Reliability of the Modified Clavien-Dindo-Sink Complication Classification System in Pediatric Orthopaedic Surgery

BACKGROUND: There is no standardized complication classification system that has been evaluated for use in pediatric or general orthopaedic surgery. Instead, subjective terms such as major and minor are commonly used. The Clavien-Dindo-Sink complication classification system has demonstrated high interrater and intrarater reliability for hip-preservation surgery and has increasingly been used within other orthopaedic subspecialties. This classification system is based on the magnitude of treatment required and the potential for each complication to result in long-term morbidity. The purpose of the current study was to modify the Clavien-Dindo-Sink system for application to all orthopaedic procedures (including those involving the spine and the upper and lower extremity) and to determine interrater and intrarater reliability of this modified system in pediatric orthopaedic surgery cases. METHODS: The Clavien-Dindo-Sink complication classification system was modified for use with general orthopaedic procedures. Forty-five pediatric orthopaedic surgical scenarios were presented to 7 local fellowship-trained pediatric orthopaedic surgeons at 1 center to test internal reliability, and 48 scenarios were then presented to 15 pediatric orthopaedic surgeons across the United States and Canada to test external reliability. Surgeons were trained to use the system and graded the scenarios in a random order on 2 occasions. Fleiss and Cohen kappa (κ) statistics were used to determine interrater and intrarater reliabilities, respectively. RESULTS: The Fleiss κ value for interrater reliability (and standard error) was 0.76 ± 0.01 (p < 0.0001) and 0.74 ± 0.01 (p < 0.0001) for the internal and external groups, respectively. For each grade, interrater reliability was good to excellent for both groups, with an overall range of 0.53 for Grade I to 1 for Grade V. The Cohen κ value for intrarater reliability was excellent for both groups, ranging from 0.83 (95% confidence interval [CI], 0.71 to 0.95) to 0.98 (95% CI, 0.94 to 1.00) for the internal test group and from 0.83 (95% CI, 0.73 to 0.93) to 0.99 (95% CI, 0.97 to 1.00) for the external test group. CONCLUSIONS: The modified Clavien-Dindo-Sink classification system has good interrater and excellent intrarater reliability for the evaluation of complications following pediatric orthopaedic upper extremity, lower extremity, and spine surgery. Adoption of this reproducible, reliable system as a standard of reporting complications in pediatric orthopaedic surgery, and other orthopaedic subspecialties, could be a valuable tool for improving surgical practices and patient outcomes.