Oral Posters: Values and Outcomes in Spine Surgery

Presented by: J.Y. Moon - View Audio/Video Presentation (Members Only)

Author(s):

N.A. Foster(1), S. Ramchandran(2), L.M. Day(3), R. Lafage(4), V. Lafage(4), T.J. Errico(2), A.J. Buckland(2)

(1) Duke University Medical Center, Department of Orthopaedic Surgery, Durham, NC, United States
(2) Hospital for Joint Diseases at NYU Langone Medical Center, Department of Orthopaedic Surgery, New York, NY, United States
(3) SUNY Downstate College of Medicine, New York, NY, United States
(4) Hospital for Special Surgery, Spine Research, New York, NY, United States

Abstract

Summary: Forty-one AIS patients ≤ 21yo who underwent surgical correction were evaluated for comparison of sagittal profile and spino-pelvic parameters with previously published normative age-matched data. Patients were normokyphotic in the thoracic spine at baseline. Surgical correction of the coronal plane in AIS patients preserved normal sagittal alignment postoperatively as compared to previously published normative age-matched values. Patients with Type 1 Lenke curves had increased pelvic tilt and thoraco-lumbar kyphosis with maintenance of normal sagittal profile in the early post-operative period.

Hypothesis: Surgical correction of Adolescent Idiopathic Scoliosis (AIS) leads to maintenance of normal sagittal alignment as compared to age-matched normative adolescent population. Design: Retrospective analysis.

Introduction: Sagittal spino-pelvic alignment in AIS has been reported, however whether or not corrective spinal fusion surgery reestablishes normal sagittal alignment remains to be verified.

Methods: Patients with diagnosis of AIS without previous fusion were included from a single institution database. Coronal and sagittal measurements including coronal Cobb angle, pelvic incidence (PI), pelvic tilt (PT), thoracic kyphosis (TK), lumbar lordosis (LL), thoraco-lumbar alignment (TL; T10 - L2), sagittal vertical axis (SVA) and T1 pelvic angle (TPA) were measured on standing full-body stereoradiographs using validated software at baseline and < 6months post-operatively. Perioperative alignment changes were measured, and postoperative alignment was compared with published adolescent norms.

Results: Forty-one patients with AIS were included (mean age, 16.6 ± 2.1 yrs; 75% F) out of which 29 had Type 1 Lenke curves. The mean pre-operative coronal curve was corrected from 53.8° to 11.7° (77.7%, p< .001). As compared to pre-op, none of the thoracic and spino-pelvic sagittal parameters changed significantly after surgery except TL alignment (p= .006). Further analysis of patients with Type 1 curves, showed TL alignment (-1.6 ± 10.1° v 3.5 ±8.2°, p= .009) and PT (8.3 ± 7.5° v 10.4 ± 7.9°, p=.03) to increase significantly post-op. Comparing the post-op sagittal parameters to a normative adolescent population (Mendoza et al, age=15.1 ± 1.9y), postoperative patients demonstrated similar alignment, except for a mildly increased TK (p< 0.05).

Conclusion: Surgical correction of the coronal plane in AIS patients preserves normal sagittal alignment postoperatively. Increased thoraco-lumbar kyphosis and pelvic tilt is observed in AIS patients with Type 1 Lenke curves.

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