Introduction: The Schwab-SRS Classification of Adult Spinal Deformity (ASD) is a validated system that provides a common language for the complex pathology of ASD. Classification reliability has been reported; however, correlation with treatment has not been assessed. Purpose: assess association between disability, classification type/modifier and ASD treatment.
Methods: Prospective analysis of consecutive ASD patients from a multi-center spinal deformity study group. Inclusion criteria: age =18 yrs and scoliosis =20°, sagittal vertical axis (SVA) =5cm, pelvic tilt (PT) =25° or thoracic kyphosis (TK)> 60°. All patients had 36” standing x-rays. Differences in demographics, health related quality of life (HRQOL; ODI, SRS, SF36), and classification curve type/modifier distribution between operative (OP) and nonoperative (NONOP) treatment were evaluated.
Results: 757 patients (mean age 53 yrs, range 18-85) met inclusion criteria. OP (n=311) were older (mean age 56 vs 51 yrs), had greater BMI (27.7 vs 25.7), more previous surgery (45% vs 19%), and greater Charlson comorbidity index (1.1 vs 0.85) than NONOP (n=446), respectively (p<0.05). OP had worse HRQOL scores on all surveys than NONOP (p<0.05). OP and NONOP had similar coronal alignment (p<0.05). OP had worse sagittal spinopelvic alignment for all measures than NONOP except cervical lordosis, TK and pelvic incidence (PI). OP had greater percentage of pure sagittal classification (type S; OP=23%, NON=14%; p<0.05). OP had worse grades for all modifier categories: PT (26% vs 16%), PI-lumbar lordosis mismatch (37% vs 21%) and global sagittal alignment (29% vs 9%), OP vs NONOP, respectively (p<0.05).
Conclusions: Prospective analysis of OP vs NONOP treated ASD patients demonstrated OP patients were older, had more co-morbidities, greater disability and worse sagittal spinopelvic alignment as defined by the Schwab-SRS Classification subtype and sagittal modifiers. This classification is descriptive, correlates with HRQOL scores, and corresponds to treatment preference for ASD.
Patient Care: This research improves patient care by providing a descriptive classification system for adult spinal deformity that can be used to enhance communication among surgeons and to more objectively classify adult spinal deformity patients for clinical studies. This research also provides validation of the proposed classification system by demonstrating its clinical relevance.
Learning Objectives: By the conclusion of this presentation, participants should: (1) appreciate the structure of the Schwab-SRS classification system for adult spinal deformity, (2) appreciate that the Schwab-SRS classification is descriptive, correlates with health-related quality of life scores, and corresponds to treatment preference for adult spinal deformity.