螺钉穿破情况的存在及方向，以及与堆叠S1AI或S2AI植入物放置直接相关的其他术中和术后并发症。
纳入2022年6月至2024年12月期间，在计算机辅助机器人引导下接受后路器械化脊柱融合至骨盆，采用S1 & S2 AI进行双侧开放性骶髂关节固定和融合的所有患者。若骨盆固定未采用堆叠基岩形式，则将患者排除。回顾并记录患者人口统计学资料、术中技术失误、并发症及其他手术参数，以及任何术后并发症。数据收集自电子病历系统中的临床图表、PACS中的放射影像以及手术记录中的手术细节。我们还从机器人规划软件系统获取术中二次注册图像以评估准确性，将其解释为实际轨迹在冠状面和矢状面与术前规划轨迹的偏差（毫米）。
51例患者（32例女性和19例男性），平均年龄66岁（34 - 80岁），在计算机辅助机器人引导下以堆叠基岩形式置入S1AI和S2AI螺钉。这些病例中，器械化脊柱-骨盆融合最常见的主要指征是脊柱侧凸（退行性脊柱侧凸 = 26例，特发性脊柱侧凸 = 8例），其次依次为退行性椎体滑脱[10例]和后凸畸形[7例]。机器人引导下所有204枚螺钉（每位患者4枚）均成功置入。骨盆两侧置入的植入物长度无显著差异，然而，S1 AI的平均长度（80毫米）显著短于S2 AI（90毫米）[p = 0.005]。所有平面的总体平均准确性为2.05 ± 1.97毫米；近端偏差值越大，远端偏差值也越大。翻修螺钉的平均偏差（3.5 ± 2.16）大于新置入螺钉（1.72 ± 1.30）[p值 = 0.003]。没有与机器人引导下螺钉置入直接相关的并发症。术后CT图像在10例患者中发现11处髂骨皮质穿破——外侧皮质和内侧皮质各5处穿破，以及1处通过下皮质穿破，但由于仅侵入周围数毫米的大块组织，未产生进一步临床后果。
机器人引导下以堆叠基岩形式置入S1和S2 AI植入物用于脊柱-骨盆固定和融合是可行的，临床结果可接受。螺钉置入的二次注册及术中准确性评估可能有助于避免因这些植入物位置不当而进行翻修手术。
