Epigenetic Age Versus Chronologic Age in Adult Spinal Deformity Surgery: A Prospective Cohort Study.

51. How good are surgeons at achieving their goal sagittal alignment following adult deformity surgery?

206. Comparison of patient factors (frailty) vs surgical factors (invasiveness) for optimization of 2-year cost utility: We should focus on the patient factors

P28. Bone mineral density t-score is an independent predictor of significant blood loss in adult spinal deformity surgery

P99. Postoperative coronal malalignment after adult spinal deformity surgery: Incidence, risk factors, and impact on 2-year outcomes

56. Predictive models identify patient and surgical variables that synergistically produce an optimal outcome following adult spine deformity (ASD) surgery

160. Increasing cost efficiency in adult spinal deformity surgery: identifying predictors of lower total costs

117. Predictive analysis of risk factors and clinical outcomes of delayed extubation in adult spinal deformity surgery

A retrospective cohort review. To develop a scoring system for predicting increased risk of postoperative complications in adult spinal deformity (ASD) surgery based on baseline nutritional and metabolic factors. Endocrine and metabolic conditions have been shown to adversely influence patient outcomes and may increase the likelihood of postoperative complications. The impact of these conditions has not been effectively evaluated in patients undergoing ASD surgery. ASD patients 18 years or above with baseline and two-year data were included. An internally cross-validated weighted equation using preoperative laboratory and comorbidity data correlating to increased perioperative complications was developed via Poisson regression. Body mass index (BMI) categorization (normal, over/underweight, and obese) and diabetes classification (normal, prediabetic, and diabetic) were used per the Centers for Disease Control and Prevention and the American Diabetes Associates parameters. A novel ASD-specific nutritional and metabolic burden score (ASD-NMBS) was calculated via Beta-Sullivan adjustment, and Conditional Inference Tree determined the score threshold for experiencing ≥1 complication. Cohorts were stratified into low-risk and high-risk groups for comparison. Logistic regression assessed correlations between increasing burden score and complications. Two hundred one ASD patients were included (mean age: 58.60±15.4, sex: 48% female, BMI: 29.95±14.31, Charlson Comorbidity Index: 3.75±2.40). Significant factors were determined to be age (+1/yr), hypertension (+18), peripheral vascular disease (+37), smoking status (+21), anemia (+1), VitD hydroxyl (+1/ng/mL), BMI (+13/cat), and diabetes (+4/cat) (model: P <0.001, area under the curve: 92.9%). Conditional Inference Tree determined scores above 175 correlated with ≥1 post-op complication ( P <0.001). Furthermore, HIGH patients reported higher rates of postoperative cardiac complications ( P =0.045) and were more likely to require reoperation ( P =0.024) compared with low patients. The development of a validated novel nutritional and metabolic burden score (ASD-NMBS) demonstrated that patients with higher scores are at greater risk of increased postoperative complications and course. As such, surgeons should consider the reduction of nutritional and metabolic burden preoperatively to enhance outcomes and reduce complications in ASD patients.

Gestational Epigenetics and Risk of Childhood Leukemia

138. Radiographic malalignment has a far greater impact on clinical outcomes than perioperative and postoperative complications in ASD surgery

