학술논문

Durability of Satisfactory Functional Outcomes Following Surgical Adult Spinal Deformity Correction: A 3-Year Survivorship Analysis
CASE SERIES
Document Type
Academic Journal
Source
Operative NeuroSurgery. February 2020, Vol. 18 Issue 2, p118, 8 p.
Subject
Maryland
Language
English
ISSN
2332-4252
Abstract
Symptomatic adult spinal deformity (ASD) can have a profound impact on health-related quality of life (HRQoL), resulting in patient-reported disability levels comparable to those of cancer or diabetes. (1) While [...]
BACKGROUND: Despite reports showing positive long-term functional outcomes following adult spinal deformity (ASD)-corrective surgery, it is unclear which factors affect the durability of these outcomes. OBJECTIVE: To assess durability of functional gains following ASD-corrective surgery; determine predictors for postoperative loss of functionality. METHODS: Surgical ASD patients > 18 yr with 3-yr Oswestry Disability Index (ODI) follow-up, and 1-yr postoperative (1Y) ODI scores reaching substantial clinical benefit (SCB) threshold (SCB < 31.3 points). Patients were grouped: those sustaining ODI at SCB threshold beyond 1Y (sustained functionality) and those not (functional decline). KaplanMeier survival analysis determined postoperative durability of functionality. Multivariate Cox regression assessed the relationship between patient/surgical factors and functional decline, accounting for age, sex, and levels fused. RESULTS: All 166 included patients showed baseline to 1Y functional improvement (mean ODI: 35.3 [+ or -] 16.5-13.6 [+ or -] 9.2, P < .001). Durability of satisfactory functional outcomes following the 1Y postoperative interval was 88.6% at 2-yr postoperative, and 71.1% at 3-yr postoperative (3Y). Those sustaining functionality after 1Y had lower baseline C2-S1 sagittal vertical axis (SVA) and T1 slope (both P < .05), and lower 1Y thoracic kyphosis (P = .035). From 1Y to 3Y, patients who sustained functionality showed smaller changes in alignment: pelvic incidence minus lumbar lordosis, SVA, T1 slope minus cervical lordosis, and C2-C7 SVA (all P < .05). Those sustaining functionality beyond 1Y were also younger, less frail at 1Y, and had lower rates of baseline osteoporosis, hypertension, and lung disease (all P < .05). Lung disease (Hazard Ratio:4.8 [1.4-16.4]), 1Y frailty (HR:1.4 [1.1-1.9]), and posterior approach (HR:2.6 [1.2-5.8]) were associated with more rapid decline. CONCLUSION: Seventy-one percent of ASD patients maintained satisfactory functional outcomes by 3Y. Of those who failed to sustain functionality, the largest functional decline occurred 3-yr postoperatively. Frailty, preoperative comorbidities, and surgical approach affected durability of functional gains following surgery. KEY WORDS: Adult spinal deformity, Disability, Functionality, Outcomes, Surgical correction