학술논문
How Does Spino-Pelvic Fixation Affect Post-Operative Compensatory Mechanisms in Adult Spinal Deformity?
Document Type
Academic Journal
Author
Zhi W; Department of Orthopedic Surgery, University of Montreal Health Center, Montreal, QC, Canada.; Boubez G; Department of Orthopedic Surgery, University of Montreal Health Center, Montreal, QC, Canada.; Al-Shakfa F; Department of Orthopedic Surgery, University of Montreal Health Center, Montreal, QC, Canada.; Kamel Y; University of Montreal, Montreal, QC, Canada.; Liu J; University of Montreal, Montreal, QC, Canada.; Shedid D; Department of Neurosurgery, University of Montreal Health Center, Montreal, QC, Canada.; Yuh SJ; Department of Neurosurgery, University of Montreal Health Center, Montreal, QC, Canada.; Rizkallah M; Department of Orthopedic Surgery, University of Montreal Health Center, Montreal, QC, Canada.
Source
Publisher: SAGE Publications Country of Publication: England NLM ID: 101596156 Publication Model: Print-Electronic Cited Medium: Print ISSN: 2192-5682 (Print) Linking ISSN: 21925682 NLM ISO Abbreviation: Global Spine J
Subject
Language
English
ISSN
2192-5682
Abstract
Study Design: Retrospective single-center multi-surgeon cohort study.
Objectives: 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).
Methods: 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.
Results: Patients with S2AI ( n = 53) and those with IS ( n = 26) screws were comparable at baseline. ΔSS averaged 9.87° in the S2AI compared to 13.2° in the IS ( P = .001), whereas the ΔKFA reached 6.01° in the S2AI as opposed to 3.06° in the IS ( P = .02). The ΔPT was comparable between both groups (6.35°[S2AI group] vs 5.21°[ISgroup], P = .42). ΔTK, ΔLL, ΔFOA and ΔAFA were comparable between both groups.
Conclusion: 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.
Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Objectives: 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).
Methods: 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.
Results: Patients with S2AI ( n = 53) and those with IS ( n = 26) screws were comparable at baseline. ΔSS averaged 9.87° in the S2AI compared to 13.2° in the IS ( P = .001), whereas the ΔKFA reached 6.01° in the S2AI as opposed to 3.06° in the IS ( P = .02). The ΔPT was comparable between both groups (6.35°[S2AI group] vs 5.21°[ISgroup], P = .42). ΔTK, ΔLL, ΔFOA and ΔAFA were comparable between both groups.
Conclusion: 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.
Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.