Inter-Rater and Intrarater Reliability of Radiographs in the Diagnosis of Pediatric Scaphoid Fractures

Abstract

Background: Pediatric scaphoid fractures can be challenging to diagnose on plain radiograph. Rates of missed scaphoid fractures can be as high as 30% to 37% on initial imaging and overall sensitivity ranging from 21% to 97%. Few studies, however, have examined the reliability of radiographs in the diagnosis of scaphoid fractures, and none are specific to the pediatric population. Reliability, both between different specialists and for individual raters, may elucidate some of the diagnostic challenges. Methods: We conducted a 2-iteration survey of pediatric orthopedic surgeons, plastic surgeons, radiologists, and emergency physicians at a tertiary children’s hospital. Participants were asked to assess 10 series of pediatric wrist radiographs for evidence of scaphoid fracture. Inter-rater and intrarater reliability was calculated using the intraclass correlation coefficient of 2.1. Results: Forty-two respondents were included in the first iteration analysis. Inter-rater reliability between surgeons (0.66; 95% confidence interval, 0.43-0.87), radiologists (0.76; 0.55-0.92), and emergency physicians (0.65; 0.46-0.86) was “good” to “excellent.” Twenty-six respondents participated in the second iteration for intrarater reliability (0.73; 0.67-0.78). Sensitivity (0.75; 0.69-0.81) and specificity (0.78; 0.71-0.83) of wrist radiographs for diagnosing scaphoid fractures were consistent with results in other studies. Conclusions: Both inter-rater and intrarater reliability for diagnosing pediatric scaphoid fractures on radiographs was good to excellent. No significant difference was found between specialists. Plain radiographs, while useful for obvious scaphoid fractures, are unable to reliably rule out subtle fractures routinely. Our study demonstrates that poor sensitivity stems from the test itself, and not rater variability.