Classification of perioperative complications in spine surgery

Perioperative complications affect surgical outcomes. Classification systems of perioperative complications are well established and widely applied in many surgical fields other than spine surgery.

The aim of this study was to construct and validate a comprehensive classification system for perioperative complications in spine surgery.

Retrospective case series.

A comprehensive classification system was constructed to stratify complications in spinal surgery and consequently applied to 934 patients who consecutively underwent spine surgery in a university hospital setting. A complication was defined as any kind of deviation from the normal perioperative course, ranging from a postoperative anemia to death. The comprehensive classifications system stratifies complications according to (1) complexity of index procedure (2) immediate cause of complication (surgical vs. medical) (3) the required treatment, and (4) potentially associated long-term functional deficits resulting from neural injury. Subsequently, the proposed classification system was validated by applying the duration of cumulative hospital stay as the primary outcome.

Perioperative complications were recorded in 135 (14.3%) out of 934 cases. There was a significant difference in the hospital stay between complications stratified according to therapeutic consequences, grade A: 5.6±1.6 (range: 3-8) days, grade B: 7.9±3.8 (range: 3-21) days, grade C: 13.1±8.1 (range: 4-59) days, and grade D: 55.2±56.6 (range: 14-198) days, respectively (p≤.001). Also, there was a significant difference in hospital stay between groups of increasing point difference of neurologic deficit, 0 versus -1 and -1 versus -2, respectively.

A comprehensive classification system for perioperative complications in spine surgery (considering four categories) is presented and validated. The categories therapeutic consequence (A-E) and decrease in neurological function correlate strongly with hospital stay.