Zhi Wang, Boubez Ghassan, Al-Shakfa Fidaa, Kamel Yousef, Liu Jia, Shedid Daniel, Yuh Sung Joo, Rizkallah Maroun
Department of Orthopedic Surgery, University of Montreal Health Center, Montreal, QC, Canada.
University of Montreal, Montreal, QC, Canada.
Global Spine J. 2025 Mar;15(2):548-553. doi: 10.1177/21925682231200832. Epub 2023 Sep 8.
Retrospective single-center multi-surgeon cohort study.
Compare the post-operative changes in the compensatory mechanisms of the sagittal balance according to the type of pelvic fixation: S2-Alar-iliac screws (S2AI) vs iliac screws (IS) in patients with Adult spine deformity (ASD).
ASD patients who underwent spino-pelvic fixation and remained with a PI-LL >10° mismatch post-operatively were included. Pre-operative and 1-year-follow-up PI, Lumbar lordosis (LL), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), femur obliquity angle (FOA), knee flexion angle (KFA) and ankle flexion angle (AFA) were analyzed on EOS imaging. Patients were categorized based on their pelvic fixation type (S2AI vs IS), and the pre-operative to 1-year-post-operative changes (ΔX°) in the compensatory mechanisms were compared between groups.
Patients with S2AI ( = 53) and those with IS ( = 26) screws were comparable at baseline. ΔSS averaged 9.87° in the S2AI compared to 13.2° in the IS ( = .001), whereas the ΔKFA reached 6.01° in the S2AI as opposed to 3.06° in the IS ( = .02). The ΔPT was comparable between both groups (6.35°[S2AI group] vs 5.21°[ISgroup], = .42). ΔTK, ΔLL, ΔFOA and ΔAFA were comparable between both groups.
The type of pelvic fixation impacts significantly the post-operative compensatory mechanisms in patients with ASD. Patients with S2AI screws are more likely to compensate their remaining post-operative PI-LL mismatch through their knees and less likely through their pelvis compared to patients with IS, despite similar changes in PT. This could be explained by an increased SI joint laxity in ASD patient and the lower resistance of the iliac connectors to the junctional mechanical stresses, allowing for sacro-iliac joint motion in patients with IS.
回顾性单中心多外科医生队列研究。
比较成人脊柱畸形（ASD）患者中，根据骨盆固定类型（S2-翼状髂骨螺钉[S2AI]与髂骨螺钉[IS]），矢状面平衡代偿机制的术后变化。
纳入接受脊柱骨盆固定且术后PI-LL>10°失配的ASD患者。在EOS成像上分析术前及1年随访时的PI、腰椎前凸（LL）、骨盆倾斜（PT）、骶骨倾斜度（SS）、胸椎后凸（TK）、股骨倾斜角（FOA）、膝关节屈曲角度（KFA）和踝关节屈曲角度（AFA）。根据骨盆固定类型（S2AI与IS）对患者进行分类，并比较两组间代偿机制从术前到术后1年的变化（ΔX°）。
S2AI组（n = 53）和IS组（n = 26）患者在基线时具有可比性。S2AI组的ΔSS平均为9.87°，而IS组为13.2°（P = .001），而S2AI组的ΔKFA达到6.01°，而IS组为3.06°（P = .02）。两组间的ΔPT具有可比性（S2AI组为6.35°，IS组为5.21°，P = .42）。两组间的ΔTK、ΔLL、ΔFOA和ΔAFA具有可比性。
骨盆固定类型对ASD患者的术后代偿机制有显著影响。与IS组患者相比，S2AI螺钉固定的患者更倾向于通过膝关节代偿术后残留的PI-LL失配，而通过骨盆代偿的可能性较小，尽管PT变化相似。这可以通过ASD患者骶髂关节松弛增加以及髂骨连接件对交界区机械应力的抵抗力较低来解释，这使得IS组患者的骶髂关节能够运动。
