Classifying Complications: Assessing Adult Spinal Deformity 2-Year Surgical Outcomes

Study Design: Retrospective review of prospective database. Objective: Complication rates for adult spinal deformity (ASD) surgery vary widely because there is no accepted system for categorization. Our objective was to identify the impact of complication occurrence, minor-major complication, and Clavien-Dindo complication classification (Cc) on clinical variables and patient-reported outcomes. Methods: Complications in surgical ASD patients with complete baseline and 2-year data were considered intraoperatively, perioperatively ('6 weeks), and postoperatively ('6 weeks). Primary outcome measures were complication timing and severity according to 3 scales: complication presence (yes/no), minor-major, and Cc score. Secondary outcomes were surgical outcomes (estimated blood loss [EBL], length of stay [LOS], reoperation) and health-related quality of life (HRQL) scores. Univariate analyses determined complication presence, type, and Cc grade impact on operative variables and on HRQL scores. Results: Of 167 patients, 30.5% (n = 51) had intraoperative, 48.5% (n = 81) had perioperative, and 58.7% (n = 98) had postoperative complications. Major intraoperative complications were associated with increased EBL (P '.001) and LOS (P =.0092). Postoperative complication presence and major postoperative complication were associated with reoperation (P '.001). At 2 years, major perioperative complications were associated with worse ODI, SF-36, and SRS activity and appearance scores (P '.02). Increasing perioperative Cc score and postoperative complication presence were the best predictors of worse HRQL outcomes (P '.05). Conclusion: The Cc Scale was most useful in predicting changes in patient outcomes; at 2 years, patients with raised perioperative Cc scores and postoperative complications saw reduced HRQL improvement. Intraoperative and perioperative complications were associated with worse short-term surgical and inpatient outcomes.