Influence of perioperative complication severity on 1- and 2-year outcomes of low back surgery.

BACKGROUND: Several factors potentially influence outcomes of surgery, including perioperative complications. Complications may take many forms and the Clavien-Dindo (CD) classification is designed to categorize them by degree of severity. The aim of this study was to evaluate the influence of perioperative complications by severity categorization on the 1-and 2-year pain and disability outcomes for patients who received low back surgery.

MATERIALS AND METHODS: Data used for the study involved a purposive sample (N = 477; 8.1%) from a spine outcomes registry of 5876 patients who received spine surgery and encountered complications. All complications were categorized using the CD classification and were collapsed according to distribution frequencies, i.e., Grade I-II and Grade III-V. Adjusted and unadjusted regression analyses were used to determine the association between CD classification and 1- and 2-year outcomes.

RESULTS: The majority of surgical complications were Grade III-V (N = 358; 75.1%), with two incidences in which death occurred. For the unadjusted models, there were no significant associations between CD classification categorizations for 1-year outcomes; however, 2-year outcomes were significantly worse (P <0.05) for those with Grade III-V categorization. When adjusted and controlled for baseline characteristics, CD classification did not influence 1-or 2-year pain and disability outcomes.

CONCLUSIONS: When control variables are considered, the severity of perioperative surgical complications does not appear to influence 1- or 2-year pain and disability outcomes.

LEVEL OF EVIDENCE: Level 4.