Lightning Podiums: Adult Spinal Deformity - Room 801A

Presented by: N. Frangella

Author(s):

T. Protopsaltis(1), A. Soroceanu(2), J. Tishelman(1), A. Buckland(1), N. Stekas(1), N. Frangella(1), G. Mundis(3), J. Smith(4), A. Daniels(5), L. Lenke(6), H.J. Kim(7), E. Klineberg(8), C. Ames(9), R. Hart((1)0), S. Bess((1)(1)), C. Shaffrey((1)(2)), F. Schwab(7), V. LaFage(7), International Spine Study Group

(1) NYU Langone Orthopedic Hospital, New York, NY, United States
(2) University of Calgary, Calgary, AB, Canada
(3) Scripps Clinic San Diego, San Diego, CA, United States
(4) University of Virginia Health System, Charlottesville, VA, United States
(5) Brown University, Providence, RI, United States
(6) Columbia University Medical Center, New York, NY, United States
(7) Hospital for Special Surgery, New York, NY, United States
(8) University of California-Davis, Sacremento, CA, United States
(9) University of California, San Francisco, CA, United States
((1) 0) Swedish Neuroscience Institute, Seattle, WA, United States
((1) (1) ) Denver International Spine Clinic, Denver, CO, United States
((1) (2) ) University of Virginia Medical Center, Charlottesville, VA, United States

Abstract

Introduction: Targets for deformity correction have been reported: SVA< 5cm, PT< 20°, PI-LL< 9°. The T1-Pelvic Angle (TPA) has gained in applications for ASD surgical planning since it directly measures the spinal alignment separate from pelvic and lower extremity compensation. Recent studies have demonstrated that ASD corrections should be age specific. This study investigates whether deformity corrections should vary by PI with an analysis in normative and ASD patients.

Methods: A prospective database of consecutive ASD patients was analyzed in conjunction with a normative spine database. Inclusion criteria: ASD, age>18, and any of the following: coronal Cobb angle >20°, SVA>5cm, thoracic kyphosis>60°, and PT>25°. Clinical measures of disability included ODI, and SF36 PCS. Baseline relationships between TPA, Age, PI and HRQL were analyzed in the ASD patients and a database of normative subjects. Age specific ODI thresholds were established through correlation to the US normative PCS values. Linear regression modeling was used to determine alignment targets based on PI and age-specific ODI.

Results: 903 ASD patients (mean age 53.7) and 111 normative subjects (mean age 50.7y) were included. Patients were subanalyzed by PI: low, medium, high (< 40, 40-75, >75); and age: elderly (>65y, n=375) middle age (MA 45-65y n=387) and young (18-45y, n=141). TPA correlated with age and PI in ASD and normative subjects (r>.42, p< .0001). ODI correlated with PCS (r=.71, p< .0001). Linear regression analysis using normative age-specific ODI values demonstrated that ideal spinopelvic alignment increases with increasing PI and age, Table 1. For low PI patients, TPA targets for young, middle aged and elderly were 8.4, 10.0 and 12.3; for medium PI, they were 17.2, 18.6 and 21.1; for high PI they were 28.3, 29.9 and 32.1.

Conclusion: Targets for ASD correction should vary by age and PI. This is demonstrated in both asymptomatic and ASD subjects. Using US normative HRQL values, TPA alignment targets are described for different age and PI categories (Table 1). The high PI patients do not require as rigorous realignments to attain age specific normative levels of health status.