Spine Surgeon NYU School of Medicine New Canaan, Connecticut, United States
Disclosure(s):
Peter G. Passias, MD: Cerapedics: Consultant (Ongoing); Globus Medical: Consultant (Ongoing); Journal of Neurosurgery: Spine: Board Member/Officer/Trustee (Ongoing); Medtronic: Consultant (Ongoing); Nuvasive: Consultant (Ongoing); Royal Biologics: Consultant (Ongoing); Spine: Board Member/Officer/Trustee (Ongoing); Terumo: Consultant (Ongoing)
Introduction: Operative intervention for adult spinal deformity (ASD) is associated with high rates of proximal junctional kyphosis (PJK) and proximal junctional Failure (PJF). Several systems have been developed to classify thoracolumbar alignment in ASD, however meeting additional alignment systems on PJK and PJF has yet to be explored. This objective is to assess rates of PJK and PJK in alignment systems.
Methods: retrospective study of a single-center ASD-database. Operative patients at baseline(BL) and 1-year(1Y) were included. Using BL and 6W radiographs, patients assessed by 5 alignment systems: (1) SRS-Schwab: PT, SVA and PI-LL; (2) GAP Score: out of 13; (3) Age-Adjusted: PT, PI-LL, and SVA-adjusted ideal; (4) Roussouly Type: ‘Match’ or ‘Mismatch’ by type; (5) Sagittal age-adjusted score (SAAS), including age-adjusted PI-LL, PT, and TPA. Means comparison tests analyzed differences in PJK and PJF across alignment systems. ANCOVA estimated means of PJK and PJF adjusting for osteoporosis and deformity.
Results: 441 patients met inclusion (Age:59.94±15.19yrs, BMI:26.84±6.38 kg/m2, CCI:1.54±1.64). By post-operative radiographics, 302 patients met SRS-Schwab, 265 patients met age-adjusted alignment, 133 met SAAS, 142 patients met GAP, and 217 patients met Roussouly. Patients that met age-adjusted alignment had lowest rates of PJK by 1Y and rates of PJK were significantly lower in age-adjusted alignment (15.1% vs. 22.7%,p=.042), compared to those that did not. With controls, patients meeting age-adjusted alignment still had significantly lower rates of PJK at 1Y (15.1% vs. 24.8%, p=.013). age-adjusted alignment had significantly lower rates of PJF compared to those that did not (0.0% vs. 1.7%,p=.033). those that met age-adjusted and SAAS had significantly lower rates PJK (14.1% vs. 23.6%,p=.021) and PJF (0.0% vs. 1.8%,p=.025) compared to those that did not.
Conclusion : We found that age-adjusted parameters resulted in lower rates of PJK and PJF. Specifically, alignment to age-adjusted criteria produced lowest rates overall and adding SAAS criteria further reduced rates.
