Clavien-Dindo classification in spinal surgery: A narrative review
The standardized reporting of postoperative complications is essential for improving surgical quality and comparing outcomes. However, spinal surgery has historically lacked a universal system and has instead relied on ambiguous terms. This narrative review synthesizes the literature on the adaptation, validation, and application of the therapy-based Clavien-Dindo classification (CDC) and its modified versions in spinal surgery. It focuses on studies across various spinal procedures and patient populations. The evidence shows that adapted CDC systems demonstrate good to excellent inter- and intrarater reliability, particularly for severe complications. These systems also facilitate direct comparison of surgical techniques. Moreover, they reveal strong correlations between complication severity, prolonged hospital stay, and patient factors such as frailty. Nevertheless, key limitations include poor correlation with certain long-term patient-reported outcomes. The CDC cannot capture intraoperative events or the cumulative burden of multiple complications. Subjectivity also exists in grading milder events. Recent spine-specific modifications that improve neurologic deficit assessment have enhanced clinical relevance. Overall, the CDC provides a critical framework for standardizing complication reporting in spinal surgery. Optimal application requires awareness of its limitations. In complex scenarios, the CDC may be applied most effectively as a component within more comprehensive, spine-specific taxonomies that incorporate surgical complexity and structured neurological assessment. The CDC remains a vital tool for improving communication, benchmarking, and ultimately enhancing patient care.