The lateral entry point S2 alar-iliac (L-S2AI) screw: a preoperative computed tomography analysis of adult spinal deformity patients.

Autor: Hey HWD; Department of Orthopaedic Sugery, National University Hospital, National University Health System, 1E Kent Ridge Road, NUHS Tower Block Level 11, Singapore, 119228, Singapore. doshhwd@nus.edu.sg., Ramos MRD; Department of Orthopaedic Sugery, National University Hospital, National University Health System, 1E Kent Ridge Road, NUHS Tower Block Level 11, Singapore, 119228, Singapore., Tay HW; Department of Orthopaedic Sugery, National University Hospital, National University Health System, 1E Kent Ridge Road, NUHS Tower Block Level 11, Singapore, 119228, Singapore., Lin S; Department of Orthopaedic Sugery, National University Hospital, National University Health System, 1E Kent Ridge Road, NUHS Tower Block Level 11, Singapore, 119228, Singapore., Liu KG; Department of Orthopaedic Sugery, National University Hospital, National University Health System, 1E Kent Ridge Road, NUHS Tower Block Level 11, Singapore, 119228, Singapore., Wong HK; Department of Orthopaedic Sugery, National University Hospital, National University Health System, 1E Kent Ridge Road, NUHS Tower Block Level 11, Singapore, 119228, Singapore.
Jazyk: angličtina
Zdroj: Spine deformity [Spine Deform] 2022 May; Vol. 10 (3), pp. 669-678. Date of Electronic Publication: 2022 Jan 28.
DOI: 10.1007/s43390-021-00462-9
Abstrakt: Purpose: To radiographically compare lateral entry point S2-alar-iliac (L-S2AI) screw with conventional S2AI (C-S2AI) and conventional iliac screw (CIS) lengths and trajectories.
Methods: Twenty-five preoperative CT scans of consecutive patients undergoing adult spinal deformity realignment surgery over a random 2-year period were analysed. Maximum in-bone length, caudal and lateral trajectories of CIS, C-S2AI, and L-S2AI screws were measured and compared using One-way ANOVA with Tukey's post hoc tests. Multivariate logistic regression was performed to identify predictors of high screw length discrepancy between C-S2AI and L-S2AI.
Results: Potential screw length was longest for CIS, followed by L-S2AI, then C-S2AI (114.5 ± 8.3 mm vs 101.4 ± 9.6 mm vs 80.6 ± 5.9 mm, respectively) in all patients (p < 0.001). Actual screw lengths found both CIS and L-S2AI to be longer than C-S2AI (95.3 ± 8.5 mm and 93.4 ± 7.5 mm vs 82.1 ± 7.3 mm; p = 0.008 and 0.003). Potential lateral angulation was smallest for CIS, followed by L-S2AI, then C-S2AI (21.9 ± 7.0° vs 31.9 ± 7.1° vs 40.9 ± 6.7°, respectively) in all patients (p < 0.001). L-S2AI and C-S2AI had the same caudal angulation (24.9 ± 6.8°), which was smaller than CIS (30.8 ± 5.8°) in all patients (p < 0.001). Univariate, but not multivariate analysis, revealed that lumbar lordosis > 40° (OR 7.2, p = 0.041), diagnosis of degenerative spondylolisthesis (OR 10.5, p = 0.017), and > 7 instrumented levels (OR 2.6, p = 0.049) were significantly associated with high screw discrepancies.
Conclusion: The L-S2AI screw combines advantages of CIS and C-S2AI screws, which includes increased screw length, reduced lateral angulation, a low-profile screw head, ease of connection to proximal hardware, and the biomechanical advantage of a quadcortical purchase.
(© 2021. The Author(s), under exclusive licence to Scoliosis Research Society.)
Databáze: MEDLINE
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