104. Highest achievable outcomes for adult spinal deformity corrective surgery by frailty

Abstract

<h3>BACKGROUND CONTEXT</h3> Frailty status has often been identified as a determining factor for outcomes after adult spinal deformity (ASD) corrective surgery and may result in a ceiling regarding the best possible outcome <h3>PURPOSE</h3> Identify cohorts of patients with low complication rates by frailty status and determine the duration of time they maintain a good surgical outcome. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study of a prospectively enrolled ASD database. <h3>PATIENT SAMPLE</h3> This study included 224 ASD patients. <h3>OUTCOME MEASURES</h3> Major complications, reoperations, patient-reported outcome measures (Oswestry Disability Index) <h3>Methods</h3> ASD patients with frailty measures, baseline (BL) and 2-year (2Y) ODI were included. Miller et al thresholds: Not Frail (NF) < 0.3; 0.3 < Frail (F) < 0.5; Severely Frail (SF) > 0.5. ANCOVA found estimated marginal means adjusting for age, invasiveness, and BL Sacral Slope, Pelvic Tilt, Pelvic Incidence, PI-LL, and SVA. Kaplan-Meier curve estimated time until major complication or reoperation. Linear regression analyzed ODI change between 1Y and 2Y. Reduction in ODI between 1Y and 2Y of 5+ points was improvement, within ±5 points maintenance, increasing by 5+ points deterioration. Minimum clinically important differences (MCID) for ODI at 2Y were also assessed. <h3>Results</h3> Of 224 patients, 54.9% NF, 29.9% F, and 15.2% SF, difference in ODI from BL to 2Y in the most improved quartile (HIGHEST) by frailty group: NF: -4.51; F: -12.3; SF: -66.3 (p<0.001). SF HIGHEST major complication rate: 58.3%, F HIGHEST 29.4%, NF HIGHEST 41.8%. At 1Y, the quartile of NF with the lowest ODI had a mean score of 2.28, F 8.98, and SF 9.66 (p<0.001). Fewer SF patients did not experience any complications and had 2Y PI-LL < 10 (6.4%) compared to F (11.6%) and NF (16.0%) (p=0.002). NF had the least deterioration (16.3%, F: 29.8%, SF: 30.6%, p=0.099); however, groups were not significantly different in improvement (NF: 37.6%, F: 30.6%, SF: 36.6%, p=0.656). Higher 1Y ODI had greater odds of improvement (1.823 [1.667-1.978], p<0.001). KM curve revealed that NF had longer estimated time before complication or reoperation (7.8 years) compared to F (6.3 years) and SF (3.9 years) (p=0.001). <h3>Conclusions</h3> Severely frail patients had the lowest estimated time before a major complication or reoperation. Frail patients had the best maintenance of ODI score between 1 and 2 years. Severe frailty may limit improvement, and improving to a lower ODI score is more difficult to maintain over the course of a year. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.