This study had 3 objectives: 1) to describe pelvic obliquity (PO) and leg-length discrepancy (LLD) and their relationship with coronal malalignment (CM); 2) to report rates of isolated PO and PO secondary to LLD; and 3) to assess the importance of preoperative PO and LLD in postoperative complications, readmission, reoperation, and patient-reported outcomes. Patients undergoing surgery (≥ 6-level fusions) for adult spinal deformity at a single institution were reviewed. Variables evaluated were as follows: 1) PO, angle between the horizontal plane and a line touching bilateral iliac crests; and 2) LLD, distance from the head to the tibial plafond. Coronal vertical axis (CVA) and sagittal vertical axis measurements were collected, both from C7. The cutoff for CM was CVA > 3 cm. The Oswestry Disability Index (ODI) was collected preoperatively and at 2 years. Of 242 patients undergoing surgery for adult spinal deformity, 90 (37.0%) had preoperative CM. Patients with preoperative CM had a higher PO (2.8° ± 3.2° vs 2.0° ± 1.7°, p = 0.013), a higher percentage of patients with PO > 3° (35.6% vs 23.5%, p = 0.044), and higher a percentage of patients with LLD > 1 cm (21.1% vs 9.8%, p = 0.014). Whereas preoperative PO was significantly positively correlated with CVA (r = 0.26, p < 0.001) and maximum Cobb angle (r = 0.30, p < 0.001), preoperative LLD was only significantly correlated with CVA (r = 0.14, p = 0.035). A total of 12.2% of patients with CM had significant PO and LLD, defined as follows: PO ≥ 3°; LLD ≥ 1 cm. Postoperatively, preoperative PO was significantly associated with both postoperative CM (OR 1.22, 95% CI 1.05-1.40, p = 0.008) and postoperative CVA (β = 0.14, 95% CI 0.06-0.22, p < 0.001). A higher preoperative PO was independently associated with postoperative complications after multivariate logistic regression (OR 1.24, 95% CI 1.05-1.45, p = 0.010); however, 2-year ODI scores were not. Preoperative LLD had no significant relationship with postoperative CM, CVA, ODI, or complications. A PO ≥ 3° or LLD ≥ 1 cm was seen in 44.1% of patients with preoperative CM and in 23.5% of patients with normal coronal alignment. Preoperative PO was significantly associated with preoperative CVA and maximum Cobb angle, whereas preoperative LLD was only associated with preoperative CVA. The direction of PO and LLD showed no consistent pattern with CVA. Preoperative PO was independently associated with complications but not with 2-year ODI scores.

The number of elderly patients undergoing adult spinal deformity (ASD) surgery has increased with the advent of new techniques and more nuanced understanding of global malalignment as patients age. The relationship between inpatient physical activity after ASD surgery and postoperative complications in elderly patients has not been reported; thus, we sought to investigate this relationship. We performed a medical record review of 185 ASD patients older than 65 years (age: 71.5 ± 4.7; body mass index: 30.0 ± 6.1, American Society of Anesthesiologists: 2.7 ± 0.5, and levels fused: 10.5 ± 3.4). We derived the number of feet walked over the first 3 days after surgery from physical therapy documentation and evaluated for association with 90-day perioperative complications. Patients who sustained an incidental durotomy were excluded from the study. The 185 patients were divided into groups based on whether they were among the 50th percentile for number of feet walked (62 ft). Walking less than 62 ft after ASD surgery was associated with higher incidence of postoperative complications (54.3%, P = 0.05), cardiac complications (34.8%, P = 0.03), pulmonary complications (21.7%, P = 0.01), and ileus (15.2%, P = 0.03). Patients who developed any postoperative complication (106 ± 172 vs 211 ± 279 ft, P = 0.001), ileus (26 ± 49 vs 174 ± 248 ft, P = 0.001), deep venous thrombosis (23 ± 30 vs 171 ± 247 ft, P = 0.001), and cardiac complications (58 ± 94 vs 192 ± 261 ft) walked less than patients who did not. Elderly patients who walked less than 62 ft in the first 3 days after ASD surgery have a higher rate of postoperative complications, specifically pulmonary and ileus compared with those patients who walked more. Steps walked after ASD surgery may be a helpful and practical addition to the surgeon's armamentarium for monitoring the recovery of their patients. Monitoring the steps walked by patients after ASD surgery can be a practical and useful tool for surgeons to track and improve their patients' recovery.

P53. Disparities in recovery and survival rates in cervical versus thoracolumbar spinal deformity patients are attributable to frailty status at presentation

P86. Patients with high preoperative activity are still satisfied at two-years following ASD surgery despite the potential for postoperative functional decline

Saturday, September 29, 2018 9:00 am–10:00 am Impact of Adult Deformity Correction: 263. Development of deployable predictive models for MCID of 2-year outcomes across all commonly used HRQOL instruments in adult spinal deformity surgery: results in 570 patients from 17 hospitals