Friday, September 28, 2018 3:00 PM–4:00 PM abstracts: spinal deformity analysis: 223. The consequence of nonoperative management in adult spinal deformity: long-term durability of alignment in nonoperative adult spinal deformity treatment relative to those undergoing correction

Abstract

BACKGROUND CONTEXT As compared to nonoperative intervention, operative ASD-treatment has been associated with superior long-term alignment outcomes; however, the literature is sparse in comparing durability of alignment between nonoperative and operative ASD patients. PURPOSE To compare the durability of alignment between nonoperative and operative ASD patients over a 2-year period. STUDY DESIGN/SETTING Retrospective review of prospective, multicenter ASD database. PATIENT SAMPLE A total of 394 ASD patients (53±17 years, 83%F, BMI: 25.3±5.1). OUTCOME MEASURES Lumbo-pelvic mismatch (PI-LL), sagittal vertical axis (SVA), pelvic tilt (PT); Oswestry Disability Index (ODI), Scoliosis Research Society Questionnaire (SRS), ASD Frailty Index (ASD-FI). METHODS Consecutive ASD patients (scoliosis≥20°, SVA≥5cm, PT≥25°, or Thoracic Kyphosis ≥60°)>18 years with baseline (BL) and 1-year postop (1Y) radiographs. Operative (Op) and nonoperative (N-Op) patients were propensity score matched (PSM) for BL PT, PI-LL, SVA, age, Charlson comorbidity index (CCI), and ASD-FI. Means comparison tests assessed differences in demographic and clinical data between cohorts. Kaplan–Meier analyses, adjusting for patients lost to follow-up, assessed durability of SVA, PI-LL, and PT alignment beginning at 1 year postop for Op patients, and BL for N-Op. Alignment was defined durable if maintained within +1 standard deviation of age-adjusted ideal. Log Rank tests compared Op and N-Op survival distributions. Pearson correlations assessed the relationship between radiographic and ODI changes. RESULTS A total of 394 patients were included in the PSM analysis (197 Op, 197 N-Op). For Op patients, fusions spanned 11±4 levels, and surgical approach included 71% posterior, 2% anterior, and 28% combined. No differences were observed in age, sex, BMI, frailty, BL sagittal alignment, or coronal curve type between Op and N-Op groups (all P>.05). N-Op patients showed significantly less durable lumbo-pelvic alignment as compared to Op patients at 1Y (NonOp: 63.5% vs. Op: 73.6%) and 2Y (52.3% vs. 65.3%, P=.026). Cumulative durability of SVA (P=.153) and PT (P=.708) did not differ between groups. At the 2 years interval, N-Op patients showed greater sagittal deformity than Op patients: SVA (30mm vs. 11mm, P=.002), PI-LL (7.1° vs. −0.4° P CONCLUSIONS For ASD patients with similar baseline age, comorbidity status, frailty status, and spinopelvic deformity, nonoperative treatment was associated with progressive decline in spinopelvic alignment and inferior clinical outcomes. Additionally, as compared to operative patients, nonoperative patients developed higher rates of hypertension and pulmonary comorbidities over the 2-year study period. These results can be used by clinicians to improve counseling for ASD patients.